Association of sleep duration and quality with blood lipids: a systematic review and meta-analysis of prospective studies

Objective sleep and cardiometabolic biomarkers: results from the community of mine study

Study Objectives

Examining multiple dimensions of sleep health may better capture associations between sleep and health risks, including cardiometabolic disease (CMD). Hispanics have elevated risk for inadequate sleep and CMD biomarkers. Few studies have explored whether associations between sleep and CMD differ by Hispanic ethnicity.

Methods

Leveraging data from the Community of Mine (CoM) study, a cross-sectional investigation of 602 ethnically diverse participants, we derived accelerometer-measured sleep duration and efficiency, and self-reported sleep quality. Accelerometer-measured sleep exposures were analyzed both as continuous and categorical variables. Multivariate and quantile regression models were used to assess associations between sleep and CMD biomarkers (insulin resistance, systolic blood pressure, and low-density-lipoprotein cholesterol), controlling for age, sex, ethnicity, education, smoking status, and body mass index. We examined the potential effect modification of Hispanic ethnicity.

Results

We observed mixed results based on CMD biomarkers and sleep exposure. Increased sleep duration was significantly related to low-density lipoprotein cholesterol in adjusted models (estimate = 0.06; 95% CI: 0.02, 0.11). Poor sleep efficiency was associated with greater insulin resistance in the adjusted quantile (estimate = 0.20; 95% CI: 0.04, 0.36) model at the 90th percentile. Self-reported sleep quality was not associated with CMD outcomes. There was no evidence of effect modification by Hispanic ethnicity.

Conclusions

In this cohort, sleep health measures were found to have mixed and at times opposing effects on CMD outcomes. These effects did not demonstrate an interaction with Hispanic ethnicity.

Paradoxical Effects of Prolonged Insufficient Sleep on Lipid Profile: A Pooled Analysis of 2 Randomized Trials

Background Insufficient sleep is associated with increased cardiovascular disease risk, but causality is unclear. We investigated the impact of prolonged mild sleep restriction (SR) on lipid and inflammatory profiles. Methods and Results Seventy-eight participants (56 women [12 postmenopausal]; age, 34.3±12.5 years; body mass index, 25.8±3.5 kg/m2) with habitual sleep duration 7 to 9 h/night (adequate sleep [AS]) underwent two 6-week conditions in a randomized crossover design: AS versus SR (AS-1.5 h/night). Total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglycerides, and inflammatory markers (CRP [C-reactive protein], interleukin 6, and tumor necrosis factor-α) were assessed. Linear models tested effects of SR on outcomes in the full sample and by sex+menopausal status (premenopausal versus postmenopausal women+men). In the full sample, SR increased high-density lipoprotein cholesterol compared with AS (β=1.2±0.5 mg/dL; P=0.03). Sex+menopausal status influenced the effects of SR on change in total cholesterol (P-interaction=0.04), LDL-C (P-interaction=0.03), and interleukin 6 (P-interaction=0.07). Total cholesterol and LDL-C decreased in SR versus AS in premenopausal women (total cholesterol: β=-4.2±1.9 mg/dL; P=0.03; LDL-C: β=-6.3±2.0 mg/dL; P=0.002). Given paradoxical effects of SR on cholesterol concentrations, we explored associations between changes in inflammation and end point lipids under each condition. Increases in interleukin 6 and tumor necrosis factor-α during SR tended to relate to lower LDL-C in premenopausal women (interleukin 6: β=-5.3±2.6 mg/dL; P=0.051; tumor necrosis factor-α: β=-32.8±14.2 mg/dL; P=0.027). Conclusions Among healthy adults, prolonged insufficient sleep does not increase atherogenic lipids. However, increased inflammation in SR tends to predict lower LDL-C in premenopausal women, resembling the "lipid paradox" in which low cholesterol associates with increased cardiovascular disease risk in proinflammatory conditions. Registration URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02835261, NCT02960776.

Association between Sleep Duration and Metabolic Disorders among Filipino Immigrant Women: The Filipino Women's Diet and Health Study (FiLWHEL)

Background

Sleep plays a complex role in metabolic regulation, and the underlying linkage has not been clearly defined. We investigated the association between sleep duration and metabolic disorders in Filipino immigrants in Korea.

Methods

We analyzed 410 participants from the 2014 to 2016 baseline population of the Filipino Women's Diet and Health Study. Usual sleep duration was self-reported, and anthropometric parameters were measured directly. Blood glucose, lipid, and insulin levels were examined from fasting serum samples. We used general linear models to acquire least squares (LS) means and logistic regression models to calculate odds ratios to test the cross-sectional association between sleep duration and metabolic markers with 95% confidence intervals (CIs).

Results

We found a statistically significant linear association between increased sleep duration and elevated triglycerides, total cholesterol, and low-density lipoprotein cholesterol (LDL-C). LS means (95% CI) of <5, 5-6, 7-8, and >8 hours of sleep were 81.74 (71.43 to 93.54), 85.15 (76.65 to 94.59), 86.33 (77.84 to 95.75), and 105.22 (88.07 to 125.71), respectively, for triglycerides (P trend=0.049) and 174.52 (165.02 to 184.57), 180.50 (172.79 to 188.55), 182.51 (174.83 to 190.53), and 190.16 (176.61 to 204.74), respectively, for total cholesterol (P trend= 0.042). For LDL-C, the LS means (95% CI) were 97.34 (88.80 to 106.71), 100.69 (93.73 to 108.18), 104.47 (97.35 to 112.10), and 109.43 (96.94 to 123.54), respectively (P trend=0.047). Statistical significance persisted after additional adjustment for body mass index. The association with triglycerides was limited to current alcohol drinkers (P interaction=0.048).

Conclusion

Longer sleep duration was associated with increased triglyceride, total cholesterol, and LDL-C levels. The association with triglycerides was more pronounced among moderate alcohol drinkers.

The associations between sleep timing and night sleep duration with dyslipidemia in a rural population: The Henan Rural Cohort Study

Evidence linking sleep timing and night sleep duration to dyslipidemia was limited and inconclusive, especially among low- and middle-income adults. The aims were to evaluate the associations between sleep timing, night sleep duration and dyslipidemia in a rural population. Based on the Henan Rural Cohort Study, a total of 37 164 participants were included. The Pittsburgh Sleep Quality Index was used to collect sleep information. Logistic regression and restrictive cubic splines were conducted to explore the associations. Of the 37 164 enrolled participants, 13881 suffered from dyslipidemia. Compared to the reference groups, people who went to sleep after 23:00 or woke up after 7:30 had higher prevalence of dyslipidemia, the adjusted odds ratios (ORs) and 95% confidence intervals (CIs)were 1.30 (1.20-1.41) and 1.34 (1.19-1.50). The adjusted OR (95%CI) of participants in the Late-sleep/Late-rise category compared to the Early-sleep/Early-rise category was 1.55 (1.08-1.23). Compared to the reference (7~≤8 h), the adjusted OR (95%CI) was 1.11 (1.03-1.20) for longer (>9 h) night sleep duration. Moreover, the combined effects of sleep duration (>9 h) with sleep time (22:00~) (OR = 1.46, 95%CI: 1.16-1.84), sleep duration (>9 h) with wake-up time (≥7:30) (OR = 1.28, 95%CI: 1.08-1.51), and sleep duration (>9 h) with the Late-sleep/Late-rise category (OR = 1.41, 95%CI: 1.14-1.75) increased the prevalence of dyslipidemia. Accordingly, our results indicate that delayed sleep timing and longer night sleep duration had independent and joint effects on higher risks of dyslipidemia in rural population.

Sleep duration, plasma metabolites, and obesity and diabetes: a metabolome-wide association study in US women

Short and long sleep duration are associated with adverse metabolic outcomes, such as obesity and diabetes. We evaluated cross-sectional differences in metabolite levels between women with self-reported habitual short (<7 h), medium (7-8 h), and long (≥9 h) sleep duration to delineate potential underlying biological mechanisms. In total, 210 metabolites were measured via liquid chromatography-mass spectrometry in 9207 women from the Nurses' Health Study (NHS; N = 5027), the NHSII (N = 2368), and the Women's Health Initiative (WHI; N = 2287). Twenty metabolites were consistently (i.e. praw < .05 in ≥2 cohorts) and/or strongly (pFDR < .05 in at least one cohort) associated with short sleep duration after multi-variable adjustment. Specifically, levels of two lysophosphatidylethanolamines, four lysophosphatidylcholines, hydroxyproline and phenylacetylglutamine were higher compared to medium sleep duration, while levels of one diacylglycerol and eleven triacylglycerols (TAGs; all with ≥3 double bonds) were lower. Moreover, enrichment analysis assessing associations of metabolites with short sleep based on biological categories demonstrated significantly increased acylcarnitine levels for short sleep. A metabolite score for short sleep duration based on 12 LASSO-regression selected metabolites was not significantly associated with prevalent and incident obesity and diabetes. Associations of single metabolites with long sleep duration were less robust. However, enrichment analysis demonstrated significant enrichment scores for four lipid classes, all of which (most markedly TAGs) were of opposite sign than the scores for short sleep. Habitual short sleep exhibits a signature on the human plasma metabolome which is different from medium and long sleep. However, we could not detect a direct link of this signature with obesity and diabetes risk.

Multidimensional Sleep and Cardiometabolic Risk Factors for Type 2 Diabetes: Examining Self-Report and Objective Dimensions of Sleep

Purpose:

The purpose of the study was to determine the association between objective and self-report measures of sleep and cardiometabolic risk factors for type 2 diabetes.

Methods:

This study examines data on Australian adults, collected as part of the Child Health CheckPoint study. Sleep was examined in terms of actigraphy-derived sleep duration, timing, efficiency and variability; and self-report trouble sleeping. Cardiometabolic risk factors for type 2 diabetes were examined in terms of body mass index and biomarkers of inflammation and dyslipidemia. Generalized estimating equations, adjusted for geographic clustering, were used to determine the association between measures of sleep and cardiometabolic risk factors.

Results:

Complete case analysis was conducted for 1017 parents (87% mothers). Both objective and self-report measures of sleep were significantly but weakly associated with cardiometabolic risk factors.

Conclusion:

Both objective and self-report measures of sleep are significantly associated with cardiometabolic risk factors for type 2 diabetes. Self-report troubled sleep is associated with poorer cardiometabolic health, independent of actigraphy-derived sleep parameters.

Sleep and Anabolic/Catabolic Hormonal Profile in Sedentary Middle-Aged Adults: The FIT-AGEING Study

Sleep quality plays an important role in the modulation of several aging markers. This influence could be explained by aging-induced hormonal changes. Indeed, poor sleep quality has been associated with the development of several endocrine-related health complications. This study examined the relationship of both subjective and objective sleep quantity and quality, with basal levels of selected plasma anabolic and catabolic hormones in sedentary middle-aged adults. A total of 74 volunteers (52.7% women; aged 53.7 ± 5.1) were recruited for this study. Subjective sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI; higher scores indicate worse sleep quality), and objective sleep quality parameters (total sleep time [TST], wake after sleep onset [WASO], and sleep efficiency [SE]) were measured using a wrist-worn accelerometer. Basal levels of plasma dehydroepiandrosterone sulphate (DHEAS), total testosterone, sex hormone binding globulin (SHBG), somatotropin, and cortisol levels, were determined. Free testosterone was calculated from the total testosterone and SHBG levels. No associations of global PSQI score, TST, WASO, and SE with DHEAS, free testosterone, and somatotropin plasma levels were found, neither in men nor in women (all p ≥ 0.05). Global PSQI score was inversely related to cortisol plasma levels in women (p = 0.043). WASO was positively associated with cortisol plasma levels, while SE was negatively associated with cortisol plasma levels in women (all p ≤ 0.027). Sleep quality is not related to levels of plasma anabolic hormones, but to levels of catabolic hormones, in sedentary middle-aged adults. Therefore, these results suggest that potential changes in aging biomarkers associated with sleep disturbances, could be mediated by age-related changes in the catabolic endocrine system.

The Relationship Between Sleep Duration and Blood Lipids Among Chinese Middle-Aged and Older Adults: Cross-Lagged Path Analysis From CHARLS

This study used data from the China Health and Retirement Longitudinal Study to investigate the temporal relationship between blood lipids and sleep duration in Chinese middle-aged and older adults. We used medical examinations and questionnaire data of 5,016 Chinese middle-aged and older adults (age 45+) in 2011 and 2015. Cross-lagged path analysis was performed to examine the bidirectional relationships between blood lipids and sleep duration. Sleep duration and lipids data were analyzed as continuous variables. Temporal relationships between sleep duration and HDL-cholesterol, LDL-cholesterol, total cholesterol, and triglycerides were different. Sleep duration was negatively associated with HDL-cholesterol 4 year later (β₁ = −0.171, P = 0.005), and HDL-cholesterol was negatively associated with sleep duration 4 year later (β₂ = −0.006, P = 0.002). Longer sleep duration was associated lower levels of LDL-cholesterol (β₁ = −0.275, P = 0.097) and total cholesterol (β₁ = −0.329, P = 0.096) 4 year later. There was a positive correlation between triglycerides and sleep duration. The path coefficient from triglycerides to sleep duration 4 year later (β₂ = 0.001, P = 0.018) was greater than that from sleep duration to triglycerides 4 year later (β₁ = 0.109, P = 0.847), with P = 0.030 for the difference between β₁ and β₂. In stratified analysis, we found that the strength and direction of the relationships may be related to age and BMI. Effects of sleep duration on blood lipids were only observed among participants aged <60 years, while the effect in the opposite direction was observed in older adults (age 60+), and the cross-lagged path coefficients were more significant in adults with BMI > 25.

Sleep Duration/Quality With Health Outcomes: An Umbrella Review of Meta-Analyses of Prospective Studies

Background

To quantitatively evaluate the evidence of duration and quality of sleep as measured by multiple health outcomes.

Methods

This review is registered with PROSPERO, number CRD42021235587. We systematically searched three databases from inception until November 15, 2020. For each meta-analysis, the summary effect size using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval were assessed; heterogeneity, evidence of small-study effects, and excess significance bias were also estimated. According to the above metrics, we evaluated the credibility of each association.

Results

A total of 85 meta-analyses with 36 health outcomes were included in the study. We observed highly suggestive evidence for an association between long sleep and an increased risk of all-cause mortality. Moreover, suggestive evidence supported the associations between long sleep and 5 increased risk of health outcomes (stroke, dyslipidaemia, mortality of coronary heart disease, stroke mortality, and the development or death of stroke); short sleep and increased risk of overweight and/or obesity; poor sleep quality and increased risk of diabetes mellitus and gestational diabetes mellitus.

Conclusions

Only the evidence of the association of long sleep with an increased risk of all-cause mortality was graded as highly suggestive. Additional studies are needed to be conducted.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021235587

Association Between Sleep Quality and Hypertension in Chinese Adults: A Cross-Sectional Analysis in the Tianning Cohort

BACKGROUND

Poor sleep quality is becoming very common in a developed society and relates to many health disorders. However, the association between sleep quality and hypertension has not been well studied in Chinese adults.

METHODS

Blood pressure was measured and sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI) for 5167 participants (mean aged 51±15 years, 41.5% males) in the Tianning Cohort. A logistic regression model was constructed to examine the association between sleep quality, as well as its components, and hypertension, adjusting for age, sex, education level, current smoking, current drinking, physical activity, obesity, glucose, and blood lipids.

RESULTS

After multivariate adjustment, a higher score Of the PSQI was significantly associated with an increased risk of prevalent hypertension (OR=1.03, P=0.018). Compared to participants with normal sleep (the PSQI score <5), those with a poor sleep quality (the PSQI score ≥5) had a 17% increased risk of prevalent hypertension (OR=1.17, P=0.042). Three of the seven components of sleep quality, such as subjective sleep quality (OR=1.17, P=0.001), sleep latency (OR=1.11, P=0.010), and sleep disturbances (OR=1.19, P=0.004), were also significantly associated with prevalent hypertension.

CONCLUSION

Poor sleep quality is increasingly prevalent in developed societies and may be related to an increased risk of hypertension in Chinese adults. The underlying causality is waiting to be studied.

Association between sleep insufficiency and dyslipidemia: a cross-sectional study among Greek adults in the primary care setting

Objective

To investigate the potential association between sleep insufficiency and dyslipidemia (DL) in the primary care setting using self-reported questionnaires.

Material and Methods

957 adults aged between 19 and 86 years old from the rural area of Thrace, Greece were enrolled in this cross-sectional study. Multistage stratifed cluster sampling was used and the subjects were classifed into three groups according to sleep duration [short (<6h), normal (6-8h), and long (>8h) sleep duration]. DL was defined by a positive response to the question "Have you ever been told by a doctor or health professional that your blood cholesterol or triglyceride levels were high?", or if they were currently taking antilipidemic agents. Sleep quality, utilizing Epworth sleepiness scale, Athens insomnia scale, Pittsburgh sleep quality index and Berlin questionnaire, was also examined.

Results

DL prevalence was significantly associated with short sleep duration (aOR=2.18, p<0.001) and insomnia (aOR=1.43, p=0.050), while its relation with poor sleep quality (aOR=1.31, p=0.094) and risk for obstructive sleep apnea (aOR=1.32, p=0.097) were of marginal statistical significance. Concerning insomnia subtypes, DL was significantly associated with difficulties maintaining sleep (aOR=2.99, p<0.001) and early morning awakenings (aOR=1.38, p=0.050), but not difficulties initiating sleep (aOR=1.18, p=0.328).

Conclusion

This study reveals an association between sleep pathology and DL. Thus, early pharmacological and cognitive or behavioral interventions that improve sleep are deemed necessary in order to decrease DL burden.

Health problems associated with single, multiple, and the frequency of months of objectively measured long working hours: a cohort study by the National Institute of Occupational Safety and Health, Japan

Purpose

We aimed to examine the prospective associations of monthly working hours measured in a month, the 6-month averaged hours, and the frequency of long working hours (≥ 205 h/month) during the past 6 months with health indicators.

Methods

This study included 6,806 Japanese company workers (response rate = 86.6%). Data on the workers’ monthly attendance during the second half of fiscal year 2016 and annual health checkups in fiscal years 2016 and 2017 were collected. We evaluated the association of the above three types of monthly working hours with subsequent health checkup data in fiscal year 2017. We adjusted for the corresponding data in fiscal year 2016.

Results

Multivariate logistic regression analyses revealed significant associations between monthly working hours and workers’ systolic and diastolic blood pressure as well as aspartate aminotransferase, alanine aminotransferase, low-density lipoprotein cholesterol (LDL), and triglyceride levels. However, the associations were not consistent between months. The average monthly working hours were significantly associated with higher LDL levels for the 220–240 h/mo group (OR: 1.49, 95%CI: 1.07–2.08) and lower triglyceride levels for the < 140 h/mo group (OR: 0.15, 95%CI: 0.03–0.77), compared to the 140–180 h/mo group. The frequency of long working hours was significantly associated with higher LDL levels.

Conclusions

Working hours over several months produced various associations with health indicators compared to those measured in a single month. Our present data suggest that the effects of average or frequency of long working hours during the past 6 months are likely to appear in LDL levels.

Sleep duration and risk of hyperlipidemia: a systematic review and meta-analysis of prospective studies

PURPOSE

Current studies indicate that the association between sleep duration and risk of hyperlipidemia is uncertain. This systematic review aimed to evaluate relevant prospective studies and make a definite conclusion.

METHODS

Three databases were searched for prospective studies on the relationship between sleep duration and hyperlipidemia risk from their inception to October 2020.

RESULTS

We identified twelve studies involving 114,439 participants. Follow-up for incident hyperlipidemia ranged from 200 days to 10 years. Neither long (RR:1.00, 95%CI:0.90-1.11, P > 0.05) nor short (RR:0.99, 95%CI:0.94-1.05, P > 0.05) sleep duration had a significant association with increased hyperlipidemia risk in adults. However, long sleep duration was decidedly associated with low HDL-C (RR:0.19, 95%CI: - 0.03-0.40, P < 0.05) and high triglycerides (RR: - 0.20, 95%CI: - 0.43-0.03, P < 0.05) in children and adolescents.

CONCLUSION

Long sleep duration has strong associations with risks of low HDL-C and high triglycerides in children and adolescents. The mechanisms underlying this association deserves to be explored in future studies.

Difficulty of falling asleep and non-high-density lipoprotein cholesterol level among Canadian older adults: a cross-sectional analysis of the Canadian Longitudinal Study for Aging baseline data

OBJECTIVE

To examine whether difficulty of falling asleep (DoFA) is associated with non-high-density lipoprotein cholesterol (non-HDL-C) level among Canadian older adults.

METHODS

26,954 individuals aged 45–85 years from the baseline data of the Canadian Longitudinal Study for Aging were included in this study. DoFA was categorized into five groups by answer to the question “Over the last month, how often did it take you more than 30 min to fall asleep?” Response options are “Never, < 1 time/week, 1−2 times/week, 3−5 times/week, or 6−7 times/week”. Non-HDL-C, the difference of total cholesterol and HDL-C, were categorized into five categories based on these cut-offs (< 2.6 mmol/L, 2.6−3.7 mmol/L, 3.7−4.8 mmol/L, 4.8−5.7 mmol/L, and ≥ 5.7 mmol/L). Ordinal logistic regression (logit link) continuation ratio models were used to estimate the odds of higher non-HDL-C levels for DoFA status. Adjusted means of non-HDL-C by DoFA status were estimated by general linear models. All analyses were sex separately using analytic weights to ensure generalizability.

RESULTS

The proportions of DoFA in five categories were 41.6%, 25.7%, 13.6%, 9.4%, 9.7% for females and 52.9%, 24.9%, 10.5%, 6.1%, 5.6% for males, respectively. After adjustment of demographical and other covariates (such as depression, comorbidity, sleeping hour, etc.) compared to those who reported never having DoFA, the ORs (95% CIs) of higher levels of non-HDL-C for those whose DoFA status in < 1 time/week, 1−2 times/week, 3−5 times/week, and 6−7 times/week were 1.12 (1.05−1.21), 1.09 (0.99−1.18), 1.20 (1.09−1.33), 1.29 (1.17−1.43) in females and 1.05 (0.98−1.13), 0.95 (0.87−1.05), 1.21 (1.08−1.37), 0.97 (0.85−1.09) in males, respectively. The adjusted means of non-HDL-C among the five DoFA status were 3.68 mmol/L, 3.73 mmol/L, 3.74 mmol/L, 3.82 mmol/L, 3.84 mmol/L for females and 3.54 mmol/L, 3.58 mmol/L, 3.51 mmol/L, 3.69 mmol/L, 3.54 mmol/L for males, respectively.

CONCLUSIONS

The results of this study have identified a risk association pattern between DoFA status and non-HDL-C levels in females but not in males. Further research is needed to confirm these findings.

Sleep duration and health outcomes: an umbrella review

PURPOSE

To collect existing evidence on the relationship between sleep duration and health outcomes.

METHODS

A thorough search was conducted in PubMed, Web of Science, Embase, and the Cochrane Database of Systematic Reviews from inception to January, 2021. Meta-analyses of observational and interventional studies were eligible if they examined the associations between sleep duration and human health.

RESULTS

In total, this umbrella review identified 69 meta-analyses with 11 outcomes for cancers and 30 outcomes for non-cancer conditions. Inappropriate sleep durations may significantly elevate the risk for cardiovascular disease (CVD), cognitive decline, coronary heart disease (CHD), depression, falls, frailty, lung cancer, metabolic syndrome (MS), and stroke. Dose-response analysis revealed that a 1-h reduction per 24 hours is associated with an increased risk by 3-11% of all-cause mortality, CHD, osteoporosis, stroke, and T2DM among short sleepers. Conversely, a 1-h increment in long sleepers is associated with a 7-17% higher risk of stroke mortality, CHD, stroke, and T2DM in adults.

CONCLUSION

Inappropriate sleep duration is a risk factor for developing non-cancer conditions. Decreasing and increasing sleep hours towards extreme sleep durations are associated with poor health outcomes.

High incidence of acute self-reported sleep disturbances in patients following arthroscopic-assisted knee surgery

OBJECTIVES

To evaluate the self-reported incidence of sleep disturbances, defined as ≤7 hours of sleep per 24-hour period, in patients undergoing arthroscopic-assisted knee surgery.

METHODS

Patients who underwent arthroscopic knee surgery over the course of a 4-month period were prospectively included. Patients were excluded if a history of insomnia or other sleep altering medical history was reported. Self-reported sleep metrics included average number of hours of sleep per night, average number of awakenings during sleep per night, perceived quality of sleep, average pain level during sleep and number of hours of physical activity/therapy per week. Data were collected at weeks 1, 3, and 6 postoperatively. Joint circumference was measured on postoperative day 1 and served as an indicator of a knee effusion. Paired t-tests were used to compare preoperative to postoperative hours of sleep. Simple and multiple linear regression were used to evaluate relationships between surgical variables and postoperative sleep metrics.

RESULTS

There were 123 patients who underwent arthroscopic knee surgery during the prospective enrolment period; 83 patients were included in the final analysis. The overall incidence of preoperative sleep disturbances was 20% (n=17). The overall incidence of self-reported postoperative sleep disturbances was 99%, 96% and 90% at weeks 1, 3 and 6, respectively. The average number of hours slept was significantly reduced at 1, 3 and 6 weeks postoperatively compared with the preinjury state (p<0.001). Knee joint circumference had a significantly negative correlation with average number of hours of sleep in the first 6 weeks postoperatively (R=-0.704; p=0.001). Surgical variables including severity of surgery, weekly postoperative pain level and weekly hours of postoperative physical therapy were not significant independent predictors of acute postoperative sleep disturbances (p>0.05).

CONCLUSION

Sleep disturbances were commonly reported in patients following arthroscopic knee surgery without correction of sleep metrics by 6 weeks postoperatively. The majority of sleep disturbances in this cohort correlated with an increased knee effusion. A multidisciplinary team approach is recommended to counsel patients regarding the potential for and problems with acute sleep disturbances following arthroscopic knee surgery.Level of evidence: 3.

Chronobiology and the case for sleep health interventions in the community

Our sleep-wake cycle is determined by the interaction between our homeostatic sleep drive and circadian rhythm. Each of us has a personalised biological rhythm or chronotype that determines the optimal time to fall asleep and wake up. Chronic sleep deprivation has been linked to the development of several physical and mental health disorders, as well as accidents and occupational errors. Around the world, growing recognition of the importance of sleep has led to the adoption of practices that promote sleep health. Given that Singaporeans were consistently found to be one of the most sleep-deprived populations in the world, we believe that there is an urgent need to pursue the introduction of community-based sleep health interventions here. This includes sleep education and promotion of sleep hygiene, adopting practices to reduce social jetlag and improve sleep health, and enhancing screening and treatment of sleep disorders.

Gestational sleep deprivation is associated with higher offspring body mass index and blood pressure

Study Objectives

The objective of this study was to evaluate the association between gestational sleep deprivation and childhood adiposity and cardiometabolic profile.

Methods

Data were used from two population-based birth cohorts (Rhea study and Amsterdam Born Children and their Development study). A total of 3,608 pregnant women and their children were followed up until the age of 11 years. Gestational sleep deprivation was defined as 6 or fewer hours of sleep per day, reported by questionnaire. The primary outcomes included repeated measures of body mass index (BMI), waist circumference, body fat, serum lipids, systolic and diastolic blood pressure (DBP) levels in childhood. We performed a pooled analysis with adjusted linear mixed effect and Cox proportional hazards models. We tested for mediation by birthweight, gestational age, and gestational diabetes.

Results

Gestational sleep deprivation was associated with higher BMI (beta; 95% CI: 0.7; 0.4, 1.0 kg/m²) and waist circumference (beta; 95% CI: 0.9; 0.1, 1.6 cm) in childhood, and increased risk for overweight or obesity (HR; 95% CI: 1.4; 1.1, 2.0). Gestational sleep deprivation was also associated with higher offspring DBP (beta; 95% CI: 1.6; 0.5, 2.7 mmHg). The observed associations were modified by sex (all p-values for interaction < 0.05); and were more pronounced in girls. Gestational diabetes and shorter gestational age partly mediated the seen associations.

Conclusions

This is the first study showing that gestational sleep deprivation may increase offspring’s adiposity and blood pressure, while exploring possible mechanisms. Attention to glucose metabolism and preterm birth might be extra warranted in mothers with gestational sleep deprivation.

ADVERSE EFFECT OF INSOMNIA ON BLOOD LIPIDS IN PATIENTS WITH HYPERTENSION

Insomnia is a risk factor for the development of arterial hypertension, obesity, type 2 diabetes mellitus, cardiac rhythm disorders, and myocardial infarction. At the same time, insomnia is one of the most frequent non-cardiac complaints in patients with cardiovascular diseases. The aim of the work was to study the presence of possible relationships between insomnia and the level of blood lipids. Materials and methods. A cross-sectional study involving 118 patients was conducted. Criteria for inclusion in the study were age over 45 years, the presence of essential hypertension. All patients included the study underwent sampling of 7 ml of venous blood in the morning under fasting conditions. The content of total cholesterol (TCS), triglycerides (TG), high-density lipoprotein cholesterol (HDL CS) was determined by enzymatic method on a biochemical analyser Humalyzer 2000. The patient was interviewed by a pre-trained study doctor.  Results. In the article a relationship between total cholesterol, low-density lipoprotein cholesterol and the presence of insomnia has been established and proved by statistical model. The overall statistical model accuracy is 89.6 % and statistical significance p < 0.005. Accuracy of insomnia prediction is 85.7 % by level of total cholesterol (TCS) and patient interview data. Only one model with best accuracy exists and it was estimated at the article. Conclusions. Relationship between total cholesterol, low-density lipoprotein cholesterol and the presence of insomnia has been established and proved by statistical model. Accuracy of insomnia prediction is 85.7 % by level of total cholesterol (TCS) and patient interview data.

Non-alcoholic fatty liver disease in a sample of individuals with bipolar disorders: results from the FACE-BD cohort

OBJECTIVE

Non-Alcoholic fatty liver disease (NAFLD) is becoming the most common liver disease in Western populations. While obesity and metabolic abnormalities are highly frequent in bipolar disorders (BD), no studies have been performed to estimate the prevalence of NALFD in individuals with BD. The aim of our study is to estimate the prevalence of NAFLD and to identify the potential associated risk factors in a large sample of BD individuals.

METHODS

Between 2009 and 2019, 1969 BD individuals from the FACE-BD cohort were included. Individuals with liver diseases, Hepatitis B or C, and current alcohol use disorders were excluded from the analyses. A blood sample was drawn from participants. Screening of NAFLD was determined using fatty liver index (FLI). Individuals with FLI> 60 were considered as having NAFLD.

RESULTS

The prevalence of NAFDL in this sample was estimated at 28.4%. NAFLD was observed in 40% of men and 21% of women. NAFLD was independently associated with older age, male gender, sleep disturbances, and current use of atypical antipsychotics or anxiolytics. As expected, the prevalence of NALFD was also higher in individuals with overweight and in those with metabolic syndrome.

CONCLUSIONS

This study reinforces the view that individuals with BD are highly vulnerable to metabolic and cardiovascular diseases. The prevalence of NAFLD in individuals with BD was two times higher than the prevalence reported in the general population. The regular screening of the MetS in individuals with BD should be therefore complemented by the additional screening of NAFLD among these vulnerable individuals.

Sleep Duration, Lipid Profile and Insulin Resistance: Potential Role of Lipoprotein(a)

Lipoprotein (a) (Lp(a)) is considered a genetic factor for cardiovascular disease playing an important role in atherogenesis and thrombosis, but the evidence about its association with sleep duration is controversial. We evaluated the relation between self-reported sleep duration and Lp(a). Among 1600 participants of the population-based sample, we selected 1427 subjects without previously known cardiovascular events, who answered the questions about their sleep duration; had valid lipid profile results (total cholesterol, low- and high-density lipoproteins, Lp(a), apolipoprotein AI (ApoAI), ApoB, and ApoB/ApoAI); and did not take lipid-lowering drugs (mean age 46 ± 12 years). We performed a structured interview, which included questions about lifestyle, medical history, complaints, and sleep duration (How long have you been sleeping per night during the last month?). Sleep duration was classified as follows: <6 h/night—short, 6–9 h/night—normal, and ≥10 h/night—long. Overall, 73 respondents (5.2%) were short-sleepers and 69 (4.8%) long-sleepers. Males were slightly more prevalent among short-sleepers. The groups matched by age, body mass index, blood pressure, diabetes mellitus, and hypertension rate. Short-sleepers had lower rates of high total cholesterol (≥5.0 mmol/L), lower Lp(a) levels and lower rates of increased Lp(a) ≥0.5 g/L, and higher insulin and insulin resistance (assessed by the homeostatic model assessment for insulin resistance (HOMA-IR)). ApoAI, ApoB, their ratio, and other lab tests were similar in the groups. The multinomial logistic regression demonstrated that only the short sleep duration was independently (odds ratio (OR) 0.29, 95% confidence interval (CI) (0.09–0.91), p = 0.033) associated with Lp(a) (χ² = 41.58, p = 0.003). Other influencing factors were smoking and HOMA-IR. Such an association was not found for long-sleepers. In conclusion, a short-sleep duration is associated with Lp(a). The latter might mediate the higher insulin resistance and higher cardiometabolic risks in short-sleepers.

Sex differences in the association between self-reported sleep duration, insomnia symptoms and cardiometabolic risk factors: cross-sectional findings from Brazilian longitudinal study of adult health

Background

The U-shaped associations between sleep durations and cardiometabolic risk factors (glycated hemoglobin levels, obesity, hypertriglyceridemia, hypertension and cholesterol levels) are still inconclusive. Moreover, as sleep is comprised of quantitative and qualitative aspects, exploring both insomnia symptoms and sleep duration are relevant when evaluating the potential effects of sleep problems on health. The aim was to evaluate sex-specific associations between sleep problems and cardiometabolic risk factors.

Methods

This cross-sectional study used data from wave two of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), including 7491 women and 6232 men. Questionnaires were administered to provide information about socioeconomic conditions, lifestyle, and sleep characteristics. A 12-h fasting blood sample was drawn to measure serum cholesterol, triglycerides, and glycated hemoglobin. Blood pressure, weight and height were also measured using standard equipment. Generalized additive models were used to evaluate the curve shape of the relationship between self-reported sleep duration and the outcomes. Logistic regression was performed to investigate the magnitude of the associations of self-reported sleep duration, insomnia symptoms, and short sleep plus insomnia symptoms with cardiometabolic risk factors.

Results

For women, self-reported sleep duration and insomnia symptoms (either separately or linked to short sleep duration) were associated with obesity, hypertension and glycated hemoglobin after adjusting for the confounders. The magnitudes of the associations between self-reported short sleep duration plus insomnia symptoms and the outcomes were slightly increased, considering sleep duration or insomnia symptoms separately. For men, both long sleep duration and insomnia symptoms were associated with hypertriglyceridemia after adjusted for the confounders.

Conclusion

These findings suggest possible sex-specific patterns, since obesity, hypertension and high glycated hemoglobin were associated with self-reported sleep duration and insomnia symptoms in women, but not in men, and reinforce the importance of considering quantitative and qualitative aspects of sleep for the prevention and management of the outcomes.

Association of daily fish intake with serum non-high-density lipoprotein cholesterol levels and healthy lifestyle behaviours in apparently healthy males over the age of 50 years in Japanese: Implication for the anti-atherosclerotic effect of fish consumption

BACKGROUND AND AIM

Higher fish consumption has been reported to be associated with a lower incidence of coronary artery disease (CAD). We hypothesized that higher fish intake may be associated with lower serum level of non-high-density lipoprotein cholesterol (non-HDL-C) levels, representing the entire dyslipidemia spectrum, and a healthy lifestyle.

METHODS AND RESULTS

This cross-sectional study was conducted in a population of 1270 apparently healthy males over the age of 50 years without lipid-modifying therapy at the Health Planning Center of Nihon University Hospital between April and August 2018. The average number of days of fish intake per week was 2.6 ± 1.4. We performed analysis of variance using fish consumption as a categorical variable (0-1 day, 2-3 days, 4-5 days, or 6-7 days per week). The serum non-HDL-C levels in the 6-7 days fish intake group were significantly lower than those in the 0-1 and 2-3days fish intake groups. Furthermore, with increasing frequency of fish intake per week, the proportion of subjects with cigarette smoking decreased (p = 0.026), that of subjects engaging in habitual aerobic exercises increased (p = 0.034), and the sleep duration of the subjects increased (p < 0.0001).

CONCLUSIONS

These results suggest that a high frequency of fish intake, that is a fish intake of 6-7 days per week, was associated with healthier lifestyle behaviours as well as lower non-HDL-C levels, and thus may represent a component of a healthy lifestyle associated with a lower risk of CAD in Japanese males over the age of 50.

CLINICAL TRIAL REGISTRATION

UMIN (http://www.umin.ac.jp/).

STUDY ID

UMIN000035899.

Interrelationships among common predictors of cardiovascular diseases in patients of OSA: A large-scale observational study

BACKGROUND AND AIMS

The apolipoprotein B/apolipoprotein A-I (ApoB/ApoA-I) and insulin resistance has been recognized as common cardiovascular diseases (CVD) risk factors. However, whether they were biomarkers for 10-year CVD risk in obstructive sleep apnea (OSA) had been rarely studied. Besides, interrelationships between the ApoB/ApoA-I, insulin resistance and OSA remain unclear.

METHODS AND RESULTS

A total of 4010 subjects were finally included. Anthropometric, fasting biochemical, and polysomnographic parameters were collected. 10-year Framingham CVD risk score (FRS) was calculated for each subjects. The relationships between insulin resistance, OSA risk and the ApoB/ApoA-I was evaluated through logistic regressions analysis, restricted cubic spline (RCS) analysis and mediation analysis. ApoB/ApoA-I, HOMA-IR and AHI were all risk factors for high10-year CVD risk as assessed by FRS (odds ratios (OR) = 5.365, 1.094, 1.010, respectively, all P < 0.001)). The fully adjusted OR (95% confidence intervals) for both OSA [1 (reference), 1.308 (1.027-1.665), 1.517 (1.178-1.953), and 1.803 (1.371-2.372)] and insulin resistance [1 (reference), 1.457 (1.173-1.711), 1.701 (1.369-2.113), 2.051(1.645-2.558)] increased from the first to the fourth quartiles of the ApoB/ApoA-I. The RCS mapped a nonlinear dose-effect relationship between the ApoB/ApoA-I and risk of insulin resistance and OSA. Mediation analyses showed HOMA-IR explain 9.7%, 4.7% and 10.8% of the association between apnea-hypopnea index, oxygen desaturation index, micro-arousal index and ApoB/ApoA-I, respectively.

CONCLUSIONS

Our study revealed that ApoB/ApoA-I, insulin resistance and OSA were risk factors for CVD. Insulin resistance may serve as a potential mediator in OSA-related lipoprotein disorders and further increase CVD risk.

Short Sleep, Insomnia, and Cardiovascular Disease

PURPOSE OF REVIEW

This review summarizes key findings linking insomnia, short sleep duration, and cardiovascular health.

RECENT FINDINGS

Early studies associations between insomnia with short sleep and cardiovascular disease Recent studies have incorporated objective data to assess sleep and identify comorbid sleep disorders (e.g. sleep apnea). Use of objective metrics has facilitated understanding of the impacts of insufficient sleep on autonomic dysregulation, metabolic syndrome, coronary artery disease and overall cardiovascular mortality. Emerging research suggests treatment of insomnia (CBT-I) may be beneficial in terms of reducing cardiovascular disease risk.

SUMMARY

From short term effects on the autonomic nervous system to lasting effects on metabolic syndrome and coronary artery disease, there is growing evidence to support a physiologic pathway by which insomnia with short sleep contributes to cardiovascular disease. More research is needed to understand the effect of insomnia treatment on cardiovascular risk.

Eight-Section Brocade Exercises Improve the Sleep Quality and Memory Consolidation and Cardiopulmonary Function of Older Adults With Atrial Fibrillation-Associated Stroke

Purpose: Poor sleep quality is harmful for everyone and potentially even more harmful for older adults with atrial fibrillation-associated stroke (AFAS). This study aims to explore the effects of eight-section brocade (ESB) on sleep quality, memory, and cardiopulmonary function in the older adults with AFAS. Methods: Older adults with AFAS and sleep disorders were recruited and divided into the ESB (EG, n = 85) and control groups (CG, general exercise, n = 85). EG patients received 60 min ESB exercises 5 times a week for 12 weeks; CG patients received normal exercise. Pittsburgh sleep quality index (PSQI) scores (poor sleepers ≥8 and normal sleepers < 8), memory for word pairs (poor memory ≤ 7 and normal memory > 7), left ventricular posterior wall (LVPW) thickness, and maximum ventilation (MV, to evaluate cardiopulmonary function) values were measured. The correlation between sleep and memory quality was analyzed using PSQI scores and word pairs via the Pearson correlation coefficients test. Adjusted Cox models were used to explore an interaction between PSQI and ESB exercise. Results: After 12-week exercise intervention, ESB improved sleep quality, latency, duration, disturbance and daytime dysfunction when compared to conventional exercise. In similar cases, the MV values in the EG were also higher than that in the CG (p = 0.009). ESB intervention could not affect the cardiac structure and left ventricular ejection fraction. Compared with the CG, the ESB intervention reduced PSQI scores and increased memorized word pairs (p < 0.001 for poor and normal sleepers in both unadjusted and adjusted analysis, p = 0.012 and 0.003 for poor and normal memory). The test of Pearson correlation coefficients showed that PSQI scores were strongly associated with the number of word pairs in both unadjusted and adjusted analyses (p < 0.0001). Conclusion: Eight-section brocade exercise improved sleep quality and memory consolidation and cardiopulmonary function by reducing PSQI scores, increasing word pairs and MV values in the older adults with AFAS.

Association between sleep quality and metabolic syndrome: A systematic review and meta-analysis

Sleep quality has been suggested to play an important role in development of metabolic syndrome (MetS). However, the results have been inconsistent. A systematic review of observational studies aimed to evaluate the association between sleep quality and MetS. A comprehensive search was conducted in PubMed and EMBASE. The pooled odd ratios (ORs) were calculated using random effects models. The construction of funnel plot was used to explore publication bias, with further application of Egger's test. 22 studies were included. The pooled finding showed that overall sleep quality had a significant positive association with MetS (OR 1.37, 95% CI 1.15-1.64), with substantial heterogeneity (I² = 62.4%, P < 0.1). Similarly, the complaints of sleep, including difficulty in falling sleep (OR 1.18, 95% CI 1.05-1.33), difficulty in maintaining sleep (OR 1.15, 95% CI 1.02-1.30) and sleep inefficiency (OR 1.40, 95% CI 1.04-1.89) were proved to be associated with the risk of MetS. Our results indicated the overall sleep quality as well as sleep complaints have significant positive associations with MetS. Further studies based on a longitudinal design using validated tools that measure both objective and subjective components of sleep quality are needed to explore the causal relationship between sleep quality and MetS.

Metabolic syndrome and actigraphy measures of sleep and circadian rhythms in bipolar disorders during remission

OBJECTIVE

This study explored the correlations between sleep and circadian rhythm measures and the metabolic syndrome (MetS) components in remitted patients with bipolar disorder (BD).

METHOD

Euthymic patients with BD (n = 67) were recorded by 3 weeks with actigraphy. We used nonparametric correlations to study the links between the MetS parameters, atherogenic index of plasma (AIP), sleep efficacy, sleep latency, fragmentation index, and phase and amplitude of rhythms. We performed multivariable analyses to take into account potential confounding factors such as sleep apnea risk, antipsychotics use, and smoker status.

RESULTS

We found correlations between lower sleep efficiency and higher triglyceride levels (P = 0.002), lower M10 onset (beginning of the 10 most active hours during the 24-h cycle) and higher systolic blood pressure (P = 0.03), higher fragmentation index and higher systolic blood pressure (P = 0.009), lower sleep efficiency, higher fragmentation index, and higher AIP (respectively P = 0.02 and P = 0.04). These correlations mostly remained significant when adjusting for confounders, with the exception of M10 onset and systolic blood pressure.

CONCLUSION

Sleep efficiency and fragmentation index might contribute to the cardiovascular risk of patients with BD independently of major confounding factors. Although these associations did not imply causality, proposing interventions on sleep quality and circadian rhythm regularity might contribute to reduce cardiovascular risk in patients with BD.