Both habitual short sleepers and long sleepers are at greater risk of obesity: a population-based 10-year follow-up in women

Sleep deprivation in development of obesity, effects on appetite regulation, energy metabolism, and dietary choices

Sleep deprivation, which is a decrease in duration and quality of sleep, is a common problem in today's life. Epidemiological and interventional investigations have suggested a link between sleep deprivation and overweight/obesity. Sleep deprivation affects homeostatic and non-homoeostatic regulation of appetite, with the food reward system playing a dominant role. Factors such as sex and weight status affect this regulation; men and individuals with excess weight seem to be more sensitive to reward-driven and hedonistic regulation of food intake. Sleep deprivation may also affect weight through affecting physical activity and energy expenditure. In addition, sleep deprivation influences food selection and eating behaviours, which are mainly managed by the food reward system. Sleep-deprived individuals mostly crave for palatable energy-dense foods and have low desire for fruit and vegetables. Consumption of meals may not change but energy intake from snacks increases. The individuals have more desire for snacks with high sugar and saturated fat content. The relationship between sleep and the diet is mutual, implying that diet and eating behaviours also affect sleep duration and quality. Consuming healthy diets containing fruit and vegetables and food sources of protein and unsaturated fats and low quantities of saturated fat and sugar may be used as a diet strategy to improve sleep. Since the effects of sleep deficiency differ between animals and humans, only evidence from human subject studies has been included, controversies are discussed and the need for future investigations is highlighted.

Sex differences in the relationship between short sleep duration and obesity among koreans

This cross-sectional study examined the relationship between short sleep duration and obesity by analysing data from 3,950 participants aged 40-69 years who took part in the 2003-2004 follow-up survey of the Korean Genome and Epidemiologic Study. Based on the subjective experience of morning fatigue, short sleep duration was defined as < 5 h of sleep. Short sleep duration was significantly associated with general obesity, as measured by body mass index (adjusted odds ratios [confidence intervals], 1.246 [1.016-1.529]); these associations became stronger as the severity of general obesity worsened. Analysing data separately by sex, we detected a relationship between short sleep duration and general obesity in females only. Considering the impact of age, the relationship was detected only in females aged 40-59 years old. In females aged 40-59 years, both general obesity (1.518 [1.110-2.075]) and neck obesity (1.425 [1.045-1.945]) were associated with short sleep duration. Our study established a correlation between short sleep duration and general obesity, specifically in females and those aged 40-59 years. This finding highlights the importance of adequate sleep to treat and prevent obesity in this demographic group.

A Prospective Study on Lifestyle Factors, Body Mass Index Changes, and Lipitension Risk in Japanese Young and Middle-Aged Women

Background: This study investigates how lifestyle factors and westernization contribute to obesity and examines the influence of body mass index (BMI) changes and lifestyle factors on "lipitension," a significant risk factor for heart disease and metabolic syndrome. Methods: This prospective study focused on women aged 20-64 without pre-existing hypertension and dyslipidemia who underwent regular medical checkups between April 2016 and March 2022. Anthropometric measurements and blood pressure, along with low-density lipoprotein, high-density lipoprotein, and triglycerides levels, were assessed. Results: Over an average 46.5-month follow-up, 11.5% of initially healthy young and middle-aged women developed lipitension. Categorizing participants based on BMI changes revealed stable (63.8%), decreased (12.5%), and increased (23.8%) groups within this 11.5%. Increased BMI is linked with a heightened hazard risk for lipitension. Women with increased BMI who refrained from snacking (aHR [95% confidence interval (CI)] = 2.750 [1.433-5.279]), avoided late-night eating (aHR [95% CI] = 1.346 [1.032-1.754]), and engaged in alcohol consumption (aHR [95% CI] = 2.037 [1.138-3.646]) showed an elevated risk. Conversely, within the decreased BMI group, behaviors like skipping breakfast (aHR [95% CI] = 0.190 [0.047-0.764]), eating quickly (aHR [95% CI] = 0.457 [0.215-0.972]), and not eating late (aHR [95% CI] = 0.665 [0.467-0.948]) were associated to a reduced lipitension. Subgroup analysis for women with BMI <23 revealed specific behaviors influencing lipitension risk in both BMI-increased and BMI-stable groups. Conclusion: Customized interventions, including for women with BMI <23, enhance heart health, mitigating global lifestyle diseases and obesity.

Short sleep duration is associated with higher risk of central obesity in adults: A systematic review and meta-analysis of prospective cohort studies

Background and Objective

The relationship between sleep duration and obesity has been the focus of numerous investigations. This systematic review and meta-analysis of prospective cohort studies aimed to assess the relationship between sleep duration, abdominal obesity, and body composition.

Methods

PubMed, Scopus, and Web of Science were searched until February 2024. Cohort studies that assessed the relationship between sleep duration at night and central obesity measures or body composition indices in adults were included. The quality of studies was assessed using the Newcastle-Ottawa scale. Random-effects meta-analysis was conducted on studies that reported risk ratio (RR) and 95% confidence intervals (CIs).

Results

Eighteen studies were eligible to be included. Eleven out of the 18 studies were not included in the analysis as 10 studies did not report RR, and in one study, the definition of short and normal sleep duration was different from others. The results of the meta-analysis indicated that short sleep duration was significantly associated with abdominal obesity (RR = 1.08; 95% CI: 1.04-1.12; I 2 = 49.1%, n = 7), but long sleep duration was not (RR = 1.02; 95% CI: 0.83-1.24; I 2 = 98.2%, n = 6).

Conclusions

Short sleep duration was associated with a slightly higher risk of central obesity, while long sleep duration was not.

Examining Physical Wellness as the Fundamental Element for Achieving Holistic Well-Being in Older Persons: Review of Literature and Practical Application in Daily Life

This review examines the impact of physical activity, nutrition, and sleep evaluations on the physical wellness (PW) and overall well-being of older individuals. A comprehensive search was conducted in databases like PubMed, Google Scholar, and EBSCO Information Services. The search spanned from January 2000 to December 2022, resulting in 19,400 articles, out of which 98 review articles met the inclusion criteria. Through the analysis of these articles, key characteristics of the literature were summarized, and opportunities to enhance the practical application of physical activity (PA), nutrition, and sleep evaluations in the daily lives of older persons were identified. Regular physical activity is crucial for older persons to maintain their physical, mental, and emotional well-being and prevent age-related health issues. Older persons have specific nutritional needs, including increased protein, vitamin D, calcium, and vitamin B12 intake. Poor sleep quality in older persons is associated with negative health outcomes such as cognitive decline, physical disability, and mortality. This review emphasizes the significance of considering physical wellness as a fundamental element for achieving holistic well-being in older persons and highlights the importance of physical activity, nutrition, and sleep evaluations in improving their overall health and well-being. By understanding and implementing these findings, we can enhance the quality of life and promote healthy aging in older persons.

Impact of Sleep Duration and Chronotype on Cardiac Structure and Function: The UK Biobank Study

Sleep duration and chronotype have been associated with increased morbidity and mortality. We assessed for associations between sleep duration and chronotype on cardiac structure and function. UK Biobank participants with CMR data and without known cardiovascular disease were included. Self-reported sleep duration was categorized as short (<7 h/d), normal (7-9 h/d) and long (>9 h/d). Self-reported chronotype was categories as "definitely morning" or "definitely evening." Analysis included 3903 middle-aged adults: 929 short, 2924 normal and 50 long sleepers; with 966 definitely-morning and 355 definitely-evening chronotypes. Long sleep was independently associated with lower left ventricular (LV) mass (-4.8%, P = 0.035), left atrial maximum volume (-8.1%, P = 0.041) and right ventricular (RV) end-diastolic volume (-4.8%, P = 0.038) compared to those with normal sleep duration. Evening chronotype was independently associated with lower LV end-diastolic volume (-2.4%, P = 0.021), RV end-diastolic volume (-3.6%, P = 0.0006), RV end systolic volume (-5.1%, P = 0.0009), RV stroke volume (RVSV -2.7%, P = 0.033), right atrial maximal volume (-4.3%, P = 0.011) and emptying fraction (+1.3%, P = 0.047) compared to morning chronotype. Sex interactions existed for sleep duration and chronotype and age interaction for chronotype even after considering potential confounders. In conclusion, longer sleep duration was independently associated with smaller LV mass, left atrial volume and RV volume. Evening chronotype was independently associated with smaller LV and RV and reduced RV function compared to morning chronotype. Sex interactions exist with cardiac remodeling most evident in males with long sleep duration and evening chronotype. Recommendations for sleep chronotype and duration may need to be individualized based on sex.

Genetic impact on the association of sleep patterns and chronic kidney disease: A prospective cohort study of 157,175 UK Biobank participants

OBJECTIVES

The association between sleep pattern and chronic kidney disease (CKD) incidence, and whether the association is dependent on the genetic backgrounds has not been addressed. We sought to investigate the association of multidimensional sleep pattern with CKD in consideration of genetic polymorphisms.

METHODS

In this prospective cohort study of 157,175 participants from the UK Biobank, sleep patterns were derived by multiple correspondence analysis (MCA) and k-means clustering of individual sleep traits (sleep duration, insomnia, chronotype, daytime sleepiness, snoring, and night shift status). Cox proportional hazard regression was used to estimate the association between sleep patterns and CKD incidence. Gene-environment-wide interaction study (GEWIS) was performed to detect whether gene polymorphisms were modifiers on this association.

RESULTS

Compared with "healthy sleep" pattern, increased CKD incidence was observed in the clusters with "long sleep duration" (hazard ratios (HR) 1.42, 95% confidence intervals (CI), 1.18-1.72) and "night shift" (HR 1.23, 95% CI, 1.05-1.45) patterns, but not with the "short sleep duration" pattern. By GEWIS, we identified 167 SNPs as suggestive effect modifiers that interacted with unhealthy sleep patterns and affected the risk of CKD.

CONCLUSIONS

Unhealthy sleep patterns, with features of long sleep duration and night shift, may increase the risk of CKD. The study highlights the interaction of sleep and individual genetic risk to affect health outcomes.

Longitudinal associations between sleep and BMI in a low-income, predominantly Black American sample

OBJECTIVE

Black individuals and those experiencing socioeconomic disadvantage are at increased risk for sleep problems and obesity. This study adds to the limited extant literature examining longitudinal associations between objectively measured sleep and changes in body mass index (BMI) in Black Americans.

DESIGN

We focused on individuals with at least 1 observation of sleep and BMI at 1 of 3 study time points (2013, 2016, and 2018). We modeled longitudinal trends in BMI as a function of time, average of each sleep variable across assessments, and within-person deviations in each sleep variable over time.

SETTING

Data were collected via interviewer-administered at-home surveys and actigraphy in Pittsburgh, PA.

PARTICIPANTS

Our sample comprised 1115 low-income, primarily Black adults, including 862 women and 253 men.

MEASUREMENTS

Sleep measures included actigraphy-measured total sleep time, sleep efficiency, and wakefulness after sleep onset, as well as self-reported sleep quality. We also included objectively measured BMI.

RESULTS

In models adjusted for age, gender, and other sociodemographic covariates (eg, income, marital status), there were no significant longitudinal associations between total sleep time, sleep efficiency, wakefulness after sleep onset, or subjective sleep quality and changes in BMI.

CONCLUSIONS

This study provides further evidence that, among a sample of low-income Black adults, sleep problems are not longitudinally predictive of BMI. Although ample cross-sectional evidence demonstrates that sleep problems and obesity commonly co-occur, longitudinal evidence is mixed. Better understanding the overlap of sleep and obesity over time may contribute to prevention and intervention efforts.

Association between visual impairment and sleep duration in college students: A study conducted in UAE and Lebanon

Objective: To examine whether self-reported sleep duration and visual impairment were associated among College students. Participants: Students (n = 1002, age 17-35 years) from Lebanon and the United Arab Emirates. Methods: Students were asked to complete a validated questionnaire between October 2018 and May 2019. The questions were related to sociodemographics, lifestyle characteristics, visual impairment status, sleeping pattern, mobile-phone use and chronic conditions. Results: 18.3% of the respondents reported to suffer from visual impairment. Among them, 72.7% were females (p < .001), 65% admitted to frequently use mobile phones before sleeping (p < .001), 54.6% reported to sleep less than 7 h (p = .008) and 71.6% reported to suffer from sleep disturbances (p = .05). Visual impairment was associated with poor sleep quality (p < .001), mobile phone use before sleeping (p < .01) and daily stress (p < .05). Conclusion: Visual impairment in college students is associated with short sleep duration, mobile phone use before sleeping and stress level.

Associations between Sleep Duration and Anthropometric Indices of Adiposity in Female University Students

OBJECTIVES

To examine associations between sleep duration as well as time of going to sleep and anthropometric indices related to the amount and distribution of adiposity.

MATERIAL

A total of 969 female university students, aged 19-24 years.

METHODS

Participants self-reported their sleep duration. Body weight, height, and waist circumference were measured. BMI, WHR and WHtR were calculated. Statistical analyses of results involved logistic regression models. Socioeconomic status and level of stress were added as covariates.

RESULTS

In 15% of the sample, sleep was too short (<6 h), and 10% slept too long (>8 h). Compared to women who followed the recommended sleep duration, among short sleepers, both underweight and overweight were more frequent, while long sleepers were more likely to be overweight. A higher prevalence of abdominal obesity and increased risk of metabolic syndrome were observed in both short and long sleepers than in recommended sleepers. Irregular sleep times were connected with higher OR, both for BMI < 18.5 and BMI > 25, for WC > 80, and WHtR below 0.4 and above 0.5. Irregular sleep times also led to an increased risk of metabolic diseases prevalence.

CONCLUSIONS

Both too long and too short sleep increases the risk of overweight, obesity and abdominal obesity and, as a consequence, the risk of metabolic syndrome in young women.

Association of sleep duration and insomnia with metabolic syndrome and its components in the Women's Health Initiative

BACKGROUND

Epidemiological evidence suggests that inadequate sleep duration and insomnia may be associated with increased risk of metabolic syndrome (MetS). However, longitudinal data with repeated measures of sleep duration and insomnia and of MetS are limited. We examined the association of sleep duration and insomnia with MetS and its components using longitudinal data from the Women's Health Initiative (WHI).

METHODS

The study included postmenopausal women (ages 50-79 years) diabetes-free at enrollment in the WHI, with baseline data on sleep duration (n = 5,159), insomnia (n = 5,063), MetS, and its components. Repeated measures of self-reported sleep duration and insomnia were available from years 1 or 3 of follow-up and of the MetS components from years 3, 6 and 9. Associations were assessed using logistic regression and generalized estimating equations models, and odds ratios and 95% confidence intervals (CI) adjusted for major risk factors were calculated.

RESULTS

In cross-sectional analysis, baseline sleep duration ≥ 9 h was positively associated with MetS (OR = 1.51; 95%CI 1.12-2.04), while sleep duration of 8- < 9 h was associated with waist circumference > 88 cm and triglycerides ≥ 150 mg/dL (OR = 1.18; 95%CI 1.01-1.40 and OR = 1.23; 95%CI 1.05-1.46, respectively). Insomnia had a borderline positive association with MetS (OR = 1.14; 95%CI 0.99-1.31), and significant positive associations with waist circumference > 88 cm and glucose ≥ 100 mg/dL (OR = 1.18; 95%CI 1.03-1.34 and OR = 1.17; 95%CI 1.02-1.35, respectively). In the longitudinal analysis, change from restful sleep to insomnia over time was associated with increased odds of developing MetS (OR = 1.40; 95%CI 1.01-1.94), and of a triglyceride level ≥ 150 mg/dL (OR = 1.48; 95%CI 1.08-2.03).

CONCLUSIONS

Among postmenopausal women in the WHI, sleep duration and insomnia were associated with current and future risk of MetS and some of its components.

Associations between night-time sleep duration and fasting glucose and ratio of triglyceride to high-density lipoprotein cholesterol among adults free of type 2 diabetes or without diagnosed type 2 diabetes: a multicentre, cross-sectional study in China

OBJECTIVES

We aimed to assess the associations between night-time sleep duration and fasting glucose (FG), triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) ratio and body mass index (BMI) among adults free of type 2 diabetes (T2D) or without diagnosed T2D.

DESIGN

Cross-sectional study.

SETTING

Medical examination centres at six hospitals in Beijing-Tianjin-Hebei region, China.

PARTICIPANTS

Participants were recruited via multistage, stratified cluster sampling. We included adults free of T2D or without diagnosed T2D who attended for physical examination and completed the validated questionnaire. 32 497 participants were included in the study, of whom 52.50% were men.

PRIMARY AND SECONDARY OUTCOME MEASURES

FG, TG, HDL-C, height and weight were measured.

RESULTS

Overall, 12.80% and 9.67% reported night sleep duration <7 hours and ≥9 hours, respectively; 6.91% had elevated FG and 3.57% had undiagnosed T2D. Sleep duration had an independent, U-shaped associated with FG (β₁ (linear term)=-0.111, p=0.047; β₂ (quadratic term)=0.008, p=0.026) with 6.9 hours of sleep associated with the lowest FG and a negative association with BMI (β=-0.154, p<0.001). BMI mediated a U-shaped association of sleep duration with TG/HDL-C (β₁=-0.040, p=0.017; β₂=0.003, p=0.023).

CONCLUSIONS

Both short and long night-time sleep was associated with elevated FG, and short sleep duration was associated with increased BMI. BMI mediated a U-shaped association between sleep duration and TG/HDL-C.

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

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

Self-Reported Sleeping Time Effects on Physical Performance and Body Composition Among Spanish Older Adults: EXERNET-Elder 3.0 study

Objective: To determine the link between physical fitness and body composition with nocturnal and nap time in Spanish older adults. Methods: Eight hundred thirty older adults underwent several tests. Sleep was measured using Jenkins Sleep Scale. Nocturnal sleep was categorized (<7, 7-9, and >9 hours), and nap time (no nap, 1-30 minutes, and >30 minutes).Physical fitness was evaluated using validated tests, and body composition by electric bioimpedance. Results: 75.1% of participants were female, mean age 77.7 ± 5.1 years. Mean nocturnal sleep and nap time was 6.7 hours and 23.3 minutes, respectively. Models showed nocturnal sleep >9 hours was significant and positively associated with body shape index (Odds ratio[OR] = 4.07 (p = .011)) and waist circumference OR = 1.04 (p = .024) in females. Males' waist and hip circumference were positively significantly related to nap time between 1 and 30 minutes, OR = 1.08, p = .009 and OR = 1.08, p = .048, respectively. In females, nap time >30 minutes was associated with greater fat mass and body shape index OR = 1.22, p = .032 and OR = 3.95, p = .027, respectively. Physical fitness showed no associations with sleep outcomes. Conclusions: Sleep patterns do not influence physical fitness but body composition, being more related to female body composition as nocturnal and nap sleep were associated with higher fat mass, waist circumference and body shape index, while only short nap times were related to higher waist and hip circumference in males.

Sleep duration as an independent factor associated with vitamin D levels in the EPISONO cohort

STUDY OBJECTIVES

Obstructive sleep apnea and short sleep duration have been separately associated with inadequate serum 25-hydroxyvitamin D [25(OH)D] levels. However, whether these 2 factors may concurrently influence 25(OH)D in the general population is unknown. We hypothesized that both obstructive sleep apnea and short sleep duration would be independently associated with lower concentrations of 25(OH)D in a sex-dependent manner.

METHODS

In this cross-sectional study, 712 individuals, part of the prospective EPISONO cohort (Brazil), underwent polysomnography, answered sleep questionnaires, and had their blood collected for serum 25(OH)D quantification.

RESULTS

Individuals with a sleep duration of < 6 hours had 2-fold increased odds of 25(OH)D < 20 ng/mL compared with those who reported 6 or more hours of sleep, even after adjusting for confounding factors. Subset sex analysis revealed that men with a sleep duration of < 6 hours had 4-fold increased odds of 25(OH)D < 20 ng/mL. In women, short sleep duration was not associated with lower 25(OH)D levels. The presence of obstructive sleep apnea (as classified according to the individual's apnea-hypopnea index) was not independently related to 25(OH)D concentrations in men or women. Sleep parameters, including sleep latency and sleep efficiency, had no association with 25(OH)D < 20 ng/mL.

CONCLUSIONS

Short sleep, but not apnea-hypopnea index, was an independent factor associated with low 25(OH)D serum levels in men, but not in women. Apnea-hypopnea index scores were not associated with 25(OH)D levels in either sex. These results raise the possibility of investigating sex-specific characteristics, such as gonadal hormone regulation, and re-evaluating obstructive events by classifying them in mild, moderate, and severe obstructive sleep apnea.

CITATION

de Oliveira DL, Dokkedal-Silva V, Fernandes GL, Kim LJ, Tufik S, Andersen ML. Sleep duration as an independent factor associated with vitamin D levels in the EPISONO cohort. J Clin Sleep Med. 2021;17(12):2439-2449.

Overweight and Obesity are Potential Risk Factors for Disrupted Nocturnal Sleep in Iranian Adults: A Cross-Sectional Study

Objectives: Obesity is a risk factor for several chronic conditions, including sleep disorders. We aimed to analyze the relationship between BMI, body fat percentage (FAT%), hip and waist circumference, and weight on the duration of nocturnal sleep. Methods: This study was part of the MASHAD cohort study. In all participants BMI and FAT% were measured. BMI was used to categorize individuals as obese, overweight, and normal subjects. FAT% was used to categorize individuals into tertile: tertile 1 (low) < 27.5, tertile 2 (medium) 27.5-41, and tertile 3 (high) > 41. The level of nightly sleep duration was categorized into three groups: <6, 6-8 (reference group), and >8 h. Results: There was a significant inverse association between body weight and duration of sleep (p < 0.05). Obese and overweight participants had 1.152 OR (CI:1.083-1.225) and 1.126 OR (CI:1.063-1.194) for a short duration of nocturnal sleep, respectively, relative to those with a normal BMI. Conclusion: BMI was an independent determinant of nocturnal sleep duration; obesity and overweight may have negative consequences on sleep duration. Weight control should be considered as a factor in adjusting sleep quality.

Is self-reported short sleep duration associated with obesity? A systematic review and meta-analysis of cohort studies

CONTEXT

A possible association between self-reported short sleep duration and risk of obesity has been studied.

OBJECTIVE

To analyze the association between sleep duration and obesity.

METHODS

The LILACS, Medline, Central, Embase, and OpenGrey databases were searched from inception until July 2020. Two authors screened the studies independently according to the PECO strategy, as follows: participants: > 18 years old; exposure: short sleep duration; control: regular sleep; outcome: obesity). Only cohort studies were included. A total of 3286 studies were retrieved with the search strategy, but only 36 were included. Disagreements were resolved by a third author. The quality of studies was assessed with Newcastle-Ottawa Quality Assessment Form for Cohort Studies. The certainty of the evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation.

RESULTS

Thirty-six studies were included, and 22 contributed quantitative data. Most of the studies (n = 27) assessed sleep by self-report. The meta-analysis showed a significant association between self-reported short sleep and development of obesity, and the chances of developing obesity increased when self-reported sleep duration decreased.

CONCLUSIONS

Self-reported short sleep was significantly associated with a higher incidence of obesity, with moderate quality of evidence.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42019130143.

COVID-19 Self-quarantine and Weight Gain Risk Factors in Adults

PURPOSE OF REVIEW

The COVID-19 pandemic is associated with weight gain in certain individuals. This review highlights the risk factors for weight gain during COVID-19 self-quarantine in adults.

RECENT FINDINGS

Among those who have gained weight during COVID-19 self-quarantine, self-reported body weight has increased between .5 and 1.8 kg (± 2.8 kg) after just 2 months of quarantine. Identified risk factors for weight gain during COVID-19 self-quarantine are the following: increased sedentary behaviors, decreased physical activity, increased snacking frequency (particularly after dinner), increased alcohol intake, decreased water intake, emotional eating, decreased sleep quality, and being overweight/obese. Having identified risk factors for weight gain during the COVID-19 pandemic, practitioners and researchers should devise plans to assist those who have gained weight to re-learn weight management/weight loss strategies.

Nutrition Habits of Polish Nurses: An Approach

BACKGROUND

Chronic stress, unlimited working time and the shift working system as well as sleep deficiency may lead to the occurrence of nutrition disorders among nurses.

AIM

The aim of the paper was an assessment of the nutrition habits of nurses. It was an observational study conducted from June 2017 to May 2018 among nurses (n = 1080) in Silesia in Poland. Data was obtained using a range of questionnaires.

RESULTS

Body mass index (BMI) of the analysed nurses demonstrated overweight/obesity in 490 (45.5%) of them. Nearly all the diets of the analysed nurses (n = 1021; 94.5%) required improvement. Younger nurses (<31 years old) demonstrated a greater tendency to indulge in habitual overeating, and those having additional employment demonstrated poorer nutrition habits compared to those without additional employment.

CONCLUSION

The analysed nurses made numerous dietary mistakes which, as a consequence, can lead to obesity. Emotional overeating was the dominant nutrition habit in the studied group of nurses. Nurses who were overweight/obese, nurses who had additional employment and younger nurses demonstrated tendencies toward improper nutrition choices, i.e., the tendency to overeat or restrain oneself from eating.

Sleep duration is associated with protein biomarkers for cardiometabolic health: A large-scale population study

Sleep problems and short sleep duration have been linked to adverse health effects, such as cardiovascular disease and diabetes, but the mechanisms are not fully understood. Finding biomarkers could explain mechanistic pathways and help in understanding relationships between sleep and cardiometabolic health. The aim was to assess if sleep duration and sleep quality affect the cardiometabolic-related protein profile. In total, 242 proteins related to cardiometabolic health were measured in 2,430 plasma samples (male:female ratio 1:1, aged 45-75 years) from the population-based EpiHealth cohort, using a proximity extension assay. The association of self-reported sleep duration and sleep quality with each of the 242 proteins (primary outcome) was assessed with linear regression modelling, adjusting for confounders, and corrected for multiple testing using the false discovery rate (5%). Potential effect modification of age and sex was also tested using an interaction term. We identified U-shaped associations between sleep duration and the plasma levels of the proteins follistatin (more prominent in younger individuals), matrix metallopeptidase 9 (men only), urokinase receptor, adrenomedullin and kidney injury molecule, all previously known to be related to cardiovascular risk. There was no relationship between sleep quality and any of the proteins, after adjustment for confounders. These results give new leads to investigate the potential mechanistic pathways between sleep and cardiometabolic health.

The association between daily naps and metabolic syndrome: Evidence from a population-based study in the Middle-East

BACKGROUND

Daily naps are a common habit in many Middle Eastern and Asian countries; however, little is known about the association between daily naps and other health consequences, including the presence of metabolic syndrome (MetS).

METHODS

Participants were recruited from the Mashhad stroke and heart atherosclerotic disorders study. We defined MetS according to International Diabetes Federation criteria. Nighttime sleeping hours were categorized into three categories: <6, 6-8, and >8 hours. Using logistic regression models, we analyzed the association between the duration of night-time sleep and daily naps with MetS and its different components.

RESULTS

A total of 9652 individuals were included in the study: 3859 with MetS (40%) and 5793 without MetS (60%), as the control group. Of all, 72% participants had a regular daily nap. Those with daily naps had a higher odd of MetS [Odds ratio:1.19, confidence interval: (1.08-1.33); P < .001]. We also observed significantly higher odds of obesity, central obesity, hypertriglyceridemia, and diabetes or impaired fasting glucose in these subjects. Men sleeping <6 hours per night had a lower odd of MetS. However, we observed higher odds of cardiovascular risk factors in participants sleeping <6 hours, including obesity and diabetes or IFG.

CONCLUSION

Napping is a common habit in middle Eastern countries. Although the cross-sectional design of our study cannot prove causality, we observed a significant association between the presence of MetS and daily naps. The public should be aware of this possibility and be educated about the importance of sleeping patterns.

Sleep and Obesity: Mechanisms of Association

Epidemiologic studies demonstrate that both prolonged and reduced sleep duration is associated with increased risk of excessive weight and obesity. The aim of the review was to analyze probable mechanisms of association of sleep duration and obesity elucidated in current scientific literature. Several proposed mechanisms of such an association exist: an imbalance of appetite regulating hormones resulting from decreased sleep duration; fatigue or decreased activity during the daytime, leading to sedentary behavior with decreased energy expenditure; changes in eating behavior with increased daily calorie intake. The article gives a comprehensive review of factors, mediating the association of sleep duration and obesity (age, gender, ethnic origin), studies of neurohormonal regulation of sleep in association with obesity (the influence of sleep duration on thermoregulation, appetite center – increased grelin-to-leptin ratio); the relationship of sleep with growth hormone and insulin-like growth factor-1, with hypothalamic-pituitary-adrenal axis, and non-hormonal factors, stimulating food intake. Data indicating that increased sleep duration is often associated with decreased sleep quality are presented. Besides traditional risk factors – unhealthy diet and decreased physical exercise, specific attention should be given to the problems, associated with sleep disorders to increase the efficacy of treatment and prevention of obesity.

Sleep duration and obesity in adulthood: An updated systematic review and meta-analysis

Short and long sleep duration have been associated with risk of obesity in children and adolescents. Evidence in adults is more mixed, with biological and psychosocial factors underlying these relationships mostly unknown. This review aimed at qualitatively and quantitatively summarizing previous studies on sleep duration as a predictor of obesity in adults in order to provide an update of the state of art in this field and clarify these relationships. Odds ratios at 95% Confidence Intervals (CI) were estimated using random-effects models. Heterogeneity of effects distribution and publication bias were tested. Twelve articles were selected for short sleep (n = 154,936) and eight for long sleep duration (n = 152,192). Results indicated that short sleep duration (OR: 1.412; 95% CI: 1.177-1.694) was significantly associated with the risk of future obesity, and that long sleep duration (OR: 0.995; 95% CI: 0.889-1.114) was not associated. Heterogeneity was high and lowered to non-significant values when considering gender and extremes of short/long sleep duration. Results seem to confirm a potential role of short sleep duration in predicting but results on long sleep are still mixed. Future investigations on potential mediators of such relationships are needed.

Association of Sleep Duration with Weight Gain and General and Central Obesity Risk in Chinese Adults: A Prospective Study

OBJECTIVE

Evidence on the association between sleep duration and obesity among adults is inconsistent. Prospective studies investigating the association in Chinese adults have been limited. This study aims to prospectively evaluate sleep duration in relation to subsequent weight gain and general and central obesity risk among Chinese adults.

METHODS

A total of 21,958 participants aged 30 to 79 years reported their daily sleep duration. Obesity indicators were objectively measured; then significant weight gain (≥ 5 kg) and general and central obesity were modeled as the outcome. Logistic regression models were used to estimate odds ratios and 95% CIs.

RESULTS

Average sleep duration was 7.5 hours at baseline. During 8.0 ± 0.8 years of follow-up, participants who reported sleeping ≤ 6 hours had higher risk for significant weight gain than those who slept 7 hours (multivariable-adjusted odds ratio: 1.13; 95% CI: 1.02-1.29). The association was stronger among those who were physically inactive at baseline (P = 0.04 for interaction). Short sleep duration was also associated with subsequent incident central obesity, with odds ratio of 1.13 (95% CI: 1.00-1.28), but not with incident general obesity (P = 0.31).

CONCLUSIONS

Compared with those who slept 7 hours per day, short sleepers had an increased risk of significant weight gain and central obesity.

Generational changes in young adults' sleep duration: a prospective analysis of mother-offspring dyads

OBJECTIVE

To quantify the changes in sleep duration over two generations of young adults.

METHODS

We used data from the Mater-University of Queensland Study of Pregnancy cohort to compare sleep duration in mother and offspring. The analyses were restricted to 1,731 mothers who were young adults (mean age 21.96 years; SD±1.90) at the baseline measurement, and their offspring who were about the same age (mean age 20.6 years; SD±0.86) when assessed 21 years later. Maternal sleep was explored by asking the mother, during the first trimester, about her typical sleep duration prior to pregnancy, while offspring participants were asked about the sleep duration in the last month at the time assessed. Multinomial logistic regression for correlated responses was used to assess generational changes.

RESULTS

We found that offspring had 3.2 (2.7, 3.9) times the odds of sleeping for short duration (≤6 hours/night) and 1.7 (1.5, 1.9) times the odds of sleeping for a longer duration (≥9 hours/night) compared with their mothers. Gender-based analysis found that daughters had 3.0 (2.3, 5.0) times the odds of sleeping for a short duration, while sons had 3.4 (2.6, 6.4) times the odds of sleeping for a short duration compared with their mothers.

CONCLUSIONS

There is a significant decline in sleep duration below recommendations as well as a substantial increase in long-duration above the recommendations over two generations of young adults. Therefore, the focus of sleep health should not be limited to short sleep, but on the need for achieving optimal sleep recommended for the age.

Sleep duration is associated with healthy diet scores and meal patterns: results from the population-based EpiHealth study

STUDY OBJECTIVES

To investigate relationships between sleep duration and adherence to healthy diets, but also associations with meal patterns, in a large population-based cohort.

METHODS

Participants (n = 23,829, males and females, aged 45 to 75 years) from the Swedish EpiHealth cohort study were included in a cross-sectional analysis. The participants filled out an extensive Internet-based questionnaire, and also visited a test center for anthropometric measurements and blood sampling. Sleep duration was classified as short (< 6 h/night; n = 1,862), normal (6 to less fewer than 9 h/night; n = 19,907) and long sleep (≥ 9 h/night; n = 858). In addition, a combination variable of sleep duration (short/normal/long) and sleep quality (good/poor) was constructed, giving six categories. Adherence to a healthy diet was assessed using the modified Mediterranean diet (mMED) score and the Healthy Nordic Food Index (HNFI) score based on food groups from a food frequency questionnaire. A regular meal pattern was considered if the participant had breakfast, lunch and dinner on a daily basis.

RESULTS

Compared with normal sleepers, short sleepers displayed lower adherence to a healthy diet when using both the mMED score (adjusted odds ratio = 0.70; 95% confidence interval 0.56-0.88) and the HNFI score (0.70; 0.56-0.88). When combining sleep duration and sleep quality, short sleepers with poor sleep quality showed an independent relationship with low adherence to a healthy diet (0.67; 0.52-0.86) compared with normal sleepers with good sleep quality. In addition, both short sleepers (0.71; 0.62-0.82) and long sleepers (0.75; 0.62-0.91) showed low adherence to regular meal patterns, compared with normal sleepers. Furthermore, short sleepers with poor sleep quality had reduced odds of having a regular meal pattern (0.67; 0.57-0.79) as compared with normal sleepers with good sleep quality.

CONCLUSIONS

Short sleep duration combined with poor sleep quality is associated with low adherence to a healthy diet and regular meal patterns.

Healthy behaviors and incidence of overweight and obesity in military veterans

PURPOSE

Research suggests that U.S. veterans have a higher obesity prevalence than nonveterans and that weight gain is high after military discharge. Few studies have assessed the joint effects of health behaviors on obesity risk.

METHODS

We prospectively assessed the incidence of overweight and obesity in relation to multiple behaviors among U.S. veterans, with follow-up beginning 2-3 years after military discharge. Self-reported physical activity, sedentary time, fast-food intake, sleep duration, smoking status, and alcohol use were categorized as "healthy" based on recommendations or prior literature. Multivariable Cox models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for overweight/obesity (body mass index [BMI] ≥25 kg/m²) and obesity (BMI ≥30 kg/m²) in relation to healthy behaviors.

RESULTS

Among 11,025 participants with baseline BMI of 18.5-24.9 kg/m², those reporting at least five of six healthy behaviors had 36% lower overweight/obesity risk compared with those reporting 0 or one healthy behavior (RR, 0.64; 95% CI, 0.54-0.74). Among 17,583 participants with baseline BMI of 25.0-29.9 kg/m², obesity risk was 38% lower for those with at least five of six relative to 0 or one healthy behavior (RR, 0.62; 95% CI, 0.54-0.72).

CONCLUSIONS

Self-reporting multiple healthy behaviors was associated with reduced overweight/obesity rates. Further research is warranted to determine whether interventions targeting several health behaviors may be more effective in reducing obesity among military veterans than interventions targeting one behavior.

Sedentary Time, Physical Activity, and Sleep Duration: Associations with Body Composition in Fibromyalgia. The Al-Andalus Project

To explore the individual–independent relationships of sedentary time (ST) and physical activity (PA) (light and moderate-to-vigorous intensity (MVPA)), with sleep duration and body composition (waist circumference, body mass index (BMI), body fat percentage, and muscle mass index) in women with fibromyalgia, and to determine whether these associations are independent of physical fitness. This cross-sectional study involved 385 women with fibromyalgia. ST and PA were assessed by triaxial accelerometry, sleep duration was self-reported. Waist circumference was measured using an anthropometric tape, and body weight, body fat percentage, and muscle mass were estimated using a bio-impedance analyzer. In individual regression models, ST and sleep were directly associated with waist circumference, BMI, and body fat percentage (β between 0.10 and 0.25; all p < 0.05). Light PA and MVPA were inversely associated with waist circumference, BMI, and body fat percentage (β between −0.23 and −0.12; all p < 0.05). In multiple linear regression models, ST (β between 0.17 and 0.23), light PA (β between −0.16 and −0.21), and sleep duration (β between 0.11 and 0.14) were independently associated with waist circumference, BMI, and body fat percentage (all p < 0.05). MVPA was associated with waist circumference independent of light physical activity (LPA) and sleep duration (β = −0.11; p < 0.05). Except for MVPA, these associations were independent of physical fitness. These results suggest that longer ST and sleep duration, and lower PA levels (especially light intensity PA), are independently associated with greater adiposity, but not muscle mass, in women with fibromyalgia. These associations are, overall, independent of physical fitness.

Long sleep duration predicts a higher risk of obesity in adults: a meta-analysis of prospective cohort studies

BACKGROUND

The connections between long sleep duration and obesity or weight gain warrant further examination. This meta-analysis aimed to evaluate whether long sleep duration was associated with the risk of obesity, weight gain, body mass index (BMI) change or weight change in adults.

METHODS

PubMed, Embase, Cochrane Library, Elsevier Science Direct, Science Online, MEDLINE and CINAHL were searched for English articles published before May 2017. A total of 16 cohort studies (n = 329 888 participants) from 8 countries were included in the analysis. Pooled relative risks (RR) or regression coefficients (β) with 95% confidence intervals (CI) were estimated. Heterogeneity and publication bias were tested, and sensitivity analysis was also performed.

RESULTS

We found that long sleep duration was associated with higher risk of obesity (RR [95% CI] = 1.04 [1.00-1.09], P = 0.037), but had no significant associations with weight gain, BMI change or weight change. Long sleep duration increased the risk of weight gain in three situations: among men, in studies with <5 years follow-up, and when sleep duration was 9 or more hours.

CONCLUSIONS

Long sleep duration was associated with risk of obesity in adults. More cohort studies with objective measures are needed to confirm this relationship.

Sleep and weight loss in low-income overweight or obese postpartum women

Background

We conducted secondary data analyses to examine the associations between sleep duration, sleep quality, sleep disturbance and ≥ 5% of weight loss in low-income overweight or obese postpartum women enrolled in a community-based lifestyle behavior intervention study aimed at prevention of weight gain.

Methods

Participants were recruited from the Special Supplemental Nutrition Program for Women, Infants, and Children in Michigan. The Pittsburgh Sleep Quality Index was used to assess sleep duration, sleep quality, and sleep disturbance. All participants were assessed and weighed at baseline (T1, 569 participants), 4-month (T2, 367 participants), and 7-month from T1 (T3, 332 participants). Descriptive statistics and mixed-effects regression analysis were performed.

Results

Participants reported longer sleep duration (p = 0.048), better sleep quality (p = 0.003) and less sleep disturbance (p < 0.001) over time. There were no significant mean body weight changes at T2 and T3. However, a significantly higher proportion of women lost ≥5% of body weight at T3 (23.1%) than T2 (12.5%, p = 0.001). Sleep duration, quality, and disturbance were not significantly associated with ≥5% of weight loss.

Conclusion

Improvements in sleep duration, sleep quality and sleep disturbance over time were not associated with ≥5% of weight loss in low-income overweight or obese postpartum women.

Trial registration

Clinical Trials NCT01839708; retrospectively registered February 28, 2013.

Association Between Self-Reported Sleep Duration and Body Composition in Middle-Aged and Older Adults

STUDY OBJECTIVES

The current study sought to examine whether self-reported sleep duration is linked to an adverse body composition in 19,709 adults aged 45 to 75 years.

METHODS

All variables used in the current study were derived from the Swedish EpiHealth cohort study. Habitual sleep duration was measured by questionnaires. Body composition was assessed by bioimpedance. The main outcome variables were fat mass and fat-free mass (in kg). Analysis of covariance adjusting for age, sex, fat mass in the case of fat-free mass (and vice versa), leisure time physical activity, smoking, and alcohol consumption was used to investigate the association between sleep duration and body composition.

RESULTS

Short sleep (defined as ≤ 5 hours sleep per day) and long sleep (defined as 8 or more hours of sleep per day) were associated with lower fat-free mass and higher fat mass, compared with 6 to 7 hours of sleep duration (P < .05).

CONCLUSIONS

These observations could suggest that both habitual short and long sleep may contribute to two common clinical phenotypes in middle-aged and older humans, ie, body adiposity and sarcopenia. However, the observational nature of our study does not allow for causal interpretation.

Sleep Patterns and Obesity: Hispanic Community Health Study/Study of Latinos Sueño Ancillar Study

BACKGROUND

The relationship of poor sleep patterns to the increased risk of obesity has been reported, but the results are variable. This study evaluated the association between objectively measured sleep patterns and obesity in a representative adult population of Hispanic/Latino subjects living in the United States.

METHODS

This cross-sectional study was an analysis of a multicenter, community-based cohort of 2,156 participants aged 18 to 64 years from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Recruitment was conducted in San Diego, California; Chicago, Illinois; Bronx, New York; and Miami, Florida. Models were controlled for age, sex, ethnic background, site, income, education, and apnea-hypopnea index. Seven days of wrist actigraphy data were collected. Obesity was defined as BMI ≥ 30 kg/m², and abdominal obesity was defined as waist circumference ≥ 88 cm in women and ≥ 102 cm in men. Napping was defined as more than one 15-min nap per week.

RESULTS

An inverse linear relationship was found between sleep duration and prevalence of obesity (P linear trend ≤ 0.01). A reduction of 1 h sleep increased obesity prevalence by 4.1% (95% CI, 1.6-6.6; P = .002) and abdominal obesity prevalence by 3.6% (95% CI, 1.1-6.1; P = .007). Daytime napping increased obesity prevalence by 10.4% (95% CI, 3.5-17.3; P = .004) and abdominal obesity prevalence by 7.1% (95% CI, 1.0-13.2; P = .02).

CONCLUSIONS

In a population of young to older adult Hispanic/Latino subjects, we found an inverse linear association between sleep duration and the prevalence of obesity. Daytime napping was strongly associated with greater adiposity. Interventional and longitudinal studies are needed to better understand how abnormal sleep patterns contribute to the obesity epidemic.

Sleep deprivation and obesity in adults: a brief narrative review

Background/aims

Obesity and sleep deprivation are two epidemics that pervade developed nations. Their rates have been steadily rising worldwide, especially in the USA. This short communication will explore the link between the two conditions and outline the proposed mechanisms behind their relationship.

Methods

Studies on the topic of sleep and obesity were reviewed, and findings were used to develop a theoretical model for the biological link between short sleep duration and obesity.

Results

Individuals who regularly slept less than 7  hours per night were more likely to have higher average body mass indexes and develop obesity than those who slept more. Studies showed that experimental sleep restriction was associated with increased levels of ghrelin, salt retention and inflammatory markers as well as decreased levels of leptin and insulin sensitivity.

Conclusions

There may be a link between obesity and sleep deprivation. We recommend further investigations are to elucidate the potential mechanisms.

Trends of self-reported sleep duration in Korean Adults: results from the Korea National Health and Nutrition Examination Survey 2007-2015

OBJECTIVE/BACKGROUND

Sleep plays a vital role in maintaining homeostasis and promoting individual health. This study aimed to investigate the trends of sleep duration in Korean adults.

PATIENTS/METHODS

We collected data from individuals who were adults (≥18 years) and participated in three cycles (2007-2009, 2010-2012, and 2013-2015) of the Korea National Health and Nutrition Examination Survey (KNHANES) for the analysis of self-reported sleep duration pattern. A total of 51,545 adults (21,937 men and 29,608 women) were included.

RESULTS

Sleep duration decreased among both men and women from 2007 to 2009 KNHANES to 2013-2015 KNHANES. Sleep duration differed by age group and sex. Moreover, sleep duration declined among middle-aged (30-49 years old) and older (50-64 years old) men and young (18-29 years old) and middle-aged (30-49 years old) women, although not among older and elderly women.

CONCLUSIONS

The young and middle-aged adult groups (18-49 years old) showed a significant decline in sleep duration in the KNHANES 2007-2015.

Association between sleep and overweight/obesity among women of childbearing age in Canada

OBJECTIVES

Tests of the relationship between sleep and overweight/obesity (OW/OB) among women have been inconsistent. Few studies reporting such associations have focused on women of childbearing age. This paper investigates this association among Canadian women of childbearing age.

METHODS

Data were from the Canadian Community Health Survey 2011-2014. The sample consisted of women aged 18-44 years. All variables were self-reported. Sleep duration was dichotomized as insufficient (< 7 h/night) or adequate (≥ 7 h/night). A composite score of sleep quality was used and dichotomized as poor none/little of the time or some/most/all of the time. Height and weight were used to calculate body mass index. Associations between sleep and OW/OB were assessed using logistic regression analyses with survey weights. Three models were computed for sleep duration/quality: model without covariates, model adjusted for demographics (age, ethnicity, level of education, household income, marital status, employment, parity, region, and season), and model adjusted for demographics and variables associated with OW/OB (mood disorder, fruit and vegetable intake, physical activity, smoking, and alcohol).

RESULTS

Total sample consisted of 9749 women of childbearing age. Thirty-eight percent had insufficient sleep duration. Sleep duration was significantly associated with OW/OB in the model with no covariates and discriminated 52.8% of women of childbearing age, but this association was no longer significant in the models adjusted for covariates. Sleep quality was not significantly linked to OW/OB in any of the models.

CONCLUSION

Targeting sleep alone would likely not contribute to lower risk of OW/OB among Canadian women of childbearing age. Additional studies, especially longitudinal ones, are needed to confirm these findings.

Insomnia symptoms and sleep duration and their combined effects in relation to associations with obesity and central obesity

OBJECTIVE

Previous studies have shown that both sleep duration and insomnia have an impact on obesity and central obesity. However, studies of the joint effects of these sleep disorders are still sparse.

METHODS

The present study utilized data from the Swedish EpiHealth cohort study. Participants (45-78 y) were asked to fill out an internet-based questionnaire. Body mass index (BMI) and central obesity (calculated from waist circumference) were based on measured data.

RESULTS

A total of 18,823 participants (mean age = 60 ys) were included in this study. The reported prevalence of short (<6 h/night) and long (>9 h/night) sleep duration was 8% and 4% respectively, and insomnia symptoms was 19%. Of the study population, 16% were obese (BMI ≥ 30 kg/m²) and 40% had central obesity. There was a U-shaped association between sleep duration and obesity and central obesity, and significant associations between insomnia symptoms and obesity. When stratifying sleep duration by concurrent insomnia symptoms, there were associations (odds ratios, (95% confidence intervals)) between the combination of both short (1.48, (1.22-1.80)) and long sleep duration (1.77 (1.00-3.16)) with insomnia symptoms and obesity and central obesity (1.36 (1.16-1.61) and 2.44 (1.41-3.24) respectively). However, there was no significant association between insomnia symptoms and obesity or central obesity in participants with normal sleep duration. For central obesity there was an association with long sleep duration regardless of insomnia symptoms, while the association with short sleep duration was significant only if insomnia symptoms were present.

CONCLUSIONS

Both short and long sleep duration, as well as insomnia symptoms, are associated with obesity and central obesity. There is an important joint effect of sleep duration and insomnia symptoms and there is no association between insomnia symptoms and obesity, as long as a normal sleeping time can be attained. This indicates that sleep duration rather than insomnia symptoms per se is of importance for the relationship between sleep and obesity.

Associations Among Sleep, Body Mass Index, Waist Circumference, and Risk of Type 2 Diabetes Among U.S. Childbearing-Age Women: National Health and Nutrition Examination Survey

BACKGROUND

Women of childbearing age (18-44 years) present an important group for understanding sleep, but few studies have focused on this population. No study has investigated the associations among sleep, overweight/obesity, and risk of type 2 diabetes among childbearing-age women in the National Health and Nutrition Examination Survey (NHANES).

METHODS

Data were from NHANES, 2005-2008. The study population consisted of 18-44 year old women. Pregnant women and those diagnosed with sleep disorders were excluded. Sleep duration and quality were self-reported. Body mass index (BMI), waist circumference (WC) measurements, and a 2-hour 75 g oral glucose tolerance test (OGTT) were performed by trained NHANES staff. An unadjusted linear regression analysis; a second adjusted for demographics only (partially adjusted model); and a third adjusted for demographics and variables associated with overweight/obesity and diabetes (fully adjusted model) were computed to assess associations among sleep duration/quality and BMI, WC, and 2-hour OGTT.

RESULTS

Total sample consisted of 2388 childbearing-age women. Only sleep duration was significantly associated with BMI and WC in the unadjusted and partially adjusted models, but was no longer significant in the fully adjusted model. Neither sleep duration nor quality was significantly associated with 2-hour OGTT in any of the models.

CONCLUSIONS

Targeting sleep duration and sleep quality alone would not likely contribute to significantly lower BMI, WC, or risk of type 2 diabetes in US childbearing-age women. Additional studies, especially longitudinal ones using objective measures of sleep, are needed to confirm these findings.

On the origin of obesity: identifying the biological, environmental and cultural drivers of genetic risk among human populations

Genetic predisposition to obesity presents a paradox: how do genetic variants with a detrimental impact on human health persist through evolutionary time? Numerous hypotheses, such as the thrifty genotype hypothesis, attempt to explain this phenomenon yet fail to provide a justification for the modern obesity epidemic. In this critical review, we appraise existing theories explaining the evolutionary origins of obesity and explore novel biological and sociocultural agents of evolutionary change to help explain the modern-day distribution of obesity-predisposing variants. Genetic drift, acting as a form of 'blind justice,' may randomly affect allele frequencies across generations while gene pleiotropy and adaptations to diverse environments may explain the rise and subsequent selection of obesity risk alleles. As an adaptive response, epigenetic regulation of gene expression may impact the manifestation of genetic predisposition to obesity. Finally, exposure to malnutrition and disease epidemics in the wake of oppressive social systems, culturally mediated notions of attractiveness and desirability, and diverse mating systems may play a role in shaping the human genome. As an important first step towards the identification of important drivers of obesity gene evolution, this review may inform empirical research focused on testing evolutionary theories by way of population genetics and mathematical modelling.

Association between long sleep duration and increased risk of obesity and type 2 diabetes: A review of possible mechanisms

For the last two decades research has revealed an alarming association between short sleep duration and metabolic disorders. In tandem, the hormonal, behavioral, and genetic mechanisms underlying this relationship have been extensively investigated and reviewed. However, emerging evidence is revealing that excessive sleep duration has remarkably similar deleterious effects. Unfortunately, to date there has been little attention to what drives this connection. This narrative review therefore aims to summarize existing epidemiological findings, experimental work, and most importantly putative molecular and behavioral mechanisms connecting excessive sleep duration with both obesity and type 2 diabetes mellitus. It will also address recent findings suggesting a worrisome bidirectional effect such that metabolic disorders create a positive feedback loop which further perpetuates excessive sleep.

Individual, social and environmental determinants of sleep among women: protocol for a systematic review and meta-analysis

INTRODUCTION

Sleep is important to promote optimal health and avoid negative health outcomes. Short-duration and low-quality sleep may be more common and more detrimental among women compared with men. Identifying the determinants of behaviour is one of the first steps in designing effective interventions. To our knowledge, no systematic review has identified the individual, social and environmental determinants of sleep among adult women.

METHODS AND ANALYSIS

Studies reporting data on adult women from 18 to 64 years of age will be included. On the basis of ecological models of health behaviour and sleep, the types of determinants that will be included in the review are individual (eg, demographic, psychological and behavioural), social (eg, family) and environmental (eg, physical environment and policies) determinants. Observational (cross-sectional and longitudinal) and experimental studies will be included. MEDLINE/PubMed, PsycINFO, CINAHL, EMBASE and Proquest Dissertations and Theses will be investigated. Data will be extracted independently by two reviewers using a standardised data extraction form. The quality of observational studies will be assessed using the National Institute of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and the quality of experimental studies will be assessed using the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Study. If there is a sufficient number of studies reporting data on a similar determinant among a similar population (k>5), a meta-analysis of the results will be performed with a random-effects model. If between-study heterogeneity is high (I2 ≥75%), it will be investigated through sensitivity analyses and meta-regression.

ETHICS AND DISSEMINATION

Formal ethical approval is not required as no primary data will be collected. The results will be published in a peer-reviewed journal. This review will provide valuable information to those interested in developing empirically based sleep interventions among women.

PROSPERO REGISTRATION NUMBER

CRD42017056894.

Behavioral interventions to promote adequate sleep among women: protocol for a systematic review and meta-analysis

BACKGROUND

Short and poor sleep have been associated with adverse health outcomes in adults, such as overweight/obesity and type 2 diabetes, especially among women. Women therefore represent an important target for interventions aimed at improving sleep and such interventions have been advocated to enhance maternal, fetal, and infant health. This systematic review will assess the efficacy or effectiveness of behavioral interventions aimed at promoting adequate sleep among women. The primary outcomes will be changes in sleep duration and/or sleep quality from baseline to post-intervention and to the last available follow-up measured either through self-reports or objectively. Secondary outcomes will be assessing the behavior change techniques that are responsible for the changes in sleep duration and quality among women.

METHODS

Behavioral interventions that are non-pharmacological and target either sleep directly or sleep hygiene behaviors will be included. Randomized controlled trials, quasi-experimental, and one-group pre-post studies will be included, but treated separately in the analyses, given that a limited number of studies on the topic of sleep is expected. MEDLINE/PubMed, PsycINFO, CINAHL, EMBASE, and Proquest Dissertations and Theses will be investigated. There will be no restriction on the year of publication of the articles, but we will include only the ones written in English or French. Two authors will independently assess articles for eligibility and will extract data using a standardized data extraction form that will have been previously pilot-tested. The quality of the studies will be assessed using the Effective Public Health Practice Project tool for quantitative study designs. The intervention procedures will be classified according to the latest validated taxonomy of behavior change techniques. If there is a sufficient number of studies (k > 5), a meta-analysis of the results will be performed with a random-effect model. If the heterogeneity is high (I 2 ≥ 75%), it will be investigated through sensitivity analyses and meta-regression.

DISCUSSION

This review will provide valuable information to those interested in promoting adequate sleep among women and, hopefully, encourage additional research in this important field to promote maternal, fetal, and infant health.

SYSTEMATIC REVIEW REGISTRATION

The study protocol was registered in PROSPERO in October 2016 (CRD42016049538).

Nicotine dependence and sleep quality in young adults

INTRODUCTION

More cigarette smokers report poor sleep quality than non-smokers, but the association between nicotine dependence (ND) and sleep quality has not been well-characterized. The objective of this study was to describe the associations among frequency and intensity of cigarette smoking, ND symptoms, and sleep quality in young adults.

METHODS

Data on past-year smoking frequency, number of cigarettes smoked in the past month, five ND indicators (i.e., withdrawal, craving, self-medication symptoms, mFTQ, ICD-10 criteria for tobacco dependence), and sleep quality (measured with the Pittsburgh Sleep Quality Index (PSQI)) were collected in 2011-12 in self-report questionnaires completed by 405 young adult smokers (mean age 24 (0.6) years; 45% male; 45% daily smokers) participating in a longitudinal investigation of the natural course of ND. Associations between indicators of cigarette smoking, ND symptoms, and sleep quality were examined in multivariable logistic regression analyses controlling for age, sex, mother's education, and alcohol use.

RESULTS

Thirty-six percent of participants reported poor sleep quality (PSQI>5). Higher cigarette consumption (OR(95% CI), 1.03(1.001-1.05)) but not frequency of past-year smoking, more frequent withdrawal symptoms (1.05(1.004-1.10)), more frequent cravings (1.05(1.004-1.10)), higher mFTQ scores (1.14(1.02-1.27)), and endorsing more ICD-10 criteria for tobacco dependence (1.19(1.04-1.36)) were also associated with poor sleep quality.

CONCLUSION

Cigarette smoking and ND symptoms are associated with poor sleep quality in young adult smokers. Advice from practitioners to cut back on number of cigarettes smoked per day and treatment of ND symptoms may improve sleep quality in young adult smokers.

Sleep duration and risk of stroke: a dose-response meta-analysis of prospective cohort studies

OBJECTIVES

Suboptimal sleep duration has been considered to increase the risk of stroke incidence. Thus we aimed to conduct a dose-response meta-analysis to examine the association between sleep duration and stroke incidence.

METHODS

We searched PubMed, Web of science and the Cochrane Library to identify all prospective studies evaluating the association of sleep duration and nonfatal and/or fatal stroke incidence. Then, restricted cubic spline functions and piecewise linear functions were used to evaluate the nonlinear and linear dose-response association between them.

RESULTS

We included a total of 16 prospective studies enrolling 528,653 participants with 12,193 stroke events. Nonlinear dose-response meta-analysis showed a J-shaped association between sleep duration and total stroke with the lowest risk observed with sleeping for 7 h. Considering people sleeping for 7 h as reference, long sleepers had a higher predicted risk of total stroke than short sleepers [the pooled risk ratios (95% confidence intervals): 4 h: 1.17 (0.99-1.38); 5 h: 1.17 (1.00-1.37); 6 h: 1.10 (1.00-1.21); 8 h: 1.17 (1.07-1.28); 9 h: 1.45 (1.23-1.70); 10 h: 1.64 (1.4-1.92); p_nonlinearity<0.001]. Short sleep durations were only significantly associated with nonfatal stroke and with total stroke in the subgroups of structured interview and non-Asian countries. Additionally, we found a slightly decreased risk of ischemic stroke among short sleepers. For piecewise linear trends, compared to 7 h, every 1-h increment of sleep duration led to an increase of 13% [the pooled risk ratios (95% confidence intervals): 1.13 (1.07-1.20); p < 0.001] in risk of total stroke.

CONCLUSION

Both in nonlinear and piecewise linear dose-response meta-analyses, long sleep duration significantly increased the risk of stroke incidence.

Sleep Duration and Obesity in Adults: What Are the Connections?

Collectively, cross-sectional and longitudinal studies on self-reported sleep duration and obesity do not show a clear pattern of association with some showing a negative linear relationship, some showing a U-shaped relationship, and some showing no relationship. Associations between sleep duration and obesity seem stronger in younger adults. Cross-sectional studies using objectively measured sleep duration (actigraphy or polysomnography (PSG)) also show this mixed pattern whereas all longitudinal studies to date using actigraphy or PSG have failed to show a relationship with obesity/weight gain. It is still too early and a too easy solution to suggest that changing the sleep duration will cure the obesity epidemic. Given novel results on emotional stress and poor sleep as mediating factors in the relationship between sleep duration and obesity, detection and management of these should become the target of future clinical efforts as well as future research.

Associations between sleep characteristics and weight gain in an older population: results of the Heinz Nixdorf Recall Study

BACKGROUND/OBJECTIVES

Sleep duration influences weight change in children and young adults, but there is less evidence in middle-aged, and, in particular, older adults. We assessed associations between sleep duration, daytime napping and sleep disturbances, respectively, with change of weight and waist circumference in older subjects. Contrary to previous studies, we also used two points in time to assess sleep characteristics.

METHODS

We used data from the population-based Heinz Nixdorf Recall study, a cohort study in Germany with a baseline and two follow-up visits (age 45-74 years, median follow-up 5.1 years for first, 5.2 years for second follow-up visit). In adjusted linear regression models (N=3751), we estimated weight change between baseline and first follow-up visit in relation to various self-reported sleep characteristics measured at baseline. Furthermore, we estimated change of weight and waist circumference, respectively, between first and second follow-up visit in relation to patterns of sleep characteristics measured at baseline and at the first follow-up visit (N=2837).

RESULTS

In all analyses, short and long sleep duration, sleep disturbances, and regular daytime napping were associated with <1 kg of weight gain and <1 cm of gain in waist circumference over 5 years compared with the respective reference categories. For example, compared with 7-<8 h night sleep, short night sleep (⩽5 h at baseline) was associated with 0.5 kg of weight gain (95% confidence interval: -0.1; 1.1 kg).

CONCLUSIONS

Our study gave no evidence that sleep characteristics were associated with clinically relevant weight gain in the older population.

Longer Sleep Duration and Midday Napping Are Associated with a Higher Risk of CHD Incidence in Middle-Aged and Older Chinese: the Dongfeng-Tongji Cohort Study

STUDY OBJECTIVES

To analyze the independent and combined relations of sleep duration and midday napping with coronary heart diseases (CHD) incidence along with the underlying changes of cardiovascular disease (CVD) risk factors among Chinese adults.

METHODS

We included 19,370 individuals aged 62.8 years at baseline from September 2008 to June 2010, and they were followed until October 2013. Cox proportional hazards models and general linear models were used for multivariate longitudinal analyses.

RESULTS

Compared with sleeping 7- < 8 h/night, the hazard ratio (HR) of CHD incidence was 1.33 (95% CI = 1.10 to 1.62) for sleeping ≥ 10 h/night. The association was particularly evident among individuals who were normal weight and without diabetes. Similarly, the HR of incident CHD was 1.25 (95% CI = 1.05 to 1.49) for midday napping > 90 min compared with 1-30 min. When sleep duration and midday napping were combined, individuals having sleep duration ≥ 10 h and midday napping > 90 min were at a greater risk of CHD than those with sleeping 7- < 8 h and napping 1-30 min: the HR was 1.67 (95% CI = 1.04 to 2.66; P for trend = 0.017). In addition, longer sleep duration ≥ 10 h was significantly associated with increases in triglycerides and waist circumference, and a reduction in HDL-cholesterol; while longer midday napping > 90 min was related to increased waist circumference.

CONCLUSIONS

Both longer sleep duration and midday napping were independently and jointly associated with a higher risk of CHD incidence, and altered lipid profile and waist circumference may partially explain the relationships.