Sleep duration, nap habits, and mortality in older persons

Imbalanced sleep increases mortality risk by 14-34%: a meta-analysis

Sleep duration is a crucial factor influencing health outcomes, yet its relationship with mortality remains debated. In this meta-analysis, we aimed to investigate the association between short and long sleep duration and all-cause mortality in adults, including sex-specific differences. A systematic search was performed in multiple databases, including PubMed, Cochrane Central, and Web of Science, up to October 2024. Retrospective and prospective cohort studies involving adults with at least 1 year of follow-up and data on sleep duration and all-cause mortality were included. Hazard ratios were pooled using a random-effects model, with subgroup analyses performed based on sex and sleep duration categories. A total of 79 cohort studies were included, with data stratified by sex and categorized into short and long sleep durations. Short sleep duration (< 7 h per night) was associated with a 14% increase in mortality risk compared to the reference of 7-8 h, with a pooled hazard ratio of 1.14 (95% CI 1.10 to 1.18). Conversely, long sleep duration (≥ 9 h per night) was associated with a 34% higher risk of mortality, with a hazard ratio of 1.34 (95% CI 1.26 to 1.42). Sex-specific analyses indicated that both short and long sleep durations significantly elevated mortality risk in men and women, although the effect was more pronounced for long sleep duration in women. Both short and long sleep durations are associated with increased all-cause mortality, though the degree of risk varies by sex. These findings underscore the importance of considering optimal sleep duration in public health strategies aimed at enhancing longevity and highlight the need for sex-specific approaches in sleep health research.

The Effects of Experimental Sleep Extension in Middle-to-Older-Aged Healthy Sleepers

Objectives  To determine the feasibility for middle-aged and older adults to extend their time in bed by 2 h per night for 3 consecutive weeks. Other aims were to examine the effects of sleep extension on mood, cognitive performance, and cardiovascular health. Methods  Ten healthy middle-aged to older adults (9 women; M  = 65.20 ± 4.78 years) who reported regularly sleeping 6 to 8 h per night participated in a randomized controlled cross-over study: 3 weeks of both habitual sleep and extended sleep (1-week recovery between treatments). Participants were asked to spend 2 additional hours in bed per night during sleep extension. Cognitive (e.g., errors, response time), psychological (e.g., depression, anxiety, mood), and physiological measures (e.g., inflammation, glucose, triglycerides, blood pressure) were assessed. Results  Compared with habitual sleep, time in bed increased 81.63 ± 33.11 min and total sleep time increased 66.33 ± 28.64 min during sleep extension; these variables did not significantly change during baseline or the habitual sleep treatment. No significant treatment differences were found in the cognitive, psychological, or physiological measures. Discussion  Neither significant positive nor negative effects of sleep extension were found for any of the variables. In terms of feasibility, it was difficult for the participants to extend their time in bed and, subsequently, attain more sleep by the targeted amount. Sleep extension by a greater degree or longer period of times might be more likely to elicit positive or negative effects.

Sleep patterns and long-term mortality among older Israeli adults: a population-based study

ABSTRACT

Introduction

The joint association of night-time sleep duration and daytime napping (siesta) with mortality remains elusive. We explored sleep patterns and long-term mortality in older adults and tested whether the relationship is modified by cognitive function.

Methods

We analysed data from 1519 participants in the National Health and Nutrition Survey of older adults aged 65+ years ('Mabat Zahav'), conducted by the Israel Center for Disease Control during 2005-2006. A detailed questionnaire was administered at study entry to gather information on sleeping habits, including night-time sleep duration and siesta. A Mini-Mental State Examination was administered to assess cognitive status (score <27 considered impaired). Mortality data were obtained from the Ministry of Health (last follow-up: June 2019; 782 deaths). Cox models were constructed to estimate the HRs for mortality associated with sleep patterns, defined according to night sleep duration (>8 vs ≤8 hours) and siesta (Y/N). Spline regression models were constructed to examine the linearity of the association across cognitive statuses.

Results

Sleep categories among participants (mean age 75; 53% women) included 291 (19.2%) with long night sleep and siesta, 139 (9.1%) with long night sleep and no siesta, 806 (53.1%) with short night sleep and siesta, and 283 (18.6%) with short night sleep and no siesta. HRs for mortality were 2.07 (95% CI: 1.63 to 2.62), 1.63 (95% CI: 1.22 to 2.18) and 1.43 (95% CI: 1.16 to 1.76) in the former three versus latter sleep patterns, respectively. Multivariable adjustment for sociodemographic, behavioural and clinical covariates attenuated the HRs to 1.27-1.41 (all p<0.05). The relationship between night sleep duration and mortality was linear (plinearity=0.047) among cognitively preserved individuals and U-shaped (pnon-linearity<0.001) among cognitively impaired ones.

Conclusions

Prolonged night sleep and siesta were associated with increased mortality, a relationship that varied by cognitive performance.

Association between napping and type 2 diabetes mellitus

As the incidence of type 2 diabetes mellitus (T2DM) is increasing rapidly and its consequences are severe, effective intervention and prevention, including sleep-related interventions, are urgently needed. As a component of sleep architecture, naps, alone or in combination with nocturnal sleep, may influence the onset and progression of T2DM. Overall, napping is associated with an increased risk of T2DM in women, especially in postmenopausal White women. Our study showed that napping >30 minutes (min) increased the risk of T2DM by 8-21%. In addition, non-optimal nighttime sleep increases T2DM risk, and this effect combines with the effect of napping. For nondiabetic patients, napping >30 min could increase the risks of high HbA1c levels and impaired fasting glucose (IFG), which would increase the risk of developing T2DM later on. For diabetic patients, prolonged napping may further impair glycemic control and increase the risk of developing diabetic complications (e.g., diabetic nephropathy) in the distant future. The following three mechanisms are suggested as interpretations for the association between napping and T2DM. First, napping >30 min increases the levels of important inflammatory factors, including interleukin 6 and C-reactive protein, elevating the risks of inflammation, associated adiposity and T2DM. Second, the interaction between postmenopausal hormonal changes and napping further increases insulin resistance. Third, prolonged napping may also affect melatonin secretion by interfering with nighttime sleep, leading to circadian rhythm disruption and further increasing the risk of T2DM. This review summarizes the existing evidence on the effect of napping on T2DM and provides detailed information for future T2DM intervention and prevention strategies that address napping.

Translation and concurrent validity, sensitivity and specificity of Chinese version of Short Orientation Memory Concentration Test in people with a first cerebral infarction

Purpose

This study aimed to translate the English version of the Short Orientation-Memory-Concentration (SOMC) test into a Chinese version, denoted the C-SOMC test, and to investigate the concurrent validity, sensitivity, and specificity of the C-SOMC test against a longer and widely used screening instrument in people with a first cerebral infarction.

Methods

An expert group translated the SOMC test into Chinese using a forward-backward procedure. Eighty-six participants (67 men and 19 women, mean age = 59.31 ± 11.57 years) with a first cerebral infarction were enrolled in this study. The validity of the C-SOMC test was determined using the Chinese version of Mini Mental State Examination (C-MMSE) as the comparator. Concurrent validity was determined using Spearman's rank correlation coefficients. Univariate linear regression was used to analyze items' abilities to predict the total score on the C-SOMC test and the C-MMSE score. The area under the receiver operating characteristic curve (AUC) was used to demonstrate the sensitivity and specificity of the C-SOMC test at various cut-off values distinguishing cognitive impairment from normal cognition.

Results

The total score for the C-SOMC test and the score for item 1 on this test exhibited moderate-to-good correlations with the C-MMSE score, with respective ρ-values of 0.636 and 0.565 (P < 0.001). The scores for each of items 2, 4, 5, 6, and 7 yielded fair correlations with C-MMSE score, with ρ-value from 0.272 to 0.495 (P < 0.05). The total score on the C-SOMC test and the item score were good predictors (adjusted R² = 0.049 to 0.615) of the C-MMSE score, and six items were good predictors (adjusted R² = 0.134 to 0.795) of the total score. The AUC was 0.92 for the C-SOMC test. A cut-off of 17/18 on the C-SOMC test gave optimal performance: correct classification of 75% of participants, with 75% sensitivity and 87.9% specificity.

Conclusion

The C-SOMC test demonstrated good concurrent validity, sensitivity and specificity in a sample of people with a first cerebral infarction, demonstrating that it could be used to screen for cognitive impairment in stroke patients.

Association of Self-Reported Nighttime Sleep Duration with Chronic Kidney Disease: China Health and Retirement Longitudinal Study

INTRODUCTION

The cohort study aimed to assess the association of nighttime sleep duration and the change in nighttime sleep duration with chronic kidney disease (CKD) and whether the association between nighttime sleep duration and CKD differed by daytime napping.

METHODS

This study included 11,677 individuals from the China Health and Retirement Longitudinal Study (CHARLS) and used data from the 2011 baseline survey and four follow-up waves. Nighttime sleep duration was divided into three groups: short (<7 h per night), optimal (7-9 h), and long nighttime sleep duration (>9 h). Daytime napping was divided into two groups: no nap and with a nap. We used Cox proportional hazards model to examine the effect of nighttime sleep duration at baseline and change in nighttime sleep duration on incident CKD and a joint effect of nighttime sleep duration and nap time on onset CKD.

RESULTS

With a follow-up of 7 years, the incidence of CKD among those with short, optimal, and long nighttime sleep duration was 9.89, 6.75, and 9.05 per 1,000 person-years, respectively. Compared to individuals with optimal nighttime sleep duration, short nighttime sleepers had a 44% higher risk of onset CKD (hazard ratio [HR]: 1.44, 95% confidence interval [CI]: 1.21-1.72). Compared to participants with persistent optimal nighttime sleep duration, those with persistent short or long nighttime sleep duration had an increased risk of incident CKD (HR: 1.44, 95% CI: 1.15-1.80). We found a lower incidence of CKD in participants with short nighttime sleep duration and a nap (HR: 0.74, 95% CI: 0.60-0.93), compared to those with short nighttime sleep duration and no nap.

CONCLUSION

Short nighttime sleep duration and persistent long or short nighttime sleep duration were associated with a higher risk of onset CKD. Keeping persistent optimal nighttime sleep duration may help reduce CKD risk later in life. Daytime napping may be protective against CKD incidence.

Association between Sleep Duration and Hand Grip Strength among COPD Patients

This study aimed to evaluate the association between night-time sleep duration and hand grip strength (HGS) among patients with chronic obstructive pulmonary disease (COPD). Participants aged ≥45 years were included in a nationally representative investigation clinical study in 2015. HGS was measured using dynamometers. The data on night-time sleep duration, sociodemographic information, and health-related variables were systematically collected. For analysis, sleep duration was categorized as <5 h, 5-7 h, 7 h, 7-9 h, and >9 h. Multivariable linear regression models were used to determine the possible association between the night-time sleep duration and HGS. Our results indicated that the shortest (<5 h) or the longest sleep duration (>9 h) was relevant to high risk of weaker HGS in females. In males, the shortest (<5 h) sleep duration was correlated to lower HGS. Thus, our findings clearly suggest that health care providers should focus on the potential influence of sleep duration on HGS among COPD patients.

Gender-Specific Association Between Sleep Duration and Body Mass Index in Rural China

BACKGROUND

This study aimed at investigating the association of sleep duration with body mass index (BMI) by gender among adult residents in rural Hanzhong of Shaanxi province, Northwest China.

METHODS

A two-level stratified random cluster sampling method was used to select adult residents between the ages of 18 and 80 years. All information including sociodemographic characteristics and lifestyles was collected by face-to-face interview with a structured questionnaire. According to standard methods, trained staff were responsible for anthropometric measurements using calibrated instruments in an empty room. By gender, both ordinary least square regression (OLS) and quantile regression (QR) were used to analyze the relationship between sleep time and BMI controlling for other confounders. The restricted cubic splines with five knots were further used to express the potentially non-linear association between sleep time and BMI.

RESULTS

A total of 3,017 eligible participants were included in the study. After controlling for confounding factors including sociodemographic characteristics and lifestyles, OLS regression did not indicate any significant association of sleep duration with BMI among men and women. Among men, it was clear that there is an inverse U-shaped relationship between sleep time and BMI beyond the 66.0th percentile (BMI ≥24). Among women, quantile regression presented a significant U-shaped relationship between BMI and sleep duration. According to the restricted cubic splines, the women who sleep for approximately 9 h had the lowest BMI, and when sleep duration approached approximately 7 h among men, their BMI would be the highest.

CONCLUSIONS

The U-shaped and inverse U-shaped relationships between sleep duration and BMI were clearly observed for women and men, respectively, in our study. The identification of potentially relevant modifiable risk factors may provide better preventive approaches to obesity.

Association of objectively measured sleep with frailty and 5-year mortality in community-dwelling older adults

STUDY OBJECTIVES

To determine whether actigraphy-measured sleep was independently associated with risk of frailty and mortality over a 5-year period among older adults.

METHODS

We used data from Waves 2 (W2) and 3 (W3) (2010-2015) of the National Social Life, Health and Aging Project, a prospective cohort of community-dwelling older adults born between 1920 and 1947. One-third of W2 respondents were randomly selected to participate in a sleep study, of whom N = 727 consented and N = 615 were included in the analytic sample. Participants were instructed to wear a wrist actigraph for 72 h (2.93 ± 0.01 nights). Actigraphic sleep parameters were averaged across nights and included total sleep time, percent sleep, sleep fragmentation index, and wake after sleep onset. Subjective sleep was collected via questionnaire. Frailty was assessed using modified Fried Frailty Index. Vital status was ascertained at the time of the W3 interview. W3 frailty/mortality status was analyzed jointly with a four-level variable: robust, pre-frail, frail, and deceased. Associations were modeled per 10-unit increase.

RESULTS

After controlling for baseline frailty (robust and pre-frail categories), age, sex, education, body mass index, and sleep time preference, a higher sleep fragmentation index was associated with frailty (OR = 1.70, 95% CI: 1.02-2.84) and mortality (OR = 2.12, 95% CI: 1.09-4.09). Greater wake after sleep onset (OR = 1.24, 95% CI: 1.02-1.50) and lower percent sleep (OR = 0.41, 95% CI: 0.17-0.97) were associated with mortality.

CONCLUSIONS

Among community-dwelling older adults, actigraphic sleep is associated with frailty and all-cause mortality over a 5-year period. Further investigation is warranted to elucidate the physiological mechanisms underlying these associations.

Joint consensus statement of the Saudi Public Health Authority on the recommended amount of physical activity, sedentary behavior, and sleep duration for healthy Saudis: Background, methodology, and discussion

The Saudi Public Health Authority recently prepared a Consensus Statement regarding how much time a person should spend engaged in physical activity, sedentary behavior, and sleep to promote optimal health across all age groups. This paper describes the background literature, methodology, and modified RAND Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation (GRADE)-ADOLOPMENT approach that guided the development process. A Leadership Group and Consensus Panels were formed, and credible existing guidelines were identified. The Panel identified clear criteria to choose the best practice guidelines for the set objectives after evaluation, based on GRADE table evidence, findings table summaries, and draft recommendations. Updating of the selected practice guidelines was performed, and the Consensus Panels separately reviewed the evidence for each behavior and decided to adopt or adapt the selected practice guideline recommendations or create de novo recommendations. Data related to cultural factors that may affect the studied behaviors, such as prayer times, midday napping or "Qailulah," and the holy month of Ramadan, were also reviewed. Two rounds of voting were conducted to reach a consensus for each behavior.

Sleep duration, vegetable consumption and all-cause mortality among older adults in China: a 6-year prospective study

BACKGROUND

Sleep duration and vegetable consumption are associated with mortality at old age (termed as sleep-mortality linkage and vegetable-mortality linkage, respectively). Yet, little is known about the interplay of sleep duration and vegetable consumption on mortality.

METHODS

A dataset of nationwide longitudinal survey with 13,441 participants aged 65 years or older recruited in 2008 and followed up till 2014 was used. Sleep duration was classified into five groups (≤5, 6, 7-8, 9, and ≥ 10 h/day). Vegetable consumption was classified as either high frequency (eating vegetables almost daily) or low frequency. We used parametric Weibull hazard regression models to estimate associations of sleep duration and frequency of vegetable consumption with mortality, adjusting for demographics, socioeconomic factors, family/social support, health practice, and health conditions.

RESULTS

Over the six-year study period, when only demographics were present, participants sleeping ≤5, 6, 9, and ≥ 10 h/day had relative hazard (RH) of mortality 1.18 (p < 0.001), 1.14(p < 0.01), 1.06 (p > 0.1), and 1.30 (p < 0.001), respectively, compared to those sleeping 7-8 h/day. The HRs were attenuated to 1.08 (p < 0.05), 1.08 (p < 0.05), 1.09 (p < 0.1), 1.18(p < 0.001), respectively, when all other covariates were additionally adjusted for. High frequency of eating vegetables was associated with 22% lower risk of mortality (RH= 0.78, p < 0.001) compared to low frequency in the demographic model, and with 9% lower risk (RH = 0.91, p < 0.05) in the full model. Subpopulation and interaction analyses show that the sleeping-mortality linkage was stronger in female, urban, oldest-old (aged ≥80), and illiterate participants compared to their respective male, rural, young-old, and literate counterparts. High frequency of vegetable intakes could offset the higher mortality risk in participants with short-sleeping duration, but low frequency of eating vegetables could exacerbate mortality risk for participants with either short or long sleep duration; and except for few cases, these findings held in subpopulations.

CONCLUSIONS

Too short and too long sleep durations were associated with higher mortality risk, and infrequent vegetable consumption could exacerbate the risk, although frequent vegetable intake could offset the risk for short sleep duration. The relationship between these two lifestyles and mortality was complex and varied among subpopulations.

Association of sleep duration with risk of all-cause mortality and poor quality of dying in oldest-old people: a community-based longitudinal study

Background

While sleep duration has been shown to be associated with health outcomes, few studies have been conducted among the oldest old. In addition, the impact of sleep duration on quality of dying is unknown. We aimed to evaluate how sleep duration affects all-cause mortality and quality of dying in people aged 80 + .

Methods

This community-based longitudinal study was performed by using data from 15,048 individuals aged ≥80 with information on sleep duration in the Chinese Longitudinal Healthy Longevity Survey. Cox and logistic regression models with penalized splines were applied to explore the shape of the association between sleep duration and all-cause mortality and poor quality of dying respectively and identify the interval of sleep duration resulting in the lowest risk of both.

Results

During a median follow-up of 3.1 years, 11,582 deaths including 4116 individuals who experienced poor quality of dying were recorded. Sleep duration showed a U-shaped association with all-cause mortality and sleeping about 8 h had the minimum risk of death; a J-shaped association was found between sleep duration and poor quality of dying. Compared with sleep duration of 7–9 h, the adjusted hazard ratio of total deaths was 1.08 (95% CI 1.03–1.13) for short duration (< 7 h) and 1.12 (95% CI 1.07–1.17) for long duration (> 9 h); the adjusted odds ratio of poor QOD was 1.10 (95% CI 1.01–1.21) for long duration, but this association was restricted to those with baseline unhealthy status (P-interaction = 0.04).

Conclusions

Sleeping a little longer may be better for individuals over 80 years old, and sleep duration of 7–9 h per day is optimal for both survival and good quality of life near death.

Association of estimated sleep duration and naps with mortality and cardiovascular events: a study of 116 632 people from 21 countries

AIMS

To investigate the association of estimated total daily sleep duration and daytime nap duration with deaths and major cardiovascular events.

METHODS AND RESULTS

We estimated the durations of total daily sleep and daytime naps based on the amount of time in bed and self-reported napping time and examined the associations between them and the composite outcome of deaths and major cardiovascular events in 116 632 participants from seven regions. After a median follow-up of 7.8 years, we recorded 4381 deaths and 4365 major cardiovascular events. It showed both shorter (≤6 h/day) and longer (>8 h/day) estimated total sleep durations were associated with an increased risk of the composite outcome when adjusted for age and sex. After adjustment for demographic characteristics, lifestyle behaviours and health status, a J-shaped association was observed. Compared with sleeping 6-8 h/day, those who slept ≤6 h/day had a non-significant trend for increased risk of the composite outcome [hazard ratio (HR), 1.09; 95% confidence interval, 0.99-1.20]. As estimated sleep duration increased, we also noticed a significant trend for a greater risk of the composite outcome [HR of 1.05 (0.99-1.12), 1.17 (1.09-1.25), and 1.41 (1.30-1.53) for 8-9 h/day, 9-10 h/day, and >10 h/day, Ptrend < 0.0001, respectively]. The results were similar for each of all-cause mortality and major cardiovascular events. Daytime nap duration was associated with an increased risk of the composite events in those with over 6 h of nocturnal sleep duration, but not in shorter nocturnal sleepers (≤6 h).

CONCLUSION

Estimated total sleep duration of 6-8 h per day is associated with the lowest risk of deaths and major cardiovascular events. Daytime napping is associated with increased risks of major cardiovascular events and deaths in those with >6 h of nighttime sleep but not in those sleeping ≤6 h/night.

The relationship between sleep duration and all-cause mortality in the older people: an updated and dose-response meta-analysis

Background

Short or long sleep duration is proposed as a potential risk factor for all-cause mortality in the older people, yet the results of published studies are not often reproducible.

Methods

Literature retrieval, study selection and data extraction were completed independently and in duplicate. Only prospective cohort studies were included. Effect-size estimates are expressed as hazard ratio (HR) and 95% confidence interval (CI).

Results

Summary data from 28 articles, involving a total of 95,259 older people, were meta-analyzed. Overall analyses revealed a remarkably significant association between long sleep duration and all-cause mortality (adjusted HR = 1.24, 95% CI: 1.16–1.33, P < .001), whereas only marginal significance was observed for short sleep duration (adjusted HR = 1.04; 95% CI: 1.00–1.09; P = .033). Funnel plots suggested no publication bias for short sleep duration (P = .392). The probability of publication bias was high for long sleep duration (P = .020), yet the trim-and-fill method strengthened its significance in predicting all-cause mortality. In subgroup analyses, the association of long sleep duration with all-cause mortality was statistically significant in both women (HR = 1.48; 95% CI: 1.18–1.86; P = .001) and men (HR = 1.31; 95% CI: 1.10–1.58; P = .003). By contrast, with regard to short sleep duration, statistical significance was observed in men (HR = 1.13; 95% CI: 1.04–1.24; P = .007), but not in women (HR = 1.00; 95% CI: 0.85–1.18; P = .999) (Two-sample Z test P = .099). Besides gender, geographic region, sleep survey method, baseline age and follow-up interval were identified as possible causes of between-study heterogeneity in subgroup analyses. Further dose-response regression analyses revealed that trend estimation was more obvious for long sleep duration (regression coefficient: 0.13; P < .001) than for short sleep duration (regression coefficient: 0.02; P = .046).

Conclusions

Our findings indicate a significantly increased risk of all-cause mortality associated with long sleep duration, especially in women, as well as with short sleep duration in men only.

The interactive effect of habitual midday napping and nighttime sleep duration on impaired fasting glucose risk in healthy adolescents

OBJECTIVES

To investigate the association between habitual midday napping and impaired fasting glucose (IFG), and the interactive effect of napping and time in bed (TIB) at night on IFG among healthy adolescents.

METHODS

The sample comprised 625 early adolescents (12.26 ± 0.63 years old) who self-reported good health status from Jintan, China. Midday napping and nighttime sleep were measured using the Youth Self-report Sleep Questionnaire. Fasting plasma glucose was dichotomized into normal (<5.6 mmol/L) and impaired (≥5.6 mmol/L) levels. The multivariate random-effect logistic regression examined the nap-glucose relationship and the interaction between nap and TIB. Marginal effects of napping were calculated when TIB was held constant at different values.

RESULTS

Of the participants, 83.20% (n = 520) took naps and 62.28% reported average nap durations ≥31 min in the past month. Moreover, 16% (n = 101) of participants had IFG. After adjusting for covariates, early adolescents who napped 3-4 days/week (OR = 1.72, p < 0.001), 5-7 days/week (OR = 1.34, p = 0.02) or ≥31 min/nap (OR = 1.52, 1.56, p's < 0.05) were associated with increased likelihoods of IFG compared to non-nappers. There was an inverse relationship between TIB and IFG among non-nappers (OR = 0.45, p = 0.03). Interaction analyses also showed significantly increased likelihoods of IFG only among nappers with TIB ≥9 hours.

CONCLUSION

The relationship between midday napping and IFG is dependent on TIB. Midday naps may increase the risk for IFG among early adolescents who have sufficient nighttime sleep. However, further research is needed to confirm our preliminary findings.

One-year changes in self-reported napping behaviors across the retirement transition

OBJECTIVE

To estimate associations of retirement with self-reported frequency and duration of naps.

DESIGN

Prospective cohort study.

SETTING

Population-based.

PARTICIPANTS

1359 current and former Wisconsin state employees, aged 54-69.

MEASUREMENTS

Four annual surveys mailed between 2010 and 2014 elicited employment status and nap characteristics. Changes in employment status and nap characteristics were identified from survey pairs measured 1 year apart (up to 3 survey pairs per subject). General linear mixed models with repeated measures were used to estimate changes in minutes napped per week (MNPW), weekly nap frequency, and individual nap duration as predicted by retirement transitions vs stable employment status. All models were adjusted for demographic characteristics, self-rated health, medical diagnoses, sleep problems, circadian preference, and change in nocturnal sleep duration.

RESULTS

There were 3101 survey pairs in the analytic sample. Full retirement (transition from working ≥35 h/wk to not working for pay) over a 1-year period predicted a statistically significantly larger mean change in MNPW than stable employment status: mean (95% confidence interval) = +48 (+16, +80) MNPW. Associations between staged retirement transitions (from full-time to part-time work, or from part-time work to full retirement) and 1-year changes in MNPW were not statistically significant. The MNPW changes associated with full retirement were attributable to nap frequency increase of +0.4 (+0.1, +0.8) d/wk; nap duration did not change significantly.

CONCLUSIONS

Compared with stable employment status, full retirement is associated with an average 1-year increase of +48 MNPW. This change is attributable to a frequency gain of 0.4 d/wk napped. Changes in nap duration were negligible.

Sleep duration and risk of all-cause mortality: a systematic review and meta-analysis

AIMS

To determine the association between the sleep duration and the risk of all-cause mortality in adults.

METHODS

A search strategy was conducted in the MEDLINE, CENTRAL, EMBASE and LILACS databases. Searches were also conducted in other databases and unpublished literature. Cohort studies were included without language, time or setting restrictions. The risk of bias was evaluated with a modified Cochrane Collaboration's tool. An analysis of random effects was conducted. The primary outcome was all-cause mortality. The measure of the effect was the risk difference (RD) with a 95% confidence interval (CI). The planned comparisons were 7-9 h of sleep v. <7 h and the same reference v. >9 h.

RESULTS

Thirty-nine studies were included in our qualitative analysis, regarding the quantitative analysis, 19 studies were included in <7 v. 7-9 h analysis, and 18 studies in the >9 v. 7-9 h. A low risk of bias was shown for most of the study items. The overall RD for all-cause mortality was 0.09 (95% CI 0.07-0.11) favouring the >9 h group compared with our reference. In contrast, no differences were found between the <7 h and the reference sleep duration groups (RD 0.00, 95% CI 0.00-0.01).

CONCLUSION

We found a probable association of long sleep duration and higher mortality; however, it could reflect an underlying systemic or neurological disease that cause sleep fragmentation, deterioration in quality and micro-awakenings.

Psychological Interventions for Late-life Insomnia: Current and Emerging Science

Purpose of Review

Late-life insomnia is a serious medical condition associated with many untoward consequences. The high prevalence of late-life insomnia, along with the concomitant risks inherent in the use of hypnotic medications in older adults necessitates non-pharmacological (i.e., psychological) treatment options. We aim to summarize and evaluate the state-of-the-science of psychological treatment options for late-life insomnia.

Recent Findings

Cumulative scientific evidence suggests the efficacy of psychological treatment of late-life insomnia. During the previous decade, trials of psychological treatments for insomnia have begun to test various modifications to treatments that have the potential to improve access for older adults, along with expanding their focus to include individuals with comorbid conditions that are common to older adults. While these modifications represent positive advances in the science of treatment for late-life insomnia, the evidence is still largely explanatory/efficacious in nature.

Summary

Psychological strategies represent the best approaches for the treatment of late-life insomnia. Future investigations would be wise to progressively move towards increasingly pragmatic/effectiveness investigations, adding to the literature base regarding the treatment of late-life insomnia under usual/real-world conditions as opposed to ideal/artificial conditions.

Self-Reported Sleep Duration and Quality and Cardiovascular Disease and Mortality: A Dose-Response Meta-Analysis

Background There is growing evidence that sleep duration and quality may be associated with cardiovascular harm and mortality. Methods and Results We conducted a systematic review, meta-analysis, and spline analysis of prospective cohort studies that evaluate the association between sleep duration and quality and cardiovascular outcomes. We searched MEDLINE and EMBASE for these studies and extracted data from identified studies. We utilized linear and nonlinear dose-response meta-analysis models and used DerSimonian-Laird random-effects meta-analysis models of risk ratios, with inverse variance weighting, and the I2 statistic to quantify heterogeneity. Seventy-four studies including 3 340 684 participants with 242 240 deaths among 2 564 029 participants who reported death events were reviewed. Findings were broadly similar across both linear and nonlinear dose-response models in 30 studies with >1 000 000 participants, and we report results from the linear model. Self-reported duration of sleep >8 hours was associated with a moderate increased risk of all-cause mortality, with risk ratio , 1.14 (1.05-1.25) for 9 hours, risk ratio, 1.30 (1.19-1.42) for 10 hours, and risk ratio, 1.47 (1.33-1.64) for 11 hours. No significant difference was identified for periods of self-reported sleep <7 hours, whereas similar patterns were observed for stroke and cardiovascular disease mortality. Subjective poor sleep quality was associated with coronary heart disease (risk ratio , 1.44; 95% confidence interval, 1.09-1.90), but no difference in mortality and other outcomes. Conclusions Divergence from the recommended 7 to 8 hours of sleep is associated with a higher risk of mortality and cardiovascular events. Longer duration of sleep may be more associated with adverse outcomes compared with shorter sleep durations.

Napping Characteristics and Restricted Participation in Valued Activities Among Older Adults

Background

Napping is associated with both positive and negative health outcomes among older adults. However, the association between particular napping characteristics (eg, frequency, duration, and whether naps were intentional) and daytime function is unclear.

Methods

Participants were 2,739 community-dwelling Medicare beneficiaries aged ≥65 years from the nationally representative National Health and Aging Trends Study. Participants reported napping frequency, duration, and whether naps were intentional versus unintentional. Restricted participation in valued activities was measured by self-report.

Results

After adjusting for potential confounders and nighttime sleep duration, those who took intentional and unintentional naps had a greater odds of any valued activity restriction (ie, ≥1 valued activity restriction), compared to those who rarely/never napped (unintentional odds ratio [OR] = 1.34, 95% confidence interval [CI] 1.01, 1.79, intentional OR = 1.49, 95% CI 1.09, 2.04). There was no difference between unintentional napping and intentional napping with respect to any valued activity restriction after adjustment for demographics. Compared to participants napping "some days," those napping most days/every day had a greater odds of any valued activity restriction (OR = 1.68, 95% CI 1.30, 2.16). Moreover, each 30-minute increase in average nap duration was associated with a 25% greater odds of any valued activity restriction (OR = 1.25, 95% CI 1.10, 1.43).

Conclusion

Older adults who took more frequent or longer naps were more likely to report activity restrictions, as were those who took intentional or unintentional naps. Additional longitudinal studies with objective measures of sleep are needed to further our understanding of associations between napping characteristics and daytime dysfunction.

Sleep duration, mortality and the influence of age

Prior work has shown that both short and long sleep predict mortality. However, sleep duration decreases with age and this may affect the relationship of sleep duration with mortality. The purpose of the present study was to assess whether the association between sleep duration and mortality varies with age. Prospective cohort study. 43,863 individuals (64% women), recruited in September 1997 during the Swedish National March and followed through record-linkages for 13 years. Sleep duration was self-reported and measured using the Karolinska Sleep Questionnaire, and grouped into 4 categories: ≤5, 6, 7 (reference) and ≥8 h. Up to 2010 3548 deaths occurred. Multivariable Cox proportional hazards regression models with attained age as time scale were fitted to estimate mortality rate ratios. Among individuals <65 years, short (≤5 h) and long (≥8 h) sleep duration showed a significant relationship with mortality (HR 1.37, 95% CI 1.09–1.71, and HR 1.27, 95% CI 1.08–1.48). Among individuals 65 years or older, no relationships between sleep duration and mortality were observed. The effect of short and long sleep duration on mortality was highest among young individuals and decreased with increasing age. The results suggest that age plays an important role in the relationship between sleep duration and mortality.

Sex and age differences in the associations between sleep behaviors and all-cause mortality in older adults: results from the National Health and Nutrition Examination Surveys

OBJECTIVE

Our aim was to examine sex- and age-specific relationships of sleep behaviors with all-cause mortality rates.

METHODS

A retrospective cohort study was conducted among 5288 adults (≥50 years) from the 2005-2008 National Health and Nutrition Examination Surveys who were followed-up for 54.9 ± 1.2 months. Sleep duration was categorized as < 7 h, 7-8 h and >8 h. Two sleep quality indices were generated through factor analyses. 'Help-seeking behavior for sleep problems' and 'diagnosis with sleep disorders' were defined as yes/no questions. Sociodemographic covariates-adjusted Cox regression models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A positive relationship was observed between long sleep and all-cause mortality rate in the overall sample (HR = 1.90, 95% CI: 1.38, 2.60), among males (HR = 1.48, 95% CI: 1.05, 2.09), females (HR = 2.32, 95% CI: 1.48, 3.61) and elderly (≥65 years) people (HR = 1.80, 95% CI: 1.30, 2.50). 'Sleepiness/sleep disturbance' (Factor I) and all-cause mortality rate were positively associated among males (HR = 1.22, 95% CI: 1.03, 1.45), whereas 'poor sleep-related daytime dysfunction' (Factor II) and all-cause mortality (HR = 0.75, 95% CI: 0.62, 0.91) were negatively associated among elderly people.

CONCLUSIONS

Sex- and age-specific relationships were observed between all-cause mortality rate and specific sleep behaviors among older adults.

Cytokine polymorphisms are associated with daytime napping in adults living with HIV

OBJECTIVE/BACKGROUND

Daytime napping longer than one hour has been associated with an increased risk for all-cause mortality. Associations between cytokine polymorphisms and daytime napping in chronic illnesses such as HIV, however, have not been well described. The purpose of this study was to examine cytokine polymorphisms associated with long daytime napping in adults living with HIV.

METHODS

A cross-sectional analysis was conducted using a convenience sample of 257 adults living with HIV. Daytime napping was assessed with wrist actigraphy data collected over three days. Participants categorized as long nappers (≥60 min) were compared to short nappers and non-nappers (<60 min). Single nucleotide polymorphisms (SNPs) for 15 candidate genes involved in cytokine signaling were analyzed. Genes included: interferon-gamma (IFNG), IFNG receptor 1 (IFNGR1), interleukins (IL1B, IL1R, IL1R2, IL2, IL4, IL6, IL8, IL10, IL13, IL17A), nuclear factors of kappa light polypeptide gene enhancer in B cells (NFKB1 and NFKB2), and tumor necrosis factor alpha (TNFA).

RESULTS

After adjusting for relevant demographic and clinical characteristics, long daytime napping was associated with 12 SNPs from seven genes: 1) IFNG rs2069728; 2) IL1B rs1143642, rs1143627, and rs16944; 3) IL2 rs2069763; 4) IL6 rs4719714, rs1554606, and rs2069845; 5) IL17A rs3819024 and rs8193036; 6) NFKB1 rs4648110; and 7) NFKB2 rs1056890.

CONCLUSIONS

Cytokine genetic variations may have a role in physiological regulation of daytime napping as well as nocturnal sleep. Cytokine polymorphisms associated with long daytime napping could help identify adults with HIV who may benefit from targeted therapeutic interventions.

Sleep in the Aging Population

There are normal changes to sleep architecture throughout the lifespan. There is not, however, a decreased need for sleep and sleep disturbance is not an inherent part of the aging process. Sleep disturbance is common in older adults because aging is associated with an increasing prevalence of multimorbidity, polypharmacy, psychosocial factors affecting sleep, and certain primary sleep disorders. It is also associated with morbidity and mortality. Because many older adults have several factors from different domains affecting their sleep, these complaints are best approached as a multifactorial geriatric health condition, necessitating a multifaceted treatment approach.

Sleep Disturbances among Older Adults in the United States, 2002-2012: Nationwide Inpatient Rates, Predictors, and Outcomes

Objective/Background: We examined the rates, predictors, and outcomes [mortality risk (MR), length of stay (LOS), and total charges (TC)] of sleep disturbances in older hospitalized patients.

Patients/Methods: Using the U.S. Nationwide Inpatient Sample database (2002–2012), older patients (≥60 years) were selected and rates of insomnia, obstructive sleep apnea (OSA) and other sleep disturbances (OSD) were estimated using ICD-9CM. TC, adjusted for inflation, was of primary interest, while MR and LOS were secondary outcomes. Multivariable regression analyses were conducted.

Results: Of 35,258,031 older adults, 263,865 (0.75%) had insomnia, 750,851 (2.13%) OSA and 21,814 (0.06%) OSD. Insomnia rates increased significantly (0.27% in 2002 to 1.29 in 2012, P-trend < 0.001), with a similar trend observed for OSA (1.47 in 2006 to 5.01 in 2012, P-trend < 0.001). TC (2012 $) for insomnia-related hospital admission increased over time from $22,250 in 2002 to $31,527 in 2012, and increased similarly for OSA and OSD; while LOS and MR both decreased. Women with any sleep disturbance had lower MR and TC than men, while Whites had consistently higher odds of insomnia, OSA, and OSD than older Blacks and Hispanics. Co-morbidities such as depression, cardiovascular risk factors, and neurological disorders steadily increased over time in patients with sleep disturbances.

Conclusion: TC increased over time in patients with sleep disturbances while LOS and MR decreased. Further, research should focus on identifying the mechanisms that explain the association between increasing sleep disturbance rates and expenditures within hospital settings and the potential hospital expenditures of unrecognized sleep disturbances in the elderly.

Nighttime sleep duration, 24-hour sleep duration and risk of all-cause mortality among adults: a meta-analysis of prospective cohort studies

A dose-response meta-analysis was conducted to summarize evidence from prospective cohort studies about the association of nighttime sleep duration and 24-hour sleep duration with risk of all-cause mortality among adults. Pertinent studies were identified by a search of Embase and PubMed databases to March 2015. A two-stage random-effects dose-response meta-analysis was used to combine study-specific relative risks and 95% confidence intervals [RRs (95% CIs)]. Thirty-five articles were included. Compared with 7 hours/day, the RRs (95% CIs) of all-cause mortality were 1.07 (1.03-1.13), 1.04 (1.01-1.07), 1.01 (1.00-1.02), 1.07 (1.06-1.09), 1.21 (1.18-1.24), 1.37 (1.32-1.42) and 1.55 (1.47-1.63) for 4, 5, 6, 8, 9, 10 and 11 hours/day of nighttime sleep, respectively (146,830 death cases among 1,526,609 participants), and the risks were 1.09 (1.04-1.14), 1.05 (1.02-1.09), 1.02 (1.00-1.03), 1.08 (1.05-1.10), 1.27 (1.20-1.36), 1.53 (1.38-1.70) and 1.84 (1.59-2.13) for 4, 5, 6, 8, 9, 10 and 11 hours/day of 24-hour sleep, respectively (101,641 death cases among 903,727 participants). The above relationships were also found in subjects without cardiovascular diseases and cancer at baseline, and other covariates did not influence the relationships substantially. The results suggested that 7 hours/day of sleep duration should be recommended to prevent premature death among adults.

Sleep duration and mortality in the elderly: a systematic review with meta-analysis

OBJECTIVE

The purpose of our study was to evaluate the association between short and long sleep duration and all-cause and cardiovascular mortality among elderly individuals.

DESIGN

Systematic review and meta-analysis of population-based cohort studies.

SETTING

Articles were retrieved from international and national electronic databases.

STUDY SELECTION

Studies were identified in PubMed, EMBASE, LILACS (Latin American and Caribbean Health Sciences Literature), IBECS (Bibliographic Index on Health Sciences from Spain) and CAPES (PhD thesis repository) between 1980 and 2015. Studies which met all criteria were eligible: participants aged 60 years or over, assessment of sleep duration as 24 h, nighttime or daytime sleep, evaluation of all-cause or cause-specific mortality, population-based cohort studies conducted on representative samples. There was no language restriction and studies published as abstracts were excluded.

DATA EXTRACTION

Data were analysed using the Comprehensive Meta-Analysis software (V.3.3.070), and summary estimates (relative risk (RR), 95% CI) were calculated using a random effects model. Heterogeneity and consistency were evaluated through Cochran's Q and the I(2) statistics, respectively, and sensitivity analyses were conducted.

PRIMARY AND SECONDARY OUTCOME MEASURES

All-cause and cardiovascular mortality.

RESULTS

Overall, 27 cohort studies were selected, comprising >70,000 elderly individuals, and followed up from 3.4 to 35 years. In the pooled analysis, long and short sleep duration were associated with increased all-cause mortality (RR 1.33; 95% CI 1.24 to 1.43 and RR 1.07; 95% CI 1.03 to 1.11, respectively), compared with the reference category. For cardiovascular mortality, the pooled relative risks were 1.43 (95% CI 1.15 to 1.78) for long sleep, and 1.18 (95% CI 0.76 to 1.84) for short sleep. Daytime napping ≥ 30 min was associated with risk of all-cause mortality (RR 1.27; 95% CI 1.08 to 1.49), compared with no daytime sleep, but longer sleep duration (≥ 2.0 h) was not (RR 1.34; 95% CI 1.95 to 1.90).

CONCLUSIONS

Among elderly individuals, long and short sleep duration are associated with increased risk for all-cause mortality. Long sleep duration is associated with cardiovascular mortality.

Predictors of Smoking Cessation in Old-Old Age

INTRODUCTION

There is a dearth of knowledge on smoking cessation in older adults. This study examined predictors of smoking cessation in persons over age 75.

METHODS

This study is a secondary analysis of a prospective longitudinal study. A sample of 619 older persons aged 75-94 was drawn from a representative cohort of older persons in Israel and was examined longitudinally. By means of interviews, we assessed smoking, health, Activities of Daily Living (ADL), Instrumental ADL, cognitive dysfunction, and well-being.

RESULTS

Continuing smokers tended to be lonelier. Participants who quit smoking took more medications and had greater cognitive dysfunction compared to those who continued smoking.

CONCLUSIONS

Greater cognitive dysfunction and high medication use or the physical causes for high medication use may precipitate smoking cessation in persons aged 75-94, potentially through a greater influence of caregivers on one's lifestyle.

IMPLICATIONS

Cognitive dysfunction and high medication use predicted smoking cessation. Smoking cessation for long time smokers may be influenced by greater ill health. Influence of caregivers may augment smoking cessation. Given these findings, for persistent smokers into old age, smoking cessation may occur at the time of physical and functional decline during the end of life period.

Daytime Napping and the Risk of Cardiovascular Disease and All-Cause Mortality: A Prospective Study and Dose-Response Meta-Analysis

STUDY OBJECTIVES

To summarize evidence about the association between daytime napping and the risk of cardiovascular disease and all-cause mortality, and to quantify the potential dose-response relation.

DESIGN

Meta-analysis of prospective cohort studies.

METHODS AND RESULTS

Electronic databases were searched for articles published up to December 2014 using the terms nap, cardiovascular disease, and all-cause mortality. We selected well-adjusted prospective cohort studies reporting risk estimates for cardiovascular disease and all-cause mortality related to napping. Eleven prospective cohort studies were identified with 151,588 participants (1,625,012 person-years) and a mean follow-up period of 11 years (60% women, 5,276 cardiovascular events, and 18,966 all-cause deaths). Pooled analysis showed that a long daytime nap (≥ 60 min/day) was associated with a higher risk of cardiovascular disease (rate ratio [RR]: 1.82 [1.22-2.71], P = 0.003, I(2) = 37%) compared with not napping. All-cause mortality was associated with napping for ≥ 60 min/day (RR: 1.27 [1.11-1.45], P < 0.001, I(2) = 0%) compared with not napping. In contrast, napping for < 60 min/day was not associated with cardiovascular disease (P = 0.98) or all-cause mortality (P = 0.08). Meta-analysis demonstrated a significant J-curve dose-response relation between nap time and cardiovascular disease (P for nonlinearity = 0.01). The RR initially decreased from 0 to 30 min/day. Then it increased slightly until about 45 min/day, followed by a sharp increase at longer nap times. There was also a positive linear relation between nap time and all-cause mortality (P for non-linearity = 0.97).

CONCLUSIONS

Nap time and cardiovascular disease may be associated via a J-curve relation. Further studies are needed to confirm the efficacy of a short nap.

Associations between Metabolic Syndrome and Inadequate Sleep Duration and Skipping Breakfast

Background

The prevalence of metabolic syndrome is increasing worldwide, and previous studies have shown that inadequate sleep duration and skipping breakfast may be related to metabolic syndrome. Therefore, we investigated the effects of inadequate sleep and skipping breakfast on metabolic syndrome using data from the Korea National Health and Nutrition Examination Survey (KNHANES) IV & V reports (2007-2009 and 2010-2012, respectively).

Methods

The sample included 12,999 subjects who participated in the KNHANES IV & V. Sleep duration and breakfast eating were self-reported, and metabolic syndrome was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III guidelines. Subjects were divided into 12 groups according to breakfast eating and sleep duration patterns, and multiple logistic regression analyses adjusted for age, sex, household income, education level, smoking status, alcohol drinking, physical activity, and total daily energy intake were conducted.

Results

In subjects under 50 years of age, sleeping less than 6 hours was significantly associated with increased metabolic syndrome except among those who ate breakfast on only 1 of the past 2 days. In subjects over 50 years of age, sleeping less than 6 hours was significantly associated with a decreased risk of metabolic syndrome among those who ate breakfast on both days.

Conclusion

In conclusion, significant associations between metabolic syndrome and sleep duration were identified, and these associations differed according to age group.

Watson NF, Badr MS, Belenky G, Bliwise DL, Buxton OM, Buysse D, Dinges DF, Gangwisch J, Grandner MA, Kushida C, Malhotra RK, Martin JL, Patel SR, Quan SF, Tasali E. Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society on the Recommended Amount of Sleep for a Healthy Adult: Methodology and Discussion

The American Academy of Sleep Medicine and Sleep Research Society recently released a Consensus Statement regarding the recommended amount of sleep to promote optimal health in adults. This paper describes the methodology, background literature, voting process, and voting results for the consensus statement. In addition, we address important assumptions and challenges encountered during the consensus process. Finally, we outline future directions that will advance our understanding of sleep need and place sleep duration in the broader context of sleep health.

Watson NF, Badr MS, Belenky G, Bliwise DL, Buxton OM, Buysse D, Dinges DF, Gangwisch J, Grandner MA, Kushida C, Malhotra RK, Martin JL, Patel SR, Quan SF, Tasali E. Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society on the Recommended Amount of Sleep for a Healthy Adult: Methodology and Discussion

The American Academy of Sleep Medicine and Sleep Research Society recently released a Consensus Statement regarding the recommended amount of sleep to promote optimal health in adults. This paper describes the methodology, background literature, voting process, and voting results for the consensus statement. In addition, we address important assumptions and challenges encountered during the consensus process. Finally, we outline future directions that will advance our understanding of sleep need and place sleep duration in the broader context of sleep health.

Meta-analysis of self-reported daytime napping and risk of cardiovascular or all-cause mortality

Background

Whether self-reported daytime napping is an independent predictor of cardiovascular or all-cause mortality remains unclear. The aim of this study was to investigate self-reported daytime napping and risk of cardiovascular or all-cause mortality by conducting a meta-analysis.

Material/Methods

A computerized literature search of PubMed, Embase, and Cochrane Library was conducted up to May 2014. Only prospective studies reporting risk ratio (RR) and corresponding 95% confidence intervals (CI) of cardiovascular or all-cause mortality with respect to baseline self-reported daytime napping were included.

Results

Seven studies with 98,163 subjects were included. Self-reported daytime napping was associated with a greater risk of all-cause mortality (RR 1.15; 95% CI 1.07–1.24) compared with non-nappers. Risk of all-cause mortality appeared to be more pronounced among persons with nap duration >60 min (RR 1.15; 95% CI 1.04–1.27) than persons with nap duration <60 min (RR 1.10; 95% CI 0.92–1.32). The pooled RR of cardiovascular mortality was 1.19 (95% CI 0.97–1.48) comparing daytime nappers to non-nappers.

Conclusions

Self-reported daytime napping is a mild but statistically significant predictor for all-cause mortality, but not for cardiovascular mortality. However, whether the risk is attributable to excessive sleep duration or napping alone remains controversial. More prospective studies stratified by sleep duration, napping periods, or age are needed.

Daytime napping, sleep duration and serum C reactive protein: a population-based cohort study

OBJECTIVES

To explore whether daytime napping and sleep duration are linked to serum C reactive protein (CRP), a pro-inflammatory marker, in an older aged British population.

DESIGN

Cross-sectional study.

SETTING

European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk study.

PARTICIPANTS

A total of 5018 men and women aged 48-92 years reported their sleep habits and had serum CRP levels measured.

OUTCOME AND MEASURES

CRP was measured (mg/L) during 2006-2011 in fresh blood samples using high-sensitivity methods. Participants reported napping habits during 2002-2004, and reported sleep quantity during 2006-2007. Multivariable linear regression models were used to examine the association between napping and log-transformed CRP, and geometric mean CRP levels were calculated.

RESULTS

After adjustment for age and sex, those who reported napping had 10% higher CRP levels compared with those not napping. The association was attenuated but remained borderline significant (β=0.05 (95% CI 0.00 to 0.10)) after further adjustment for social class, education, marital status, body mass index, physical activity, smoking, alcohol intake, self-reported health, pre-existing diseases, systolic blood pressure, hypnotic drug use, depression and in women-only hormone replacement therapy use. The geometric means (95% CI) of CRP levels were 2.38 (2.29 to 2.47) mg/L and 2.26 (2.21 to 2.32) mg/L for those who reported napping and no napping, respectively. A U-shaped association was observed between time spent in bed at night and CRP levels, and nighttime sleep duration was not associated with serum CRP levels. The association between napping and CRP was stronger for older participants, and among extremes of time spent in bed at night.

CONCLUSIONS

Daytime napping was associated with increased CRP levels in an older aged British population. Further studies are needed to determine whether daytime napping is a cause for systemic inflammation, or if it is a symptom or consequence of underlying health problems.

Trends and determinants of time in bed in Geneva, Switzerland

STUDY OBJECTIVES

There is limited information regarding sleep duration and determinants in Switzerland. We aimed to assess the trends and determinants of time in bed as a proxy for sleep duration in the Swiss canton of Geneva.

METHODS

Data from repeated, independent cross-sectional representative samples of adults (≥ 18 years) of the Geneva population were collected between 2005 and 2011. Self-reported time in bed, education, monthly income, and nationality were assessed by questionnaire.

RESULTS

Data from 3,853 participants (50% women, 51.7 ± 10.9 years) were analyzed. No significant trend was observed between 2005 and 2011 regarding time in bed or the prevalence of short (≤ 6 h/day) and long (> 9 h/day) time in bed. Elderly participants reported a longer time in bed (year-adjusted mean ± standard error: 7.67 ± 0.02, 7.82 ± 0.03, and 8.41 ± 0.04 h/day for 35-50, 50-65, and 65+ years, respectively, p < 0.001), while shorter time in bed was reported by non-Swiss participants (7.77 ± 0.03 vs. 7.92 ± 0.03 h/day for Swiss nationals, p < 0.001), participants with higher education (7.92 ± 0.02 for non-university vs. 7.74 ± 0.03 h/day for university, p < 0.001) or higher income (8.10 ± 0.04, 7.84 ± 0.03, and 7.70 ± 0.03 h/day for < 5,000 SFr; 5,000-9,500 SFr, and > 9,500 SFr, respectively, p < 0.001). Multivariable-adjusted polytomous logistic regression showed short and long time in bed to be positively associated with obesity and negatively associated with income.

CONCLUSION

In a Swiss adult population, sleep duration as assessed by time in bed did not change significantly between 2005 and 2011. Both clinical and socioeconomic factors influence time in bed.

The risks of sleeping "too much". Survey of a National Representative Sample of 24671 adults (INPES health barometer)

Background

A significant U-shaped association between sleep duration and several morbidity (obesity, diabetes or cardiovascular disease) and mortality risks has been regularly reported. However, although the physiological pathways and risks associated with “too short sleep” (<5 hours/day) have been well demonstrated, little is known about “too much sleeping”.

Purpose

To explore socio-demographic characteristics and comorbidities of “long sleepers” (over 10 hours/day) from a nationally representative sample of adults.

Methods

A cross-sectional nationally representative sample of 24,671 subjects from 15 to 85-year-old. An estimated total sleep time (TST) on non-leisure days was calculated based on a specifically designed sleep log which allows to distinguish “long sleepers” from “short sleepers” (<5 hours/day). Insomnia was assessed according to the International classification of sleep disorders (ICSD-2).

Results

The average TST was 7 hours and 13 minutes (+/− 17 minutes). Six hundred and twelve subjects were “long sleepers” (2.7%) and 1969 “short sleepers” (7.5%). Compared to the whole group, “long sleepers” were more often female, younger (15–25 year-old) or older (above 65 year-old), with no academic degree, mostly clerks and blue collar workers. “Long sleepers” were significantly more likely to have psychiatric diseases and a greater body mass index (BMI). However, long sleep was not significantly associated with the presence of any other chronic medical disease assessed. Conversely, short sleep duration was significantly associated with almost all the other chronic diseases assessed.

Conclusions

In the general population, sleeping too much was associated with psychiatric diseases and higher BMI, but not with other chronic medical diseases.

Subclinical hearing loss, longer sleep duration, and cardiometabolic risk factors in Japanese general population

Hearing loss leads to impaired social functioning and quality of life. Hearing loss is also associated with sleeping disorders and cardiometabolic risk factors. Here, we determined whether subclinical hearing loss is associated with sleep duration and cardiometabolic risk factors in a cross-sectional and longitudinal study of healthy Japanese general population. 48,091 men and women aged 20-79 years who underwent medical checkups were included in a cross-sectional study, and 6,674 were included in an 8-year longitudinal study. The prevalence of audiometrically determined hearing loss (>25 dB) at 4000 and 1000 Hz increased significantly with increasing sleep duration in any age strata. Logistic regression analysis showed that compared with reference sleep duration (6 h) longer sleep duration (≥8 h) was significantly associated with hearing loss, even after adjusting for potential confounding factors. Simultaneously, hearing loss was significantly associated with male sex, diabetes, and no habitual exercise. In the longitudinal study, the risk of longer sleep duration (≥8 h) after 8 years was significantly greater in subjects with hearing loss at 4000 Hz at baseline. In conclusion, current results suggest a potential association of subclinical hearing loss with longer sleep duration and cardiometabolic risk factors in a Japanese general population.

Sleep duration is associated with white matter hyperintensity volume in older adults: the Northern Manhattan Study

Self-reports of long or short sleep durations have indicated an association with cardiovascular morbidity and mortality, but there are limited data evaluating their association with white matter hyperintensity volume (WMHV), a marker of cerebral small vessel disease. We conducted a cross-sectional analysis of self-reported sleep duration to test for a correlation with white matter hyperintensities, measured by quantitative magnetic resonance imaging (MRI), in the Northern Manhattan Study. We used multivariable linear regression models to assess associations between both short (<6 h) and long (≥9 h) sleep durations and log-transformed WMHV, adjusting for demographic, behavioural and vascular risk factors. A total of 1244 participants, mean age 70 ± 9 years, 61% women and 68% Hispanics were analysed with magnetic resonance brain imaging and self-reported sleep duration. Short sleep was reported by 23% (n = 293) and long sleep by 10% (n = 121) of the sample. Long sleep (β = 0.178; P = 0.035), but not short sleep (β = -0.053; P = 0.357), was associated with greater log-WMHV in fully adjusted models. We observed an interaction between sleep duration, diabetes mellitus and log-WMHV (P = 0.07). In fully adjusted models, stratified analysis showed that long sleep duration was associated with greater WMHV only in those with diabetes (β = 0.78; P = 0.0314), but not in those without diabetes (β = 0.022; P = 0.2), whereas short sleep was not associated with white matter hyperintensities in those with or without diabetes. In conclusion, long sleep duration was associated with a greater burden of white matter lesions in this stroke-free urban sample. The association was seen mainly among those with diabetes mellitus.

Daytime napping and the risk of all-cause and cause-specific mortality: a 13-year follow-up of a British population

Epidemiologic studies have reported conflicting results on the relationship between daytime napping and mortality risk, and there are few data on the potential association in the British population. We investigated the associations between daytime napping and all-cause or cause-specific mortality in the European Prospective Investigation Into Cancer-Norfolk study, a British population-based cohort study. Among the 16,374 men and women who answered questions on napping habits between 1998 and 2000, a total of 3,251 died during the 13-year follow-up. Daytime napping was associated with an increased risk of all-cause mortality (for napping less than 1 hour per day on average, hazard ratio = 1.14, 95% confidence interval: 1.02, 1.27; for napping 1 hour or longer per day on average, hazard ratio = 1.32, 95% confidence interval: 1.04, 1.68), independent of age, sex, social class, educational level, marital status, employment status, body mass index, physical activity level, smoking status, alcohol intake, depression, self-reported general health, use of hypnotic drugs or other medications, time spent in bed at night, and presence of preexisting health conditions. This association was more pronounced for death from respiratory diseases (for napping less than 1 hour, hazard ratio = 1.40, 95% confidence interval: 0.95, 2.05; for napping 1 hour or more, hazard ratio = 2.56, 95% confidence interval: 1.34, 4.86) and in individuals 65 years of age or younger. Excessive daytime napping might be a useful marker of underlying health risk, particularly of respiratory problems, especially among those 65 years of age or younger. Further research is required to clarify the nature of the observed association.

Actigraphy-measured sleep disruption as a predictor of survival among women with advanced breast cancer

BACKGROUND

Poor sleep, prevalent among cancer survivors, is associated with disrupted hormonal circadian rhythms and poor quality of life. Using a prospective research design, this study aimed to clarify the relationship between objective measures of sleep efficiency and sleep disruption with survival among women with advanced breast cancer.

METHOD

We examined sleep quality and duration via wrist-worn actigraphy and sleep diaries for 3 days among 97 women in whom advanced breast cancer was diagnosed (age = 54.6 ± 9.8 years). Sleep efficiency was operationalized using actigraphy as the ratio of total sleep time to total sleep time plus wake after sleep onset.

RESULTS

As hypothesized, better sleep efficiency was found to predict a significant reduction in overall mortality (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.94-0.98; P < 0.001) at median 6 y follow-up. This relationship remained significant (HR, 0.94; 95% CI, 0.91-0.97; P < 0.001) even after adjusting for other known prognostic factors (age, estrogen receptor status, cancer treatment, metastatic spread, cortisol levels, and depression). Secondary hypotheses were also supported (after adjusting for baseline prognostic factors) showing that less wake after sleep onset (HR, 0.41; 95% CI, 0.25-0.67; P < 0.001), fewer wake episodes, (HR, 0.93; 95% CI, 0.88-0.98; P = 0.007); and shorter wake episode duration (HR, 0.29; 95% CI, 0.14-0.58; P < 0.001) also contributed to reductions in overall mortality.

CONCLUSIONS

These findings show that better sleep efficiency and less sleep disruption are significant independent prognostic factors in women with advanced breast cancer. Further research is needed to determine whether treating sleep disruption with cognitive behavioral and/or pharmacologic therapy could improve survival in women with advanced breast cancer.

Self-reported sleep disturbances in renal transplant recipients

BACKGROUND

Poor sleep quality (SQ) and daytime sleepiness (DS) are common in renal transplant (RTx) recipients; however, related data are rare. This study describes the prevalence and frequency of self-reported sleep disturbances in RTx recipients.

METHODS

This cross-sectional study included 249 RTx recipients transplanted at three Swiss transplant centers. All had reported poor SQ and / or DS in a previous study. With the Survey of Sleep (SOS) self-report questionnaire, we screened for sleep and health habits, sleep history, main sleep problems and sleep-related disturbances. To determine a basis for preliminary sleep diagnoses according to the International Classification of Sleep Disorders (ICSD), 164 subjects were interviewed (48 in person, 116 via telephone and 85 refused). Descriptive statistics were used to analyze the data and to determine the frequencies and prevalences of specific sleep disorders.

RESULTS

The sample had a mean age of 59.1 ± 11.6 years (60.2% male); mean time since Tx was 11.1 ± 7.0 years. The most frequent sleep problem was difficulty staying asleep (49.4%), followed by problems falling asleep (32.1%). The most prevalent sleep disturbance was the need to urinate (62.9%), and 27% reported reduced daytime functionality. Interview data showed that most suffered from the first ICSD category: insomnias.

CONCLUSION

Though often disregarded in RTx recipients, sleep is an essential factor of wellbeing. Our findings show high prevalences and incidences of insomnias, with negative impacts on daytime functionality. This indicates a need for further research on the clinical consequences of sleep disturbances and the benefits of insomnia treatment in RTx recipients.

Sleep duration and all-cause mortality: a critical review of measurement and associations

PURPOSE

Variation in sleep duration has been linked with mortality risk. The purpose of this review is to provide an updated evaluation of the literature on sleep duration and mortality, including a critical examination of sleep duration measurement and an examination of correlates of self-reported sleep duration.

METHODS

We conducted a systematic search of studies reporting associations between sleep duration and all-cause mortality and extracted the sleep duration measure and the measure(s) of association.

RESULTS

We identified 42 prospective studies of sleep duration and mortality drawing on 35 distinct study populations worldwide. Unlike previous reviews, we find that the published literature does not support a consistent finding of an association between self-reported sleep duration and mortality. Most studies have employed survey measures of sleep duration, which are not highly correlated with estimates based on physiologic measures.

CONCLUSIONS

Despite a large body of literature, it is premature to conclude, as previous reviews have, that a robust, U-shaped association between sleep duration and mortality risk exists across populations. Careful attention must be paid to measurement, response bias, confounding, and reverse causation in the interpretation of associations between sleep duration and mortality.