Long-term associations between objective sleep quality and quantity and verbal memory performance in normal cognition and mild cognitive impairment

Introduction

Although the link between sleep and memory function is well established, associations between sleep macrostructure and memory function in normal cognition and Mild Cognitive Impairment remain unclear. We aimed to investigate the longitudinal associations of baseline objectively assessed sleep quality and duration, as well as time in bed, with verbal memory capacity over a 7-9 year period. Participants are a well-characterized subsample of 148 persons (mean age at baseline: 72.8 ± 6.7 years) from the Cretan Aging Cohort. Based on comprehensive neuropsychiatric and neuropsychological evaluation at baseline, participants were diagnosed with Mild Cognitive Impairment (MCI; n = 79) or found to be cognitively unimpaired (CNI; n = 69). Sleep quality/quantity was estimated from a 3-day consecutive actigraphy recording, whereas verbal memory capacity was examined using the Rey Auditory Verbal Learning Test (RAVLT) and the Greek Passage Memory Test at baseline and follow-up. Panel models were applied to the data using AMOS including several sociodemographic and clinical covariates.

Results

Sleep efficiency at baseline directly predicted subsequent memory performance in the total group (immediate passage recall: β = 0.266, p = 0.001; immediate word list recall: β = 0.172, p = 0.01; delayed passage retrieval: β = 0.214, p = 0.002) with the effects in Passage Memory reaching significance in both clinical groups. Wake after sleep onset time directly predicted follow-up immediate passage recall in the total sample (β = -0.211, p = 0.001) and in the MCI group (β = -0.235, p = 0.02). In the total sample, longer 24-h sleep duration was associated with reduced memory performance indirectly through increased sleep duration at follow-up (immediate passage recall: β = -0.045, p = 0.01; passage retention index: β = -0.051, p = 0.01; RAVLT-delayed recall: β = -0.048, p = 0.009; RAVLT-retention index:β = -0.066, p = 0.004). Similar indirect effects were found for baseline 24-h time in bed. Indirect effects of sleep duration/time in bed were found predominantly in the MCI group.

Discussion

Findings corroborate and expand previous work suggesting that poor sleep quality and long sleep duration predict worse memory function in elderly. Timely interventions to improve sleep could help prevent or delay age-related memory decline among non-demented elderly.

A Pilot Study on the Effectiveness of Prazosin as a Treatment of Post-Traumatic Stress Disorder-Related Nightmares in Women with Bulimia Nervosa

Objectives Post-traumatic stress disorder (PTSD) symptoms are reported in over 36% of individuals with bulimia nervosa. To date, none of the clinical trials have examined nightmare reduction in this population. We evaluated the effectiveness of prazosin in bulimic females experiencing PTSD-related nightmares. We hypothesized that prazosin will decrease nightmares, normalize cortisol levels and secretory patterns, and improve sleep. Methods Our seven-week prospective, randomized, double-blind, placebo-controlled crossover pilot trial recruited eight adult women. Each participant received three weeks of prazosin and a placebo, separated by a one-week washout period. The order of treatment was counterbalanced across participants. Self-reports, clinician-administered scales, and salivary cortisol was collected to measure outcomes. Results A significant treatment effect was seen in nightmare intensity on the Clinician-Administered PTSD Scale (CAPS-I) (p=0.026) and a marginally significant effect on nightmare frequency (p=0.069). The only significant main effect of treatment on self-reported sleep parameters was on nightmares. Cortisol secretory patterns did not change, but on average, study participants had significantly higher cortisol levels compared to normative values. ANOVA showed a significant main effect of time for cortisol (F(4, 28) = 6.15, p=.001) but no within or between groups significant effects (ps>.179). Follow-up tests showed the effect of time was linear (F(1, 7) = 10.77, p=.013). Conclusion Prazosin significantly reduced intensity and marginally reduced the frequency of PTSD-related nightmares in bulimia nervosa but did not affect subjective sleep efficiency, quality, cortisol levels, or diurnal cortisol secretory pattern. Larger trials using objective sleep measures are warranted to replicate these findings.

Suicidality Prevalence in a Pediatric Psychiatric Clinic: Relation to Social and Environmental Risk Factors

Suicidality is a growing public health problem in children and adolescents. The aim of this retrospective data analysis study was to estimate the prevalence of suicidality in pediatric patients admitted to an academic Pediatric Psychiatric Clinic (PPC) and to analyze social and environmental risk factors associated with suicide. Suicidal ideation was assessed by the Self-Injurious Thoughts and Behaviors Interview. Using established psychometric scales, social and stressful events were analyzed. During the four-year study, 249 episodes of care were experienced by 152 individuals (mean age 15.2 ± 2 years, girls/boys 107/45). Twenty-eight patients (11.2%) were admitted from the Pediatric Intensive Care Unit and the Department of Pediatrics, 162 (65.1%) from the Pediatric Emergency Department, and 59 (23.7%) from other Hospitals (p = 0.003). A significant longitudinal increase in admissions to PPC, with increasing trends of suicidal ideation, suicide attempts, and suicidality, was recorded. Suicidal behavior, bullying, internet addiction, friends quarreling, and family problems were risk factors for suicide attempts and suicidality. Our results have implications for prevention programs, highlighting an increasing need for care for suicide attempts and suicidal ideation, related to specific stressful events and contextual socio-environmental status.

Study of Alzheimer's disease- and frontotemporal dementia-associated genes in the Cretan Aging Cohort

Using exome sequencing, we analyzed 196 participants of the Cretan Aging Cohort (CAC; 95 with Alzheimer's disease [AD], 20 with mild cognitive impairment [MCI], and 81 cognitively normal controls). The APOE ε4 allele was more common in AD patients (23.2%) than in controls (7.4%; p < 0.01) and the PSEN2 p.Arg29His and p.Cys391Arg variants were found in 3 AD and 1 MCI patient, respectively. Also, we found the frontotemporal dementia (FTD)-associated TARDBP gene p.Ile383Val variant in 2 elderly patients diagnosed with AD and in 2 patients, non CAC members, with the amyotrophic lateral sclerosis/FTD phenotype. Furthermore, the p.Ser498Ala variant in the positively selected GLUD2 gene was less frequent in AD patients (2.11%) than in controls (16%; p < 0.01), suggesting a possible protective effect. While the same trend was found in another local replication cohort (n = 406) and in section of the ADNI cohort (n = 808), this finding did not reach statistical significance and therefore it should be considered preliminary. Our results attest to the value of genetic testing to study aged adults with AD phenotype.

Abstract MP47: Sleep Disordered Breathing is Adversely Associated With Cardiac Autonomic Modulation in Adolescents

Introduction: Sleep disordered breathing (SDB), as measured by the apnea/hypopnea index (AHI), is a known risk factor for cardiovascular disease (CVD) in adults. Although SDB is prevalent in pediatric populations, there has been less focus on SDB as a primary risk factor for CVD in youth. The recent AHA scientific statement on SDB and CVD in children and adolescents suggests that, in order to better understand the long-term CVD-related risk associated with SDB in youth, additional longitudinal studies incorporating noninvasive markers of CVD are needed. The current study aimed to fill this important gap.

Hypothesis: We hypothesized that SDB is associated with decreased HRV in adolescents.

Methods: We studied 421 subjects from the Penn State Child Cohort who were 8.7 (1.7) years old at baseline and were followed-up as adolescents 16.5 (2.3) years old. We estimated the AHI from 9-hour, in-lab polysomnography (PSG), and frequency and time-domain heart rate variability (HRV) indices from 24-h Holter EKG monitoring immediately following PSG. We stratified 24-h HRV data into daytime and nighttime periods. Linear regression analyses examined the association between AHI with 24-h HRV indices, while adjusting for age, sex, race/ethnicity, BMI percentile, and metabolic syndrome (MetS) score in adolescence as well as AHI and nighttime HRV indices in childhood.

Results: While there were no significant associations between AHI and daytime (p=0.233) or nighttime (p=0.147) HR, there were significant associations with frequency and time-domain HRV indices. A higher AHI was associated with lower Log-HF, Log-LF, SDNN and RMSSD, yet higher LF/HF, for both daytime and nighttime periods (all p<0.05). For example, for each additional apnea or hypopnea per hour of sleep there was a decrease of -1.74ms (0.73) and -1.65ms (0.77) in SDNN during the daytime (p=0.018) and nighttime (p=0.033), respectively, even after adjusting for all covariates including MetS, childhood AHI and SDNN. More specifically, the 24-h SDNN of adolescents with an AHI≥5, indicative of moderate-to-severe SDB, was 10.9ms (4.4) lower than that of adolescents with an AHI=0 (p=0.014).

Conclusions: SDB is associated with impaired cardiac autonomic balance in adolescence independently of MetS, prior SDB and prior HRV status. These data further support the role of SDB as an independent risk factor for CVD early in life.

Abstract 13: Circadian Misalignment is Associated With Impaired Heart Rate Variability in Adolescents

Introduction: Adequate sleep has been recognized by AHA as part of Life’s Essential 8 in the prevention of cardiovascular disease (CVD). The circadian system, which governs the sleep-cycle, is also involved in cardiac, metabolic and autonomic regulation. Heart rate variability (HRV), a marker of cardiac autonomic modulation (CAM), is known to predict CVD. As a result, circadian misalignment of the sleep-wake cycle, which is highly prevalent in adolescents, may impact CAM and be a potential risk factor for adverse CVD outcomes in early life.

Hypothesis: We hypothesize that deviations in the circadian timing of sleep are associated with blunted HRV in adolescents.

Methods: We analyzed data from 337 population-based randomly-selected adolescents from the Penn State Child Cohort (median 16 years; 47% female; 21% racial/ethnic minority) who had at least 3-night at-home actigraphy (ACT), in-lab 9-h polysomnography (PSG) and 24-h Holter-monitoring heart rate variability (HRV) data. ACT-sleep duration and sleep midpoint (SM) were calculated as the intra-individual mean total sleep time and midpoint of the sleep period, respectively. ACT-sleep variability and sleep regularity (SR) were calculated as the intra-individual standard deviation of sleep duration and sleep midpoint across nights, respectively. Frequency and time-domain HRV indices, including HR oscillations at high frequencies (HF), standard deviation between normal heart beats or R-R intervals (SDNN), and root mean square of successive differences between normal heartbeats (RMSSD), were primary outcomes. Linear regression models tested SM and SR as predictors of HRV indices, while accounting for sex, race/ethnicity, age, body mass index, ACT-sleep duration, ACT-sleep variability, and PSG-apnea/hypopnea index.

Results: While there were no meaningful associations between SM or SR with daytime HRV, there were significant associations between SM with nighttime HRV. A later SM was associated with lower nighttime Log-HF, SDNN and RMSSD, yet higher nighttime LF/HF (all p<0.03). For each standard deviation increase in SM (i.e., 1.5 hours later), there was a decrease of -5.50ms (1.92) in nighttime RMSSD (p=0.004). More specifically, the nighttime RMSSD of adolescents with a SM at 5:30 (i.e., sleep onset at 2:00, sleep offset at 9:00), was 18.2ms (6.7) lower (p=0.007) than that of adolescents with a SM at 2:30 (i.e., sleep onset at 23:00, sleep offset at 6:00).

Conclusions: A delayed sleep phase is associated with impaired CAM in adolescents. These data support that circadian misalignment of the sleep-wake cycle may independently contribute to CVD risk.

0726 Visceral adiposity and daytime sleepiness are associated with hypertension in mild-to-moderate sleep apnea: age-related differences

Introduction

Mild-to-moderate obstructive sleep apnea (OSA) affects 15-40% of the adult general population and is associated with incident hypertension, particularly in young and middle-aged adults. We examined whether visceral adiposity, a key predictor of OSA, and excessive daytime sleepiness (EDS), a cardinal symptom of OSA, are associated with hypertension in middle-aged and older adult patients with mild-to-moderate OSA.

Methods

A clinical sample of 148 adults (53.79±12.45y, 36.5% female) with mild-to-moderate OSA (5≤AHI&lt;30) underwent 8-hour polysomnography, a clinical history and physical examination, including measures of blood pressure. EDS was defined as an Epworth Sleepiness Scale (ESS) score ≥11. Hypertension was defined as blood pressure ≥140/90mmHg or the use of anti-hypertensive medication. Visceral Adiposity Index (VAI) was calculated within each sex using Amato et al (2010) standardized formulas based on waist, BMI, triglycerides and HDL cholesterol. Logistic regression models examined the association between VAI, AHI and EDS with hypertension, adjusting for sex and stratifying by age. Under the receiver-operating characteristics (ROC) curves (AUC) with sex, BMI, AHI, VAI and EDS as independent variables examined predictive risk of hypertension.

Results

VAI (OR=1.64, 95%CI=1.23-2.20, p=0.001) and EDS (OR=2.73, 95%CI=1.04-7.17, p=0.042), but not AHI (OR=1.05, 95%CI=0.98-1.13, p=0.165), were associated with significantly increased odds of hypertension in adults aged &lt;60y (46.81±8.83y), while none of these associations were significant in adults aged ≥60y (67.06±5.65y). Adding VAI and EDS to standard clinical factors (age, sex, and BMI) yielded a strong risk model for hypertension in adults aged &lt;60y (AUC= 0.80), and weaker in adults aged ≥60y (AUC=0.62).

Conclusion

These data indicate that the combination of visceral adiposity and subjective sleepiness improves markedly the ability for clinicians to detect cases of mild-to-moderate OSA with increased cardiovascular risk, an association that is strongest in young and middle-aged adults. These findings also further support that OSA in older subjects is a distinctly different phenotype than in young and middle-aged adults.

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0031 Sleep Regularity is Associated with DNA Methylation in Cognitive, Cardiovascular and Mood-related Genes: A GWAS-informed Study in Adolescents

Introduction

Adolescence is associated with a delay in the circadian timing of sleep. However, social factors prevent adolescents from adapting to a later sleep-wake pattern, leading to different forms of circadian misalignment that may increase the risk of cardiovascular and mental health disorders. Several GWAS have identified genes associated with sleep and circadian phenotypes, however, little is known regarding the epigenetic basis and significance of sleep timing and its regularity in adolescence.

Methods

We analyzed data from 230 adolescents from the Penn State Child Cohort follow-up study who provided a blood sample for DNA extraction and had complete at-home 7-night (at least 3) actigraphy (ACT) data. ACT-measured sleep midpoint was calculated as the intra-individual mean of the 7-night midpoint (zeroed to midnight) of the sleep period. ACT-measured sleep regularity was calculated as the intra-individual standard deviation of the 7-night sleep midpoint. Epigenome-wide single nucleotide resolution of DNA methylation in cytosine-phosphate-guanine (CpG) sites and surrounding regions were obtained from peripheral leukocytes. This study focuses on methylation sites in GWAS-informed genes previously associated with sleep and circadian phenotypes. Linear regression assessed the association between sleep midpoint and sleep regularity with site-specific methylation levels, adjusting for sex, age, race/ethnicity, body mass index, and psychotropic medication use. Using the Benjamini & Hochberg method to adjust for a false discovery rate. Adjusted p-values are reported as q-values.

Results

Sleep midpoint was not associated with a significant change in methylation at any of the measured intragenic sites. Sleep regularity was significantly associated with differential methylation at 238 intragenic sites in 147 genes with an adjusted p&lt;0.05, of which, three sites were within GWAS-informed sleep/circadian-related genes. Higher sleep irregularity was associated with hypermethylation in MAD1L1 (q=2.4x10-2) and with hypomethylation in CALN1 (q=3.8 x 10-4) and ZNF618 (q=3.8 x 10-2).

Conclusion

Sleep irregularity is associated with altered DNA methylation in genes previously identified in GWAS of sleep/circadian phenotypes. Our data provides evidence for a potential epigenetic link between sleep irregularity and genes involved in neurocognitive functioning (CALN1), internalizing disorders (MAD1L1) and blood pressure (ZNF618).

Support (If Any)

National Institutes of Health (R01HL136587, R01MH118308, UL1TR000127)

0190 Association of Sleep Spindle Activity with Cognition in Youth from the General Population

Introduction

Sleep spindle activity has been increasingly studied as an underlying mechanism of cognition. In youth, it appears the relationship between spindle activity and cognition depends upon the spindle metric and cognitive domain examined. Prior research has been conducted primarily in highly selective experimental studies of typically developing youth. We aimed to clarify the relationship between spindle activity and lower and higher order cognitive functions in children and adolescents from the general population.

Methods

We studied 639 children aged 5-12y (median 9y) and 418 adolescents aged 12-23y (median 16y) from a population-based cohort. All subjects underwent a 9-hour, in-lab polysomnography. We calculated sleep spindle density (SSD), the total number of spindles per minute of stage 2 of non-rapid eye movement sleep, and peak spindle frequency (PSF) in the 10-16 Hz range at central, frontal and fronto-occipital derivations. Wechsler intelligence testing assessed verbal and non-verbal intelligence quotients (IQ), processing speed (coding) and working memory (digit span backward [DSB]). Multivariable-adjusted linear regression models with age, sex, race/ethnicity, body mass index, apnea/hypopnea index, and insomnia symptoms as covariates examined the association between SSD and PSF with cognitive outcomes.

Results

At ages 5-12, central SSD was positively associated with verbal IQ (p=0.04), non-verbal IQ (p=0.03), coding (p=0.01) and DSB (p&lt;0.01); additionally, frontal SSD was positively associated with coding and DSB (both p&lt;0.01) and fronto-occipital SSD with DSB (p&lt;0.01). Also, central (p&lt;0.01) and frontal (p=0.01) PSF was positively associated with DSB. At ages 12-23, fronto-occipital SSD was positively associated with non-verbal IQ (p=0.02), while no other statistically significant associations were observed for SSD or PSF with cognitive outcomes (all p≥0.08).

Conclusion

Spindle density is a strong correlate of general ability (both verbal and non-verbal IQ) in childhood, and it remains for non-verbal IQ in adolescence. Both increased spindle density and peak frequency are associated with better working memory in childhood, yet not in adolescence. These developmental differences may be due to cortical (e.g., synaptic pruning) and thalamocortical (e.g., increased myelination) maturational changes occurring during adolescence.

Support (If Any)

National Institutes of Health (R01MH118308, UL1TR000127)

0724 Age-related AHI cut-offs associated with cardiovascular and cerebrovascular disorders: clinical implications

Introduction

Several studies have shown that the association of obstructive sleep apnea (OSA) with clinical outcomes, such as hypertension, weakens in older adults. An apnea hypopnea index (AHI) ≥5 is recommended as the cut-off for initiating treatment without any consideration of possible age differences. We aimed to examine at which cut-off point of AHI, OSA is associated with cardiovascular and/or cerebrovascular diseases (CBVD) in middle-aged adults and in older adults.

Methods

We studied 1,741 adults from the Penn State Adult Cohort (age 20-88 years, 52.3% female, 12.4% racial/ethnic minority), who underwent a 1-night sleep laboratory evaluation, clinical history and physical examination. Hypertension was defined as a diastolic blood pressure ≥90 mmHg or a systolic blood pressure ≥140 mmHg or the use of anti-hypertensive medication. CBVD was defined based on a self-report of a physician diagnosis of heart disease and/or stroke. Logistic regression models examined the odds of having hypertension or CBVD in a step-wise manner starting from an AHI ≥5 up to AHI ≥30 by increments of 5 events, while simultaneously adjusting for sex, race and BMI and stratifying by age.

Results

The odds of hypertension were significantly increased in adults aged &lt;60y (43.2±9.1y) with an AHI≥5 (OR=1.56, 95% CI 1.01-2.41, p=0.045), while the odds of hypertension were not significantly increased in adults aged ≥60y (68.4±6.3y) for any given AHI cut-off. The odds of CBVD were significantly increased in adults aged ≥60y with an AHI≥15 (OR=2.50, 95% 1.24-5.04, p=0.011), while the odds of CBVD were not significantly increased in adults aged &lt;60y for any given AHI cut-off.

Conclusion

These data suggest that AHI cut-offs warranting treatment of OSA should be adjusted based on age and prevalent clinical disorders, consistent with the concept of personalized medicine. These findings are also consistent with the notion that OSA in older adults is a distinctly different phenotype than in young and middle-aged adults.

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0636 Objective sleep as a predictor of cognitive decline among non-demented elderly: preliminary results from the Cretan Aging Cohort

Introduction

Sleep disturbances have been linked with cognitive decline and previous cross-sectional have shown that long sleep duration is a marker of disease severity in patients Mild Cognitive Impairment (MCI) and Dementia.Our aim was to examine the longitudinal associations between sleep quantity and quality indices and cognitive progression in non-demented community-dwelling elderly.

Methods

A sub-sample of 62 participants (72.6% females) were recruited from a large population-based cohort in the island of Crete, Greece of 3,140 older adults (&gt;60yrs). Participants were followed-up 8 years later (phase III). All participants underwent neuropsychiatric/neuropsychological evaluation (phases II & III) and a 3-day 24h actigraphy (phase II).Participants were diagnosed as CNI(N=38) and MCI(N=24) during phase II, and CNI (N=22), MCI (N=27) and Dementia (N=13) during phase III. On follow-up, 28 participants progressed to a cognitively declined diagnosis compared to phase II (deteriorated group), while 34 did not (non-deteriorated group). Objective sleep variables at phase II were compared between the deteriotated/non-deteriorated groups using ANCOVA controlling for confounders. Also, differences in neuropsychological testing scores (phase II- phase III) were calculated and associations of differences with sleep variables were examined using partial correlation models controlling for confounders.

Results

The deteriorated group compared to non-deteriorated had significantly longer night total sleep time (TST) (442±72.6min vs. 407±53.6min, p=0.033), 24h-TST (484±8.9min vs. 434±66.4min, p=0.008), night time in bed (TMB) (537±78.7min vs. 497±62.7min, p=0.03), and 24h-TMB (603±85min vs. 539±85min, p=0.005). Episodic memory worsening was moderately correlated with night TST (r=.316), night and 24h-TMB (r=.526, and r= .442 respectively), wake time after sleep onset (r=.351), and average duration of night awakenings (r=.405). Immediate episodic memory recall decline was positively correlated with night TMB (r=.338).

Conclusion

Preliminary results from the Cretan aging cohort indicate that almost half of the participants deteriorated cognitively in 8 years and this decline was predicted by objective sleep duration at baseline. Long sleep at baseline may predict deterioration of clinical cognitive status in non-demented elderly at follow-up. It appears that prolonged objective sleep duration and time in bed are novel and clinically useful prognostic factors of cognitive deterioration in elderly with or without cognitive deficits.

Support (If Any)

National Strategic Reference Framework (NSRF) - Research Funding Program: THALES entitled “UOC-Multidisciplinary network for the study of Alzheimer’s Disease” Grant Cod: MIS 377299HELLENIC FOUNDATION FOR REASEARCH AND INNOVATION (HFRI)- Research Funding Program: ELIDEK entitled “Sleep Apnea (OSA) and poor sleep as Risk Factors for decreased cognitive performance in patients with Mild Cognitive Impairment: the Cretan Aging Cohort (CAC)”, Grant Cod: HFR1-FM17-4397

0032 Objective and Subjective Measures of Sleep Initiation are Differentially Associated with DNA Methylation in Adolescents

Introduction

The onset of puberty is associated with a shift in the circadian timing of sleep leading to delayed sleep initiation [i.e., later sleep onset time (SOT)] driven by later bedtimes and/or longer sleep onset latency (SOL). Subjective sleep initiation, as per self-reports, and objective sleep initiation, as per actigraphy (ACT) or polysomnography (PSG), assess equally relevant but different domains of the same physiological process. Several GWAS have identified genes associated with sleep and circadian phenotypes; however, little is known regarding the epigenetic basis and significance of delayed sleep initiation in adolescence, a critical developmental period.

Methods

We analyzed data from 263 adolescents from the Penn State Child Cohort follow-up study who had complete subjective (self-reported questionnaires), at-home 7-night ACT, and in-lab 9-hour PSG data for bedtime, SOL and SOT. Epigenome-wide single-nucleotide resolution of DNA methylation in cytosine-phosphate-guanine (CpG) sites and surrounding regions were obtained from peripheral leukocytes. Linear regression assessed the association between bedtime, SOL and SOT with site-specific methylation levels, adjusting for sex, age, race/ethnicity, body mass index, and psychotropic medication use. P-values were adjusted using the Benjamini & Hochberg method to correct for false discovery rate and, thus, q-values are reported.

Results

Exome-wide analysis showed differential methylation in 1450 unique genes across the 9 sleep measurements, while GWAS-informed analysis yielded 57 genes. Gene hits were identified for bedtime (PSG), SOL (subjective, ACT and PSG) and SOT (subjective and PSG): 14 genes were associated with both subjective and PSG-measured SOL, 34 with both ACT- and PSG-measured SOL, and one (TBC1D22A) with subjective, ACT- and PSG-measured SOL. One gene (ABTB2) was associated with subjective and PSG-measured SOT.

Conclusion

Objective and subjective sleep initiation in adolescents is associated with altered DNA methylation in genes previously identified in adult GWAS of sleep and circadian phenotypes. Our data provides evidence for a potential epigenetic link between habitual (subjective and ACT) SOL and in-lab SOT and DNAm in genes involved in circadian regulation (i.e., RASD1, RAI1), metabolism (i.e., FADS1, WNK1, SLC5A6), and neuropsychiatric disorders (i.e., PRR7, SDK1, FAM172A).

Support (If Any)

National Institutes of Health (R01HL136587, R01MH118308, UL1TR000127)

0663 Association of Insomnia Phenotypes based on Objective Sleep Duration with Suicide Attempts, Ideation and Completion

Introduction

Sleep disturbances, including insomnia and short sleep duration, are known risk factors for suicidal ideation, attempts, and death. Insomnia is a heterogeneous disorder, with phenotypes of short and normal sleep duration based on objective sleep measures showing differential pathophysiology, natural course, cardiometabolic and neurocognitive morbidity. However, little is known about the association of these insomnia phenotypes with suicidality in adults.

Methods

We analyzed data from the Penn State Adult Cohort (N = 1741, M age = 52.46, SD = 13.43, 57.4% female), a randomly selected population-based sample who underwent a thorough clinical history and in-lab polysomnography (PSG). Suicidality was ascertained by a lifetime history of suicide attempts, suicidal ideation or suicide as cause of death by December 31 2018 (n = 102). Insomnia symptoms were defined as a complaint of moderate-to-severe difficulties initiating or maintaining sleep, early morning awakening and non-restorative sleep, or chronic insomnia (n = 719). Short sleep duration was defined as &lt; 6-h of in-lab PSG-measured sleep (n = 879). Binary logistic regression was used to examine the association between insomnia phenotypes with suicidality, while controlling for sex, age, race/ethnicity, and medical and psychiatric comorbidities. Given the low suicidality prevalence in this sample, 1000 bootstrapped samples were drawn to provide stable estimates.

Results

Compared to normal sleepers who slept &gt; 6-h, subjects with insomnia symptoms who slept &lt; 6-h and those who slept &gt; 6-h were associated with 1.96-fold (95%CI = 1.04-4.00) and 2.46-fold (95%CI = 1.30-5.04) increased odds of suicidality, respectively. After further adjusting for substance use, subjects with insomnia symptoms who slept &lt; 6-h and those who slept &gt; 6-h were associated with 1.72-fold (95%CI = 0.90-3.58) and 2.22-fold (95%CI = 1.15-4.60) increased odds of suicidality, respectively. Normal sleepers who slept &lt; 6-h were not associated with significantly increased odds of suicidality (OR = 1.32; 95%CI = 0.56-2.94).

Conclusion

Adults with insomnia, particularly those with normal sleep duration, were associated with increased suicidality. These data further support that objectively-defined insomnia phenotypes may confer risk for differential adverse health outcomes (e.g., cardiometabolic vs. psychopathologic) via distinct mechanistic pathways.

Support (If Any)

American Heart Association (14SDG19830018)

0219 Interplay of School Days and Free Days with Sleep Midpoint on the Association of Visceral Adiposity with Blood Pressure in Adolescents

Introduction

The circadian timing of sleep, including its variability, has emerged as an important contributor to obesity and cardiovascular health, such as elevated blood pressure. Adolescence is a particularly vulnerable period for circadian misalignment, which may express differently if youth are in school or on free-days. We examined whether deviations in sleep midpoint increase the impact of visceral adiposity on elevated blood pressure in adolescents as a function of being entrained to school or not.

Methods

We analyzed cross-sectional data from the Penn State Child Cohort follow-up study, a random population-based sample of 303 adolescents (16.2 ± 2.2 y; 47.5% female; 21.5% minority). Actigraphy-measured sleep midpoint was calculated as the midpoint (zeroed to midnight) of the sleep period for weekdays (5-nights) and weekends (2-nights). Actigraphy-measured sleep regularity was calculated as the intra-individual standard deviation of the 5-night weekdays sleep midpoint. Visceral adipose tissue (VAT) was measured via dual-energy X-ray absorptiometry scan. Systolic (SBP) and diastolic (DBP) blood pressure was measured three times in the seated position. Multivariable linear regression models were stratified by “in school” and “on break” to test sleep midpoint and sleep regularity as effect modifiers of VAT on SBP/DBP levels. Analyses were adjusted for sex, race/ethnicity, age, actigraphy-measured sleep duration and polysomnography-measured apnea/hypopnea index.

Results

When participants were studied while “in school”, significant interactions were found between VAT and weekdays sleep midpoint on SBP (p-interaction=0.027) and DBP (p-interaction=0.046), so that the later the sleep midpoint on school days, the greater the association of VAT with SBP/DBP. When participants were studied while “on break”, a significant interaction was found between VAT and weekdays sleep regularity on SBP (p-interaction=0.039), so that the higher the sleep irregularity on weekdays, the greater the association of VAT with SBP. No other significant interactions were found.

Conclusion

A delayed and an irregular sleep midpoint during school days and during breaks, respectively, best identified those adolescents with greater cardiovascular risk associated with visceral obesity. These data suggest that not only the circadian timing of sleep contributes to adverse cardiovascular outcomes but its distinct biomarkers require measurement under different entrainment conditions in adolescents.

Support (If Any)

National Institutes of Health (R01HL136587, UL1TR000127)

0432 Insomnia is Associated with Endothelial Dysfunction in Young Adulthood: the Penn State Child Cohort

Introduction

Clinical and population-based studies in middle-aged and older adults have shown that insomnia is associated with prevalent and incident cardiovascular diseases. However, there is a lack of studies demonstrating an association between insomnia and subclinical cardiovascular measures such as endothelial function in young adults from the general population.

Methods

We studied 200 subjects from the Penn State Child Cohort (20-30 years old, 47% male, 22% racial/ethnic minority), who underwent a thorough clinical history and physical examination to ascertain the presence of sleep disorders and body mass index (BMI), in-lab polysomnography to ascertain the apnea/hypopnea index (AHI), and Doppler ultrasound to assess flow-mediated dilation (FMD). We identified the presence of moderate-to-severe difficulties initiating and/or maintaining sleep (i.e., poor sleep) and of insomnia, the latter including a physician diagnosis of the disorder. The study outcome was FMD as a continuous measure and the square root of FMD (sqrt-FMD) to test the robustness of the analysis. General linear models adjusted for sex, age, race/ethnicity, BMI, AHI, alcohol intake, and sleep medication use.

Results

Compared to normal sleepers (0.111±0.003), subjects with poor sleep (0.104±0.006) and insomnia (0.092±0.008) showed a significant association with lower FMD levels (p-linear&lt;0.05), with subjects with insomnia having significantly lower FMD levels (p=0.029). Results remained significant and in the same direction based on sqrt-FMD (p-linear=0.015).

Conclusion

These data indicate that insomnia is associated with increased risk for cardiovascular disease as early as young adulthood, and independent of major contributors such as obesity, sleep apnea or alcohol use. These data further reinforce the need to include insomnia as a target in the preventative efforts for cardiovascular disease.

Support (If Any)

National Institutes of Health (R01HL136587, UL1TR000127)

0488 Trajectories of Insomnia Symptoms since Childhood Associated with Treatment of Internalizing Disorders in Adulthood

Introduction

Internalizing disorders (ID) are the most common form of psychopathology, with a large proportion of individuals seeking treatment in young adulthood. Childhood insomnia symptoms, i.e., difficulties initiating or maintaining sleep (DIMS), have been shown to be associated with ID, however, little is known about the developmental trajectories of insomnia symptoms and their associated risk of receiving pharmacotherapy for ID. The present study examined the longitudinal association between trajectories of childhood insomnia symptoms and risk of receiving treatment for ID in young adulthood.

Methods

We analyzed data from the Penn State Child Cohort, a population-based sample of 505 children (Mdn=9y), who were followed-up 8 years later as adolescents (Mdn=16y) and 15 years later as young adults (Mdn=24y). Insomnia symptoms were defined as parent-reported (childhood) or self-reported (adolescence and young adulthood) moderate-to-severe DIMS. The trajectories of insomnia symptoms across the three time-points were identified as never, remitted, waxing-and-waning, incident and persistent. The presence of ID was defined as a self-report of a diagnosis of mood and/or anxiety disorders, whether they had received treatment or not and whether treatment consisted of prescription psychotropic medication (i.e., antidepressants, anxiolytics). Logistic regression models were adjusted for sex, race/ethnicity, age, and any childhood or adolescent history of a psychiatric diagnosis or psychotropic medication use.

Results

Persistent (OR=3.0) and incident (OR=3.3) trajectories, but not waxing-and-waning (OR=1.1) or remitted (OR=0.8) trajectories, were associated with increased odds of ID that did not receive treatment in adulthood. Additionally, the odds of receiving treatment for ID with prescription psychotropic medication in adulthood were increased in those with persistent (OR=3.4), incident (OR=3.5) and waxing-and-waning (OR=2.1) trajectories, but not in those with a remitted trajectory (OR=0.7).

Conclusion

Childhood-onset persistent insomnia symptoms as well as adult-onset incident insomnia symptoms are strong risk factors for receiving treatment for mood/anxiety disorders in adulthood, while childhood insomnia symptoms that fully remit over time are not. Treatment of insomnia in youth should be an essential target as to decrease the risk of developing severe forms of mood/anxiety disorders requiring psychotropic treatment in adulthood.

Support (If Any)

National Institutes of Health (R01HL136587, R01MH118308, UL1TR000127)

0727 Age-related association of visceral adiposity with cardiometabolic disorders in mild-to-moderate sleep apnea

Introduction

Visceral adiposity is a key predictor of both metabolic syndrome and obstructive sleep apnea (OSA). Both metabolic syndrome and OSA are associated with cardiometabolic disorders, however, the association of OSA with these disorders weakens in older adults. We compared the relative strength of the association between visceral adiposity vs. OSA with hypertension and diabetes and whether this association is stronger in middle-aged vs. older adults.

Methods

A clinical sample of 148 adults (53.79±12.45y, 36,5% female) with mild-to-moderate OSA (5≤AHI&lt;30) underwent 8-hour polysomnography, a clinical history and physical examination, including measures of blood pressure and fasting glucose. Hypertension was defined as blood pressure ≥140/90mmHg or use of anti-hypertensive medication. Diabetes was defined as fasting glucose ≥100mg/dL or receiving treatment for diabetes, except insulin. Visceral Adiposity Index (VAI) was calculated within each sex using Amato et al (2010) standardized formulas based on waist, BMI, triglycerides and HDL cholesterol. Logistic regression models examined the association between VAI and AHI with hypertension and diabetes, while simultaneously adjusting for sex and stratifying by age. We also generated under the receiver-operating characteristics (ROC) curves (AUC) having hypertension and diabetes as outcomes and gender, age, BMI, AHI and VAI as independent variables.

Results

VAI was associated with greater odds of having hypertension (OR=1.57, 95%CI=1.20-2.06, P=0.001) and diabetes (OR=1.27, 95%CI=1.02-1.57, p=0.031) compared to AHI (OR=1.05, 95%CI=0.98-1.13, p=0.185; and OR=1.07, 95% CI=1.00-1.14, p=0.690, respectively) in adults aged &lt;60y. There was no association between VAI or AHI with hypertension and diabetes in adults aged ≥60y. Adding VAI to standard clinical factors (age, sex, and BMI) yielded moderately-good risk models for hypertension (AUC=0.73) and diabetes (AUC=0.70) in adults aged &lt;60y, while suboptimal risk models (AUC=0.61 and 0.68, respectively) in adults aged ≥60y.

Conclusion

These data indicate that visceral adiposity, but not AHI, is associated with cardiometabolic disorders in patients with mild-to-moderate OSA, an association that is stronger in middle-aged adults. Visceral obesity should be a priority in preventive/therapeutic interventions in young and middle-aged patients with OSA. These findings also further support that OSA in older adults is a distinctly different phenotype.

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0254 Association of Slow Wave Activity and Odds Ratio Product with Internalizing and Externalizing Problems in Children and Adolescents

Introduction

The association of metrics of sleep microstructure with internalizing and externalizing problems in youth has remained elusive. While one study found increased frontal slow wave activity (SWA) in depressed adolescents, there is lack of evidence for a relationship between dimensional measures of behavior and metrics of sleep depth/intensity. We examined the association between two measures of sleep depth/intensity, slow wave activity (SWA) and odds ratio product (ORP), with internalizing and externalizing problems in children and adolescents.

Methods

We calculated SWA and ORP during non-rapid eye movement (NREM) sleep at central, frontal and fronto-occipital derivations in 639 children (5-12y, median 9y) and 418 adolescents (12-23y, median 16y) from the Penn State Child Cohort via in-lab polysomnography. ORP provides a standardized measure of NREM sleep depth, while ORP-9 (average ORP in the 9-seconds following NREM arousals) provides a metric of arousability. SWA (0.4-4Hz) absolute power (µV2) was determined during NREM sleep. Internalizing and externalizing problems were assessed on Achenbach’s Behavior Checklist by parent (subjects≤17y) or self-report (subjects≥18y). For each scale, T-scores with a mean of 50 and standard deviation of 10 were obtained following standardized scoring. Multivariable-adjusted linear regression models examined the association between SWA/ORP and clinical outcomes.

Results

At ages 5-12, fronto-occipital SWA was negatively associated with externalizing behaviors (p=0.05), while fronto-occipital and frontal ORP, and frontal ORP-9 were positively associated with internalizing symptoms (all p&lt;0.01). At ages 12-23, central SWA was negatively associated with internalizing symptoms (p=0.05), while central (p=0.05) and frontal (p=0.03) ORP and central ORP-9 (p=0.03) were positively associated with externalizing behaviors.

Conclusion

Reductions in SWA in childhood or adolescence are associated with developmentally appropriate behavioral problems, as depression/anxiety are more prevalent in adolescence. In contrast to SWA, increased ORP (lighter sleep) and ORP-9 (greater arousability) are associated with more anxiety/depression in childhood, yet more externalizing behaviors in adolescence. These distinct associations, such as SWA with externalizing behaviors and ORP with internalizing symptoms during childhood, may reflect how SWA captures local/synaptic control, while ORP global/state control, of sleep depth, making both sleep EEG biomarkers important from a developmental standpoint.

Support (If Any)

National Institutes of Health (R01MH118308, UL1TR000127)

0536 Association of a Novel EEG Biomarker of Sleep Depth with Sleep Disordered Breathing in Adolescents

Introduction

The odds ratio product (ORP) provides a standardized, continuous measure of sleep depth that ranges from 0 (deep sleep) to 2.5 (full wakefulness). ORP has been shown to increase during adolescence, representing the decline in sleep depth that occurs during this developmental period. In adults, higher ORP has been associated with sleep disordered breathing (SDB), including obstructive sleep apnea (OSA), while there have been no studies in youth. We aimed to determine the association of ORP with SDB in adolescents.

Methods

We extracted ORP from the sleep EEG of 261 typically developing adolescents aged 12-23y (median 16y) from the Penn State Child Cohort. Higher ORP during rapid eye movement (REM) and non-REM sleep indicates less deep sleep, while higher ORP-9 (i.e., average ORP in the 9-seconds following non-REM cortical arousals) indicates greater arousability. We used general linear models, adjusted for sex, age and race/ethnicity, to examine mean differences in ORP metrics among clinically meaningful groups of SDB based on the apnea/hypopnea index (AHI) consisting of no SDB (AHI&lt;2 and no snoring, n=100), primary snoring (AHI&lt;2 and snoring, n=75), 2≤AHI&lt;5 (n=64), and AHI≥5 (n=22).

Results

Adolescents with primary snoring or 2≤AHI&lt;5 did not significantly differ in ORP metrics from those without SDB (all p≥0.12). Adolescents with AHI≥5 had higher ORP-NREM compared to those without SDB, with primary snoring or with 2≤AHI&lt;5 (all p≤0.01), while ORP-REM was significantly higher compared to those without SDB (p=0.02). ORP-9 was significantly greater in adolescents with AHI≥5 compared to those with no SDB (p&lt;0.01) and those with primary snoring (p=0.02), but not when compared to those with 2≤AHI&lt;5 (p=0.07).

Conclusion

Our data suggest that adolescents with OSA experience lower REM and non-REM sleep depth/intensity (higher ORP) compared to those without SDB. In addition, these adolescents experience a slower progression back to deep sleep following cortical arousals (higher ORP-9), which suggests they remain in a high arousability state and, thus, are more likely to repeat arousals. Commensurate with previous studies in adults, our data show that ORP is a useful sleep EEG biomarker able to capture decreased sleep depth in adolescents with OSA.

Support (If Any)

National Institutes of Health (R01MH118308, UL1TR000127)

Interactions of Mediterranean Diet, Obesity, Polypharmacy, Depression and Systemic Inflammation with Frailty Status

Objective:Comprehensive characterization of potential frailty determinants, including sociodemographic, clinical, dietary, psychological, cognitive and systemic inflammation parameters. Methods:A rural cohort of 186 subjects aged 60-89 years recruited from a community-based study in Crete, Greece (the Cretan Aging Cohort). Frailty was assessed with the Simple "Frail" Questionnaire Screening Tool. Results:Univariate analyses revealed significant (a) positive associations (p<0.01) between frailty and age, widowhood, Geriatric Depression Scale (GDS) score, waist circumference, polypharmacy, IL-6 and (b) negative associations between frailty and frequency of contact with friends, Mini Mental State Examination (MMSE), and adherence to the Mediterranean diet. Multivariate analyses revealed a significant independent contribution of the following variables to frailty: age (B=0.035, p<0.001), GDS score (B=0.041, p=0.034), polypharmacy (B=0.568, p<0.001), waist circumference (B=0.015, p=0,006), plasma IL-6 levels (B=0.189, p=0.004), and adherence to the Mediterranean diet (B=-0.036, p=0.015). Conclusion:Older age, depression symptoms, polypharmacy, waist circumference, poor adherence to Mediterranean diet and IL-6 plasma levels are associated with increased frailty.

The association of basal cortisol levels with episodic memory in older adults is mediated by executive function

Elevated basal cortisol levels in elderly may indicate dysregulation of the internal stress-related system, as well as dysfunction and structural alterations in brain structures necessary for cognition, such as hippocampus and prefrontal cortex. Because of the close relation of executive functions and episodic memory processing, in this study we explored whether the association of elevated cortisol levels on episodic memory could be partly attributed to cortisol effects on executive functions. In this cross-sectional study we analyzed data from a sample of 236 community-dwelling older adults from the Cretan Aging Cohort aged 75.56 ± 7.21 years [53 with dementia due to probable Alzheimer's disease, 99 with Mild Cognitive Impairment (MCI) and 84 cognitively non-impaired participants (NI)]. Morning serum cortisol levels were higher in the probable AD as compared to the NI group (p = .031). Mediated regression models in the total sample supported the hypothesis that the negative association of basal cortisol levels with delayed memory was fully mediated by the relation of basal cortisol levels with executive functions and immediate memory (adjusted for age and self-reported depression symptoms). Moderated mediation regression models revealed that the direct effect of cortisol on executive function and the effect of executive function on delayed memory performance were statistically significant among participants diagnosed with MCI, while the immediate memory effect on delayed memory was more pronounced in AD patients, as compared to the NI group. The current findings corroborate neuroimaging research highlighting cortisol effects on executive functions and immediate memory and further suggest that dysregulation of systems involved in these functions may account for the purported detrimental long-term effects of high cortisol levels on delayed memory.

Abstract 038: Cumulative Exposure To Sleep Disordered Breathing From Childhood Through Young Adulthood Is Associated With Impaired Endothelial Function

Introduction: Clinical and population-based studies in adults have shown that sleep disordered breathing (SDB) is associated with impaired endothelial function. However, there is a lack of population-based studies demonstrating an association between SDB and endothelial dysfunction in young adults using a developmental approach.

Hypothesis: Exposure to SDB since childhood is associated with long-term impaired flow-mediated dilation (FMD) in young adulthood.

Methods: We tested this hypothesis in a subsample of the Penn State Child Cohort, a population-based study of 700 children (median age 9y), of whom 421 were followed-up 6-13 years later during adolescence (median age 16y), and 178 have been followed-up 11-19 years later during young adulthood (median age 24y). Subjects (54.5% female, 20.8% racial/ethnic minority) underwent in-lab polysomnography to ascertain the apnea/hypopnea index (AHI) at all three time points, and ultrasounds to assess FMD in young adulthood. Based on the AHI truncated at ≥5 events/hour of sleep to include subjects already on positive airway pressure therapy, we averaged the exposure to AHI over the three time points (cAHI). The study outcomes were FMD, as a continuous measure, and endothelial dysfunction, defined as FMD<10.3% based on the median of the sample. Linear and logistic regression models simultaneously adjusted for sex, age, race/ethnicity, overweight and length of follow-up.

Results: The mean cAHI was 1.31 (1.35) ranging from 0 to 5 and the mean FMD was 0.11 (0.04) ranging from 0.03 to 0.25. Linear models showed that cAHI was associated with significantly lower FMD in young adulthood (β = -0.006; 95% CI = -0.011, -0.0013; p = 0.014). To test the robustness of the analysis, we applied the same model with the square root of FMD as the outcome and similar results were obtained (β = -0.009; 95% CI = -0.016, -0.0017; p = 0.015). Logistic models showed that each point increase in cAHI was associated with 51% higher odds of endothelial dysfunction in young adulthood (OR = 1.51; 95% CI = 1.14, 2.06; p = 0.006).

Conclusions: The preliminary data of this ongoing longitudinal study indicates that exposure to SDB during early stages of life is associated with increased risk for cardiovascular disease in young adults from the general population.

Abstract MP63: Childhood-onset Obstructive Sleep Apnea Is Associated With Increased Risk Of Adolescent Hypertension

Introduction: Obstructive sleep apnea (OSA) is an established risk factor for hypertension in adults. However, the association of childhood OSA with an increased risk of hypertension has remained elusive.

Hypothesis: Childhood-onset OSA is longitudinally associated with hypertension in adolescence.

Methods: We tested this hypothesis in a population-based sample of 421 children (5-12 years) from the Penn State Child Cohort who were followed-up 6-13 years later as adolescents (12-23 years). In-lab polysomnography, to ascertain the apnea/hypopnea index (AHI), and seated blood pressure were assessed at baseline and at follow-up. The presence of hypertension at follow-up was defined based on pediatric criteria dependent upon the subject’s age (below and above 13 years). Logistic regression analyses adjusted for sex, race/ethnicity, age, body mass index percentile and systolic blood pressure percentile at baseline.

Results: Childhood OSA that persisted in the transition to adolescence was associated with 2.9-fold (95%CI=1.1-7.4) higher odds of adolescent hypertension. In contrast, childhood OSA that remitted in the transition to adolescence was not associated with increased odds of adolescent hypertension (OR=0.9, 95%CI=0.3-2.6). Adolescent-onset OSA was associated with 1.7-fold (95%CI=1.1-2.9) increased odds of adolescent hypertension.

Conclusions: Childhood-onset persistent OSA is a risk factor for hypertension in adolescence. Remission of childhood OSA during this transitional period, which previous research has shown to be highly determined by weight loss, does not confer a significant risk of adolescent hypertension. Early life chronic adverse sleep exposures predict cardiovascular risk in adolescence, a critical developmental period.

369 Insomnia with objective short sleep duration is associated with increased cortisol in patients with Mild Cognitive Impairment

Introduction

Mild cognitive impairment (MCI) is frequent in the elderly and is in a continuum with dementia in a significant amount of people. Both insomnia and increased cortisol levels have been suggested as risk factors for MCI. The goal of this study was to examine whether activation of the hypothalamic-pituitary-adrenal (HPA) axis, as measured by plasma cortisol levels, is associated with the insomnia with short sleep duration (ISS) phenotype, as measured by actigraphy, in elderly with MCI.

Methods

A sub-sample of 109 subjects with MCI and 92 cognitively non-impaired controls 60 years or older (75.37±6.54y) was recruited from a population-based cohort residing on Crete, Greece. Subjects underwent medical history, physical examination, neuropsychiatric evaluation, neuropsychological testing, 3-day 24-h actigraphy, assessment of subjective insomnia symptoms (i.e., difficulties initiating and/or maintaining sleep), and a morning blood draw to assay for plasma cortisol levels. The ISS phenotype was defined by the presence of at least one insomnia symptom and an actigraphy-measured sleep efficiency below the median of the entire sample (i.e., ≤81%). Group differences in plasma cortisol levels between MCI subjects with and without the ISS phenotype were tested using ANCOVA adjusting for age, gender, BMI and depression.

Results

Subjects with MCI had higher cortisol levels compared to controls (105.34±9.34 vs. 70.3±10.02 nmol/L, p&lt;0.05). Subjects with MCI and the ISS phenotype (138.38±16.57 nmol/L) had significantly higher cortisol levels compared to those without insomnia (97.74±19.68 nmol/L) or those with insomnia and normal sleep duration (INS; 79.97±16.02 nmol/L, p=0.044). The association between the ISS phenotype and cortisol levels was modified by amnestic symptoms (p-interaction=0.079); commensurate, the ISS phenotype was associated with higher cortisol levels among the amnestic MCI subgroup (INS: 79.12±21.93 vs. ISS: 155.55±20.40 nmol/L, p=0.040), but not among the non-amnestic MCI subgroup (INS: 64.06±23.62 vs. ISS: 89.33±29.00 nmol/L, p=0.559).

Conclusion

The ISS phenotype is associated with increased cortisol levels in elderly with MCI, particularly those with amnestic type. Improving sleep quality, decreasing cortisol levels and lengthening sleep duration may slow down the progression of these individuals into dementia.

Support (if any)

National Strategic Reference Framework(NSRF), Program: THALES entitled “UOC-Multidisciplinary network for the study of Alzheimer’s Disease” Grant Cod:MIS 377299

628 Longitudinal Association between NREM Sleep Depth and Arousability with ADHD and Internalizing Disorders in Adolescence

Introduction

Sleep depth decreases in the transition from childhood to adolescence, even in typically developing (TD) youth. However, it remains unknown whether this developmental trajectory in NREM sleep depth differs across adolescents with psychiatric/behavioral disorders.

Methods

We analyzed the sleep EEG of 392 subjects aged 5–12 at baseline and 12–22 at follow-up (45.2% female, 23.2% racial/ethnic minority), of whom 246 were TD adolescents (controls), 62 were diagnosed with a psychiatric/behavioral disorder and were taking stimulant, anti-depressant, anxiolytic, sedative and/or anti-psychotic medications, and 84 were un-medicated. NREM sleep depth was measured at both time points using the odds ratio product (ORP), which provides a standardized continuous EEG measure of NREM sleep depth/arousability (higher ORP reflects lighter NREM sleep). General linear models examined mean differences between groups on the percent change in ORP between baseline and follow-up (ΔORP) while adjusting for sex, race/ethnicity, age, BMI and AHI at follow-up, and PSG system, psychiatric/behavioral disorders, psychoactive medications and ORP at baseline as well as time-to-follow-up.

Results

Overall, medicated (80.4%, 95%CI=66.2–94.6) and un-medicated (66.1%, 95%CI=53.0–79.1) subjects showed a higher ΔORP compared to controls (52.2%, 95%CI=40.0–64.5, p&lt;0.01 and p&lt;0.05, respectively) but did not differ between each other (p=0.134). Specifically, un-medicated subjects with ADHD (n=56) showed a higher ΔORP (77.3%, 95%CI=62.4–92.1) compared to controls (p&lt;0.01), while subjects with ADHD on stimulant medication (n=36) did not differ (66.1%, 95%CI=48.9–93.2) from controls (p=0.268) or from un-medicated ADHD subjects (p=0.303). Subjects with internalizing disorders on psychoactive medications (n=29) showed a higher ΔORP (104.9%, 95%CI=82.8–127.0) compared to controls (p&lt;0.01) and to un-medicated subjects (n=27) with internalizing disorders (60.1%, 95%CI=36.8–83.3, p&lt;0.01), who did not differ from controls (p=0.772).

Conclusion

The greater increase in ORP in the transition to adolescence in un-medicated youth with ADHD suggests that decreased NREM sleep depth may be a biomarker of the disorder. In contrast, the greater increase in ORP in medicated youth with internalizing disorders suggests that psychoactive medications impact NREM sleep depth in these children as they transition to adolescence. These data have important implications for sleep EEG studies that include medicated and un-medicated youth with comorbid psychiatric disorders.

Support (if any)

NIH Awards Number R01MH118308, R01HL136587, R01HL97165, R01HL63772, UL1TR000127

178 Sleep Disparities in Adolescent Women: Role of Pubertal Development, Menstrual Cycle and Premenstrual Symptoms

Introduction

About 20-30% of children experience sleep difficulties and about 50-60% of those persist into adolescence. Sex differences in sleep become more apparent after the onset of puberty, suggesting a role for maturational changes in the sleep of males and females. In addition, adolescent females experience greater sleep difficulties with the advancement of pubertal stages and around the time of menstruation. Although adult studies have shown sex differences in sleep continuity and architecture, there is a large gap of knowledge in adolescents.

Methods

We analyzed data from the Penn State Child Cohort, a random, population-based sample of 421 adolescents (16.5±2.3y, 53.9% male) who underwent one-night in-lab polysomnography (PSG) and seven-night at-home actigraphy (ACT) as well as a thorough physical exam and clinical history, including self-reports of Tanner staging, menstrual cycle and use of oral contraceptives (OC).

Results

Upon PSG, females had a longer sleep latency (p&lt;0.05), while males a greater number of awakenings (p&lt;0.05), longer wake after sleep onset (p&lt;0.01) and greater stage N1 (p&lt;0.05). Per ACT, females had longer total sleep time and greater sleep efficiency (p&lt;0.01). Sex differences in PSG and ACT parameters were more prominent among adolescents reporting Tanner stages 4-5, including females having greater stage N3 than males (p&lt;0.01) and females reporting premenstrual symptoms (PMS) having a longer sleep latency than males or than those not reporting PMS (P&lt;0.05). Among females, those who had their last period 8-14 days prior to the PSG had a shorter sleep latency than those who had their period within the previous 7 days (p&lt;0.01) or 15-25 days before (p&lt;0.05). Females using OC (n=38) did not show significantly different PSG or ACT parameters than those not using OC (n=156).

Conclusion

Our study provides evidence for sex-related health disparities in objective sleep arising in adolescence. Females sleep objectively better than males from a sleep continuity and sleep architecture perspective, particularly when examined at the same pubertal stage. Additionally, sleep onset is significantly impacted by the menstrual cycle and associated symptoms but females preserve greater levels of deep sleep, a sign of sleep resilience.

Support (if any)

NIH Awards Number R01MH118308, R01HL136587, R01HL97165, R01HL63772, UL1TR000127

010 Association between Objective Sleep Duration and DNA methylation in Adolescents

Introduction

Insufficient sleep and circadian misalignment are highly prevalent in adolescents and have been associated with physical and mental health disorders. Several genome wide association studies (GWAS) in adults have identified genes that may be involved in the regulation of sleep and circadian traits. However, little is known regarding the epigenetic basis and significance of short sleep duration in adolescence, a critical developmental period.

Methods

To investigate the association between objective sleep duration, as measured by 9-hour in-lab polysomnography (PSG), and DNA methylation in GWAS-informed sleep-related genes, data from 263 adolescents of the Penn State Child Cohort (12-23y, 55.9% male, 23.2% racial/ethnic minorities) were analyzed. Using DNA extracted from peripheral leukocytes, epigenome-wide and GWAS-informed single nucleotide resolution of DNA methylation in cytosine-phosphate-guanine (CpG) sites and surrounding regions were obtained. Multivariable-adjusted linear regression models assessed the association between PSG sleep duration and site-specific methylation levels. Covariates in these models included sex, age, race/ethnicity, body mass index percentile, and psychoactive medication use (i.e., stimulants, anti-depressants, anxiolytics, sedatives, and/or anti-psychotics). P-values were adjusted using the Benjamini & Hochberg method to correct for false discovery rate and, thus, q-values are reported.

Results

PSG sleep duration was associated with differential methylation at 162 intragenic sites in the epigenome-wide analysis with a q&lt;0.05. In GWAS-informed analysis, five genes were associated with altered DNA methylation, by which shorter PSG sleep duration was associated with hypermethylation in MAD1L1 (q=0.02), MAP2K1 (q=0.03), and RBM19 (q=0.01) and with hypomethylation in Brain Enriched Guanylate Kinase Associated (BEGAIN; q=0.0005) and SLC39A8 (q=0.02).

Conclusion

Objective sleep duration in adolescents is associated with altered DNA methylation in genes previously identified in adult GWAS of sleep and circadian traits. Importantly, our data also provides evidence for a potential epigenetic link between objective short sleep duration and genes involved in postsynaptic density (BEGAIN), circadian regulation (MAP2K1/RBM19) as well as internalizing (MAD1L1) and psychotic (SLC38A8) disorders.

Support (if any)

NIH Awards Number R01HL136587, R01MH118308, R01HL97165, R01HL63772, UL1TR000127

150 Impact of Behavioral Disorders and their Pharmacological Treatment on the Maturational Trajectories of NREM Slow Wave Activity

Introduction

Slow wave activity (SWA) in the delta (0.4-4 Hz) frequency range declines in typically developing (TD) children as they transition to adolescence. However, it remains unknown whether the maturational trajectory of NREM delta power differs between TD youth and those with psychiatric/behavioral disorders.

Methods

We analyzed the sleep EEG of 664 subjects aged 6 to 21 (46.8% female, 24.7% racial/ethnic minority) from the Penn State Child Cohort, of whom 449 were TD, 123 were un-medicated and diagnosed with psychiatric/behavioral disorders, and 92 were medicated with stimulants, anti-depressants, anxiolytics, sedatives and/or anti-psychotics. Multivariable regression models adjusting for sex, race/ethnicity, BMI, AHI and PSG system tested the age-related trajectories of NREM delta power within each diagnostic group.

Results

Delta power in TD and un-medicated youth showed cubic age-related trajectories (both p-cubic&lt;0.05). In TD youth, delta power was highest at age 6.6 and lowest at age 19.9, while in un-medicated youth it was highest at age 8.9 and lowest at age 18.6. The decreasing slope in delta power was 39.7% steeper in un-medicated youth (-22422 ± 5891/year, p&lt;0.01) than TD youth (-16047 ± 2605/year, p&lt;0.01). Delta power in medicated youth showed a distinct linearly decreasing trajectory (-13518 ± 4597/year, p-linear&lt;0.01) from age 6 (highest) to age 21 (lowest).

Conclusion

TD and un-medicated youth with psychiatric/behavioral disorders show SWA trajectories typical of brain maturation biomarkers (e.g., gray matter volume), characterized by a decreasing slope at the onset of puberty that reaches its nadir by late adolescence. However, SWA in un-medicated youth peaks two years later and reaches its nadir a year earlier than in TD youth. Thus, while TD children experience a smooth decline in SWA in the transition to adolescence, those with psychiatric/behavioral disorders experience a faster steep decline. In contrast, SWA in medicated youth appears to be dampened in early childhood and its slope linearly decreases with age. These data suggest that these youth may have a more severe disorder requiring pharmacological treatment, that the latter produces greater cortical arousability reflected in lower SWA power, and/or that psychoactive medications directly impact normal neurodevelopmental processes (e.g., synaptic pruning).

Support (if any)

NIH Awards Number R01MH118308, R01HL136587, R01HL97165, R01HL63772, UL1TR000127

757 Associations Between Sleep Complaints, Suicidal Ideation and Depression Among Adolescents and Young Adults in Greece

Introduction

Suicide risk begins to increase among adolescents and young adults representing the leading cause of death in this age group. The aim of this study was to assess associations between sleep complaints, suicidal ideation and depression in a large, representative sample of adolescents and young adults of the general population in Greece.

Methods

A structured telephone questionnaire was conducted in a representative sample of 2.741 young Greeks aged 15–24 years, including sociodemographic variables, life-style habits, and substance use. symptoms were assessed using the PhQ-9. Suicidal ideation and sleep complaints, i.e. insomnia/ hypersomnia symptoms, were assessed based on the relevant questions of the PhQ-9 questionnaire. We conducted a direct and indirect effect analysis between the modified PhQ-7 scale, sleep complaints and suicidality controlling for gender, family income, education and substance use.

Results

In our sample prevalence of suicidal ideation was 7.8%, while 47.9% reported sleep complaints. The mean PhQ-7 score was 6.15±4.11. The direct paths from depression to sleep, as well as from sleep to ideation were both statistically significant with p-values &lt;0.001. Indirect mediation analysis revealed a significant indirect effect of depression on ideation mediated by sleep complaints as indicated by the sobel test (z=3.59, p=0.0003). This is a partial mediation given that the direct effect of depression on ideation controlling for sleep (the mediator) remains significant (p&lt;.001). The percentage of the effect of depression on ideation accounted for by the indirect effect through sleep is estimated at 16.5%. The mediation remains significant (p&lt;.001) after controlling for income, gender, education, and substance use.

Conclusion

Our study supports that among youth there is direct associations between depression, sleep complaints and suicidal ideation. Furthermore, we found an indirect effect of depression on suicidal ideation mediated by sleep complaints. Our findings highlight the presence of complex interactions between subjective psychiatric symptoms and perceived sleep problems to account for suicidal ideation Therefore, treatment of sleep among youth with depression may significantly independently further reduce suicidal risk.

Support (if any)

EEA/Norwegian Financial Mechanism 2009–2014, under Project Contract n° EEA Grants/ GR07- 3757

627 Adolescent Delayed Sleep Phase and Circadian Irregularity Associated with Substance (Mis)Use in Young Adulthood

Introduction

Substance use disorders are reaching epidemic proportions among adolescents and young adults. While disturbed, insufficient sleep is known to be associated with substance use, little is known about the role of circadian misalignment in precipitating or perpetuating substance misuse.

Methods

The Penn State Child Cohort is a population-based sample of 700 children (Mdn=9y), who were followed-up 8 years later as adolescents (N=421, Mdn=16y) and 15 years later as young adults (N=492, Mdn=24y). In adolescence, a delayed sleep phase was defined as a 7-night actigraphy-measured mean sleep midpoint later than 4:00 AM, while an irregular circadian phase as a within-subjects standard deviation in sleep midpoint greater than 1 hour. Alcohol, tobacco, and drug use was ascertained by parent- and/or self-reports in adolescence, while alcohol, tobacco and marijuana use was ascertained by self-reports in young adulthood. Logistic regression models tested the association between delayed and irregular circadian phase with substance use adjusted for age, sex, race/ethnicity, BMI, SES, mental health problems and psychoactive medications.

Results

Adolescents with a delayed sleep phase (n=164) showed later bed and wakeup times, lower morningness scores and greater circadian phase irregularity. Cross-sectionally, a delayed sleep phase in adolescence was associated with 1.9-fold odds (95%CI=1.1–3.2) of alcohol, tobacco and/or drug use; specifically, the odds of alcohol and tobacco use associated with a delayed sleep phase were 1.9-fold (95%CI=1.1–3.4) and 2.4-fold (95%CI=1.1–5.3), respectively, while non-significant for drug use (n=28) for which mental health problems were among the strongest risk factors (OR=3.0, 95%CI=1.3–6.8). Longitudinally, an irregular circadian phase in adolescence was associated with 2.2-fold odds (95%CI=1.1–4.5) of alcohol, tobacco and/or marijuana use in young adulthood; specifically, the odds of alcohol use in young adulthood associated with an irregular circadian phase in adolescence were 1.9-fold (95%CI=1.1–3.5), while non-significant for tobacco (n=58) or marijuana use (n=76) for which mental health problems were the strongest risk factor (OR=2.2, 95%CI=1.3–3.7).

Conclusion

A delayed or irregular circadian phase in adolescence is associated with substance use, particularly alcohol use in the transition to adulthood. Beyond disturbed and insufficient sleep, circadian misalignment should become a target of early interventions to prevent substance use disorders.

Support (if any)

R01MH118308, R01HL136587, R01HL97165, R01HL63772, UL1TR000127

151 Sex Differences in the Maturational Trajectories of Sleep Spindles in the Transition from Childhood to Adolescence

Introduction

Sleep spindles occur as bursts of EEG activity in the sigma (11-16 Hz) frequency range and are purported biomarkers of cortical development. However, the few studies examining maturational changes in sleep spindles are limited by small samples and/or short follow-up periods. Thus, large longitudinal population-based studies are needed to determine their developmental trajectories as the child transitions to adolescence.

Methods

We analyzed the sleep EEG of 572 un-medicated subjects aged 6-21 (47.6% female, 25.9% racial/ethnic minority), of whom 332 were 5-12 years at baseline and followed-up at ages 12-22. Multivariable-adjusted models tested the cross-sectional and longitudinal trajectories of sleep spindle density, frequency, and power.

Results

From age 6 to 21, the trajectory of sleep spindle density was best fit by a quadratic model (p=0.02), particularly in males (p-quadratic=0.05). Females maintained more stable levels of sleep spindle density (p-linear=0.26), as shown by a longitudinal increase 37.6% lower than males by age 14 (p=0.01). Sleep spindle frequency increased (p-linear&lt;0.01), while sleep spindle power decreased (p-linear&lt;0.01), from age 6 to 21. The trajectory of sleep spindle frequency diverged between females (p-linear&lt;0.01) and males (p-quadratic=0.02), in whom it plateaued by age 15 onwards. Females had experienced a longitudinal increase in sleep spindle frequency 2.4% higher than males by age 20-22 (p=0.05). Males had experienced a steeper decreasing slope in sleep spindle power (p-linear&lt;0.01) than females (p-linear=0.12), as confirmed by a longitudinal decline 25.4% greater than females by age 19 (p=0.02).

Conclusion

Sleep spindle metrics follow distinct maturational trajectories from each other and from other EEG oscillations (e.g., slow wave activity). The increase in sleep spindle density from childhood to early adolescence coupled with the linear increase in sleep spindle frequency from childhood to young adulthood may represent the emergence of fast sleep spindles, which appears to occur earlier in females. Overall, males experience greater maturational changes in all sleep spindle metrics and sex differences become prominent in young adulthood, when males show lower sleep spindle density and sleep spindle frequency, indicative of less fast sleep spindles.

Support (if any)

NIH Awards Number R01MH118308, R01HL136587, R01HL97165, R01HL63772, UL1TR000127

327 Developmental Trajectories of Insomnia and Risk of Internalizing Disorders in Young Adulthood

Introduction

Internalizing disorders (ID) are the most common form of psychopathology and a large proportion of individuals experience their first onset after the age of 18. Childhood insomnia symptoms, i.e., difficulties initiating or maintaining sleep (DIMS), have been shown to be associated with ID. However, little is known about the developmental trajectories of insomnia symptoms and their associated risk of ID as the child transitions into adulthood. The present study examined the risk of ID in young adulthood associated with the longitudinal trajectories of insomnia symptoms across three developmental stages.

Methods

The Penn State Child Cohort is a population-based sample of 700 children (Mdn=9y), who were followed-up 8 years later as adolescents (N=421, Mdn=16y) and 15 years later as young adults (N=492, Mdn=24y). Insomnia symptoms were defined as parent-reported (childhood) or self-reported (adolescence and young adulthood) moderate-to-severe DIMS. The developmental trajectories of insomnia symptoms across the three time-points were identified as never, remitted, waxing-and-waning, persistent and incident. The presence of ID was defined as a self-report of a diagnosis or treatment for mood and/or anxiety disorders. Cox regression models were adjusted for sex, race/ethnicity, age and childhood/adolescent history of ID or psychoactive medication use.

Results

A persistent developmental trajectory was associated with a 2.8-fold increased risk of adult ID (HR=2.83, 95%CI=1.79–4.49) and an incident trajectory with a 1.9-fold risk (HR=1.88, 95%CI=1.10–3.20), while a waxing-and-waning trajectory was marginally associated with adult ID (HR=1.70, 95%CI=0.99–2.91). A remitting trajectory was not associated with an increased risk of adult ID (HR=0.92, 95%CI=0.38–2.24).

Conclusion

This 15-year longitudinal study with three developmental stages shows that childhood-onset insomnia symptoms that persist across the life-course are strong determinants of ID in young adulthood, independent of past diagnosis or medication use. In contrast, childhood insomnia symptoms that remit in the transition to adolescence do not confer increased risk of ID in young adulthood. Given that insomnia symptoms may precipitate and/or maintain ID, these data further reinforce the need for early sleep interventions to prevent mental health disorders.

Support (if any)

NIH Awards Number R01HL136587, R01MH118308, R01HL97165, R01HL63772, UL1TR000127

Objective Daytime Napping is Associated with Disease Severity and Inflammation in Patients with Mild to Moderate Dementia1

BACKGROUND

Patients with dementia report excessive daytime sleep/sleepiness, which is associated with worse cognitive performance. Inflammatory markers may be elevated in patients with dementia and have been proposed as mediators of sleep/sleepiness.

OBJECTIVE

To examine the association of objective daytime napping with cognitive performance and peripheral markers of inflammation in patients with dementia as compared to not cognitively impaired (NCI) controls.

METHODS

A sub-sample of 46 patients with mild-to-moderate dementia and 85 NCI controls, were recruited from a large, population-based cohort of 3,140 elders (≥60 years) in Crete, Greece. All participants underwent medical history/physical examination, extensive neuropsychiatric and neuropsychological evaluation, 3-day 24 h actigraphy and a single morning measure of IL-6 and TNFα plasma levels. Comparisons of sleep parameters and inflammation markers between diagnostic groups, and between nappers and non-nappers within each diagnostic group, were conducted using ANCOVA controlling for demographics/related clinical factors. Associations between inflammatory markers, sleep variables, and neuropsychological performance were assessed within each group using partial correlation analysis controlling for confounders.

RESULTS

Patients with dementia slept 15 minutes longer during the day than NCI. Within dementia patients, nappers had significantly worse performance on autobiographic memory (p = 0.002), working memory (p = 0.007), episodic memory (p = 0.010), and assessment of daily function (p = 0.012) than non-nappers. Finally, IL-6 levels were significantly associated with nap duration within dementia patients who napped (r = 0.500, p = 0.01).

CONCLUSIONS

Daytime napping in patients with dementia is associated with worse cognitive performance and increased IL-6 levels. In dementia, objective daytime napping, may be a marker of the severity of the disease.

Insomnia disorder: clinical and research challenges for the 21st century

BACKGROUND AND PURPOSE

Insomnia is a common and debilitating disorder that is frequently associated with important consequences for physical health and well-being.

METHODS

An international expert group considered the current state of knowledge based on the most relevant publications in the previous 5 years, discussed the current challenges in the field of insomnia and identified future priorities.

RESULTS

The association of trajectories of insomnia with subsequent quality of life, health and mortality should be investigated in large populations. Prospective health economics studies by separating the costs driven specifically by insomnia and costs attributable to its long-term effects are needed. Ignoring the heterogeneity of insomnia patients leads to inadequate diagnosis and inefficient treatment. Individualized interventions should be promoted. More data are needed on both the impact of sleep on overnight effects, such as emotion regulation, and the potential compensatory effort to counteract diurnal impairments. Another gap is the definition of neurocognitive deficits in insomnia patients compared to normal subjects after chronic sleep loss. There are also a number of key gaps related to insomnia treatment. Expert guidelines indicate cognitive-behavioural therapy for insomnia as first-line treatment. They neglect, however, the reality of major healthcare providers. The role of combined therapy, cognitive-behavioural therapy for insomnia plus pharmacological treatment, should be evaluated more extensively.

CONCLUSION

Whilst insomnia disorder might affect large proportions of the population, there are a number of significant gaps in the epidemiological/clinical/research studies carried out to date. In particular, the identification of different insomnia phenotypes could allow more cost-effective and efficient therapies.

Apolipoprotein E ɛ4 (APOE ɛ4) Allele is Associated with Long Sleep Duration Among Elderly with Cognitive Impairment

Background: Apolipoprotein E gene (APOE) ɛ4 allele increases the risk for Alzheimer’s disease (AD). Furthermore, among patients with cognitive impairment, longer sleep duration is associated with worse cognitive performance. To date, literature examining the associations between APOE ɛ4 allele and objective sleep duration is limited. Objective: Our aim was to assess the association between APOE ɛ4 and objective sleep duration, among patients with mild cognitive impairment (MCI) and AD. A sub-sample of 89 patients with AD (n = 49) and MCI (n = 40) were recruited from a large, population-based cohort of 3,140 elders (>60 years) residing on Crete, Greece. Methods: All participants underwent medical history/physical examination, extensive neuropsychiatric and neuropsychological evaluation, 3-day 24 h actigraphy and APOE ɛ4 allele genotyping. Comparisons of sleep duration variables between APOE ɛ4 allele carriers and non-carriers were assessed using ANCOVA, controlling for confounders. Results: The sample included 18 APOE ɛ4 carriers and 71 non-carriers, aged 78.6±6.6 and 78.2±6.5 years, respectively. Comparisons between the APOE ɛ4 carriers and non-carriers revealed no significant differences in terms of demographic and clinical variables. In terms of objective sleep duration across the two groups, APOE ɛ4 carriers compared to non-carriers had significantly longer nighttime Total Sleep Time (nTST) (7.7±1.4 versus 7.2±1.3  h, respectively, p = 0.011), as well as 24 h TST (8.5±1.6 versus 7.8±1.5  h, respectively, p = 0.012). Conclusion: Among patients with MCI and AD, APOE ɛ4 carriers have longer objective nighttime and 24 h sleep duration compared to non-carriers. These findings further support that objective long sleep duration is a genetically-driven pre-clinical marker associated with worse prognosis in elderly with cognitive impairment.

Cognitive Impairment and Dementia in Primary Care: Current Knowledge and Future Directions Based on Findings From a Large Cross-Sectional Study in Crete, Greece

Introduction: Dementia severely affects the quality of life of patients and their caregivers; however, it is often not adequately addressed in the context of a primary care consultation, especially in patients with multi-morbidity. Study Population and Methods: A cross-sectional study was conducted between March-2013 and December-2014 among 3,140 consecutive patients aged >60 years visiting 14 primary health care practices in Crete, Greece. The Mini-Mental-State-Examination [MMSE] was used to measure cognitive status using the conventional 24-point cut-off. Participants who scored low on MMSE were matched with a group of elders scoring >24 points, according to age and education; both groups underwent comprehensive neuropsychiatric and neuropsychological assessment. For the diagnosis of dementia and Mild-Cognitive-Impairment (MCI), the Diagnostic and Statistical Manual-of-Mental-Disorders (DSM-IV) criteria and the International-Working-Group (IWG) criteria were used. Chronic conditions were categorized according to ICD-10 categories. Logistic regression was used to provide associations between chronic illnesses and cognitive impairment according to MMSE scores. Generalized Linear Model Lasso Regularization was used for feature selection in MMSE items. A two-layer artificial neural network model was used to classify participants as impaired (dementia/MCI) vs. non-impaired. Results: In the total sample of 3,140 participants (42.1% men; mean age 73.7 SD = 7.8 years), low MMSE scores were identified in 645 (20.5%) participants. Among participants with low MMSE scores 344 (54.1%) underwent comprehensive neuropsychiatric evaluation and 185 (53.8%) were diagnosed with Mild-Cognitive-Impairment (MCI) and 118 (34.3%) with dementia. Mental and behavioral disorders (F00-F99) and diseases of the nervous system (G00-G99) increased the odds of low MMSE scores in both genders. Generalized linear model lasso regularization indicated that 7/30 MMSE questions contributed the most to the classification of patients as impaired (dementia/MCI) vs. non-impaired with a combined accuracy of 82.0%. These MMSE items were questions 5, 13, 19, 20, 22, 23, and 26 of the Greek version of MMSE assessing orientation in time, repetition, calculation, registration, and visuo-constructive ability. Conclusions: Our study identified certain chronic illness-complexes that were associated with low MMSE scores within the context of primary care consultation. Also, our analysis indicated that seven MMSE items provide strong evidence for the presence of dementia or MCI.

Cognitive impairment in a primary healthcare population: a cross-sectional study on the island of Crete, Greece

OBJECTIVES

Cognitive impairment is known to have a significant impact on the quality of life of individuals and their caregivers, yet it is often underdiagnosed. The objective of this study is to assess the extent of cognitive impairment among elders visiting primary healthcare (PHC) practice settings, to explore associated risk factors and discuss current care challenges for PHC providers.

DESIGN

A cross-sectional study was conducted between March 2013 and May 2014.

SETTING

Fourteen PHC units located in rural and urban areas of the Heraklion district in Crete, Greece.

PARTICIPANTS

Consecutive visitors aged at least 60 years attending selected PHC practices.

PRIMARY AND SECONDARY OUTCOME MEASURES

The Mini-Mental State Examination (MMSE) was used to indicate cognitive status. Associations of low MMSE scores (≤23/24, adjusted for education level) with 12 socio-demographic factors, comorbidities and lifestyle factors were assessed.

RESULTS

A total of 3140 PHC patients met inclusion criteria (43.2% male; mean age 73.7±7.8 years). The average MMSE score was 26.0±3.8; 26.7±3.5 in male and 25.4±3.9 in female participants (p<0.0001). Low MMSE scores were detected in 20.2% of participants; 25.9% for females vs 12.8% for males; p<0.0001. Female gender (adjusted OR (AOR)=2.72; 95% CI 2.31 to 3.47), age (AOR=1.11; 95% CI 1.10 to 1.13), having received only primary or no formal education (AOR=2.87; 95% CI 2.26 to 3.65), alcohol intake (AOR=1.19; 95% CI 1.03 to 1.37), reporting one or more sleep complaints (AOR 1.63; 95% CI 1.14 to 2.32), dyslipidaemia (AOR=0.80; 95% CI 0.65 to 0.98) and history of depression (AOR=1.90; 95% CI 1.43 to 2.52) were associated with low MMSE scores.

CONCLUSIONS

This study identified a relatively high prevalence of low MMSE scores among persons attending PHC practices in a southern European community setting and associations with several known risk factors.

1120 Inverse U-Curve Association Between Sleep Duration and Cognitive Performance Among Patients with Dementia: Findings From the Cretan Aging Cohort

Introduction

Previous research reports an inverse U-curve association between subjective sleep duration and cognition in elderly, while findings on objective sleep duration are inconsistent. Only one study found weak association between objective short sleep duration and cognition, mainly driven by demented elders. Our aim was to examine the non-linear associations between objective sleep duration and cognitive performance among community-dwelling patients with dementia.

Methods

A sub-sample of 46 patients with mild-to-moderate dementia(AD) [mean age: 80.3 (SD=5.6) years, 40% males] and 85 cognitively intact controls(NI) [mean age: 73.0 (SD=7.4) years, 37% males], were recruited from a large, population-based cohort [Cretan Aging Cohort] in the island of Crete, Greece of 3,140 older adults (≥60yrs). All participants underwent medical history/physical examination, extensive neuropsychiatric and neuropsychological evaluation, and 3-day 24-h actigraphy. Comparisons between AD and NI participants on sleep parameters and neuropsychological performance were made using ANOVA controlling for demographics. Associations between 24-TST, and age- and education-adjusted cognitive scores and Independent Activity of Daily Living Scale (IADL) scores were assessed using hierarchical, non-linear, regression models, controlling for confounders.

Results

Dementia patients had significantly longer 24-h total sleep time (24h-TST) (491.2±107.1 min vs. 444.6±88.5 min, respectively, p=0.027), as well as lower cognitive/IADL sores as compared to the NI group. Significant associations between objective sleep and various cognitive /IADL scores were found only among patients with dementia. Specifically, we found a negative curvilinear association between 24-h TST and IADL, episodic memory indices (AVLT Retention, autobiographic memory) and visuomotor coordination speed (Trail Making Test, Part A).

Conclusion

Our study showed an inverse U-curve association between objective sleep duration and daily function, memory, and executive function in patients with dementia. Possibly, sleep loss may lead to cognitive impairment, whereas, prolonged sleep may be an indicator of worse cognitive performance among patients with dementia.

Support

National Strategic Reference Framework (ESPA) 2007-2013, Program: THALES, University of Crete, title: “A multi-disciplinary network for the study of Alzheimer’s Disease” (Grant: MIS 377299).

1035 Sleep Duration and Metabolic Syndrome: An Updated Systematic Review and Meta-Analysis

Introduction

To systematically examine the association between sleep duration and metabolic syndrome (Mets) risk in cross-sectional and prospective cohort studies.

Methods

Data were collected from 36 cross-sectional and 9 longitudinal studies with a total of 164799 MetS subjects and 430895 controls. Odds ratios (ORs) for MetS in cross-sectional studies and risk ratios (RRs) for incident MetS were calculated through meta-analyses of adjusted data from individual studies. Subgroup analyses were performed to investigate the association between MetS and the duration of short-and-long sleep.

Results

Short sleep duration was significantly associated with increased prevalent MetS (OR= 1.11, 95% CI =1.05-1.18) and incident MetS (RR= 1.28, 95% CI =1.07-1.53,) in cross-sectional and longitudinal studies, respectively. Furthermore, long sleep duration was significantly associated with increased prevalent MetS in cross-sectional studies (OR= 1.14, 95% CI =1.05-1.23), rather than incident MetS (RR= 1.16, 95% CI =0.95-1.41) in longitudinal studies. Interestingly, the association between long sleep and prevalent MetS was found in sleep duration defined by 24-hour sleep (including naps) rather than nighttime sleep. In cross-sectional studies, pooled odds for MetS were 1.36 (95% CI=1.04-1.78, I2=83.3%) in ≤ 5 hours, 1.09 (95% CI=1.02-1.16, I2=67.8%) in ≤6 hours, 1.01 (95% CI=0.93-1.10, I2=24.9%) in &lt;7 hours, 1.11 (95% CI=1.02-1.21, I2=67.0%) in ≥9 hours and 1.31 (95% CI=1.22-1.40, I2=0%) in ≥10 hours, respectively. The association of short sleep and MetS was stronger in young and middle age adults, but lost in adults age &gt;60 years.

Conclusion

Our findings suggest 1) a “U-shape” relationship between sleep duration and MetS in cross-sectional studies and 2) association between short sleep duration, but not long sleep duration with incident MetS. Future studies should shed light on the underlying mechanisms related to the association between sleep duration and MetS and examine if normalizing sleep duration reduces MetS risk in the general population.

Support

This study was supported by National Natural Science Foundation of China (No. 81600068 & 81970087), the Young Elite Scientists Sponsorship Program by CAST (No. YESS20160072), Medical Science Foundation of Guangdong Provence (A2018296) and Grant for Key Disciplinary Project of Clinical Medicine under the Guangdong High-level University Development Program.

0506 Short and Long-Term Effects of Trazodone vs. Cognitive-Behavioral Treatment on EEG Power During NREM Sleep in Chronic Insomnia

Introduction

Both trazodone and cognitive-behavioral treatment of insomnia (CBT-I) are widely used to treat patients with chronic insomnia. Animal studies have shown that trazodone increases slow wave sleep (i.e., increased EEG delta power). However, no study to date has compared the long term effects of trazodone vs. CBT-I on spectral EEG activity during sleep in humans.

Methods

We addressed this question in a sample of 19 middle-aged men and women who received either trazodone (n=8) or CBT-I (n=11) treatment for 9 months. We examined delta (0.39-3.91 Hz), theta (4.30-7.81 Hz), alpha (8.20-11.72 Hz), sigma (12.11-14.84 Hz), beta (15.23-35.16 Hz) and gamma (35.55-49.61 Hz) relative power during NREM sleep after 3-month and 9-month of treatment.

Results

Compared to CBT-I, trazodone significantly increased relative delta power (p=0.05) and decreased relative sigma (p=0.004) and beta (p=0.05) power during NREM sleep across 9-month treatment. Furthermore, compared to CBT-I, trazodone significantly increased relative delta power (3-month: Δ2.00 ± 3.27 vs. Δ-2.63 ± 5.88, p=0.006, Cohen’s d=0.93; 9-month: Δ2.63 ± 4.11 vs. Δ-1.10 ± 3.93, p=0.006, Cohen’s d=0.93), while decreased relative sigma power (3-month: Δ-1.55 ± 1.75 vs. Δ0.90 ± 1.82, p=0.009, Cohen’s d=1.37; 9-month: Δ-1.33 ± 1.95 vs. Δ1.05 ± 1.79, p=0.014, Cohen’s d=1.28) during NREM sleep in 3-month and 9-month, respectively. Relative beta power (3-month: Δ-0.85 ± 0.60 vs. Δ0.35 ± 1.14, p=0.016, Cohen’s d=1.03;) was significantly decreased in 3-month treatment in trazodone group compared to CBT-I. Moreover, across 9-month treatment, relative sigma (p=0.040, ω p2 = 0.29) and beta (p=0.021, ω p2 = 0.12) power during NREM sleep were significantly decreased within trazodone group, while relative sigma power (p=0.096, ω p2 = 0.230) increased within CBT-I group.

Conclusion

Our findings suggest that trazodone, but not CBT-I, even after 9-month of use increases slow wave sleep and decreases high-frequency EEG power during NREM sleep. This effect may explain the long-term usefulness of trazodone in chronic insomnia patients with physiologic hyperarousal i.e., activation of the stress system. Further studies should examine this effect in large samples of insomnia.

Support

NIH C06 RR016499, UL1 TR 000127

1130 Insomnia Short Sleep Phenotype is Associated With Frailty in Patients With Mild Cognitive Impairment (MCI)

Introduction

Insomnia short sleep phenotype is associated with cardiometabolic morbidity and mortality and neuropsychological impairment. In elderly untreated insomnia is associated with worse cognitive performance. The goal of the study was to examine the association between insomnia, objective sleep duration and physical and mental health in elderly patients with Mild Cognitive Impairment (MCI).

Methods

A sub-sample of 105 patients with MCI (mean age: 75.9 years, males 36%) were recruited from a large population-based cohort (Cretan Aging Cohort) in the island of Crete, Greece of 3,140 elders (≥ 60yrs). All participants underwent a complete medical history/ physical examination, extensive neuropsychiatric and neuropsychological evaluation and 3-day 24hr actigraphy. Insomnia was defined based on a question “do you have insomnia for more than a year”. Frailty was assessed with the Simple “Frail” Questionnaire Screening Tool. Comparisons between patients with insomnia and without insomnia were made using ANOVA controlling for age, gender and BMI.

Results

MCI patients with insomnia (n=23) compared to those without insomnia (n=82), had significantly shorter objective total sleep time (TST: 377 vs. 410 min, p=0.05) and significantly higher scores on the Geriatric Depression Scale and the Hospital Anxiety Scale (both p &lt;0.001). Furthermore, total frailty score, as well as scores in individual items, were significantly lower in MCI patients with insomnia (p&lt;0.01). This association remained significant after controlling for demographics, depression and anxiety. Finally, there was a statistical trend of association between insomnia and hypertension (p= 0.1).

Conclusion

In MCI patients, insomnia is associated with objective short sleep duration, and frailty. Improving insomnia and lengthening sleep duration may decrease frailty, a major problem associated with morbidity, disability and mortality in elders with cognitive decline.

Support

National Strategic Reference Framework (ESPA) 2007-2013, Program: THALES, University of Crete, title: “A multi-disciplinary network for the study of Alzheimer’s Disease” (Grant: MIS 377299).

NEET status among young Greeks: Association with mental health and substance use

BACKGROUND

Prior studies have shown that young people "not in education, employment or training" ("NEET") are at higher risk for psychopathology and substance abuse. Similar studies are lacking in Southern European populations. We aimed to examine the associations of anxiety and depressive symptoms, and substance use with NEET status in a large, randomized population-based sample in Greece.

METHODS

A telephone structured questionnaire was conducted in a representative sample of 2771 young Greeks aged 15-24 years. Anxiety and depressive symptoms were assessed with GAD-7 and PHQ-9 scales, respectively. Substances use and several sociodemographic parameters were also examined.

RESULTS

In our sample 16.4% were NEETs. In multivariate analyses, NEETs compared to non-NEETs were older, with lower family income, without insurance and more likely to be married and smoke. Furthermore, NEET status was associated with a higher GAD-7 score among older NEETs and long-term NEETs (NEETs unemployed for more than a year). Moreover, being NEET among older participants was associated with severe symptoms of anxiety and moderate/severe symptoms of depression.

LIMITATIONS

This was a telephone survey and a clinical evaluation of the patients was not performed. Furthermore, the structured interview was not designed to detect the level of substance use or the reasons for being NEET.

CONCLUSIONS

NEET status is frequent among young Greeks. Older, and long-term NEETs appear to be at higher risk for presenting anxiety/depression symptoms. Whether NEET status is associated with adverse outcomes later in life requires longitudinal studies.

Associations between sleep duration and cognitive impairment in mild cognitive impairment

The prevalence of mild cognitive impairment (MCI) increases among elderly people and is associated with a high risk of dementia. Identifying factors that may contribute to the progress of MCI to dementia is critical. The objective of this study was to examine the association of objective sleep with cognitive performance in MCI patients. A subsample of 271 participants with a diagnosis of probable Alzheimer's disease (AD; N = 50) or mild cognitive impairment (MCI; N = 121) and 100 persons who were not cognitively impaired (NI) were recruited from a large population-based cohort in the island of Crete, Greece (3140 older adults aged >60 years). All participants underwent extensive neuropsychiatric/neuropsychological evaluation and a 3-day 24-hr actigraphy. Objective sleep variables and their association with neuropsychological performance were examined across the three groups, controlling for demographics, body mass index, depression, sleep apnea symptoms and psychotropic medications. Patients with AD had significantly longer 24-hr total sleep time (TST) compared to the MCI and NI groups. Long 24-hr TST was associated with reduced performance on tasks that placed significant demands on attention and processing speed in the MCI group and the AD group. Elderly patients with MCI have similar objective sleep duration to normal controls, whereas AD patients sleep longer. Long sleep duration in patients with multidomain subtypes of MCI is associated with critical non-memory cognitive domains. It appears that within the MCI group those that sleep longer have more severe cognitive impairment.

'Suicide rates in Crete, Greece during the economic crisis: the effect of age, gender, unemployment and mental health service provision'

BACKGROUND

Recently, suicides in Greece have drawn national and international interest due to the current economic crisis. According to published reports, suicides in Greece have increased up to 40% and Crete has been highlighted as an area with the sharpest increase.

AIM

To investigate the suicide mortality rates in Crete between 1999 and 2013 and their association with the economic crisis.

METHODS

Data on suicides were selected from the Department of Forensic Medicine files of the University of Crete.

RESULTS

Our analysis showed that (1) Crete, has the highest suicide mortality rate in Greece, however no significant increase was observed between 1999 and 2013, (2) there were opposing trends between men and women, with women showing a decrease whereas men showed an increase in that period, (3) there was a significant increase of suicides in middle-aged men (40-64 yrs) and elderly, although the highest unemployment rates were observed in young men and women, and (4) finally, there was a regional shift of suicides with a significant decrease in Western Crete and a significant increase in Eastern Crete.

CONCLUSIONS

Although, Crete has the highest suicide mortality rates in Greece, we did not observe an overall increase during the last 15 years, including the period of economic crisis. Furthermore, there was an increase in middle-aged and elderly men, whereas young men and women showed oppositional trends during the years of austerity. This may be related to the culturally different expectations for the two genders, as well as that younger individuals may find refuge to either strong family ties or by immigrating abroad. Finally, the relative increase of suicides in Eastern Crete may be explained by factors, such as the lack of community mental health services in that area.