Sleep Duration and Midday Napping with 5-Year Incidence and Reversion of Metabolic Syndrome in Middle-Aged and Older Chinese

Effect of health lifestyle on the risk of stroke: a prospective cohort study from Chongqing, China

OBJECTIVE

To prospectively investigate the associations of healthy lifestyle factors on the risk of stroke and stroke subtypes, as studies exploring this relationship are limited in China.

METHODS

The 22,661 participants in the prospective cohort study in Chongqing, China, aged 30-79 years and stroke-free at baseline completed follow-up from 2018 to 2022. We included seven healthy lifestyle factors, including non-smoking, non-excessive drinking, sufficient physical activity, healthy diet, sleep duration of 7-9 h/d, and standard range of body mass index and waist-to-hip ratio. The healthy lifestyle score was calculated based on the number of healthy lifestyle factors.

RESULTS

Compared with participants who had scores ≤2, participants with scores ≥6 had an HRs (95% CIs) of 0.56 (0.34, 0.92) for total stroke and 0.53 (0.30, 0.93) for ischemic stroke. For every 1-point increase in healthy lifestyle scores, the HRs (95% CIs) for total stroke and ischemic stroke was 0.86 (0.78, 0.95) and 0.86 (0.77, 0.96), respectively.

CONCLUSIONS

Maintaining multiple healthy lifestyle factors can significantly reduce the risk of stroke. As the number of healthy lifestyle factors increased, the stroke risk gradually decreased. Our findings emphasize the significance of comprehensive lifestyle interventions.

The Global Prevalence of Metabolic Syndrome in Connection with Sleep Duration: A Systematic Review and Meta-Analysis

The duration and quality of sleep are believed to significantly influence the onset of metabolic syndrome (MetS), but existing data lack consistency. The meta-analysis aims to evaluate the prevalence of the MetS in association with sleep duration. We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 guidelines. A comprehensive search of PubMed, Google Scholar, and Research Gate databases was performed to identify cohort and cross-sectional studies published in English between 2013 and 2023. We included studies that examined the association between sleep duration/quality and MetS, and two independent reviewers assessed study quality and bias using the Newcastle-Ottawa scale. The systematic review included 11 studies with a total of 343,669 participants, including 4 cohort studies and 7 cross-sectional studies. Sample sizes varied widely, ranging from 293 to 162,121 individuals. The studies had different follow-up periods, participant ages ranging from 10 to 80 years, and predominantly male populations. The prevalence of MetS was higher in average sleepers [52%, 95% confidence interval (CI): 40%-64%] compared with short sleepers (13%, 95% CI: 8%-18%) and long sleepers (15%, 95% CI: 9%-24%). Globally, North American countries exhibit the highest prevalence of MetS across short- (25.3%, 95% CI: 4.2%-72.4%) and long-sleeper (22.4%, 95% CI: 2.8%-74.1%) categories, whereas Asian countries experience the highest prevalence among the average sleeper category (58.7%, 95% CI: 44.1%-71.9%). Our meta-analysis indicates an elevated prevalence of MetS in average sleepers. Future research endeavors address delve into the underlying mechanisms and incorporate objective measures to understand the multifaceted connection between sleep patterns and MetS, guiding more effective preventive and management strategies.

Associations between sleep health and obesity and weight change in adults: The Daily24 Multisite Cohort Study

OBJECTIVES

To examine cross-sectional and longitudinal associations of individual sleep domains and multidimensional sleep health with current overweight or obesity and 5-year weight change in adults.

METHODS

We estimated sleep regularity, quality, timing, onset latency, sleep interruptions, duration, and napping using validated questionnaires. We calculated multidimensional sleep health using a composite score (total number of "good" sleep health indicators) and sleep phenotypes derived from latent class analysis. Logistic regression was used to examine associations between sleep and overweight or obesity. Multinomial regression was used to examine associations between sleep and weight change (gain, loss, or maintenance) over a median of 1.66 years.

RESULTS

The sample included 1016 participants with a median age of 52 (IQR = 37-65), who primarily identified as female (78%), White (79%), and college-educated (74%). We identified 3 phenotypes: good, moderate, and poor sleep. More regularity of sleep, sleep quality, and shorter sleep onset latency were associated with 37%, 38%, and 45% lower odds of overweight or obesity, respectively. The addition of each good sleep health dimension was associated with 16% lower adjusted odds of having overweight or obesity. The adjusted odds of overweight or obesity were similar between sleep phenotypes. Sleep, individual or multidimensional sleep health, was not associated with weight change.

CONCLUSIONS

Multidimensional sleep health showed cross-sectional, but not longitudinal, associations with overweight or obesity. Future research should advance our understanding of how to assess multidimensional sleep health to understand the relationship between all aspects of sleep health and weight over time.

Association between length of daily siesta and brachial-ankle pulse wave velocity (baPWV): a community-based cross sectional study in North China

INTRODUCTION

To date, many studies have shown a link between siesta and cardiovascular events. Little is known regarding the connection between siesta and brachial-ankle pulse wave velocity (baPWV) levels, even though baPWV can determine the degree of atherosclerosis and vascular stiffness. Thus, we examined the relationship between siesta time and baPWV in a cross-sectional study.

METHODS

Interviews, physical examinations, lab testing, and electron beam computed tomography were all part of the baseline evaluation for participants aged older than 35. Baseline data were compared for 3 different siesta habits: irregular or no siestas, daily short siestas (1 h or less), and daily long siestas (> 1 h). Utilizing logistic regression models and multivariate linear regression, the link between siesta time and baPWV was determined.

RESULTS

Among all 6566 participants, the different siesta groups had a significant difference of the degrees of AS (P < 0.001). The same outcome was true for both males (P < 0.001) and females (P < 0.001). Numerous cardiovascular risk variables and markers of subclinical atherosclerosis were positively correlated with daily extended siestas. Results from the fully adjusted model showed that long siestas (> 60 min, OR = 1.18, 95%CI: 1.06-1.31, P = 0.002) were linked to a more severe level of the baPWV. For age or gender stratification, we found significant differences between non-siesta and > 60 min siesta groups. Multiple linear regression analysis revealed a positive connection between siesta duration and baPWV (β = 0.197, P = 0.038).

CONCLUSIONS

An elevated risk of atherosclerosis was shown to accompany prolonged siestas. These results need to be followed up on with prospective studies and additional lab work.

Association of sleep behaviors, insulin resistance surrogates, and the risk of hypertension in Chinese adults with type 2 diabetes mellitus

Objective

Our aim was to evaluate the association between midday napping, combined sleep quality, and insulin resistance surrogates and the risk of hypertension in patients with type 2 diabetes mellitus (T2DM).

Methods

Data were collected using a standardized questionnaire. Binary logistic regression was performed to estimate the odds ratio (OR) and 95% confidence interval (CI) for the risk of hypertension. Systolic and diastolic blood pressure were grouped as categorical variables and unpaired two-sided Student's t-test and Spearman correlation analysis were performed to estimate the association between different blood pressure levels and insulin resistance surrogates.

Results

The overall prevalence rate of hypertension was 50%. Age (OR = 1.056, 95% CI:1.044-1.068), poor sleep quality (OR = 1.959, 95% CI:1.393-2.755), hyperlipidemia (OR = 1.821, 95% CI:1.462-2.369), family history of hypertension (OR = 2.811, 95% CI:2.261-3.495), and obesity (OR = 5.515, 95% CI:1.384-21.971) were significantly associated with an increased risk of hypertension. Midday napping for 1-30 min was negatively correlated with the risk of hypertension (OR = 0.534, 95% CI:0.305-0.936, P <0.05).

Conclusion

Poor sleep quality and obesity are independent risk factors for hypertension. Midday napping (1-30 min) is associated with a decreased risk of hypertension in patients with T2DM.

Long Sleep Duration and Stroke-Highly Linked, Poorly Understood

Stroke is one of the leading causes of disability and mortality. Both short and long sleep durations are associated with adverse health outcomes. Cross-sectional studies have shown an increased prevalence of stroke in long sleepers. Long sleep duration increases stroke incidence and mortality in prospective epidemiological studies. Accumulating evidence suggests that the magnitude of the association between sleep and stroke appears to be stronger for longer sleep than shorter sleep, yielding a J-shaped curve. Potential links between long sleep duration and stroke include increased incidence of diabetes and atrial fibrillation, elevated levels of inflammation, arterial stiffness, and blood pressure variability. Long sleep duration is a strong marker and a plausible risk factor for stroke and should be considered in future scoring for risk stratification and stroke prevention.

Daytime Napping and Metabolic Syndrome: A 4-Year Follow-Up Study of Chinese Middle-Aged and Older Adults

The current study examined the relationship between napping duration and metabolic syndrome (MetS) among Chinese middle-aged and older adults over 4 years. We included 4,526 individuals aged ≥50 years who completed the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study. General linear models were conducted to analyze the association of napping duration (none, 1 to 29 minutes, 30 to 59 minutes, 60 to 89 minutes, and ≥90 minutes) with MetS. At baseline, a higher prevalence of MetS was observed among participants with longer napping durations (60 to 89 minutes or ≥90 minutes) compared to non-nappers (odds ratio [OR] = 1.27, OR = 1.51, respectively). Among all participants, a napping duration ≥90 minutes at baseline was correlated with an increased risk of MetS 4 years later (OR = 1.58). Among participants without MetS at baseline, excessive napping (≥90 minutes) was predictive of a higher incidence of MetS 4 years later (OR = 1.46). Results revealed that excessive napping was related to an increased prevalence and incidence of MetS among Chinese middle-aged and older adults. [Research in Gerontological Nursing, xx(x), xx-xx.].

Adherence to a Mediterranean lifestyle improves metabolic status in coronary heart disease patients: A prospective analysis from the CORDIOPREV study

BACKGROUND AND OBJECTIVES

A Mediterranean lifestyle may prevent and mitigate cardiometabolic disorders. We explored whether adherence to a Mediterranean lifestyle was prospectively associated with the risk of metabolic syndrome (MetS) among coronary heart disease (CHD) patients.

METHODS

The Coronary Diet Intervention with Olive Oil and Cardiovascular Prevention (CORDIOPREV) study was an interventional diet study to compare a Mediterranean diet with a low-fat diet, in 1002 CHD patients. The Mediterranean lifestyle (MEDLIFE) index was used to assess adherence to a MEDLIFE at baseline, and after 5 years, in 851 participants from the CORDIOPREV study. Subjects were classified as having high (>13 points), moderate (12-13 points), and low (<12 points) adherence to the MEDLIFE. Multivariable logistic regression models were used to determine the association between MEDLIFE adherence and the risk of MetS development or reversal.

RESULTS

During the 5-year follow-up, CORDIOPREV participants with high adherence to MEDLIFE had a lower risk of MetS development (odds ratio [OR] 0.37, 95% confidence interval [CI] 0.19-0.75, p < 0.01) and a higher likelihood of reversing preexisting MetS (OR 2.08 CI 95% 1.11-3.91, p = 0.02) compared with participants in the low MEDLIFE adherence group. Each additional one-point increment in the MEDLIFE index was associated with a 24% lower risk of MetS development (OR 0.76, 95% CI 0.64-0.90, p < 0.01) and a 21% higher likelihood of reversing preexisting MetS (OR 1.21 CI 95% 1.04-1.41, p = 0.01).

CONCLUSIONS

Our results showed that greater adherence to a MEDLIFE reduced the risk of subsequent MetS development and increased the likelihood of reversing preexisting MetS among patients with CHD at baseline.

Bidirectional Associations between Daytime Napping Duration and Metabolic Syndrome: A Nationally Representative Cohort Study

BACKGROUND

We aimed to examine the bidirectional associations between daytime napping duration and metabolic syndrome (MetS).

METHODS

Using data from the China Health and Retirement Longitudinal Study from 2011 to 2015, modified Poisson regression models were performed to explore the longitudinal associations of baseline napping duration with the occurrence and remission of MetS. Generalized estimating equation was conducted to explore the association between baseline MetS status with subsequent changes in daytime napping duration. Cross-lagged panel analysis was performed to further verify their bidirectional relationships.

RESULTS

During the four-year follow-up, among 5041 participants without MetS at baseline, extended naps were significantly associated with MetS occurrence, compared with non-napping. This association was only significant in individuals with adequate night-time sleep duration or good sleep quality of the 2898 participants with MetS at baseline. Excessive napping duration may be not favorable for MetS remission especially for adequate night-time sleepers. With respect to reverse associations, baseline MetS status significantly increased the napping duration during the subsequent follow-up period. Finally, there were significant bidirectional cross-lagged associations between napping duration and MetS severity score after adjusting for all covariates.

CONCLUSIONS

Our study indicates bidirectional relationships exist between daytime napping duration and MetS. Interestingly, longer napping duration was detrimental to cardiometabolic health only in those with sufficient night-time sleep duration or good sleep quality.

Association of Sleep Duration, Midday Napping with Atrial Fibrillation in Patients with Hypertension

Objective

This study aimed to assess the associations of sleep duration, midday napping and the risk of atrial fibrillation (AF) in patients with hypertension.

Methods

We conducted a cross-sectional study enrolling 11,524 hypertensive participates from the Chinese Hypertension Registry Study. Information on sleep duration and midday napping were obtained by a self-administered questionnaire. Multivariate logistic regression analyses were performed to estimate odds ratio (OR) and 95% confidence intervals (CIs) for the risk of AF.

Results

Compared with sleeping 6 to ≤8 hours/night, those reporting shorter sleep duration (≤5 hours/night) had a greater risk of AF (OR 1.95; 95% CI 1.28–2.95) in the fully adjusted model, while longer sleep (≥9 hours/night) was not significantly associated with the risk of AF. Compared with nonhabitual nappers, nappers had a higher risk of AF (OR 1.28; 95% CI 1.03–1.60) in the fully adjusted model. Moreover, we observed significant joint effects of sleeping ≤5 hours/night and nap (OR 2.13; 95% CI 1.09–4.14) on the risk of AF after adjusting for confounding factors.

Conclusion

Short sleep duration and midday napping were independently and jointly associated with higher risks of AF in patients with hypertension.

Association between social capital and sleep duration among rural older adults in China

OBJECTIVE

Sleep disturbances are great challenges to older adults' health promotion. The study tested gender differences in the association between different dimensions of social capital and self-reported sleep duration of Chinese rural older adults.

DESIGN

The data of rural older adults were extracted from a national cross-sectional survey of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and analyzed in this study.

SETTING

CLHLS covered 23 provinces in China.

PARTICIPANTS

The 6552 rural respondents aged ≥65 years old were involved.

MAIN OUTCOME MEASURES

Generalized trust, informal social participation, formal social participation and social support were used to assess social capital. Self-reported sleep duration was measured as health outcome.

RESULTS

Low level of generalized trust had harmful effect on insufficient sleep (AOR 1.110, 95% CI 1.018-1.324), and having no formal or informal social participation was significantly positively associated with long sleep (AOR_formal 1.424, 95% CI 1.007-2.013; AOR_informal 1.241, 95% CI 1.016-1.516). Rural older female adults with no emotional social support had higher odds of insufficient sleep (AOR 1.502, 95% CI 1.258-1.978). Meanwhile, both informal and formal social participation showed inverse association with long sleep for females.

CONCLUSIONS

This study found the relationship between social capital, sleep duration and the gender differences in Chinese rural older adults. More targeted sleep disturbance interventions could be taken in social capital of rural older adults, and gender differences should be considered when making social capital-embedded health promotion policies and interventions.

Relationship Between Sleep Duration and Stroke History in Middle-Aged and Elderly in Guiyang: A Cross-Sectional Survey

BACKGROUND

With over 2 million new cases annually, stroke is associated with the higher amount of disability-adjusted life-years lost than any other disease in China; however, the relationship between sleep time and stroke has not been concluded yet. Aim of this study was to analyze the relationship between sleep duration and stroke history in middle-aged and elderly people in Guiyang, China.

METHODS

This study was a cross-sectional survey carried out in 40-99-years-old permanent residents of Guiyang. Yunyan, Wudang, and Baiyun districts and Xiuwen County were selected by stratified multilevel sampling for a face-to-face survey. Demographics, history of stroke, and self-reported sleep behavior data were collected, and multivariable logistic regression models were used to gradually adjust possible confounding factors.

RESULTS

A total of 5065 participants were included, of them 126 (2.5%) had a history of stroke. Short sleep (<7 h) was observed in 11.0%, sufficient sleep (7-9 h) in 69.4%, and long sleep (>9 h) in 19.6%. Sleep duration and stroke prevalence showed a U-shaped distribution. When taking the sleep duration of 7-9 h as a reference, sleep duration >9 h was associated with stroke (all P < 0.05) in the univariable model (OR = 2.68, 95% CI: 1.83-3.93) and in the multivariable models 1 (OR = 2.35, 95% CI: 1.59-3.47), 2 (OR = 2.27, 95% CI: 1.53-3.37), 3 (OR = 2.25, 95% CI: 1.51-3.33), and 4 (OR = 2.11, 95% CI: 1.39-3.19). There were no significant differences between the <7 and 7-9 h groups (P > 0.05).

CONCLUSION

Thus, long sleep duration (>9 h) is independently associated with history of stroke in middle-aged and elderly people in Guiyang.

Prevalence of metabolic syndrome, its risk factors and associated lifestyles in Myanmar adult people: A community based cross-sectional study

OBJECTIVES

Metabolic syndrome (MetS) is the constellation of cardio-metabolic risk factors, and it can illustrate the coming burden of cardiovascular diseases and diabetes mellitus. Myanmar faces larger pressure from cardio-metabolic diseases and there is no existing data to understand the magnitude of MetS in adult population. This study aimed to investigate the extent of existing people with MetS in the community and to know the related lifestyle factors to MetS.

METHODS

A community based cross-sectional study was performed in convenient sample of 302 Myanmar adult people. Prevalence of MetS and associated risk factors were identified by collecting sociodemographic information, anthropometric measurements, and blood investigation of glucose and lipid profiles. Logistic regression analysis was performed for developing statistical models to estimate the odd ratios (OR) and confidence intervals (CI).

RESULTS

Prevalence of MetS is 29.1%, and there is no significant difference between male and female prevalence. Abdominal obesity is the highest component of MetS (OR: 28.37, CI: 12.41-64.85, p < 0.001) especially for female (OR: 44.52, CI: 17.19-115.31, p < 0.001), and hypertriglyceridemia (OR: 11.05, CI: 6.20-19.66, p < 0.001) is the commonest in male. Age is the constant risk for developing MetS (OR: 4.06, CI: 1.91-8.64, p < 0.001) whereas the practice of midday nap is the behavior related to increased occurrence of MetS (OR: 1.97, CI: 1.16-3.38, p < 0.05). Dietary pattern, smoking status, drinking alcoholic beverages and physical activity involvement do not impact on the development of MetS. Education, occupation, income and other sociodemographic factors do not produce significant effect on cardio-metabolic status. Obesity, diabetes, and hypertensive conditions of community residents are also explored.

CONCLUSIONS

Modifiable pathophysiological conditions such as abdominal obesity, and obesity play a vital role in preventing MetS before it occurs while unmodifiable risk factor such as getting older and female sex are not as much important as changeable lifestyle habits.

Risk of Developing Metabolic Syndrome Is Affected by Length of Daily Siesta: Results from a Prospective Cohort Study

Background: Siesta has been associated with increased incidence of cardiovascular disease but the mechanism remains unclear. New studies into the relationship between siesta and metabolic syndrome have identified siesta length as a crucial differential, suggesting that siesta less than 40 min is associated with decreased risk of metabolic syndrome, while longer siesta is associated with increased risk. We aimed to investigate the effect of siesta duration on development of metabolic syndrome in a Mediterranean population using a prospective cohort study design. Methods: Our sample consisted of 9161 participants of the SUN cohort without components of metabolic syndrome at baseline. Siesta exposure was assessed at baseline and the development of metabolic syndrome components was assessed after an average 6.8 years of follow-up. We estimated odds ratios and fitted logistic regression models to adjust for potential cofounders including night-time sleep duration and quality, as well as other diet, health, and lifestyle factors. Results: We observed a positive association between average daily siesta >30 min and development of metabolic syndrome (aOR = 1.39 CI: 1.03–1.88). We found no significant difference in risk of developing metabolic syndrome between the group averaging ≤30 min of daily siesta and the group not taking siesta (aOR = 1.07 CI: 0.83–1.37). Further analysis suggested that average daily siesta <15 min may reduce risk of metabolic syndrome. Conclusions: Our study supports the J-curve model of the association between siesta and risk of metabolic syndrome, but suggests the protective effect is limited to a shorter range of siesta length than previously proposed.

Nighttime sleep duration, daytime napping, and metabolic syndrome: findings from the China Health and Retirement Longitudinal Study

PURPOSE

This study aimed to assess the association between nighttime sleep, daytime napping, and metabolic syndrome (MetS) in an elderly Chinese population.

METHODS

A cross-sectional study was conducted using data from the 2011 China Health and Retirement Longitudinal Study (CHARLS) to examine the association between nighttime sleep, daytime napping, and MetS (defined according to the Chinese Diabetes Society criteria). Sleep duration was assessed by a self-reported questionnaire. Binary logistic regression models were used to estimate odds ratios and 95% confidence intervals of the associations adjusting for covariates.

RESULTS

Among 4785 elderly Chinese aged over 65 years old, there was no association between short-time sleep duration (< 7 h/day) and MetS. However, long-time sleep duration (> 8 h/day) decreased the odds of MetS by 53% (aOR= 0.47; 95% CI 0.23-0.96) compared to normal sleep duration (7-8 h/day). Compared to no daytime napping, short-time napping (≤ 30 min/day) was associated with increased odds of MetS (aOR = 1.55, 95% CI 1.02-2.36) and long-time napping (> 30 min/day) was associated with even higher odds of MetS (aOR = 1.77, 95%CI 1.24-2.53). Individuals who were over 75 years old, with elementary school education, and good health status had lower odds of MetS, while women, individuals living in rural areas, and those who reported poor health status had higher odds of MetS.

CONCLUSION

Long-time sleep duration decreased and daytime napping increased the risk of MetS among the elderly Chinese population. We speculate that increasing nighttime sleep duration and decreasing daytime napping may help reduce the risk of MetS.

Sleep duration and metabolic syndrome: An updated systematic review and meta-analysis

We examined the association between self-reported sleep duration and metabolic syndrome (MetS). Data were collected from 36 cross-sectional and 9 longitudinal studies with a total of 164,799 MetS subjects and 430,895 controls. Odds ratios (ORs) for prevalent MetS and risk ratios (RRs) for incident MetS were calculated through meta-analyses of adjusted data from individual studies. Short sleep duration was significantly associated with increased prevalent MetS (OR = 1.11, 95% CI = 1.05-1.18) and incident MetS (RR = 1.28, 95% CI = 1.07-1.53) in cross-sectional and longitudinal studies, respectively. Furthermore, long sleep duration was significantly associated with increased prevalent MetS in cross-sectional studies (OR = 1.14, 95% CI = 1.05-1.23), but not incident MetS (RR = 1.16, 95% CI = 0.95-1.41) in longitudinal studies. Interestingly, the association between long sleep and prevalent MetS was found in sleep duration defined by 24-h sleep (including naps) rather than nighttime sleep. Our findings suggest 1) a "U-shape" relationship between sleep duration and MetS in cross-sectional studies and 2) association between short sleep duration, but not long sleep duration with incident MetS. Future studies should shed light on the underlying mechanisms related to the association between sleep duration and MetS and examine if normalizing sleep duration reduces MetS risk in the general population.

Longitudinal association between sleep and 5-year incident metabolic syndrome in older Chinese adults: a community-based cohort study

PURPOSE

Our aim was to investigate the association between sleep and the development of metabolic syndrome (MetS) in Chinese older adults and to accumulate evidence for the prevention of MetS through sleep management.

METHODS

This prospective study followed 3005 participants aged over 60 derived from the Weitang Geriatric Diseases Study who were without MetS at baseline. MetS was defined according to the Adult Treatment Panel III (ATP III) criteria. Logistic regression models were fit to assess the association between sleep and MetS incident and a linear regression model was used to examine the impact of sleep duration on every component of MetS. Data on sleep-related parameters were obtained based on a self-reported questionnaire.

RESULTS

After five-year follow-up, 13.51% participants developed MetS, of which 46.86% were women. The incidence of MetS was highest among adults who slept 6 h or less and lowest among those who slept 7 h after adjusted for multiple variables. Subgroup analyses showed no gender specificity. The variation of fasting plasma glucose (FBG) for ≥9 h per night was significantly lower than that for 7.01-7.99 h per night (β = -0.18, P < 0.05). Sleeping for 8-8.99 h also decreased the variation of diastolic blood pressure (DBP) compared to 7.01-7.99 h (β = -0.84, P < 0.05).

CONCLUSION

We conclude that both short and long sleep duration are risk factors for MetS incident in older adults.

The Association Between Sleep and Metabolic Syndrome: A Systematic Review and Meta-Analysis

PURPOSE

Sleep duration is thought to play a key role in the development of metabolic syndrome. However, the results have been inconsistent.

METHODS

We conducted a systematic review and meta-analysis of cohort studies and searched publications in PubMed, Embase, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov. The summary relative risks (RRs) were estimated using a random model. The sensitivity analysis was performed by sequentially excluding each study to test the robustness of the pooled estimates.

FINDING

We included 13 studies involving 300,202 patients in which short sleep and long sleep significantly increased the risk of metabolic syndrome 15% (RR = 1.15, 95%CI = 1.09-1.22, p < 0.001) and 19% (RR = 1.19, 95%CI = 1.05-1.35, p < 0.001). Moreover, the relationship between sleep duration and metabolic syndrome risk presented a U-shaped curve. Short and long sleep increased the risk of obesity by 14% (RR = 1.14, 95%CI = 1.07-1.22, p<0.001) and 15% (RR = 1.15, 95%CI = 1.00-1.30, p = 0.04), and high blood pressure 16% (RR = 1.16, 95%CI = 1.02-1.31, p = 0.03) and 13% (RR = 1.13, 95%CI = 1.04-1.24, p = 0.01), respectively. Short sleep can potentially increase the risk of high blood sugar by 12% (RR = 1.12, 95%CI = 1.00-1.15, P = 0.05).

IMPLICATIONS

Based on our findings, sleep is a behavior that can be changed and is economical. Clinically doctors and health professionals should be encouraged to increase their efforts to promote healthy sleep for all people.

Exploration of Sleep as a Specific Risk Factor for Poor Metabolic and Mental Health: A UK Biobank Study of 84,404 Participants

PURPOSE

Short and long sleep durations have adverse effects on physical and mental health. However, most studies are based on self-reported sleep duration and health status. Therefore, this longitudinal study aims to investigate objectively measured sleep duration and subsequent primary health care records in older adults to investigate the impact of sleep duration and fragmentation on physical and mental health.

METHODS

Data on objective sleep duration were measured using accelerometry. Primary care health records were then obtained from the UK Biobank (n=84,404). Participants (mean age, 62.4 years) were divided into five groups according to their sleep duration derived from the accelerometry data: <5 hours, 5-6 hours, 6-7 hours, 7-8 hours and >8 hours. ICD-10 codes were used for the analysis of primary care data. Wake after sleep onset, activity level during the least active 5 hours and episodes of movement during sleep were analysed as an indication for sleep fragmentation. Binary regression models were adjusted for age, gender and Townsend deprivation score.

RESULTS

A "U-shaped" relationship was found between sleep duration and diseases including diabetes, hypertension and heart disease and depression. Short and long sleep durations and fragmented sleep were associated with increased odds of disease.

CONCLUSION

Six to eight hours of sleep, as well as less fragmented sleep, predicted better long-term metabolic and mental health.

The effect of Mid-Day Sleep on blood pressure levels in patients with arterial hypertension

STUDY OBJECTIVES

Lifestyle changes decrease blood pressure (BP) levels by 3-5 mmHg in hypertensive patients. We assessed the effect of mid-day sleep on BP levels in hypertensive patients.

METHODS

We prospectively studied two hundred and twelve hypertensive patients. Mid-day sleep duration, lifestyle habits, anthropometric characteristics, office BP, ambulatory BP monitoring, pulse wave velocity (PWV), augmentation index (AI) were recorded. A standard echocardiographic evaluation was performed.

RESULTS

53.8% were females, mean age was 62.5±11.0 years and mean body mass index was 28.9±5.4kg/m². Mean average 24h systolic and diastolic BP (SBP & DBP) was 129.9±13.2/76.7±7.9 mmHg respectively. The majority was non-smokers (70.3%) and did not have diabetes (74.7%). The mean midday sleep duration was 48.7±54.3 min. Average 24h SBP (127.6±12.9 mmHg vs 132.9±13.1 mmHg), average daytime SBP & DBP were lower in patients who sleep at midday, compared to those who do not (128.7±13/76.2±11.5 vs 134.5±13.4/79.5±10.4 mmHg) (p<0.005). The effect was not correlated to the dipping status. Midday sleep duration was negatively correlated with average 24h SBP & daytime SBP. In a linear regression model, for every 60 min of midday sleep, 24h average SBP decreases by 3 mmHg (p<0.001). There were no differences in the number of antihypertensive medications, PWV, AI or echocardiographic indices between study groups.

CONCLUSIONS

Mid-day sleep significantly decreases average 24h and daytime SBP/DBP in hypertensives. Its effect seems to be as potent as other well-established lifestyle changes and is independent of dipping status.

Association of Nap Duration after Lunch with Prevalence of Metabolic Syndrome in a Chinese Government Employee Population

Metabolic syndrome is an important risk factor for cardiovascular disease, type 2 diabetes mellitus, and all-cause mortality. However, the relationship between napping and metabolic syndrome remains contradictory. The aim of this study was to evaluate the association between nap duration after lunch and prevalence of metabolic syndrome, and subgroup differences in the associations among a government employee population. A total of 5129 participants (mean age 39.4 years) were included in this study. Nap duration after lunch was self-reported, and metabolic syndrome was defined according to the Joint Interim Statement in 2009. Multivariate logistic regression models and adjusted restricted cubic spline functions were used to examine the association and dose-response relationship between nap duration after lunch and prevalence of metabolic syndrome. Of the participants, 17.3% had metabolic syndrome and 81.4% were habitual nappers. Adjusted odds ratio (OR) (95% confidence interval (CI)) of metabolic syndrome for longer nap duration (>90 min) per day was 1.77 (95% CI 1.09 to 2.89), compared with reference (~30 min). Results of stratification analyses indicated the association was found only among females (OR 3.02, 95% CI 1.38 to 6.57), participants without mood symptoms (OR 1.97, 95% CI 1.19 to 3.25), and those having longer night sleep duration (≥8 h) (OR 2.34, 95% CI 1.20 to 4.56). Longer nap duration was also associated with components of metabolic syndrome, including elevated waist circumference, elevated fasting plasma glucose, and elevated triglycerides. In conclusion, longer nap duration after lunch was associated with a higher prevalence of metabolic syndrome in females, people without mood symptoms, and people having longer night sleep duration.

Association of daytime napping with incident stroke in middle-aged and older adults: a large community-based study

BACKGROUND AND PURPOSE

There are conflicting reports on the association between daytime napping and incident stroke. This study was designed to investigate the relationship between daytime napping and stroke within a community-based cohort.

METHODS

The present prospective study was based on the Sleep Heart Health Study. Napping habits were assessed with a self-reported Sleep Habits Questionnaire. Participants with napping habits of different durations and frequencies were followed up until the first stroke occurred or the final censoring date. Cox proportional hazards models were used to estimate the relationship between napping habits and stroke.

RESULTS

A total of 4757 participants (2219 men, mean age 63.6 ± 11.1 years) were enrolled in this study. Compared with those taking no naps, multivariate proportional hazards models analysis indicated that individuals taking naps with a duration of >60 min [hazard ratio (HR), 2.460; 95% confidence interval (CI), 1.538-3.934] had a higher risk of stroke. There was also an increased risk of stroke among participants taking naps daily (HR, 1.563; 95% CI, 1.059-2.307) or five to six times/week (HR, 1.548; 95% CI, 1.026-2.335). After combining napping durations and frequencies, regular long naps (HR, 1.903; 95% CI, 1.182-3.065) and regular short naps (HR, 1.451; 95% CI, 1.010-2.084) were independent risk factors for incident stroke.

CONCLUSION

Daytime napping with a long duration (>30 min) or a high frequency (≥5 times/week) may increase the risk of stroke.

Sleep duration, midday napping, and sleep quality and incident stroke

Objective

To investigate the associations of sleep duration, midday napping, sleep quality, and change in sleep duration with risk of incident stroke and stroke subtypes.

Methods

Among 31,750 participants aged 61.7 years on average at baseline from the Dongfeng-Tongji cohort, we used Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident stroke.

Results

Compared with sleeping 7 to <8 hours/night, those reporting longer sleep duration (≥9 hours/night) had a greater risk of total stroke (hazard ratio [HR] 1.23; 95% confidence interval [CI] 1.07–1.41), while shorter sleep (<6 hours/night) had no significant effect on stroke risk. The HR (95% CI) of total stroke was 1.25 (1.03–1.53) for midday napping >90 minutes vs 1–30 minutes. The results were similar for ischemic stroke. Compared with good sleep quality, those with poor sleep quality showed a 29%, 28%, and 56% higher risk of total, ischemic, and hemorrhagic stroke, respectively. Moreover, we observed significant joint effects of sleeping ≥9 hours/night and midday napping >90 minutes (HR 1.85; 95% CI 1.28–2.66), and sleeping ≥9 hours/night and poor sleep quality (HR 1.82; 95% CI 1.33–2.48) on risk of total stroke. Furthermore, compared with persistently sleeping 7–9 hours/night, those who persistently slept ≥9 hours/night or switched from 7 to 9 hours to ≥9 hours/night had a higher risk of total stroke.

Conclusions

Long sleep duration, long midday napping, and poor sleep quality were independently and jointly associated with higher risks of incident stroke. Persistently long sleep duration or switch from average to long sleep duration increased the risk of stroke.

Extended afternoon naps are associated with hypertension in women but not in men

BACKGROUND

The impact of afternoon napping duration on the risk of hypertension has not been well established, particularly with regards to sex and age differences.

OBJECTIVE

To examine the association between afternoon napping duration and hypertension stratified by sex and age among Chinese adults over 45 years of age.

METHODS

The 2011-2012 survey of the China Health and Retirement Longitudinal Study (CHARLS) was used, including 7,980 participants. We conducted logistic regression models in the overall sample, and then stratified by sex and age groups.

RESULTS

Middle-aged and older women who napped over 90 min were 39% and 54% more likely to have hypertension, respectively; however, the associations were not significant in middle-aged and older men.

CONCLUSION

Extended afternoon napping (≥90 min) was associated with hypertension in both the middle-aged women and older women but not in men. Future studies are needed to further examine the association and possible mechanisms.

Sleep Duration and Risk of Atrial Fibrillation: a Systematic Review

Background

Little is known about a possible association between sleep duration and the incidence of atrial fibrillation (AF), in healthy people. In this systematic review, we conducted a literature search to examine possible association between sleep duration and the incidence of AF.

Methods

Scientific databases (PubMed, Web of Knowledge and Embase) were searched using relevant Medical Subject Headings and keywords, to retrieve studies written in English and published until November 2017. Only observational studies were included. Since sleep duration categories were not consistent, it was feasible to run a meta-analysis.

Results

Six eligible studies were included. Long sleep duration (≥ 8 hours) was found to be associated with an increased risk of AF (adjusted hazard ratio (aHR) = 1.13; 95% CI: 1.00-1.27 and aHR= 1.5, 95% CI: 1.07-2.10) in two studies. One study reported that sleep duration less than 6 hours was associated with an increased risk of AF (aHR= 1.58, 95% CI: 1.18 -2.13) compared to sleeping for 6-7 hours. In two studies, mean sleep duration was lower in AF groups compared to the non-AF group. Insomnia was associated with an increased risk of AF in another study (aHR= 1.33, 95% CI: 1.25-1.41).

Conclusions

Unhealthy sleep duration, defined as either less than 6 hours or more than 8 hours, may be associated with an increased risk of AF.

Central obesity transition increased urinary levels of 8-hydroxydeoxyguanosine in male adults: A 3-year follow up study

OBJECTIVE

Association of oxidative DNA damage with gain in anthropometric indices has not been fully elucidated.

METHODS

In this study, participants (n = 1151) were derived from the baseline visit of Wuhan residents in the Wuhan-Zhuhai Cohort Study. The participants finished the physical examinations at both baseline and 3-year follow up. Urinary levels of 8-hydroxydeoxyguanosine (8-OHdG) were measured by gradient-elution high performance liquid chromatography method and then calibrated by urinary creatinine (Cr) values.

RESULTS

Generalized linear models showed that after adjusted for confounding factors, baseline central obesity individuals with a ≥2.5% hip circumference (HC) loss or >5% HC gain had a 0.290 μmol/mol Cr (95% confidence interval (CI): 0.108, 0.472) or 0.553 μmol/mol Cr (95% CI: 0.273, 0.833) increase in urinary 8-OHdG levels compared with those with a -2.5%-2.5% HC gain (both P < 0.05). Moreover, compared with non-central obesity at both baseline and 3-year follow-up, we observed that central obese men at both baseline and 3-year follow-up had a 0.46 μmol/mol Cr (95% CI: 0.16, 0.75) increased in urinary 8-OHdG levels.

CONCLUSIONS

HC gain showed dose-dependent associations with urinary 8-OHdG levels. Moreover, male central obesity at both baseline and 3-year follow-up had an increased risk for urinary 8-OHdG levels.

The Relationship Between Sleep Duration, Falls, and Muscle Mass: A Cohort Study in an Elderly Chinese Population

Epidemiological studies report that more than half of the people over the age of 65 years suffer from variable sleep problems. In this study, we conducted a cohort study to investigate the relationship between sleep duration, muscle mass, and function within a community-dwelling, elderly Chinese population. Our study population consisted of residents living in the township central hospital of suburban Tianjin, China. We measured muscle strength and walking speed. We divided sleep duration into the following four groups: <7 hours, 7-8 hours, >8-9 hours, and >9 hours. A total of 902 participants completed the 3-year follow-up. We observed a U-shaped relationship between sleep duration and fall risk. Compared with the 7-8-hour group, fall risk within the <7-hour group was 3.67 (2.59, 5.42) times higher and fall risk within the >9-hour group was 2.35 (1.29, 3.52) times higher. After adjustment, muscle mass declined by -6.82% (-11.27%, -3.83%) in the <7-hour group. In summary, we observed a U-shaped relationship between sleep duration and falls. Short sleep duration has a negative relationship with muscle mass decline in a community-dwelling, elderly Chinese population.

Does long sleep duration increase risk of metabolic syndrome in Azar cohort study population?

Background: We decided to assess the correlation between metabolic syndrome (MetS) risks,sleep and napping duration in Azar cohort population according to the increasing incidence of MetS in the world and inconsistence results about sleep duration and MetS. Methods: In this cross-sectional study, MetS and sleep habits of 14916 subjects (35-70 years old) who inhabited in Shabestar city were determined by ATPIII and Pittsburg questionnaire respectively. Inclusion criteria were subjects with 35-70 years old and living in Shabestar for at least 9 months of the year. Results: According to the results, age, living place, body mass index, hypnotic drug use, sleep and napping duration and TV time were the risk factors of MetS. In this regard, long sleep duration (>9 h/24 h), napping (0.25-2 h/day), hypnotic drug use and watching TV (2 h/day)increased the risk of MetS by 1.18 (1.05-1.33), 1.16(1.07-1.26), 1.35(1.13-1.60), and 1.13(1.04-1.23) respectively. Conclusion: According to these results, it appears that proper education for improvement of sleep habit is necessary to reduce incidence of MetS and its consequences. However, there is need for more longitudinal researches and using objective method of sleep habits evaluation for more precise results.

Prevalence and predictors of metabolically healthy obesity in adolescents: findings from the national "Jeeluna" study in Saudi-Arabia

BACKGROUND

Obese children and adolescents may vary with respect to their health profile, an observation that has been highlighted by the characterization of metabolically healthy obesity (MHO). The objectives of this study were to examine the prevalence of MHO amongst obese adolescents in Saudi-Arabia, and investigate the anthropometric, socio-demographic, and lifestyle predictors of MHO in this age group.

METHODS

A national cross-sectional school-based survey (Jeeluna) was conducted in Saudi-Arabia in 2011-2012 (n = 1047 obese adolescents). Anthropometric, blood pressure and biochemical measurements were obtained. A multicomponent questionnaire covering socio-demographic, lifestyle, dietary, psychosocial and physical activity characteristics was administered. Classification of MHO was based on two different definitions. According to the first definition, subjects were categorized as MHO based on the absence of the following traditional cardiometabolic risk (CR) factors: systolic blood pressure (SBP) or diastolic blood pressure (DBP) >90th percentile for age, sex, and height; triglycerides (TG) > 1.25 mmol/L; high density lipoprotein-cholesterol (HDL-C) ≤1.02 mmol/L; glucose ≥5.6 mmol/L. The second definition of MHO was based on absence of any cardiometabolic risk factor, according to the International Diabetes Federation (IDF) criteria.

RESULTS

The prevalence of MHO ranged between 20.9% (IDF) and 23.8% (CR). Subjects with MHO were younger, less obese, had smaller waist circumference (WC) and were more likely to be females. Based on stepwise logistic regression analyses, and according to the IDF definition, body mass index (BMI) (OR = 0.89, 95% CI: 0.84-0.93) and WC (OR = 0.97, 95% CI: 0.96-0.98) were the only significant independent predictors of MHO. Based on the CR definition, the independent predictors of MHO included female gender (OR = 1.76, 95% CI: 1.29-2.41), BMI (OR = 0.97, 95% CI: 0.94-1.00), and weekly frequency of day napping (OR = 1.06, 95% CI: 1.00-1.12). Analysis by gender showed that vegetables' intake and sleep indicators were associated with MHO in boys but not in girls.

CONCLUSION

The study showed that one out of five obese adolescents is metabolically healthy. It also identified anthropometric factors as predictors of MHO and suggested gender-based differences in the association between diet, sleep and MHO in adolescents. Findings may be used in the development of intervention strategies aimed at improving metabolic heath in obese adolescents.

Longer time spent in bed attempting to sleep is associated with rapid renal function decline: the Dongfeng-Tongji cohort study

INTRODUCTION

Prospective evidence on the relation between time in bed and renal dysfunction remains limited. We aimed to investigate the association of time spent in bed attempting to sleep (TSBS) with renal function decline in a middle-aged and elderly Chinese population.

METHODS

About 16,733 eligible participants with a mean age of 62.3 years at baseline were included. Rapid renal function decline was defined as (baseline eGFR - revisit eGFR)/years of follow-up ≥5 mL/min per 1.73 m²/year. A total of 1738 study participants experienced rapid renal function decline after a median 4.6-year follow-up. Logistic regression models were used for multivariate analyses.

RESULTS

The adjusted odds ratio (OR) of rapid renal function decline was 1.18 (95% CI: 1.02, 1.37) for TSBS ≥9 h/night compared with TSBS 7 to <8 h/night. This association remained significant (OR = 1.19, 95% CI: 1.03, 1.38) after further adjustment for sleep quality, midday napping and usage of sleeping pills. Particularly, the association appeared to be prominent in individuals with diabetes.

CONCLUSIONS

Longer TSBS (≥9 h) was independently associated with an increased risk of rapid renal function decline. Our findings emphasized the importance to have optimal TSBS. Key messages Our study firstly investigated the association between time spent in bed attempting to sleep (TSBS) and renal dysfunction in Chinese adults. Compared with individuals TSBS 7 to <8 h, individuals with TSBS ≥9 h had 19% increased risk for rapid renal function decline after adjustment for multivariate confounders. The association appeared to be prominent in individuals with diabetes.

Longitudinal Association of Sleep Duration with Depressive Symptoms among Middle-aged and Older Chinese

This study aimed to evaluate the associations of nighttime sleep duration and midday napping with risk of depressive symptoms incidence and persistence among middle-aged and older Chinese. Data from China Health and Retirement Longitudinal Study, CHARLS (2011–2013), were analyzed. Depressive symptoms were identified by the 10-item version of the Centre for Epidemiological Studies Depression scale (CESD-10). Multivariate binary logistic regression models were fitted. There were 7156 individuals with CESD-10 scores < 10 and 3896 individuals with CESD-10 scores ≥ 10 at baseline included in this study. After controlling for potential covariates, nighttime sleep duration <6 hours was associated with high risk of incident depressive symptoms (OR = 1.450, 95%CI: 1.193, 1.764 for middle aged population, and OR = 2.084, 95%CI:1.479, 2.936 for elderly) and persistent depressive symptoms (OR = 1.404, 95%CI: 1.161, 1.699 for middle aged population, and OR = 1.365, 95%CI: 0.979, 1.904 for elderly). For depressed individuals, longer midday napping (≥60 minutes) was associated with lower persistent depressive symptoms (OR = 0.842, 95%CI: 0.717, 0.989). Our study concluded that short nighttime sleep duration was an independent risk factor of depressive symptoms incidence and persistence. Depressed individuals with long midday napping were more likely to achieve reversion than those who have no siesta habit.

Long Sleep Duration Is an Independent Risk Factor for Incident Atrial Fibrillation in a Chinese Population: A Prospective Cohort Study

There is limited information on the relation between sleep duration and incident atrial fibrillation. We aimed to investigate this association in a Chinese population using cohort data from a study in Kailuan. The analysis included 87,693 participants (age range, 18–98 years) free of atrial fibrillation at the baseline survey. Participants were divided into three categories according to self-reported sleep duration: ≤6.0 hours, 7 hours (ref), ≥8.0 hours. Atrial fibrillation diagnosis was made on a standard 12-lead electrocardiogram and via self-reported history. Cox proportional hazards models were used to calculate hazard ratio (HR) and confidence interval (CI) for atrial fibrillation, according to sleep duration. During median follow-up of 7.89 (range, 6.36–8.57) years, 322 cases of atrial fibrillation had occurred. Using 7 hours of sleep as the reference group, multivariable adjusted HRs (95% CI) for atrial fibrillation were 1.07 (0.75–1.53), 1.0 (ref), and 1.50 (1.07–2.10), from lowest to highest category of sleep duration. Secondary analysis showed no evidence of interactions between sleep duration and sex and snoring on the risk of incident atrial fibrillation (p = 0.75/0.25). We conclude long sleep duration may be a potential predictor/marker for incident atrial fibrillation.

The association between sleep duration and physical performance in Chinese community-dwelling elderly

Background

Physical performance is an important healthy factor in elder people. Good living habits, which include sleep, can maintain physical strength and physical performance. The aim of the present study was to conduct a cross-sectional study to determine the association between total sleep duration and physical performance.

Methods

Our study population comprised residents of the township central hospital in the suburban of Tianjin, China. We measured muscle strength, walk speed and balance function by grip, 4-m walk test and timed up and go test (TUGT). We divided sleep duration into four groups <7h, 7-8h, >8-9h, >9h.

Results

A total 898 participants had completed data (392 men and 506 women, mean age 67.71 years). In man, adjusted sleep duration was associated with lower grip in > 9 h group, the mean value (95% CI) was 0.429 (0.409, 0.448), and longer TUGT time was also associated with long sleep duration, 10.46s (9.97 s, 10.95 s). In women, adjusted slower 4-m walk speed present an inverse U-shaped relation with sleep duration, by 0.93 m/s (0.86 m/s, 0.98 m/s), 0.97 m/s (0.96 m/s, 1.00 m/s), 0.97 m/s (0.95 m/s, 0.99 m/s) and 0.92 m/s (0.89 m/s, 0.96 m/s); longer TUGT time were associated with long sleep duration (> 9 h), by 11.23 s (10.70 s, 11.77 s).

Conclusion

In Chinese community-dwelling elderly, lower muscle strength and lower balance function were associated with long sleep duration in men. Slower walk speed and lower balance function were associated with long sleep duration in women.