Sleep duration, sleep quality, and obesity risk among older adults from six middle-income countries: findings from the study on global AGEing and adult health (SAGE)

Self-Reported Sleep Duration Is a Useful Tool to Predict Sarcopenia in Chilean Older Adults: Evidence from the ALEXANDROS Longitudinal Study

Age-related sleep disorders share common pathways with sarcopenia. Prospective data from Latin American populations are scarce, and the association between sleep disorders and sarcopenia in Chileans remains unknown. Thus, we aimed to study the longitudinal association between sleep disorders and sarcopenia in a cohort study of 1116 community-dwelling Chilean older people ≥60 years old from the ALEXANDROS cohorts. After the exclusion criteria, 318 subjects were followed. Sociodemographic data, self-reported chronic diseases, sedentarism, sleep characteristics, anthropometric measurements, handgrip strength, and muscle performance were assessed. Results indicated that at baseline, the prevalence of sarcopenia was 24.10% without gender differences, and the prevalence of self-reported sleep problems was 23.3%, higher in women (26.46% versus 17.15% in men). The adjusted Cox regression models for sarcopenia showed an association between sarcopenia, sleep disorders (HR = 2.08, 95% IC 1.14-3.80), and long sleep duration (HR = 2.42, 95% IC 1.20-4.91). After 8.24 years of follow-up, there were 2.2 cases of sarcopenia per 100 person-years. This study demonstrates that sleep disorders are an independent risk factor for sarcopenia in Chilean older people. The identification of sleep disorders through self-reported data provides an opportunity for early identification of risk and cost-effective sarcopenia prevention.

Investigating the linkages between food insecurity, psychological distress, and poor sleep outcomes among U.S. college students

OBJECTIVE

Research overwhelmingly demonstrates that sleep is key to human health and wellbeing. Several factors likely contribute to sleep quality, including factors, such as food security and low income. In addition, exposure to structural inequalities early in life likely have downstream effects upon multiple dimensions of health. The objective of this study is to fill gaps in literature by specifically examining the associations between childhood food insecurity, current food insecurity, psychological distress, and sleep among college students.

METHODS

QR codes were randomly distributed to students, linking them to an online quantitative survey. The survey measured sociodemographic variables, food security (current and childhood), diet, mental distress, and sleep quality. A total of n = 134 completed the entire survey. Data were analyzed using binary and multiple linear regressions, as well as cross-tabulations.

RESULTS

The findings revealed that psychological distress was the primary factor influencing sleep health (𝛽 = 1.51, p < .01). Students reporting higher childhood food insecurity were more likely to experience extreme psychological distress (OR = 4.61), food insecurity in college (OR = 8.41), and lack of stable housing (OR = 5.86).

CONCLUSION

This study demonstrates that potential linkages exist between childhood food insecurity, poor sleep, and greater psychological distress. While acknowledging the contribution of other factors, the study highlights the importance of addressing food insecurity in relation to sleep health, considering the significant impact of sleep to overall health and wellbeing.

The AUstralian multidomain Approach to Reduce dementia Risk by prOtecting brain health With lifestyle intervention study (AU-ARROW): A study protocol for a single-blind, multi-site, randomized controlled trial

INTRODUCTION

The Finnish Geriatric Intervention Study (FINGER) led to the global dementia risk reduction initiative: World-Wide FINGERS (WW-FINGERS). As part of WW-FINGERS, the Australian AU-ARROW study mirrors aspects of FINGER, as well as US-POINTER.

METHOD

AU-ARROW is a randomized, single-blind, multisite, 2-year clinical trial (n = 600; aged 55-79). The multimodal lifestyle intervention group will engage in aerobic exercise, resistance training and stretching, dietary advice to encourage MIND diet adherence, BrainHQ cognitive training, and medical monitoring and health education. The Health Education and Coaching group will receive occasional health education sessions. The primary outcome measure is the change in a global composite cognitive score. Extra value will emanate from blood biomarker analysis, positron emission tomography (PET) imaging, brain magnetic resonance imaging (MRI), and retinal biomarker tests.

DISCUSSION

The finalized AU-ARROW protocol is expected to allow development of an evidence-based innovative treatment plan to reduce cognitive decline and dementia risk, and effective transfer of research outcomes into Australian health policy.

Highlights

Study protocol for a single-blind, randomized controlled trial, the AU-ARROW Study.The AU-ARROW Study is a member of the World-Wide FINGERS (WW-FINGERS) initiative.AU-ARROW's primary outcome measure is change in a global composite cognitive score.Extra significance from amyloid PET imaging, brain MRI, and retinal biomarker tests.Leading to development of an innovative treatment plan to reduce cognitive decline.

Effects of non-invasive ventilation on sleep in chronic hypercapnic respiratory failure

Chronic respiratory disease can exacerbate the normal physiological changes in ventilation observed in healthy individuals during sleep, leading to sleep-disordered breathing, nocturnal hypoventilation, sleep disruption and chronic respiratory failure. Therefore, patients with obesity, slowly and rapidly progressive neuromuscular disease and chronic obstructive airways disease report poor sleep quality. Non-invasive ventilation (NIV) is a complex intervention used to treat sleep-disordered breathing and nocturnal hypoventilation with overnight physiological studies demonstrating improvement in sleep-disordered breathing and nocturnal hypoventilation, and clinical trials demonstrating improved outcomes for patients. However, the impact on subjective and objective sleep quality is dependent on the tools used to measure sleep quality and the patient population. As home NIV becomes more commonly used, there is a need to conduct studies focused on sleep quality, and the relationship between sleep quality and health-related quality of life, in all patient groups, in order to allow the clinician to provide clear patient-centred information.

Association between patterns of nutrient intake and circulating vitamin D with sleep status among Iranian adults

Nutrient pattern analysis is an easy way to compare nutrient intakes across different nations due to the universality of nutrients nature. The purpose of this study was to examine the relationship between dietary nutrient patterns (NPs) and circulating 25(OH)D concentrations with sleep duration and sleep quality among Iranian adults. We used a multistage cluster random sampling method to enroll 535 adults in this cross-sectional investigation. A validated food frequency questionnaire was applied to evaluate typical dietary intakes. Fasting blood samples were obtained to determine levels of circulating 25(OH)D. Sleep characteristics were assessed using the Pittsburgh Sleep Quality Index (PSQI). Participants had a mean age of 42.57 years and 51.2% of them had insufficient or deficient levels of serum vitamin D. Three NPs were identified: "high animal protein", "high vegetable" and "high carbohydrate". After adjustments for potential confounders, no significant associations were observed between "high animal protein" pattern and short sleeping or sleep quality. Greater adherence to "high vegetable" NP was associated with lower odds of short sleeping (OR 0.24; 95% CI 0.10, 0.54) and poor sleep quality (OR 0.45; 95% CI 0.20, 1.05). Stratified analysis revealed that these associations were stronger in normal-weight participants. Greater adherence to "high carbohydrate" NP, on the other hand, was connected to higher odds of short sleeping (OR 2.83; 95% CI 1.20, 6.72). Low adherence to "high vegetable" pattern and vitamin D insufficiency/deficiency were jointly associated with increased odds of short sleeping (OR 3.42, 95% CI 1.42, 6.64). High adherence to pattern comprising mainly of vegetable nutrients was associated with a reduced likelihood of being short sleepers and having poor sleep quality in Iranian adults, especially among those with a normal weight. Lower adherence to vegetable NP and insufficient/deficient vitamin D levels were synergistically associated with greater likelihood of being short sleepers. Greater adherence to carbohydrate NP was associated with an increased likelihood of short sleeping.

Sleep duration, sleep quality and the risk of being obese: Evidence from the Australian panel survey

BACKGROUND

Sleep difficulty is an unmet public health concern affecting a vast proportion of the world's population. Poor sleep duration (short or long sleep length) and quality affect more than half of older people. Sleep difficulty is associated with negative health outcomes such as obesity and reduced longevity. We aimed to assess whether poor sleep duration and quality are significant risk factors for obesity in adults aged 15 and over in Australia by examining a nationally representative panel data.

METHODS

We used three waves (waves 13, 17, and 21) of the nationally representative Household, Income and Labour Dynamics in Australia (HILDA) survey data. The study applied generalized estimating equations (GEE) logistic regression model to assess the relationship between sleep duration and quality with obesity.

RESULTS

The study found that the odds of being obese was significantly higher amongst the study participants with poor sleep duration (adjusted odds ratio [aOR]: 1.24, 95% confidence interval [CI]: 1.16-1.32) and poor sleep quality (aOR: 1.29, 95% CI: 1.02-1.38) compared with their counterparts who had good sleep duration and quality, respectively.

CONCLUSION

Having short or long sleep at night and poor sleep quality are associated with an increased risk of obesity. Obesity poses a significant threat to the health of Australian adults. Enacting policies that raise public awareness of the significance of good sleep hygiene and encouraging healthy sleeping habits should be considered to address the alarming rise in the obesity rate.

Associations between sleep characteristics, chronotype and body mass index among Chinese college freshmen

Research indicates that sleep problem is a behavioral risk factor of obesity. However, few research have applied a multi-dimensional approach to investigate the relationship between sleep health and adiposity. Therefore, the current study aimed to examine the associations of sleep characteristics (duration, quality) and chronotype with overweight/obesity as measured by body mass index. Data were obtained from 2014 college students from the Dali University in the Yunnan province of China in the year 2021. Sleep characteristics and chronotype were measured using self-reported questionnaires. The presence of overweight/obesity was assessed by anthropometric measurements. Multiple logistic regression models and restricted cubic spline hazard models were established to examine associations between sleep characteristics, chronotype and adiposity. After adjusting for demographic characteristics and other obesity-related behavioral risk factors, evening type was positively associated with overweight/obesity, and an L-shaped dose-effect relationship was observed between chronotype scores and the presence of overweight/obesity. However, sleep duration and quality were not associated with the presence of overweight/obesity in the logistic regression models and restrictive cubic splines models. This study indicated that Chinese college students who had the evening chronotype were more likely to be affected by overweight/obesity. Chronotype as an important dimension of sleep health should be incorporated in obesity intervention programs.

Higher frailty levels are associated with lower cognitive test scores in a multi-country study: evidence from the study on global ageing and adult health

Background

Frailty has been recognized as a growing issue in older adults, with recent evidence showing that this condition heralds several health-related problems, including cognitive decline. The objective of this work is to determine if frailty is associated with cognitive decline among older adults from different countries.

Methods

We analyzed the baseline the Study on Global Ageing and Adult Health (SAGE), that includes six countries (Ghana, South Africa, Mexico, China, Russia, and India). A cross-section analysis was used to assess how Frailty was related with the Clinical Frailty Scale decision tree, while cognitive decline was evaluated using standardized scores of tests used in SAGE.

Results

A total of 30,674 participants aged 50 years or older were included. There was an association between frailty levels and cognitive performance. For example, women had an inverse relationship between frailty levels and cognitive scores, even when comparing robust category with frailty level 2 (RRR = 0.85; p = 0.41), although the relative risks decrease significantly at level 3 (RRR = 0.66; p = 0.03). When controlling for age, the relative risks between frailty levels 4 to 7 significantly decreased as cognitive performance increased (RRR = 0.46, RRR = 0.52, RRR = 0.44, RRR = 0.32; p < 0.001).

Conclusion

Our results show an association between frailty levels measured in a novel way, and cognitive decline across different cultural settings.

The Gut Microbiome and Ferroptosis in MAFLD

Metabolic-associated fatty liver disease (MAFLD) is a new disease definition, and is proposed to replace the previous name, nonalcoholic fatty liver disease (NAFLD). Globally, MAFLD/NAFLD is the most common liver disease, with an incidence rate ranging from 6% to 35% in adult populations. The pathogenesis of MAFLD/NAFLD is closely related to insulin resistance (IR), and the genetic susceptibility to acquired metabolic stress-associated liver injury. Similarly, the gut microbiota in MAFLD/NAFLD is being revaluated by scientists, as the gut and liver influence each other via the gut-liver axis. Ferroptosis is a novel form of programmed cell death caused by iron-dependent lipid peroxidation. Emerging evidence suggests that ferroptosis has a key role in the pathological progression of MAFLD/NAFLD, and inhibition of ferroptosis may become a novel therapeutic strategy for the treatment of NAFLD. This review focuses on the main mechanisms behind the promotion of MAFLD/NAFLD occurrence and development by the intestinal microbiota and ferroptosis. It outlines new strategies to target the intestinal microbiota and ferroptosis to facilitate future MAFLD/NAFLD therapies.

Association of sleep problems with urinary concentrations of personal care and consumer product chemicals: a nationally representative, population-based study

Sleep problems are common in modern society and may be related to environmental chemicals. The objective of this study is to investigate the association between exposure to personal care and consumer product chemicals (PCCPCs) and sleep-related disorders. Nationally representative data from the National Health and Nutrition Examination Survey (NHANES) were used in this study (N=2415). Sleep-related variables, including sleep duration, snoring, and self-reported sleep problems, were included as outcome variables to assess sleep quality. Urinary PCCPC concentrations were used to assess the association of PCCPCs with sleep problems and adjusted for variables similar to those used in related studies. PCCPC levels were analysed as quartiles. Multivariate logistic regression and weighted quantile sum (WQS) regression were used to analyse the association of urinary PCCPCs with sleep problems. Nine of the 12 kinds of PCCPCs with a detection rate greater than 50% were included in our study. Specifically, the concentrations of bisphenol A (BPA), bisphenol F (BPF), methyl paraben (MP) and triclosan (TCS) were significantly related to insufficient sleep. Based on the WQS model, combined exposure to PCCPCs was also significantly related to insufficient sleep; TCS, BPA, and MP were the compounds with the greatest impact regarding combined exposure. A variety of PCCPCs were associated with insufficient sleep in participants but were not significantly associated with the other sleep problems reported in the NHANES. As poor quality sleep is associated with multiple adverse health outcomes, our study provides insight into the health risks of PCCPC exposure.

Trends and disparities in sleep quality and duration in older adults in China from 2008 to 2018: A national observational study

Background

Poor sleep status as a common concern is a risk factor for many health problems among older people. China with an aging society lacks relevant nationwide data on the sleep status among older people. Therefore, the purpose of this study was to investigate trends and disparities in sleep quality and duration among older adults, and exploring influencing factors of poor sleep in China between 2008 and 2018.

Method

We used the four-waves data of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) from 2008 to 2018. Sleep quality and average sleep hours per day was investigated by using questionnaires in the CLHLS. We categorized sleep duration as three groups including ≤5 h (short duration), 5-9 h (normal duration), or ≥9 h (long duration) per day. Multivariate logistic regression models were used to examine trends and risk factors of poor sleep quality, short sleep duration, and long sleep duration.

Results

The prevalence of poor sleep quality significantly increased from 34.87% in 2008 to 47.67% in 2018 (p < 0.05). Short sleep duration significantly increased from 5.29 to 8.37%, whereas long sleep duration decreased from 28.77 to 19.27%. Multivariate analysis showed that female sex, poor economic status, a greater number of chronic diseases, underweight, poor self-reported quality of life, and poor self-reported health were associated with poor sleep quality and short sleep duration (p < 0.05).

Conclusion

Our findings revealed that older adults had increased prevalence of poor sleep quality and short sleep duration from 2008 to 2018. More attention should be paid to the increased sleep problems among older adults and early interventions should be made to improve sleep quality and guarantee enough sleep time.

Üniversite Öğrencilerinde Vücut Kompozisyonu ve Antropometrik Ölçümlerin Uyku Süresi ve Uyku Kalitesiyle İlişkisi

Amaç: Bu çalışmada üniversite öğrencilerinde vücut kompozisyonu ve antropometrik ölçümlerin uyku süresi ve uyku kalitesiyle ilişkisinin incelenmesi amaçlanmıştır.Yöntem: Kesitsel tipteki çalışma bir fakültede öğrenim gören, araştırmaya katılmayı kabul eden ve dahil edilme kriterlerini karşılayan Bandırma Onyedi Eylül Üniversitesi Sağlık Bilimleri Fakültesinin 310 öğrencisiyle yürütülmüştür. Araştırmanın verileri Tanıtıcı Bilgi Formu ve Pittsburg Uyku Kalitesi İndeksi’ni içeren anket formu kullanılarak yüz yüze görüşme yöntemiyle toplanmıştır. Öğrencilerin vücut kompozisyonlarının belirlenmesinde Biyoelektrik İmpedans Analizi (BİA) ile yağsız vücut kütlesi, vücut yağ ve kas kütlesi incelenmiş, Beden Kütle İndeksi (BKİ), bel çevresi, Bel Kalça Oranı (BKO), Bel Boy Oranı (BBO) ve triseps, supskapular, biseps, suprailiak Deri Kıvrım Kalınlıkları (DKK) değerlendirilmiştir. Verilerin analizinde sayı, yüzde, ortalama, standart sapma, Student’s t testi ve Pearson korelasyon analizi kullanılmıştır.Bulgular: Öğrencilerin uyku süresi ortalama 7,10±1,66 saattir, %74,8’i kötü uyku kalitesine sahiptir. Her iki cinsiyette yağsız vücut kütlesi (kg) ve vücut kas kütlesi (kg) ile uyku kalitesi skoru arasında istatistiksel olarak anlamlı, negatif yönlü zayıf ilişki, erkek öğrencilerde ise suprailiak DKK ve biseps DKK ile uyku kalitesi arasında istatistiksel olarak anlamlı, pozitif yönlü zayıf ilişki saptanmıştır (p&lt;0,05).Sonuç: Üniversite öğrencilerinin uyku süreleri önerilen düzeydedir, buna karşın öğrencilerin dörtte üçü kötü uyku kalitesine sahiptir. Kız ve erkek öğrencilerde yağsız vücut kütlesi (kg) ve vücut kas kütlesi (kg) azaldıkça uyku kalitesi kötüleşmekte, erkek öğrencilerde ise suprailiak DKK ve biseps DKK arttıkça uyku kalitesi kötüleşmektedir.  

Real-world association of self-reported sleep duration and quality with falls among older adults: A representative nationwide study of China

INTRODUCTION

Falls are the leading cause of injury-related morbidity and mortality among older adults (aged ≥65 years) worldwide. However, previous studies examining sleep and falls were confined to community subpopulations, and few studies included both sleep quality and sleep duration when discussing risk factors of falls. This nationwide representative study aimed to examine the links between sleep duration, sleep quality and falls among Chinese community-dwelling older adults.

METHOD

Cross-sectional analyses were conducted with 14,681 older individuals (aged ≥65 years) from 23 Chinese provinces from the Chinese Longitudinal Healthy and Longevity Study (CLHLS) in 2018. Individual variables, including sociodemographic factors, lifestyle, and behavioral factors, were measured using a self-reported questionnaire. Falls were confirmed through face-to-face interviews. Three multivariate logistic regression models were conducted to assess the association between sleep duration and sleep quality with falls.

RESULTS

There were 21.7% (95%CI: 21.0-22.4%) participants who had experienced falls in the past year. After controlling demographic and individual variables, falls in older adults were associated with self-reported sleep quality and self-reported sleep duration. Those who reported poor sleep quality were more likely to fall (OR = 1.149; 95%CI = 1.004,1.316). Participants who reported sleep duration that was too short (<5) (OR = 1.349; 95% CI = 1.191 to 1.528) or too long (>8) (OR = 1.267; 95% CI = 1.151 to 1.394) were both associated with higher fall prevalence.

CONCLUSION

Nearly one-fifth of older adults in this study had experienced falls in the past year. The study found that falls were significantly associated with less sleep duration, longer sleep duration, and overall poor sleep quality among the old Chinese population.

The associations of BMI, chronic conditions and lifestyle factors with insomnia symptoms among older adults in India

Background

The aim of the study was to estimate the prevalence of insomnia symptoms and to examine the associations of body mass index (BMI), chronic diseases, and lifestyle factors with self-reported insomnia symptoms among older people in India.

Methods

We conducted a cross-sectional study using data from the baseline wave of the Longitudinal Ageing Study in India (LASI) that was collected during 2017–18. A sample of 31,358 older adults aged 60 and above was included in the analyses. Descriptive statistics and bivariate and multivariable analyses were performed to obtain the results.

Results

In this study, insomnia symptoms were reported by around 36 percent of older adults aged 60 and above. After controlling for socio-demographic factors, insomnia symptoms were positively associated with the risk of being underweight [AOR: 1.289, CI: 1.211–1.372] and negatively associated with obesity/overweight [AOR: 0.928, CI: 0.872–0.990] as compared to older adults with normal BMI. The odds of insomnia symptoms were higher among those who reported the following chronic conditions, i.e., hypertension [AOR:1.356, CI:1.278–1.438], diabetes [AOR:1.160, CI:1.074–1.254], chronic lung diseases [AOR:1.485, CI:1.351–1.632], bone-related diseases [AOR:1.561, CI:1.458–1.670] and any psychiatric disorders [AOR:1.761, CI:1.495–2.074]. In addition, older adults who were physically active [AOR: 0.850, CI:0.804–0.900] were less likely to report insomnia symptoms.

Conclusions

The study suggests a high prevalence of insomnia symptoms among the older population in India. Early identification of the signs of insomnia in older population is crucial, as is timely treatment for any kind of sleep problems. In addition, nutrition-based interventions and individual disease-specific management programs may help minimize the stressful situations in later life and develop a good night’s sleep for the older population.

Changes and predictors of sleep quality with a 2-year follow-up in older adults according to living arrangements

OBJECTIVES

This study aimed to explore changes and predictors of sleep quality with a 2-year follow-up in Chinese elderly individuals and to further present them according to living arrangements.

METHODS

A total of 3005 individuals were effectively surveyed at baseline and at the 2-year follow-up. Generalized estimating equation (GEE) was performed to explore associations between sleep quality and predictor variables.

RESULTS

The rate of poor sleep quality was 32.6% at baseline and 27.4% at follow-up. According to living arrangements, sleep quality improved among empty nesters living as a couple (P < 0.001). After adjusting for sex, age, and other influencing factors, empty nesters living alone had poorer sleep quality (OR = 1.399, 95% CI = 1.022-1.917) than nonempty nesters. Sex, age, education, self-reported health, depression, and social support were predictors of poor sleep quality for all participants. In the subgroup analyses, self-reported physical health and body mass index (BMI) were predictors of sleep quality in the nonempty-nester group, but depression was not a predictor. Depression was a predictor of sleep quality in the empty-nester group.

CONCLUSIONS

Sleep quality was improved in this 2-year follow-up survey. However, sleep quality problems in the elderly cannot be ignored, especially empty nesters living alone. Therefore, according to living arrangements, different intervention methods should be selected to prevent and control poor sleep quality.

Age-associated differences in sleep duration in the US population: potential effects of disease burden

OBJECTIVES

We contrasted the relative risks (RR) of short [<7 h] and long [>8 h] sleep experienced by middle-aged (45-64 years) and older (≥65 years) adults, compared with young adults (20-44 years).

METHODS

We utilized NHANES data (2005-2016), capturing sociodemographic, socioeconomic, and health-related data among US adults.

RESULTS

The Relative Risk (RR) of short sleep between young and middle-aged adults did not differ [RR = 1.02, NS]. However, the RR of short sleep was significantly reduced among older participants [RR = 0.81, p < 0.01]. Middle-aged adults had significantly lower RR of long sleep [RR = 0.80, p < 0.01], whereas older adults had significantly greater RR of long sleep [RR = 1.41, p < 0.01]. Compared with young adults, older adults with or without increased disease burden had significantly lower RR of short sleep [RR = 0.81, p < 0.01 and RR = 0.80, p < 0.01], respectively. However, for middle-aged adults, the RR of short sleep did not differ whether they reported a greater disease burden. Relative to young adults, older adults with or without disease burden had higher RRs of long sleep [RR = 1.39, p < 0.01] and [RR = 1.45, p < 0.01], respectively. For middle-aged adults without disease burden, the RR of long sleep was lower than among young adults [RR = 0.72, p < 0.01].

CONCLUSIONS

Compared with young adults, older adults were not at increased risk for short sleep. Rather, they reported longer sleep time regardless of the presence of disease burden. Future studies should investigate longitudinal effects of aging on objective sleep time, with or without common diseases.

Effect of Restricted Feeding on Metabolic Health and Sleep-Wake Rhythms in Aging Mice

Aging, an irreversible and unavoidable physiological process in all organisms, is often accompanied by obesity, diabetes, cardiovascular diseases, sleep disorders, and fatigue. Thus, older adults are more likely to experience metabolic symptoms and sleep disturbances than are younger adults. Restricted feeding (RF) is a dietary regimen aimed at improving metabolic health and extending longevity, as well as reorganizing sleep-wake cycles. However, the potential of RF to improve metabolic health and sleep quality in older adults who are known to show a tendency toward increased weight gain and decreased sleep is unknown. To elucidate this issue, aged mice were assigned to an RF protocol during the active phase for 2 h per day for 2 weeks. Sleep-wake cycles were recorded during the RF regime in RF group and control mice. At the end of this period, body weight and blood biochemistry profiles, including blood glucose, cholesterol, and enzyme activity, in addition to dopamine concentrations in the brain, were measured in the RF group and age-matched controls. RF for 2 weeks improved the metabolic health of aged mice by reducing their body weights and blood glucose and cholesterol levels. At the beginning of the RF regime, sleep decreased in the dark period but not in the light period. After stable food entrainment was achieved (7 days post-RF commencement), the amount of time spent in wakefulness during the light period dramatically increased for 2 h before food availability, thereby increasing the mean duration of awake episodes and decreasing the number of wakefulness episodes. There was no significant difference in the sleep-wake time during the dark period in the RF group, with similar total amounts of wakefulness and sleep in a 24-h period to those of the controls. During the RF regime, dopamine levels in the midbrain increased in the RF group, pointing to its potential as the mechanism mediating metabolic symptoms and sleep-wake regulation during RF. In conclusion, our study suggested that RF during aging might prohibit or delay the onset of age-related diseases by improving metabolic health, without having a severe deleterious effect on sleep.

Association between height and sleep duration in Korean adults

The relationship between height and sleep duration is poorly understood in adults. We analysed the data from 32 698 adults collected by the 2007-2016 Korean National Health and Nutrition Examination Survey. A total of 44.4% and 9.1% participants reported short (≤6 h) and long (≥9 h) sleep duration, respectively. A shorter height was significantly associated with increased likelihood of both short and long sleep. A sex-stratified analysis revealed that the relationship between height and sleep duration was only significant in males. In conclusion, height was independently related to sleep duration in Korean men.

Sleep and cardiometabolic health in children and adults: examining sleep as a component of the 24-h day

STUDY OBJECTIVES

Sleep, physical activity and sedentary time are all known to play a role in cardiometabolic health. Compositional data analysis (CoDA) enables us to examine associations between 24-h use of time and health outcomes.

METHODS

Data were collected in the Child Health CheckPoint study, a one-off national population-cohort study conducted between February 2015 and March 2016. Wrist-worn actigraphy monitors (GENEActiv Original, Cambs, UK) were used to measure activity behaviours (sleep, physical activity and sedentary time) and sleep characteristics (sleep variability, midsleep, efficiency). CoDA was applied to determine the association between 24-h use of time and cardiometabolic risk markers (blood pressure; body mass index; apolipoprotein B/A1; glycoprotein acetyls; and composite metabolic syndrome score). Substitution modelling (one-for-remaining and one-for-one) examined the associations of reallocating sleep time with other activity behaviours.

RESULTS

Data were available for 1073 Australian children aged 11-12 years (50% male) and 1337 adults (13% male). Strong association was found between 24-h use of time and all cardiometabolic health outcomes. Longer sleep was associated with more favourable cardiovascular health. Sleep characteristics other than duration (efficiency, timing, variability) were weakly and inconsistently associated with outcomes. Reallocating time from sleep to moderate-vigorous physical activity (MVPA) had favourable associations with cardiometabolic health, but reallocating from sleep to sedentary time was associated with less favourable cardiometabolic health.

CONCLUSION

The 24-h activity composition is strongly associated with cardiometabolic health in children and adults. Days with more sleep and MVPA are associated with improved cardiometabolic health.

Establishing associations between residential greenness and markers of adiposity among middle-aged and older Chinese adults through multilevel structural equation models

OBJECTIVES

Residential greenness may prevent overweight/obesity, but the matter has not been investigated among middle-aged and older adults in China. This study 1) assessed associations between residential greenness and markers of adiposity among middle-aged and older Chinese adults and 2) investigated physical activity, sedentary behaviours, particulate matter (PM) with a diameter of <2.5 μm (PM_2.5) concentrations, and perennial mean temperature as mediators of the associations.

METHODS

We used data from the World Health Organization's Study on Global Ageing and Adult Health (SAGE) between 2007 and 2010. Overweight/obesity and abdominal obesity were measured by body mass index and waist circumference. Exposure to neighbourhood greenness was measured by the normalized difference vegetation index (NDVI). Multilevel structural equation models were fitted to investigate the associations between neighbourhood greenness, the four potential mediators, and the prevalence of overweight/obesity and central obesity.

RESULTS

The results showed that greenness was inversely associated with the odds of overweight/obesity (odds = 0.73, 95% confidence interval (CI) 0.58-0.92) and abdominal adiposity (odds = 0.55, 95% CI 0.33-0.91). The greenness-overweight/obesity association varied significantly by sex and age, and the greenness-central obesity varied significantly by sex, age, and education. We found some indication that PM_2.5 concentrations had a suppressive effect on the greenness-adiposity associations. There was no evidence that physical activity, sedentary behaviours, and perennial mean temperature mediated the associations between neighbourhood greenness and markers of adiposity.

CONCLUSIONS

Exposure to higher levels of residential greenness was associated with lower odds of overweight/obesity and abdominal obesity among middle-aged and older Chinese adults. However, underlying mechanisms explaining these associations remain unclear requiring longitudinal studies and natural experiments.

Reliability, Validity, and Factor Structure of Pittsburgh Sleep Quality Index in Community-Based Centenarians

BACKGROUND

The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report questionnaire that measures general sleep quality in general populations. However, its psychometric properties have yet to be thoroughly examined in longevous persons.

OBJECTIVES

This study aimed to explore the reliability, validity and factor structure of the Chinese-language version of the PSQI in community-dwelling centenarians.

METHODS

A total of 958 centenarians (mean age = 102.8 years; 81.8% females) recruited from 18 regions in Hainan, China, completed the PSQI scale. Cronbach's alpha coefficient was used to measure the internal consistency. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were performed to explore the validity and factor structure of the PSQI in this sample. Correlations between the global PSQI score and physical function, depression symptoms, self-reported health status and subjective well-being were used to assess divergent validity.

RESULTS

The Cronbach's α coefficient of the PSQI was 0.68, and it increased to 0.78 after two components (medication use and daytime dysfunction) were removed. The Spearman correlation coefficients of the PSQI score with each component were statistically significant (P<0.01). EFA yielded a two-factor structure model of the original PSQI-7 and a one-factor structure model of the simplified PSQI-5. The one-factor model with five components (χ2/df =1.59, CFI=0.99, RMSEA=0.03) fit the data well and had good configural invariance across demographic characteristics (0.53<Δχ2<5.58, P>0.05).

CONCLUSIONS

The original PSQI showed acceptable applicability in Chinese community-dwelling centenarians, and its psychometric characteristics moderately improved after sleeping medication and daytime dysfunction were removed. Further validation studies on PSQI are needed among centenarians from varied backgrounds.

Prevalence and correlates of poor sleep quality among college students: a cross-sectional survey

Background

Sleep problems are widespread among college students around the globe, especially in China. This study was designed to investigate the prevalence of poor sleep quality and identify associated factors among college students in Jilin Province, China.

Methods

A total of 6284 participants were completely collected by stratified cluster sampling in 2016. Information on basic demographics, lifestyles, social and family support, and subjective sleep quality was collected by questionnaire. The Pittsburgh Sleep Quality Index (PSQI) is a self-administered questionnaire used to assess sleep for one month.

Results

1951 (31.0%) participants were classified into poor sleep quality group, as defined by a PSQI score > 5. Males scored significantly higher than females on sleep duration and use of sleep medication, while females scored significantly higher than males on PSQI total and sleep disturbances. The results of the multivariate logistic regression show the following factors to be significant predictors of poor sleep quality: freshman (OR = 1.523, 95% CI: 1.168–1.987), alcohol use (OR = 1.634, 1.425–1.874), gambling behaviors (OR = 1.167, 95% CI: 1.005–1.356), exercised for more than 30 min a week on less than one day (OR = 1.234, 95% CI: 1.016–1.498), the feelings of satisfied with parental love (OR = 1.849, 95% CI: 1.244–2.749), and harmonious/neutral relationship with classmates (OR = 2.206, 95% CI: 1.312–3.708; OR = 1.700, 95% CI: 1.414–2.045),. No study pressure of this academic year (OR = 0.210, 95% CI: 0.159–0.276), no truancy in the past month (OR = 0.510, 95% CI: 0.354–0.735), never had self-injurious behaviors (OR = 0.413, 95% CI: 0.245–0.698), very harmonious family relationship (OR = 0.377, 95% CI: 0.219–0.650), frequent communication with parents (OR = 0.524, 95% CI: 0.312–0.880), the feelings of satisfied with maternal love (OR = 0.432, 95% CI: 0.257–0.725), and frequent excursions to gymnasium (OR = 0.770, 95% CI: 0.659–0.899) were the protective factors.

Conclusions

The implication of the present study may be that college students must be made aware of the consequences of inadequate sleep quality and risk factors could be improved if students tried to change their behavior and subjective consciousness.

Factors affecting sleep among Thai people with dementia attending an outpatient psychiatric department

Sleep quality is a well-studied aspect of overall health, especially for those who have other compounded health issues like dementia. This study identified what factors affected sleep quality among Thai people with dementia who attended an outpatient psychiatric department. While we considered factors associated with poor sleep quality, we discussed the impact that family relationship specifically has on sleep quality for this population. A cross-sectional study was conducted among 80 patient–caregiver dyads. All patients were assessed by the TMSE, a neuropsychiatric assessment (Thai Mental State Examination). The PSQI (Pittsburgh Sleep Quality Index) was administered and multiple factors affecting sleep were investigated through face-to-face interviews with each patient and caregiver dyad. Interviews were conducted by a psychiatric nurse at a hospital offering outpatient psychiatric care. A chi-square test, t test, Spearman correlation, Pearson’s correlation, and logistic regression were applied to identify statistically significant associations. Overall, we found that the prevalence of poor sleep in our target population was 70%, with a high sleep score (8.14 ± 4.20). Factors affecting sleep included mental health problems, night-time cough and urinary frequency, pain and fever during the night, sleep environment problems, and stimulant use (63.8%, 57.5%, 47.5%, 20%, and 7.5%, respectively). Other factors previously associated with poor sleep quality in other studies were not associated in this study. Those with perceived poor family relationships are at a 5.57 times greater risk for poor sleep than those with perceived good family relationships. On the contrary, those without mental health problems significantly decreased their overall risk for poor sleep. Further investigation into these associations should be studied. In conclusion, health-care providers are encouraged to consider the impact of family context on sleep quality for people with dementia.

Time use and sexual maturity-related indicators differentially predict youth body mass indices, Peruvian girls versus boys

Rapid development in Latin America has been accompanied by lifestyle shifts, including changes in time use and social environments. Overweight/obesity has also emerged as a public health challenge. We examined whether lifestyle changes and sexual maturity-related indicators (early pubertal development and having a child) predict increases in adiposity among Peruvian youth. Using longitudinal data from Young Lives, we examined changes in adiposity between ages 8 and 15 years old for the younger cohort and ages 15 and 22 years old for the older cohort. Boys and girls in both cohorts demonstrated substantial increases in age-adjusted adiposity measures, but predictors were different for boys versus girls. For boys, increases in time spent in work and domestic chores predicted increases in adiposity body mass index and BMI-for-age Z-score and increases in time spent sleeping were associated with decreases in adiposity (waist circumference and waist-to-height ratio). For girls, sexual maturity-related indicators (early menarche and childbearing) predicted increases in adiposity, regardless of time use. Potential mechanisms for these results may include diet, physical activity, wealth, and urban-rural residence. Time use among youth was associated with diet quality and physical activity, but in different ways for boys versus girls. Strategies for dealing with rising overweight and obesity should incorporate sex-based specificities.

Associations between sleep and obesity indices in older adults: results from the HELIAD study

BACKGROUND

Short sleep duration and low sleep quality are negatively associated with obesity in young adults, but in older people the results are inconsistent.

AIMS

The aim of the present study was to examine the associations between sleep duration and quality with both body mass index (BMI) and waist circumference (WC) and to investigate sex- and age-specific associations in a population-representative cohort of older adults.

METHODS

1781 participants ≥ 65 years old from the HELIAD study were included. Sleep duration and quality were based on self-report, whereas BMΙ and WC were evaluated clinically.

RESULTS

Sleep duration was inversely related to WC, only in women, even after adjustment for age, sex, years of education, total energy intake and level of physical activity. Furthermore, sleep quality was negatively related to both BMI and WC in women. In men, however, no significant relationships were observed between these variables. Associations between sleep and weight did not differ between those aged < 73 and ≥ 73 years old.

DISCUSSION

To the best of our knowledge, this is the first study examining both sleep duration and quality with BMI and WC in older adults, performing by-sex analysis. Although additional studies are needed, improvements in sleep habits should be considered in weight management of older individuals.

CONCLUSIONS

Our results suggest that poor sleep is associated to adverse weight effects in older women, but not men.

Sleep quality is inversely related to body mass index among university students

OBJECTIVE

The purpose of this study was to investigate the prevalence of overweight and obesity and its association with sleep quality in university students from the Anhui province in China.

METHODS

A cross-sectional study was conducted in China with 1328 participants. The prevalence of underweight and obesity in university students was estimated according to the reference working group on obesity in China. The sleep quality was evaluated using the standard PSQI (Pittsburgh Sleep Quality Index).

RESULTS

This study included 470 male and 858 female students from a university in Anhui; 4.4% of the females and 17.7% of the males were overweight or obese. The prevalence of obesity in males was significantly higher than in females, and the prevalence of obesity in higher years was greater than in other years (p<0.05). In general, the mean score for sleep quality was 4.91±2.67; 36.5% of male and 39.1% of female students had poor sleep quality (PSQI score >5). Among the seven components of sleep quality, sleep duration and the use of sleep medication showed significant differences between male and female students and different years (p<0.05). An obvious correlation was found between sleep quality and body mass index (BMI)(p<0.000) in females who took hypnotic drugs.

CONCLUSION

This study suggests that the sleep quality of females is probably associated with their BMI. College students are a special group of young adults whose cause of poor sleeping quality and BMI may be significant to study, so the health status of university students can be improved.

Impact of socio-demographic factors, lifestyle and health status on nutritional status among the elderly in Taiwan

BACKGROUND/OBJECTIVES

Aging is an imperative problem for many countries in this century, and presents several challenges for the maintenance of good nutritional status. This study aims to assess the impact of socio-demographic factors, lifestyle and health status on the nutritional status among the elderly in Taiwan.

SUBJECTS/METHODS

A cross-sectional study was carried out in Taiwan. Data were obtained from the Mei Jau Health Management Institution, which is a private health evaluation provider with multiple health screening centers in Taiwan and Asia. This study included 7947 adults aged 65 years or above. The data were extracted between 2001 to 2010. Nutritional status was assessed using anthropometric data, biochemical data and dietary intake information.

RESULTS

Among the 7947 participants with mean age of 70.1 (SD = 4.5) years, 20.2%, 6.6%, 10.5% and 52.5% experienced underweight, protein malnutrition, anemia and inadequate dietary intake in the past month, respectively. Age was negatively correlated with body weight (r = -0.19, P = 0.02), body mass index (r = -0.41, P < 0.001), albumin level (r = -0.93, P < 0.001) and hemoglobin level (r = -0.30, P = 0.008). Age above 70 years, gender, unmarried status, retirement, lack of education, low family income, smoking, alcohol drinking, sleep duration of 6-8 hours, vegetarian diet, multiple medications, comorbidity and dysphagia were positively associated with malnutrition in older adults.

CONCLUSIONS

Underweight and inadequate dietary intake are prevalent among the elderly in Taiwan. Vegetarian diet, multiple medications, comorbidity, dysphagia and lifestyle factors such as smoking, alcohol drinking and sleep duration of 6-8 hours are risk factors for undernutrition in older adults.

Secondary data analysis to answer questions in human biology

Despite a growing number of publicly available datasets, the use of these datasets for secondary analyses in human biology is less common compared with other fields. Secondary analysis of existing data offers an opportunity for human biologists to ask unique questions through an evolutionary and biocultural lens, allowing for an analysis of cultural and structural nuances that affect health. Leveraging publicly available datasets for human biology research is a way for students and established researchers to complement their data collection, use existing data for master's and doctoral theses, pilot test questions, and use existing data to answer interesting new questions or explore questions at the population level. Here we describe where publicly available data are stored, highlighting some data repositories and how to access them. We then discuss how to decide which dataset is right, depending on the research question. Next, we describe steps to construct datasets, analytical considerations and methodological challenges, best practices, and limitations depending on the structure of the study. We close by highlighting a number of publicly available datasets that have been used by human biologists and other datasets that may be of interest to the community, including research that has been conducted on some example datasets.

Assessing potential shared genetic aetiology between body mass index and sleep duration in 142,209 individuals

Observational studies find an association between increased body mass index (BMI) and short self-reported sleep duration in adults. However, the underlying biological mechanisms that underpin these associations are unclear. Recent findings from the UK Biobank suggest a weak genetic correlation between BMI and self-reported sleep duration. However, the potential shared genetic aetiology between these traits has not been examined using a comprehensive approach. To investigate this, we created a polygenic risk score (PRS) of BMI and examined its association with self-reported sleep duration in a combination of individual participant data and summary-level data, with a total sample size of 142,209 individuals. Although we observed a nonsignificant genetic correlation between BMI and sleep duration, using LD score regression (rg  = -0.067 [SE = 0.039], P = 0.092) we found that a PRS of BMI is associated with a decrease in sleep duration (unstandardized coefficient = -1.75 min [SE = 0.67], P = 6.13 × 10-7 ), but explained only 0.02% of the variance in sleep duration. Our findings suggest that BMI and self-reported sleep duration possess a small amount of shared genetic aetiology and other mechanisms must underpin these associations.

Working in Shifts and the Metabolic Syndrome: Epidemiological Evidence and Physiopathological Mechanisms

The Metabolic syndrome (MetS) is considered as an association of the abdominal obesity, abnormal metabolism of the lipids and glucose (high level of triglycerides, low level of HDL-cholesterol and high level of glycemia) and high values of blood pressure, determined by an underlying mechanism of insulin resistance. As a result of environmental-gene interaction, MetS is associated with unhealthy nutrition, smoking, alcohol abuse, lack of physical activity, shorter sleep duration and desynchronization of the circadian rhytm caused by working in shifts. The aim of this article is to review the effects of working in shifts on the MetS through the epidemiological evidence and the perspective of the physiopathological mechanisms.

Sex and race differences in the association between sleep duration and adiposity: the Bogalusa Heart Study

BACKGROUND

Short sleep duration has been consistently associated with obesity. However, few studies in adults have assessed whether this association varies by sex and race.

METHODS

In the 2013-2016 examination of 1116 participants from the biracial Bogalusa Heart Study, habitual sleep duration was measured in categories (<6 hours, 6-7 hours, 7-8 hours, > 8 hours) using self-report. Anthropometry was performed and adiposity was assessed using body mass index (BMI) and waist circumference. Linear regression models estimated the relationship between sleep duration and adiposity adjusting for age, education, employment, bed partner status, depressive symptoms, smoking status, physical activity, and the use of alcohol and sleeping pills. Effect modification by sex and race was examined using cross-product terms in the models and marginal means were reported.

RESULTS

Of 1116 participants (mean age 48.2 years), 58.3% were female, and 31.7% were Black. In adjusted analyses, women sleeping <6 hours had a 3.2 (95% CI 1.4, 5.0) kg/m² greater BMI and 6.1 (1.8, 10.4) cm greater waist circumference compared to women sleeping 7-8 hours. In contrast, men had similar BMIs and waist circumferences regardless of sleep duration (p's for interaction = 0.04 & 0.11). There was no effect modification by race.

CONCLUSIONS

In this sample, lower habitual sleep duration was associated with greater adiposity among women compared to men. Further research is needed to understand the potential mechanisms of the adverse metabolic effects of short sleep in women.

Sleep quality as predictor of BMI in non-depressed caregivers of people with dementia

PURPOSE

Although most cross-sectional and longitudinal studies of children and adolescents have found a link between short duration of sleep and obesity, the literature related to adults provides a non-consensual framework. The aim of the present study was to examine the association between sleep quality and BMI in a population of caregivers looking after people suffering from dementia, with a view to identifying the moderating role of depressive symptoms in the relationship between sleep problems and BMI.

METHODS

A total of 117 subjects took part in the study, filling in a Sociodemographic Questionnaire, the Pittsburgh Sleep Quality Index, the Eating behavior Questionnaire and The Center for Epidemiologic Studies-Depression.

RESULTS

Depressive symptoms were greater in females than in males. The sample was divided into two subgroups based on depressive-symptom scores. Only within the subsample with low depressive symptoms, higher sleep disturbances influenced BMI positively. Within this subsample of participants with low depressive symptoms, the variables that seem to play a pivotal role in explaining a high BMI are: female gender, sleep problems, and diet quality, while within the subsample with high depressive symptoms only the female gender factor was found to influence BMI.

CONCLUSIONS

Depressive symptoms seem to act as moderators in the relationship between sleep and BMI. They should be evaluated to identify the risk of high BMI, and to differentiate clinical intervention, at least in this population, which experiences the stress of caregiving chronically, though not suffering from clinical eating disorders.

LEVEL OF EVIDENCE

Level II, cross-sectional study.

Relationship of body mass index to sleep duration, and current smoking among medical students in Tabuk City, Saudi Arabia

Background

Being overweight is associated with cardiometabolic risk, and lifestyles including smoking and good sleep hygiene are also implicated. We aimed to assess the dietary habit, time spent on social media, and sleep duration relationship to body mass index (BMI) among medical students in Tabuk, Saudi Arabia.

Methods

A cross-sectional study was conducted among 147 clinical phase medical students in the Medical College, University of Tabuk (Saudi Arabia) from January 2018 to May 2018. A checklist questionnaire was used to measure variables such as age, sex, smoking, level of exercise, whether taking meals and snacks regularly, eating fast food, fruit and vegetable consumption, sleep duration, time spent on social media, and breakfast skipping. Data were analyzed by IBM-SPSS version 20, using one-way ANOVA and Pearson's production-moment correlation (r). A p-value of less than 0.05 was considered statistically significant.

Results

Participants consisted of 51% males, mean age (Mean ± SD) was 22.90±1.27 years, sleep duration was 7.50±2.17 hours, time spent on social media was 5.54±3.49 hours, body mass index was 24.8±5.19, and breakfast skipping, fast food consumption, smoking, and regular exercise were reported in 52.4%, 87.7%, 12.9%, and 36.1% respectively. A significant negative correlation was evident between BMI and sleep duration (r= -0.185, p=0.025), cigarette smokers were more likely to be obese compared to their counterparts (27.28±6.85 vs. 24.10±4.98, p=0.018). No significant statistical relationship was evident between BMI, breakfast skipping, fast food, fruit and vegetable intake, and time spent on social media.

Conclusion

BMI was higher among smokers and those with shorter sleep duration, there was no association between BMI and other students' characteristics. Measures to smoking quitting and good sleep hygiene are recommended.

Insufficient Sleep Duration and Overweight/Obesity among Adolescents in a Chinese Population

OBJECTIVES

The objective of this study was to investigate the relationship between sleep duration and overweight/obesity among Chinese adolescents.

METHODS

A school-based cross-sectional study was conducted among Chinese adolescents in 2016. In total, 2795 school-aged Chinese children aged 12 to 13 years participated in this study. Participants were asked to complete self-administered surveys during a 45-min class period in their classroom. Details of the questionnaire about health-related behaviors included sleep habits, physical activity, screen time, cigarette use, and alcohol use. Height, weight, waist circumference and hip circumference were directly measured.

RESULTS

The mean sleep duration was 8.7 h/day. In total, 43.0% of the participants had a sleep duration of less than 9 h/day. Sleep duration was significantly inversely related to BMI, waist circumference, hip circumference and WHtR in multiple linear regression analyses in both genders. Logistic regression models showed that insufficient sleep (<9 h/day) was associated with high odds of overweight/obesity among both young boys and girls.

CONCLUSIONS

Insufficient sleep duration was associated with overweight/obesity in Chinese adolescents, and short sleep duration was probably associated with central adiposity, especially among boys.

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.

Is poor sleep associated with obesity in older adults? A narrative review of the literature

INTRODUCTION

To address the worldwide epidemic of obesity, a sizable literature implicates sleep problems in the onset of obesity in younger populations. However, less is known about how this process may operate among older adults, which is of concern, given demographic shifts that have resulted in a much higher proportion of developed nations around the world reaching late life.

METHODS

We offer a current review of the literature studying older adults and examining associations between sleep quality and obesity in this population. We consider both subjective and objectively measured sleep as well as both cross-sectional and longitudinal studies offering stronger causal inference.

RESULTS

We discuss seemingly contradictory literature showing that shorter sleep duration as well as longer sleep duration are associated with obesity risk, then review studies that tested for non-linear relationships and reported a U-shape pattern, suggesting that too much or too little sleep is detrimental. Besides sleep duration, we discuss evidence showing that other forms of sleep dysfunction related to night-time awakenings, REM sleep, slow-wave sleep, and daytime sleepiness, which are indicators of sleep quality, are also linked to obesity. Specific psychological and physiological mediators and moderators, suggesting possible mechanisms whereby sleep problems may affect obesity in older adults, are described.

CONCLUSION

We conclude by discussing areas, where additional research could help clarify this association, considering such factors as medical comorbidities common in late life, and health-related behaviors that may stem from poor sleep (such as disordered eating behavior). Such insights will have great value for clinical practice.

LEVEL OF EVIDENCE

Level V, narrative review.

Associations between Poor Sleep Quality, Obesity, and the Anthropometric Measurements of Women in Turkey

Recent studies have shown that poor sleep quality is significantly associated with obesity. The aim of this study is to examine the association of sleep quality with obesity and specific anthropometric measurements. A total of 105 women aged 20-55 years with no chronic diseases participated in this study. They filled out the Pittsburgh Sleep Quality Index (PSQI), their anthropometric measurements were taken, and their dietary data were collected with a food frequency questionnaire (FFQ). There was no significant relationship between sleep quality and BMI, waist circumference, triceps skinfold thicknesses, body fat ratio (%), and body fat mass (p > .05), but high bread consumption was significantly associated with poor sleep quality (p < .05). The women with poor sleep quality consumed significantly more bread, but not other foods, than the women with good sleep quality. Sleep quality can thus be related to eating habits.

The epidemiology of sleep and obesity

Sleep is a state of consciousness that is preserved across animal species whose exact function is not yet clear but which has a vital impact on health and well-being. Epidemiological evidence suggests sleep duration in both children and adults has been decreasing over the past half-century, while at the same time rates of overweight and obesity have been increasing. Short sleep duration along with other dimensions of poor sleep has been associated with obesity both cross-sectionally and longitudinally. These data suggest a potential causal relationship between poor sleep and greater rates of weight gain that may be related to effects of sleep on dietary intake or physical activity. However, there is also potential for reverse causation as obesity leads to many co-morbidities including sleep apnea that can disrupt sleep. Medium and long term interventional studies are needed to evaluate the potential for healthy sleep interventions to help combat the epidemic of obesity.

Exploring the mediating role of energy balance-related behaviours in the association between sleep duration and obesity in European adults. The SPOTLIGHT project

Sleep restriction is a risk factor for weight gain and obesity. Few studies have formally investigated the mediating role of energy balance-related behaviours in the sleep - obesity association. The aim of this study was to explore the mediating role of physical activity, sedentary behaviours and dietary habits in the association of sleep duration with obesity in adults in five European urban regions. Data on self-reported sleep duration, energy balance-related behaviours, height and weight and other covariates were collected between February and September 2014 from participants to the SPOTLIGHT survey (N=5900, mean age 52years). Participants were recruited from 60 urban neighbourhoods in Belgium, France, Hungary, the Netherlands and the United Kingdom. Multilevel logistic regression analyses were used to assess the associations of sleep duration, energy balance-related behaviours and obesity and mediating effects were calculated using MacKinnon's product-of-coefficients method. Results indicated that a 1h increase in sleeping time was associated with a 14% lower likelihood of being obese (OR=0.86, 95%CI=0.80; 0.93). Only work-related sedentary behaviour was identified as a statistically significant mediator in the association between sleep duration and obesity for the total sample, and youngest and oldest age group. We did not find evidence for a mediating role of dietary habits and physical activities.

Sleep Duration, Sleep Quality, Body Mass Index, and Waist Circumference among Young Adults from 24 Low- and Middle-Income and Two High-Income Countries

Obesity and its comorbidities have emerged as a leading public health concern. The aim of this study was to explore the relationship between body mass index (BMI), waist circumference (WC) and sleep patterns, including duration and disturbances. A cross-sectional questionnaire survey and anthropometric measurements were conducted with undergraduate university students that were randomly recruited in 26 universities in 24 low- and middle-income and two high-income countries. The sample included 18,211 (42.1% male and 57.9% female, mean age 21.0 in male and 20.7 years in female students) undergraduate university students. The overall BMI was a mean of 22.5 kg/m² for men and 22.0 kg/m² for women, and the mean WC was 78.4 cm for men and 73.8 cm for women. More than 39% of the students reported short sleep duration (≤6 h/day) and over 30% reported moderate to extreme sleep problems. In a linear multivariable regression, adjusted for sociodemographic and lifestyle factors, short sleep duration was positively associated with BMI in both men and women, and was positively associated with WC among women but not among men. Sleep quality or problems among men were not associated with BMI, while among women mild sleep problems were inversely associated with BMI, and poor sleep quality or problems were positively associated with WC both among men and women. The study confirmed an association between short sleep duration and increased BMI and, among women, increased WC, and an association between poor sleep quality and increased WC but not BMI. Further, differences in the association between sleep characteristics and BMI and WC were found by region and country income.

Sleep duration is associated with increased risk for cardiovascular outcomes: a pilot study in a sample of community dwelling adults in Ghana

BACKGROUND

Associations between sleep duration and cardiovascular disease (CVD) risk factors have been demonstrated in past studies. However, previous studies have not investigated these relationships using objective sleep measures in sub-Saharan Africa. Our objective was to investigate the association between sleep duration and cardiovascular risk factors in a sample of community-dwelling Ghanaian adults.

METHODS

We used wrist actigraphy along with a seven-day sleep diary to measure sleep duration, wake after sleep onset, sleep latency, and sleep quality. Participants were randomly selected from among those participating in the RODAM study in rural and urban Ghana. Outcome measurements included 10-year risk of CVD events, prevalent CVD, and metabolic syndrome. Additional participant characteristics were assessed using a structured questionnaire. Linear and logistic regression analyses were used to assess the relationships between sleep measures and CVD risk.

RESULTS

A total of 263 participants from rural and urban Ghana participated. Total sleep time was positively associated with a 10-year CVD risk; this association remained after adjusting for age, sex, urban vs rural location, socio-economic status, physical activity, and sleep disturbance (β = 0.990, p = 0.015). Short sleep, defined as sleeping less than seven hours per night on average, was negatively associated with a 10-year CVD risk, and this relationship remained in the fully adjusted model (β = -2.100, p = 0.011). Sleep duration was not associated with prevalence of CVD or metabolic syndrome.

CONCLUSION

Using actigraphy to measure sleep duration among a population of community-dwelling adults in sub-Saharan Africa is feasible. We found a positive association between sleep and CVD risk. No association was found between sleep duration and prevalent CVD or metabolic syndrome. The implications and new directions relating to these findings are stated.

Investigating the Bidirectional Associations of Adiposity with Sleep Duration in Older Adults: The English Longitudinal Study of Ageing (ELSA)

Cross-sectional analyses of adiposity and sleep duration in younger adults suggest that increased adiposity is associated with shorter sleep. Prospective studies have yielded mixed findings, and the direction of this association in older adults is unclear. We examined the cross-sectional and potential bi-directional, prospective associations between adiposity and sleep duration (covariates included demographics, health behaviours, and health problems) in 5,015 respondents from the English Longitudinal Study of Ageing (ELSA), at baseline and follow-up. Following adjustment for covariates, we observed no significant cross-sectional relationship between body mass index (BMI) and sleep duration [(unstandardized) B = −0.28 minutes, (95% Confidence Intervals (CI) = −0.012; 0.002), p = 0.190], or waist circumference (WC) and sleep duration [(unstandardized) B = −0.10 minutes, (95% CI = −0.004; 0.001), p = 0.270]. Prospectively, both baseline BMI [B = −0.42 minutes, (95% CI = −0.013; −0.002), p = 0.013] and WC [B = −0.18 minutes, (95% CI = −0.005; −0.000), p = 0.016] were associated with decreased sleep duration at follow-up, independently of covariates. There was, however, no association between baseline sleep duration and change in BMI or WC (p > 0.05). In older adults, our findings suggested that greater adiposity is associated with decreases in sleep duration over time; however the effect was very small.

Relationship between sleep characteristics and measures of body size and composition in a nationally-representative sample

BACKGROUND

Short sleep has been linked to obesity. However, sleep is a multidimensional behavior that cannot be characterized solely by sleep duration. There is limited study that comprehensively examined different sleep characteristics in relation to obesity.

METHODS

We examined various aspects of sleep in relation to adiposity in 2005-2006 NHANES participants who were 18 or older and free of cardiovascular disease, cancer, emphysema, chronic bronchitis and depression (N = 3995). Sleep characteristics were self-reported, and included duration, overall quality, onset latency, fragmentation, daytime sleepiness, snoring, and sleep disorders. Body measurements included weight, height, waist circumference, and dual-energy X-ray absorptiometry measured fat mass.

RESULTS

Snoring was associated with higher BMI (adjusted difference in kg/m² comparing snoring for 5+ nights/week with no snoring (95 % confidence interval), 1.85 (0.88, 2.83)), larger waist circumference (cm, 4.52 (2.29, 6.75)), higher percentage of body fat (%, 1.61 (0.84, 2.38)), and higher android/gynoid ratio (0.03 (0.01, 0.06)). The associations were independent of sleep duration and sleep quality, and cannot be explained by the existence of sleep disorders such as sleep apnea. Poor sleep quality (two or more problematic sleep conditions) and short sleep duration (<6 h) were also associated with higher measures of body size and fat composition, although the effects were attenuated after snoring was adjusted.

CONCLUSION

In a nationally representative sample of healthy US adults, snoring, short sleep, and poor sleep quality were associated with higher adiposity.

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.

Bisphenol-A and Sleep Adequacy among Adults in the National Health and Nutrition Examination Surveys

STUDY OBJECTIVES

To evaluate bisphenol-A (BPA) level and its relationship to sleep adequacy in a nationally representative sample of U.S. adults.

METHODS

A population-based cross-sectional study was conducted using 2005-2010 National Health and Nutrition Examination Survey whereby data were collected using in-person interviews, physical examination and laboratory testing. BPA level was measured in urine samples and analyzed as loge-transformed variable and in quartiles (< 0.9 ng/mL; 0.9 to < 1.9 ng/mL; 1.9 to < 3.7 ng/mL; 3.7+ ng/mL). Sleep adequacy was operationalized with three questions: "How much sleep do you usually get at night on weekdays or workdays?", "Have you ever told a doctor or other health professionals that you have trouble sleeping?" and "Have you ever been told by a doctor or other health professional that you have a sleep disorder?" Sleep duration was further categorized as (< 6 h, ≥ 6 h); (< 7 h, 7-8 h, > 8 h); (< 5 h, 5-6 h, 7-8 h, ≥ 9 h). Linear, binary, and ordinal logistic regression models were constructed.

RESULTS

Loge-transformed BPA level was inversely related to sleep duration defined, in hours, as a continuous variable, a dichotomous variable (≥ 6, < 6), or an ordinal variable (≥ 9, 7-8, 5-6, < 5), after adjustment for confounders. Help-seeking behavior for sleep problems and diagnosis with sleep disorders were not significantly associated with loge-transformed BPA level in fully adjusted models.

CONCLUSIONS

Loge-transformed BPA level may be associated with fewer hours of sleep among U.S. adults, with implications for prevention. Further research involving diverse populations are needed to confirm these study findings.