A scoping review of the effect of chronic stretch training on sleep quality in people with sleep disorders

PURPOSE

The widespread and health-detrimental sleep disorders have resulted in stretching exercises being investigated as a non-drug solution for enhanced sleep quality. However, a comprehensive understanding of the impact of stretching exercises on individuals with sleep disorders is lacking.

METHODS

This scoping review systematically maps the existing literature and identifies research gaps on the impact of stretching exercises on sleep quality in individuals with sleep disorders.

RESULTS

Sixteen eligible studies were included, where the weighted mean changes indicate a positive trend in sleep quality improvement, ranging from trivial to very large magnitudes. However, concerning the individual study results only 5 out of 16 studies reported significant improvements. Notable enhancements include a small 1.22% overall sleep quality improvement, a large 6.51% reduction in insomnia severity, a large 8.88% increase in sleep efficiency, a moderate 4.36% decrease in sleep onset latency, a large 8.27% decrease in wake after sleep onset, and a very large 14.70% improvement in total sleep time. Trivial changes are noted in sleep duration (0.58%), sleep disturbance reduction (0.07%), and daytime dysfunction reduction (0.19%). Likely mechanisms for the improvement of sleep include autonomic nervous system modulation, muscle tension relief, cortisol regulation, enhanced blood circulation, and psychological benefits such as stress reduction and mood enhancement.

CONCLUSION

There is little evidence that stretching exercises positively impact sleep quality in individuals with sleep disorders. Additionally, further research is vital for designing optimal protocols, understanding of the long-term effects, and clarification of the mechanisms.

Sleep disruption and sleep position: Increased wake frequency in supine predicts lateral position preference

Little is known about the physiological and biomechanical factors that determine individual preferences in lying posture during sleep. This study investigated relationships between position preference and position-specific arousals, awakenings, limb movements and limb movement arousals to explore the mechanisms by which biomechanical factors influence position preference. Forty-one mature-aged adults underwent 2 nights of at-home polysomnography ~2 weeks apart, on a standardised firm foam mattress, measuring nocturnal sleep architecture and position. The lateral supine ratio and restlessness indices specific to lateral and supine positions including limb movement index, limb movement arousal index, arousal index, wake index, respiratory arousal index and apnea-hypopnea index were calculated and analysed via linear mixed-effects regression. In the supine position, all restlessness indices were significantly increased compared with the lateral position, including a 379% increase in respiratory arousals (β = 7.0, p < 0.001), 108% increase in arousal index (β = 10.3, p < 0.001) and 107% increase in wake index (β = 2.5, p < 0.001). Wake index in the supine position increased significantly with more lateral sleep (β = 1.9, p = 0.0013), and significant correlation between lateral supine ratio polysomnography 1 and lateral supine ratio polysomnography 2 (β = 0.95, p < 0.001) indicated strong consistency in sleep preference. Overall, the findings suggest that some individuals have low tolerance to supine posture, represented by a comparatively high wake index in the supine position, and that these individuals compensate by sleeping a greater proportion in the lateral position.

Does obstructive sleep apnea increase the risk of cancer and cancer mortality in combined community-based cohorts?

Obstructive sleep apnea (OSA) has been linked to cancer in several clinical and community-based cohorts. The effect in community-based studies free of clinical referral bias needs to be replicated. In this observational prospective cohort study, we pooled data from three community-based prospective cohorts (Uppsala Sleep and Health in Men cohort [UMEN]; Sleep and health in women [SHE]; Men Androgen Inflammation Lifestyle Environment and Stress Cohort [MAILES]; nTotal = 1467). All cohorts had objective data on obstructive sleep apnea and registry linkage data on cancer and cancer mortality. Analyses for different obstructive sleep apnea measures (apnea-hypopnea index [AHI], oxygen desaturation index [ODI], and minimal saturation) as risk factors for cancer incidence (all cancers) were performed using Cox proportional hazards models (follow-up 5-16 years). We did not find an overall increased risk of cancer after adjustment for age, sex, and BMI (HRAHI [95% CI] = 1.00 [0.98; 1.01] and HRODI [95% CI] = 0.99 [0.97; 1.01]). Stratifying by daytime sleepiness did not influence the association. Cancer mortality was not significantly associated with obstructive sleep apnea. Taken together, we did not observe an overall increased risk of cancer or cancer mortality in relation to obstructive sleep apnea, however, our confidence limits remain wide for important diagnostic categories of sleep apnea severity. The relationship between obstructive sleep apnea and cancer needs further investigation in a comprehensive multi-cohort approach with greater statistical precision. For future studies we may need to find and then combine every community-based cohort study that can provide a definitive answer to the question on the risk of cancer from obstructive sleep apnea in the general population.

Sleep, Health Outcomes and Body Weight (SHOW) study: a measurement burst design study on sleep and risk factors for obesity in black emerging adults in North Carolina, USA

INTRODUCTION

Black emerging adults (18-28 years) have the highest risk of short sleep duration and obesity. This increased risk may be partly explained by greater stress levels, which may result from race-related stress (racial discrimination and heightened race-related vigilance) or living in more disadvantaged home and neighbourhood environments. Insufficient sleep may also impact obesity risk via several weight-related mechanisms including energy balance, appetite and food reward, cortisol profiles and hydration status. This paper describes the rationale, design and methods for the Sleep, Health Outcomes and Body Weight (SHOW) study. This study aims to prospectively assess the effects of sleep, race-related stress and home/neighbourhood environments on weight-related mechanisms and obesity markers (body weight, waist circumference and fat mass) in 150 black emerging adults.

METHODS AND ANALYSIS

The SHOW study follows a measurement burst design that includes 3, 7-day data collection bursts (baseline, 6-month and 12-month follow-ups). Sleep is measured with three methods: sleep diary, actigraphy and polysomnography. Energy balance over 7 days is based on resting and postprandial energy expenditure measured via indirect calorimetry, physical activity via accelerometry and self-reported and ad libitum energy intake methods. Self-reported methods and blood biomarkers assess fasting and postprandial appetite profiles and a behavioural-choice task measures food reward. Cortisol awakening response and diurnal cortisol profiles over 3 days are assessed via saliva samples and chronic cortisol exposure via a hair sample. Hydration markers are assessed with 24-hour urine collection over 3 days and fasting blood biomarkers. Race-related stress is self-reported over 7 days. Home and neighbourhood environments (via the Windshield Survey) is observer assessed.

ETHICS AND DISSEMINATION

Ethics approval was granted by the University of North Carolina at Greensboro's Institutional Review Board. Study findings will be disseminated through peer-reviewed publications, presentations at scientific meetings and reports, briefs/infographics for lay and community audiences.

Prevalence and utility of overnight pulse oximetry as a screening tool for obstructive sleep apnoea in newly diagnosed idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a condition of raised intracranial pressure (ICP). Obstructive sleep apnoea (OSA) has been shown to cause episodic rises in ICP and is frequently reported in patients with IIH. The aim of this study is to identify the prevalence of OSA in a cohort of IIH patients.

METHODS

We conducted a retrospective case notes review as part of a service evaluation of newly diagnosed IIH patients who were all referred for OSA screening with overnight pulse oximetry. The 3% oxygen desaturation index (3% ODI) was used to evaluate the presence and severity of OSA. The clinical outcomes of patients who received continuous positive airway pressure (CPAP) therapy as treatment for OSA were reviewed.

RESULTS

In our cohort of newly diagnosed IIH patients, the yield of overnight pulse oximetry as a screening tool was 48.6% for OSA and 15.3% for moderate to severe OSA. We found that age (p = 0.0008), BMI (p < 0.0001), vitamin B₁₂ (p = 0.0183), and a higher Epworth Sleep Score (p = 0.0269) correlated with more severe OSA. Eleven (10%) patients had CPAP therapy and those with good adherence alongside weight loss or medical therapy found improvements in symptoms of raised ICP.

CONCLUSION

We report the largest series of consecutive IIH patients screened for OSA using overnight pulse oximetry. The high rate of OSA highlights a potential role for the recognition and management of OSA in the IIH patient cohort. Further studies on the potential contribution of OSA as a cause of raised ICP in the IIH cohort is warranted.

The association between daytime sleep and general obesity risk differs by sleep duration in Iranian adults

BACKGROUND

Sleep duration and daytime napping and obesity are related to adiposity; however, it is not clear whether the association between daytime napping and adiposity measures can differ by sleep duration.

AIM

To clarify the association between daytime napping and general and abdominal obesity based on sleep duration of participants.

SUBJECTS AND METHODS

This cross-sectional study was conducted on 1,683 individuals (837 men and 846 women) aged ≥ 35 years. Height, weight and waist circumference (WC) were measured according to the standard protocols. Body mass index (BMI) was calculated. Self-reported sleep duration (in a 24-hour cycle) was recorded. The odds of general and abdominal obesity were compared between nappers and non-nappers, stratified by their sleep duration (≤ 6 h, 6-8 h, ≥ 8 h).

RESULTS

The mean (SD) age of participants was 47.48 ± 9.35 years. Nappers with a short sleep duration (≤ 6 h) had greater BMI and higher risk for overweight/obesity compared with counterpart non-nappers after adjustment for potential confounders (OR = 1.61, 95% CI = 1.07-2.41). In subjects with moderate sleep duration (6-8 h), nappers had a tendency towards higher BMI in comparison with non-nappers (28.04 ± 0.25 vs. 26.93 ± 0.51 kg/m²; p = 0.05), however, no significant difference was observed for the risk of obesity. Daytime napping was not related to the risk of obesity in long sleepers. No significant association was observed for abdominal obesity measures.

CONCLUSIONS

Daytime napping is associated with increased risk of overweight/obesity in short sleepers. However, in subjects with longer sleep duration, it is not related to the risk of overweight/obesity.

Lifestyle management in polycystic ovary syndrome - beyond diet and physical activity

Polycystic ovary syndrome (PCOS) is a common condition affecting reproductive-aged women with reproductive, metabolic and psychological consequences. Weight and lifestyle (diet, physical activity and behavioural) management are first-line therapy in international evidence-based guidelines for PCOS. While these recommend following population-level diet and physical activity guidelines, there is ongoing interest and research in the potential benefit of including psychological and sleep interventions, as well as a range of traditional, complimentary and integrative medicine (TCIM) approaches, for optimal management of PCOS. There is limited evidence to recommend a specific diet composition for PCOS with approaches including modifying protein, carbohydrate or fat quality or quantity generally having similar effects on the presentations of PCOS. With regards to physical activity, promising evidence supports the provision of vigorous aerobic exercise, which has been shown to improve body composition, cardiorespiratory fitness and insulin resistance. Psychological and sleep interventions are also important considerations, with women displaying poor emotional wellbeing and higher rates of clinical and subclinical sleep disturbance, potentially limiting their ability to make positive lifestyle change. While optimising sleep and emotional wellbeing may aid symptom management in PCOS, research exploring the efficacy of clinical interventions is lacking. Uptake of TCIM approaches, in particular supplement and herbal medicine use, by women with PCOS is growing. However, there is currently insufficient evidence to support integration into routine clinical practice. Research investigating inositol supplementation have produced the most promising findings, showing improved metabolic profiles and reduced hyperandrogenism. Findings for other supplements, herbal medicines, acupuncture and yoga is so far inconsistent, and to reduce heterogeneity more research in specific PCOS populations, (e.g. defined age and BMI ranges) and consistent approaches to intervention delivery, duration and comparators are needed. While there are a range of lifestyle components in addition to population-recommendations for diet and physical activity of potential benefit in PCOS, robust clinical trials are warranted to expand the relatively limited evidence-base regarding holistic lifestyle management. With consumer interest in holistic healthcare rising, healthcare providers will be required to broaden their knowledge pertaining to how these therapies can be safely and appropriately utilised as adjuncts to conventional medical management.

A study on the effects of health behavior and sports participation on female college students' body mass index and healthy promoting lifestyle

Objective

Life form and body composition may affect the health of college students. This study will explore the relationship between the demographic variables of female college students and their body composition and health promoting lifestyle, so as to provide useful reference for the future design and planning of college students' physical and mental health courses and improving their physical activity level.

Methods

Using the method of questionnaire and bioelectrical resistance measurement, a questionnaire on healthy lifestyle of college students was constructed on the basis of consulting a large number of relevant research literature. Relevant survey samples were obtained through random sampling, and their body composition was measured; use SPSS21.0 statistical analysis software to conduct statistical analysis on relevant indicators.

Results and conclusions

(1) at present, female college students generally lack leisure activities and sleep, the proportion of regular fitness habits is low, and the number of snacks and average daily online time are generally too high; The overweight rate and body fat rate of female college students are generally too high, while the standard rate of muscle weight is generally too low. (2) Female college students' health promoting lifestyle has the highest score of self-realization, followed by interpersonal support and the worst behavior of sports participation; The older the college students, the worse their sports participation and overall health promotion behavior; The better the Conscious health status, the better the self-realization, exercise participation and nutritional behavior; The more exercise time per day, the higher their participation in sports and the stronger their health responsibility; The more time spent on the Internet every day, the worse the health responsibility and sports participation. (3) The more time female college students spend on the Internet every day, the higher the probability of overweight. Those with regular exercise habits have a lower proportion of overweight and high body fat rate, while the better their sleep and night snack behavior, the lower their body fat rate. The older college students are, the larger their visceral fat area is, the better their exercise habits and sleep behavior are, the smaller their visceral fat area is, and the lower their visceral fat level is.

The relationship between sleep and appetitive conditioning: A systematic review and meta-analysis

This systematic review and meta-analysis (PROSPERO registration animal/human studies: CRD42021234793/CRD42021234790) examined the relationship between sleep and appetitive conditioning. Inclusion criteria included: a) appetitive conditioning paradigm; b) measure of conditioning; c) sleep measurement and/or sleep loss; d) human and/etor non-human animal samples; and e) written in English. Searches of seven databases returned 3777 publications. The final sample consisted of 42 studies using primarily animal samples and involving food- and drug-related conditioning tasks. We found sleep loss disrupted appetitive conditioning of food rewards (p < 0.001) but potentiated appetitive conditioning of drug rewards (p < 0.001). Furthermore, sleep loss negatively impacted extinction learning irrespective of the reward type. Post-learning sleep was associated with increases in REM sleep (p = 0.02). Findings suggest sleep loss potentiates the impact of psychoactive substances in a manner likely to produce an increased risk of problematic substance use. In obese/overweight populations, sleep loss may be associated with deficits in the conditioning and extinction of reward-related behaviours. Further research should assess the relationship between sleep and appetitive conditioning in humans.

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.

The role of sleep in PCOS: what we know and what to consider in the future

INTRODUCTION

Sleep disturbance and clinical sleep conditions disrupt endocrine signals, energy expenditure and nutritional intake. Women with polycystic ovary syndrome (PCOS) are at higher risk of sleep disturbances and clinical conditions. It is possible that sleep may contribute to the exacerbation of PCOS. This review aims to explore the relationship between sleep and chronic disease, particularly in women with PCOS.

AREAS COVERED

This review narratively explores what sleep is, how to measure sleep and the possible mechanisms that support the link between sleep in adipose tissue deposition, insulin resistance and the presentation of PCOS.

EXPERT OPINION

Research shows that disturbed sleep and clinical sleep conditions disrupt energy expenditure. This may increase adipose tissue deposition and exacerbate insulin resistance which are known to worsen the presentation of PCOS. Further, sleep disturbance in women with PCOS may ameliorate any positive lifestyle changes made after diagnosis. Cognitive behavioural therapy interventions for sleep are a successful strategy for the management of sleep disturbances in the general population. However, such interventions are yet to be trialled in women with PCOS. Given the proposed implications, interventions to improve sleep could provide additional support for women with PCOS to successfully implement lifestyle strategies and should be further investigated.

Assessment of sex differences in associations between sleep duration and lipid/glucose metabolism in urban Japan: a cross-sectional study

Inadequate sleep durations (short or long) are related to worsening of lipid/glucose metabolism, leading to atherosclerotic cardiovascular diseases (ASCVD). Few data exist on sex differences in this relationship that, to date, has been scarcely reported. This cross-sectional study included 6678 men and 4700 women at the Health Planning Center of Nihon University Hospital, located in the center of Tokyo, between September 2015 and October 2016. The prevalence of diabetes and dyslipidemia in the participants was 3.3% and 6.5%, respectively. Sleep duration was divided into five categories: < 5 h, 5-6 h, 6-7 h, 7-8 h, and ≥ 8 h. We examined the odds ratio (OR) and 95% confidence interval (CI) of lipid/glucose metabolism-related markers for the reference value defined in each guideline with 6-7 h as the reference of comparison. In men, a sleep duration of < 5 h was associated with ORs of 1.32 and 1.33 (95% CI, 1.01-1.73 and 1.02-1.74) for LDL-C level ≥ 120 mg/dL and non-HDL-C level of ≥ 150 mg/dL (defined as "borderline hyper" by the Japan Atherosclerosis Society Guidelines for Prevention of ASCVD 2017), respectively. Moreover, a sleep duration of < 5 h was associated with an OR of 1.77 (1.33-2.35) for fasting blood glucose of ≥ 100 mg/dL (defined as "high" by a specialized lifestyle checkup program in Japan). In women, sleep duration of < 5 h was associated with an OR of 1.70 (1.24-2.33) for HbA1c level of ≥ 5.6% (defined as "high" by a specialized life style checkup program in Japan). However, there was no association between sleep duration and serum lipid profile. Inadequate short sleep duration was as a potential risk factor of adverse lipid and/or glucose metabolism in both sexes. However, there were sex differences in associations between sleep duration and lipid/glucose metabolism in urban Japan. To further reduce risks of ASCVD, it is of particular importance to emphasize adequate sleep duration in both sexes.Trial registration UMIN ( http://www.umin.ac.jp/ ) Study ID: UMIN000037643 retrospectively registered on August 9, 2019.

Timing and Length of Nocturnal Sleep and Daytime Napping and Associations With Obesity Types in High-, Middle-, and Low-Income Countries

IMPORTANCE

Obesity is a growing public health threat leading to serious health consequences. Late bedtime and sleep loss are common in modern society, but their associations with specific obesity types are not well characterized.

OBJECTIVE

To assess whether sleep timing and napping behavior are associated with increased obesity, independent of nocturnal sleep length.

DESIGN, SETTING, AND PARTICIPANTS

This large, multinational, population-based cross-sectional study used data of participants from 60 study centers in 26 countries with varying income levels as part of the Prospective Urban Rural Epidemiology study. Participants were aged 35 to 70 years and were mainly recruited during 2005 and 2009. Data analysis occurred from October 2020 through March 2021.

EXPOSURES

Sleep timing (ie, bedtime and wake-up time), nocturnal sleep duration, daytime napping.

MAIN OUTCOMES AND MEASURES

The primary outcomes were prevalence of obesity, specified as general obesity, defined as body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 30 or greater, and abdominal obesity, defined as waist circumference greater than 102 cm for men or greater than 88 cm for women. Multilevel logistic regression models with random effects for study centers were performed to calculate adjusted odds ratios (AORs) and 95% CIs.

RESULTS

Overall, 136 652 participants (81 652 [59.8%] women; mean [SD] age, 51.0 [9.8] years) were included in analysis. A total of 27 195 participants (19.9%) had general obesity, and 37 024 participants (27.1%) had abdominal obesity. The mean (SD) nocturnal sleep duration was 7.8 (1.4) hours, and the median (interquartile range) midsleep time was 2:15 am (1:30 am-3:00 am). A total of 19 660 participants (14.4%) had late bedtime behavior (ie, midnight or later). Compared with bedtime between 8 pm and 10 pm, late bedtime was associated with general obesity (AOR, 1.20; 95% CI, 1.12-1.29) and abdominal obesity (AOR, 1.20; 95% CI, 1.12-1.28), particularly among participants who went to bed between 2 am and 6 am (general obesity: AOR, 1.35; 95% CI, 1.18-1.54; abdominal obesity: AOR, 1.38; 95% CI, 1.21-1.58). Short nocturnal sleep of less than 6 hours was associated with general obesity (eg, <5 hours: AOR, 1.27; 95% CI, 1.13-1.43), but longer napping was associated with higher abdominal obesity prevalence (eg, ≥1 hours: AOR, 1.39; 95% CI, 1.31-1.47). Neither going to bed during the day (ie, before 8pm) nor wake-up time was associated with obesity.

CONCLUSIONS AND RELEVANCE

This cross-sectional study found that late nocturnal bedtime and short nocturnal sleep were associated with increased risk of obesity prevalence, while longer daytime napping did not reduce the risk but was associated with higher risk of abdominal obesity. Strategic weight control programs should also encourage earlier bedtime and avoid short nocturnal sleep to mitigate obesity epidemic.

Factors associated with seeking medical care for low back pain in a twin adult sample

BACKGROUND

Previous studies have only investigated how symptom presentation and socio-demographic factors influence care-seeking for low back pain (LBP). However, the influence of health and lifestyle factors remains unclear, and the potential confounding effects of aggregated familial factors (including genetics and the early shared environment) has not been considered extensively.

METHODS

A cross-sectional analysis was performed on 1605 twins enrolled in the Murcia Twin Registry (Spain). The outcome was seeking medical care for LBP and various self-reported demographic, health and lifestyle factors were considered predictors. All variables except sleep quality and diabetes were collected in 2013, which were cross-referenced from 2009 to 2010. A multivariate logistic regression model was performed on the total sample, followed by a co-twin case-control analysis.

RESULTS

The only significant factor found to increase the odds of seeking medical care for LBP without being affected by familial factors was poor sleep quality (total sample OR = 1.58, 95%CI 1.24-2.01; case-control OR = 1.75, 95%CI 1.14-2.69). The factors that were associated with reduced odds of seeking medical care for LBP and not confounded by familial factors were male sex (case-control OR = 0.55, 95%CI 0.33-0.93), alcohol intake (case-control OR = 0.90, 95%CI 0.82-0.99) and a history of diabetes (case-control OR = 0.50, 95%CI 0.25-0.97). No other factors significantly influenced medical care-seeking for LBP.

CONCLUSIONS

People reporting poor sleep quality are more likely to seek medical care for LBP in the long term, with this relationship being independent from aggregated familial factors. Conversely, males, people reporting higher alcohol intake, and people with a history of diabetes are less likely to seek medical care for LBP.

SIGNIFICANCE

This is the first study investigating the factors that influence seeking medical care for LBP, while adjusting for the influence of familial factors using a co-twin control design. Poor sleep quality is associated with seeking medical care for LBP in the long term and does not appear to be confounded by familial factors. Early screening for indicators of poor sleep quality and appropriate referral to interventions for improving sleep quality or reducing pain in sleep may improve LBP management.

Chronotherapeutic efficacy of suvorexant on sleep quality and metabolic parameters in patients with type 2 diabetes and insomnia

AIMS

This study aimed to assess the chronotherapeutic efficacy of suvorexant on subjective sleep parameters and metabolic parameters in patients with type 2 diabetes and insomnia.

METHODS

Thirteen patients with type 2 diabetes who met the Pittsburg Sleep Quality index criteria for primary insomnia took suvorexant 20 mg/day (15 mg/day for ≥65 years) for 14 ± 2 weeks. The following parameters were assessed before and after the treatment: sleep diary for sleep duration and quality (i.e., sleep onset latency, waking after sleep onset, and sleep efficiency [sSE]), Insomnia Severity Index, clinical and biochemical data, continuous glucose monitoring (CGM), and validated self-administered questionnaire on food intake.

RESULTS

Suvorexant significantly improved sSE, abdominal circumference, and sucrose intake (all p < 0.05), but did not change HbA1c, CGM parameters, or body weight. Correlation analysis revealed that changes in sSE were associated with those in HbA1c and body weight (r = -0.61 and r = -0.66, respectively; both p < 0.05).

CONCLUSIONS

Suvorexant significantly improved sleep quality and obesity-associated parameters in patients with type 2 diabetes in 14 weeks. Improvements in sleep quality were associated with improvements in glycemic control. Sleep disorder treatment using suvorexant may provide metabolic benefits for patients with type 2 diabetes.

Novel anthropometric parameters to define obesity and obesity-related disease in adults: a systematic review

Context

Obesity is defined as an abnormal or excessive accumulation of body fat. Traditionally, it has been assessed using a wide range of anthropometric, biochemical, and radiological measurements, with each having its advantages and disadvantages.

Objective

A systematic review of the literature was conducted to identify novel anthropometric measurements of obesity in adults.

Data Sources

Using a combination of MeSH terms, the PubMed database was searched.

Data Extraction

The current systematic review was conducted in accordance with the PRISMA guidelines. The data extracted from each study were (1) details of the study, (2) anthropometric parameter(s) evaluated, (3) study methods, (4) objectives of the study and/or comparisons, and (5) main findings/conclusions of the study.

Data Analysis

The search yielded 2472 articles, of which 66 studies were deemed eligible to be included. The literature search identified 25 novel anthropometric parameters. Data on novel anthropometric parameters were derived from 26 countries. Majority were descriptive cross-sectional studies (n = 43), while 22 were cohort studies. Age range of the study populations was 17–103 years, while sample size varied from 45 to 384 612.

Conclusions

The novel anthropometric parameters identified in the present study showed variable correlation with obesity and/or related metabolic risk factors. Some parameters involved complex calculations, while others were derived from traditional anthropometric measurements. Further research is required in order to determine the accuracy and precision.

Association Between Sleep and Obesity in African Americans in the Jackson Heart Study

BACKGROUND

In the United States, data from the National Health and Nutrition Examination Survey suggest that 68% of adults are overweight and obese. Obesity has been shown in previous cross-sectional and longitudinal studies to be influenced by short sleep duration, which can lead to unregulated appetite, excessive eating during awake time, and decreased energy expenditure.

OBJECTIVE

To examine the associations among sleep duration, sleep quality, body mass index (BMI), and waist circumference (WC) in African Americans.

METHODS

The sample included participants in the Jackson Heart Study. During a clinic visit, the sleep habits of participants were recorded via a sleep history questionnaire, and BMI and WC measurements were also recorded. Multivariate analysis was used to examine the associations among sleep duration, sleep quality, general obesity (measured by BMI), and abdominal obesity (measured by WC).

RESULTS

The authors studied participants who provided data for the variables of interest (N=3778; 1363 men and 2415 women). Of all participants, 3317 (87.8%) were overweight, and 2149 (56.9%) were obese. The mean (SD) BMI was 32.1 (7.2) kg/m2, and the mean (SD) WC was 103.3 (16.0) cm. Mean sleep duration was 6.3 (1.4) hours for men and 6.4 (1.5) hours for women. Among the men, a significant negative relationship was found between sleep duration and body composition: longer sleep was associated with lower BMI levels but negatively associated with WC in men (β=-1.06; P<.01)]. Sleep quality was positively associated with WC in men (β=1.20; P<.01) and women (β=0.61; P<.05).

CONCLUSIONS

This study's findings highlight the high rate of overweight and obesity among participants in the Jackson Heart Study. About one-fourth of the participants described themselves as enjoying ideal health. In men, longer sleep duration was associated with lower BMI levels and lower WC; in both men and women, good sleep quality was associated with lower WC. However, more research is needed to examine sleep and body composition as risk factors for disease development in African Americans.

Short sleep-poor sleep? A polysomnographic study in a large population-based sample of women

There is a lack of studies on the association between total sleep time (TST) and other polysomnographical parameters. A key question is whether a short sleep is an expression of habitual short sleep, or whether it reflects temporary impairment. The purpose of the present study was to investigate the association between TST and amount of sleep stages and sleep continuity measures, in a large population-based sample of women (n = 385), sleeping at home in a normal daily life setting. The results show that sleep efficiency, N1 (min), N2 (min), REM (min), REM% and proportion of long sleep segments, increased with increasing TST, whereas the number of awakenings/hr, the number of arousals/hr, N1% and REM intensity decreased. In addition, longer sleep was more associated with TST being perceived as of "usual" duration and with better subjective sleep quality. TST was not associated with habitual reported sleep duration. It was concluded that short TST of a recorded sleep in a real-life context may be an indicator of poor objective sleep quality for that particular sleep episode. Because individuals clearly perceived this reduction, it appears that self-reports of poor sleep quality often may be seen as indicators of poor sleep quality. It is also concluded that PSG-recorded sleep duration does not reflect habitual reported sleep duration in the present real-life context.

Habitual Sleep Measures are Associated with Overall Body Fat, and not Specifically with Visceral Fat, in Men and Women

OBJECTIVE

This study aimed to investigate the associations of sleep duration and sleep quality with visceral adipose tissue (VAT) in middle-aged individuals.

METHODS

In this cross-sectional analysis of baseline measurements of the Netherlands Epidemiology of Obesity (NEO) study, participants underwent anthropometry and completed the Pittsburgh Sleep Quality Index (PSQI) for assessing short sleep duration (as sex-specific age-adjusted percentiles) and poor quality (PSQI > 5). VAT was assessed by magnetic resonance imaging in a random subgroup. We performed linear regression analyses to examine associations of short sleep and poor sleep with measures of body fat, adjusted for confounding, including total body fat in models with VAT.

RESULTS

A total of 5,094 participants (52% women; mean age of 56 [SD 6] years), 1,947 of whom had VAT measurements, were analyzed. The difference in VAT between poor sleep (PSQI > 5) and good sleep (PSQI ≤ 5) was 7.2cm² (95% CI: 1.2-13.8) in women and 16.1cm² (95% CI: 6.2-26.0) in men. These differences attenuated toward the null after the adjustment for total body fat. Similar patterns of associations were observed for short sleep (lowest 10% compared with median 60%).

CONCLUSIONS

Our results suggest that measures of sleep are not specifically associated with a higher amount of VAT.

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.

Sleeping oxygen saturation, rapid eye movement sleep, and the adaptation of postprandial metabolic function in insulin sensitive and resistant individuals without diabetes

AIMS

Sleeping oxygen saturation (SaO₂) and sleep stage duration have been linked with prediabetic alterations but the pathogenic pathways are not well understood. This study of insulin sensitive and resistant adults examined the effect on postprandial metabolic regulation of repeated mixed-meal challenges of different carbohydrate loading. The aim was to examine whether the relationship between lower sleeping oxygen saturation (SaO₂) and poorer fasting and postprandial metabolic function may be linked with reduced slow wave sleep (SWS) and rapid eye movement (REM) duration, independent of age, sex and total adiposity.

METHODS

The 24 men and women, aged 25-54 years, had no diabetes or other diagnosed conditions, were evaluated with polysomnography to derive indices of SaO₂ and sleep architecture. In addition, an OGTT and two 14-h serial mixed-meal tests were administered over 3 successive in-patient days. The carbohydrate content of the mixed-meals was manipulated to compare a standard-load day with a double-load day (300 vs. 600 kcal/meal). Quantitative modeling was applied to derive β-cell glucose sensitivity (β-GS), early insulin secretion rate sensitivity (ESRS), and total postprandial insulinemia (AUC_INS).

RESULTS

Analyses showed that, for the 14-h tests, the SaO₂ relationship with metabolic outcomes was associated significantly with percent time spent in REM but not SWS, independent of age, sex and total adiposity. Specifically, indirect pathways indicated that lower SaO₂ was related to shorter REM duration, and shorter REM was respectively associated with higher β-GS, ESRS, and AUC_INS for the 300- and 600-load days (300 kcal/meal: β = -8.68, p < .03, β = -8.54, p < .002, and β = -10.06, p < .008; 600 kcal/meal: β = -11.45, p < .003, β = -11.44, p < .001, and β = -11.00, p < .03).

CONCLUSION

Sleeping oxygen desaturation and diminished REM duration are associated with a metabolic pattern that reflects a compensatory adaptation of postprandial insulin metabolism accompanying preclinical diabetic risk.

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.

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.

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).

Association between Sleep and Body Weight: A Panel Data Model Based on a Retrospective Longitudinal Cohort of Chinese Infants

The focus of this article is on sleep duration and sleep problems in infants and their association with body weight. A retrospective birth cohort of 519 infants was enrolled in a community-based study conducted in Changsha, China. Infant weight and other health-related information were collected during regular standard checkups at the Community Health Service Centers when infants were 1, 3, 6, 8, and 12 months old. The sleep duration and sleep problems of infants were assessed by maternal self-reports. Panel data model was used to evaluate the association of sleep duration and sleep problems with infant body weight. Significant relevance between self-reported sleep duration and weight of infants has been reported in the literature tested by the fixed effects model (p < 0.01). However, this study indicated that sleep problems of infants had no effect on their weight (p = 0.151), after adjusting feeding patterns and socioeconomic factors of their families. This paper argues that, as a potentially modifiable risk factor, infant sleep duration deserves more attention from their parents and families in order to prevent and control overweight or obesity in infants as well as reducing the incidence of obesity in adults.

Actigraphy Measured Sleep Indices and Adiposity: The Multi-Ethnic Study of Atherosclerosis (MESA)

STUDY OBJECTIVES

To investigate the cross-sectional relationship between objectively measured sleep characteristics and multiple indices of adiposity in racially/ethnically diverse older adults within the MESA Sleep study (n = 2,146).

METHODS

7-day actigraphy was used to assess sleep duration, sleep efficiency, and night-to-night variability. Body mass index (BMI), waist circumference, and total body fat were modeled continuously and according to obesity cut-points. Models were adjusted for demographic, socioeconomic, and behavioral variables.

RESULTS

Participants who slept less than 6 hours a night had significantly higher BMI, waist circumference, and body fat relative to those who slept 7-8 hours. Those who slept less than 5 hours had a 16% higher prevalence of general obesity (BMI ≥ 30 vs. < 25 kg/m(2)) (95% [CI]: 0.08-0.24) and a 9% higher prevalence of abdominal obesity (waist circumference: women ≥ 88 centimeters, men ≥ 102 centimeters; 95% CI: 0.03-0.16) compared to those who slept 7-8 hours. Results were similar for sleep efficiency and night-to-night sleep variability.

CONCLUSIONS

Among an older multi-ethnic cohort, we found robust associations across multiple indices of sleep and adiposity. Targeting sleep characteristics may be of benefit in obesity interventions, but more research is needed to rule out reverse causality.

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.

Effect of Slow Wave Sleep Disruption on Metabolic Parameters in Adolescents

STUDY OBJECTIVES

Cross-sectional studies report a correlation between slow wave sleep (SWS) duration and insulin sensitivity (SI) in children and adults. Suppression of SWS causes insulin resistance in adults but effects in children are unknown. This study was designed to determine the effect of SWS fragmentation on SI in children.

METHODS

Fourteen pubertal children (11.3-14.1 y, body mass index 29(th) to 97(th) percentile) were randomized to sleep studies and mixed meal (MM) tolerance tests with and without SWS disruption. Beta-cell responsiveness (Φ) and SI were determined using oral minimal modeling.

RESULTS

During the disruption night, auditory stimuli (68.1 ± 10.7/night; mean ± standard error) decreased SWS by 40.0 ± 8.0%. SWS fragmentation did not affect fasting glucose (non-disrupted 76.9 ± 2.3 versus disrupted 80.6 ± 2.1 mg/dL), insulin (9.2 ± 1.6 versus 10.4 ± 2.0 μIU/mL), or C-peptide (1.9 ± 0.2 versus 1.9 ± 0.1 ng/mL) levels and did not impair SI (12.9 ± 2.3 versus 10.1 ± 1.6 10(-4) dL/kg/min per μIU/mL) or Φ (73.4 ± 7.8 versus 74.4 ± 8.4 10(-9) min(-1)) to a MM challenge. Only the subjects in the most insulin-sensitive tertile demonstrated a consistent decrease in SI after SWS disruption.

CONCLUSION

Pubertal children across a range of body mass indices may be resistant to the adverse metabolic effects of acute SWS disruption. Only those subjects with high SI (i.e., having the greatest "metabolic reserve") demonstrated a consistent decrease in SI. These results suggest that adolescents may have a unique ability to adapt to metabolic stressors, such as acute SWS disruption, to maintain euglycemia. Additional studies are necessary to confirm that this resiliency is maintained in settings of chronic SWS disruption.

Metabolic disturbances: role of the circadian timing system and sleep

The incidence of metabolic disorders such as obesity and diabetes is on the rise, and food quality is not alone to blame. Sleep disturbances, altered feeding time and circadian disruption are linked to metabolic disturbances in many clinical research studies and cross-sectional analyses. This review tried to summarize the role of the circadian timing system and sleep on energy and metabolic homeostasis. We also tried to explain the molecular and endocrine mechanisms behind circadian misalignment and sleep disorders that lead to metabolic disorders.

The Link Between Inadequate Sleep and Obesity in Young Adults

The prevalence of obesity has increased dramatically over the past decade. Although an imbalance between caloric intake and physical activity is considered a key factor responsible for the increase, there is emerging evidence suggesting that other factors may be important contributors to weight gain, including inadequate sleep. Overall research evidence suggests that inadequate sleep is associated with obesity. Importantly, the strength and trajectory of the association seem to be influenced by multiple factors including age. Although limited, the emerging evidence suggests young adults might be at the center of a "perfect health storm," exposing them to the highest risk for obesity and inadequate sleep. Unfortunately, the methods necessary for elucidating the complex relationship between sleep and obesity are lacking. Uncovering the underlying factors and trajectories between inadequate sleep and weight gain in different populations may help to identify the windows of susceptibility and to design targeted interventions to prevent the negative impact of obesity and related diseases.

Percentage of REM sleep is associated with overnight change in leptin

Sleep contributes importantly to energy homeostasis, and may impact hormones regulating appetite, such as leptin, an adipocyte-derived hormone. There is increasing evidence that sleep duration, and reduced rapid eye movement sleep, are linked to obesity. Leptin has central neural effects beyond modulation of appetite alone. As sleep is not a unifrom process, interactions between leptin and sleep stages including rapid eye movement sleep may play a role in the relationship between sleep and obesity. This study examined the relationship between serum leptin and rapid eye movement sleep in a sample of healthy adults. Participants were 58 healthy adults who underwent polysomnography. Leptin was measured before and after sleep. It was hypothesized that a lower percentage of rapid eye movement sleep would be related to lower leptin levels during sleep. The relationship between percentage of rapid eye movement sleep and leptin was analysed using hierarchical linear regression. An increased percentage of rapid eye movement sleep was related to a greater reduction in leptin during sleep even when controlling for age, gender, percent body fat and total sleep time. A greater percentage of rapid eye movement sleep was accompanied by more marked reductions in leptin. Studies examining the effects of selective rapid eye movement sleep deprivation on leptin levels, and hence on energy homeostasis in humans, are needed.

Habitual sleep variability, mediated by nutrition intake, is associated with abdominal obesity in adolescents

OBJECTIVE

To investigate habitual sleep duration (HSD) and habitual sleep variability (HSV) in relation to abdominal obesity and nutrient intake as mediating factors in adolescents.

METHODS

We analyzed data from 305 adolescents who participated in the Penn State Child Cohort follow-up examination. An actigraphy device was used for seven consecutive nights to calculate HSD and HSV. Abdominal obesity was assessed by dual-energy x-ray absorptiometry. The Youth/Adolescent Food Frequency Questionnaire was used to obtain daily total caloric, protein, fat, and carbohydrates intakes. Linear regression models were used to associate HSD and HSV with abdominal obesity and to qualitatively identify mediating factors. The mediating effect was quantitatively estimated by mediation models.

RESULTS

After adjusting for major covariates and HSD, higher HSV was significantly associated with abdominal obesity measures. For example, with 1-hour increase in HSV, android/gynoid fat ratio and visceral fat area increased by 0.02 cm(2) (standard error = 0.01, p = 0.03) and 6.86 cm(2) (standard error = 2.82, p = 0.02), respectively. HSD was not associated with abdominal obesity in HSV-adjusted models. Total caloric, fat, and carbohydrate intakes were significant mediating factors. For instance, 20% of the association between HSV and visceral fat can be attributed to carbohydrate intake.

CONCLUSIONS

Higher HSV, not HSD, is significantly associated with abdominal obesity, which can be partially explained by increased caloric intake, especially from carbohydrate, in adolescents. This study suggests that more attention should be paid to establish and maintain regular sleep patterns in adolescents.

Sleep Deficiency is a Modifiable Risk Factor for Obesity and Cognitive Impairment and Associated with Elevated Visfatin

AIM

To study the interaction between sleep deprivation, obesity and cognitive functions, and the effect of following a balanced low caloric diet and increasing sleep duration on those variables.

SUBJECTS AND METHODS

Ninety two obese females with mean age 47.00 ± 2.00 years and body mass index (BMI) 36.14 ± 3.00 kg/m² were divided into 3 groups according to their sleeping hours. They followed balanced low-caloric diet and were instructed to increase sleeping hours. Full clinical examination, 24 hours dietary intake recall, anthropometric measurements, mini mental state test, questionnaire for subjective sleep and life style evaluation were performed at baseline and after 2 months. Serum visfatin, fasting blood glucose and C-peptide were assessed; Modified homeostatic model assessment of insulin resistance was calculated.

RESULTS

About one third of our sample slept less than 6 hours daily, group (1), all patients had elevated visfatin serum level (33.87 ± 2.8 ng/ml) with the highest level in group (1). At base line, group (1) showed the highest BMI, lowest cognitive functions, highest visfatin level and highest insulin resistance (P < 0.05). After 2 months of intervention, improvement was recorded in all variables, with the best improvement in group (1) after extending sleep duration (P < 0.05).

CONCLUSION

Sleep deprivation may be a modifiable risk factor for obesity, cognitive impairment and visfatin elevation.

Habitual sleep variability, not sleep duration, is associated with caloric intake in adolescents

OBJECTIVE

The objective of this study was to investigate the associations between objectively measured habitual sleep duration (HSD), habitual sleep variability (HSV), and energy and snack intake in adolescents.

METHODS

We used data from 324 adolescents who participated in the Penn State Child Cohort follow-up examination. Actigraphy was used over seven consecutive nights to estimate nightly sleep duration. The seven-night mean and standard deviation of sleep duration were used to represent HSD and HSV, respectively. The Youth/Adolescent Food Frequency Questionnaire was used to obtain the daily average total energy, protein, fat, and carbohydrate intake, and number of snacks consumed. Linear regression models were used to investigate the associations between habitual sleep patterns and caloric, protein, fat, and carbohydrate intake. Proportional odds models were used to associate habitual sleep patterns with snack consumption.

RESULTS

After adjusting for age, sex, race, body mass index (BMI) percentile, and smoking status, an increased HSV was associated with a higher energy intake, particularly from fat and carbohydrate. For example, with a 1-h increase in HSV, there was a 170 (66)-kcal increase in the daily total energy intake. An increased HSV was also related to increased snack consumption, especially snacks consumed after dinner. For instance, a 1-h increase in HSV was associated with 65% and 94% higher odds of consuming more snacks after dinner during school/workdays and weekends/vacation days, respectively. Neither energy intake nor snack consumption was significantly related to HSD.

CONCLUSION

High habitual sleep variability, not habitual sleep duration, is related to increased energy and food consumption in adolescents. Maintaining a regular sleep pattern may decrease the risk of obesity in adolescents.

The impact of sleep disorders on glucose metabolism: endocrine and molecular mechanisms

Modern lifestyle has profoundly modified human sleep habits. Sleep duration has shortened over recent decades from 8 to 6.5 hours resulting in chronic sleep deprivation. Additionally, irregular sleep, shift work and travelling across time zones lead to disruption of circadian rhythms and asynchrony between the master hypothalamic clock and pacemakers in peripheral tissues. Furthermore, obstructive sleep apnea syndrome (OSA), which affects 4 - 15% of the population, is not only characterized by impaired sleep architecture but also by repetitive hemoglobin desaturations during sleep. Epidemiological studies have identified impaired sleep as an independent risk factor for all cause of-, as well as for cardiovascular, mortality/morbidity. More recently, sleep abnormalities were causally linked to impairments in glucose homeostasis, metabolic syndrome and Type 2 Diabetes Mellitus (T2DM). This review summarized current knowledge on the metabolic alterations associated with the most prevalent sleep disturbances, i.e. short sleep duration, shift work and OSA. We have focused on various endocrine and molecular mechanisms underlying the associations between inadequate sleep quality, quantity and timing with impaired glucose tolerance, insulin resistance and pancreatic β-cell dysfunction. Of these mechanisms, the role of the hypothalamic-pituitary-adrenal axis, circadian pacemakers in peripheral tissues, adipose tissue metabolism, sympathetic nervous system activation, oxidative stress and whole-body inflammation are discussed. Additionally, the impact of intermittent hypoxia and sleep fragmentation (key components of OSA) on intracellular signaling and metabolism in muscle, liver, fat and pancreas are also examined. In summary, this review provides endocrine and molecular explanations for the associations between common sleep disturbances and the pathogenesis of T2DM.

Objectively Measured Sleep Patterns in Young Adult Women and the Relationship to Adiposity

Purpose.

The purpose of this study was to examine the relationship between sleep patterns and adiposity in young adult women.

Design.

Cross-sectional.

Setting.

The study took place at two Mountain West region universities and surrounding communities.

Subjects.

Subjects were 330 young adult women (20.2 ± 1.5 years).

Measures.

Sleep and physical activity were monitored for 7 consecutive days and nights using actigraphy. Height and weight were measured directly. Adiposity was assessed using the BOD POD.

Analysis.

Regression analysis, between subjects analysis of variance, and structural equation modeling were used.

Results.

Bivariate regression analysis demonstrated that sleep efficiency was negatively related to adiposity and that the 7-day standard deviations of bedtime, wake time, and sleep duration were positively related to adiposity (p < .05). Controlling for objectively measured physical activity strengthened the relationship between sleep duration and adiposity by 84% but had a statistically negligible impact on all other relationships that were analyzed. However, multivariate structural equation modeling indicated that a model including sleep efficiency, sleep pattern inconsistency (latent variable consisting of the 7-day standard deviations of bedtime, wake time, and sleep duration), and physical activity was the best for predicting percent body fat.

Conclusion.

Inconsistent sleep patterns and poor sleep efficiency are related to adiposity. Consistent sleep patterns that include sufficient sleep may be important in modifying risk of excess body fat in young adult women.

Sleep debt and obesity

Short sleep duration has been shown to be associated with elevated body mass index (BMI) in many epidemiological studies. Several pathways could link sleep deprivation to weight gain and obesity, including increased food intake, decreased energy expenditure, and changes in levels of appetite-regulating hormones, such as leptin and ghrelin. A relatively new factor that is contributing to sleep deprivation is the use of multimedia (e.g. television viewing, computer, and internet), which may aggravate sedentary behavior and increase caloric intake. In addition, shift-work, long working hours, and increased time commuting to and from work have also been hypothesized to favor weight gain and obesity-related metabolic disorders, because of their strong link to shorter sleep times. This article reviews the epidemiological, biological, and behavioral evidence linking sleep debt and obesity.

Predictive equations for central obesity via anthropometrics, stereovision imaging and MRI in adults

OBJECTIVE

Abdominal visceral adiposity is related to risks for insulin resistance and metabolic perturbations. Magnetic resonance imaging (MRI) and computed tomography are advanced instruments that quantify abdominal adiposity; yet field use is constrained by their bulkiness and costliness. The purpose of this study is to develop prediction equations for total abdominal, subcutaneous, and visceral adiposity via anthropometrics, stereovision body imaging (SBI), and MRI.

METHODS

Participants (67 men and 55 women) were measured for anthropometrics and abdominal adiposity volumes evaluated by MRI umbilicus scans. Body circumferences and central obesity were obtained via SBI. Prediction models were developed via multiple linear regression analysis, utilizing body measurements and demographics as independent predictors, and abdominal adiposity as a dependent variable. Cross-validation was performed by the data-splitting method.

RESULTS

The final total abdominal adiposity prediction equation was -470.28 + 7.10 waist circumference - 91.01 gender + 5.74 sagittal diameter (R2 = 89.9%), subcutaneous adiposity was -172.37 + 8.57 waist circumference - 62.65 gender - 450.16 stereovision waist-to-hip ratio (R2 =90.4%), and visceral adiposity was -96.76 + 11.48 central obesity depth - 5.09 central obesity width + 204.74 stereovision waist-to-hip ratio - 18.59 gender (R2 = 71.7%). R2 significantly improved for predicting visceral fat when SBI variables were included, but not for total abdominal or subcutaneous adiposity.

CONCLUSIONS

SBI is effective for predicting visceral adiposity and the prediction equations derived from SBI measurements can assess obesity.

Excessive daytime sleepiness in the elderly: association with cardiovascular risk, obesity and depression

OBJECTIVE: To observe the relationship between Excessive Daytime Sleepiness (EDS) and the presence of risk factors for cardiovascular dysfunction, depression and obesity in the elderly. METHODS: We interviewed 168 elderly from the community of Campina Grande, Paraíba. They were selected according to health districts in the period of 2010. We used the Epworth Sleepiness Scale to diagnose excessive daytime sleepiness (> 10 points); waist circumference for the risk of cardiovascular dysfunction (> 94 or > 80 cm); Geriatric Depression Scale for depression (>10 points) and body mass index for obesity (> 25 kg/m2). Association analysis was performed by the Chi-square test adjusted for sex and age group, adopting α < 0.05. RESULTS: One hundred and sixty eight elderly individuals with mean age of 72.34 ± 7.8 years old participated in this study, being 122 (72.6%) women. EDS was identified in 53 (31.5%) of them; depression, in 72 (42.9%); overweight/obesity, in 95 (64.46%); and risk of cardiovascular dysfunction, in 129 (79.6%). Depressed men (78.6%, p = 0.0005) and risk of cardiovascular dysfunction (57.1%, p = 0.02) were more prone to EDS. In women, only obesity was related to sleepiness (42.1%, p = 0.01). Only those aged between 70 - 79 years old showed association between sleepiness and obesity. CONCLUSION: It was found that obesity for women, and depression and cardiovascular dysfunction risking for men were associated with EDS in the elderly. The variable sex is a confusion condition for the association with sleepiness.

Polysomnographically determined sleep and body mass index in patients with insomnia

We assessed associations between polysomnographically determined sleep, especially the amount of slow-wave sleep (SWS), and body mass index (BMI) in patients with insomnia. One hundred and forty-one insomniacs and 55 healthy volunteers completed overnight polysomnographic recordings, and we measured height and body weight. No significant correlations were obtained between total sleep time and BMI among insomniacs. Compared with normal volunteers, insomnia patients exhibited longer sleep latency and shorter total sleep duration. While the two groups had no significant differences in BMI, insomniacs presented with more N1 but less time spend in SWS and rapid eye movement sleep (REMS). Based on their SWS time, we divided insomnia patients into three groups: short (26.99±13.88), intermediate (59.24±8.12), and long (102.21±26.17) SWS groups. The short-SWS group had significantly greater BMI than the long-SWS group. Further analyses with multiple linear regression showed a significant negative correlation between the amount of SWS and BMI scores in insomniacs, whereas no such correlation was found in healthy volunteers after controlling for potential confounds (e.g., age, sex and AHI). Our study suggests that low amounts of SWS may be associated with higher BMI in patients with insomnia.

Associations of self-reported and actigraphy-assessed sleep characteristics with body mass index and waist circumference in adults: moderation by gender

OBJECTIVES

Self-reported sleep duration has been linked to body mass index (BMI) and waist circumference in previous work; however, data regarding if these associations are stronger in men or women have been mixed, and few studies have objectively measured sleep. We investigated self-reported and actigraphy-assessed sleep characteristics in relation to BMI and waist circumference and examined the extent to which these associations differ by gender.

DESIGN

Archived cross-sectional data collected from 2004 to 2006 from the National Survey of Midlife Development in the United States (MIDUS) Biomarkers Study were used. Participants included 1248 adults (43% men) who reported their habitual sleep duration, and a subset of participants (N=441; 40% men) who underwent seven nights of wrist actigraphy.

RESULTS

Self-reported total sleep time (TST), actigraphy-assessed TST, and actigraphy-assessed sleep efficiency (SE) were inversely associated with BMI in the full sample of both men and women. Gender moderated associations between actigraphy assessments of sleep and anthropometric variables; however, TST and SE were related to BMI and waist circumference in women only. Associations between sleep and waist circumference were independent of BMI.

CONCLUSIONS

Sleep duration and sleep continuity are associated with body weight and distribution of body fat, but these associations were stronger or were only present in women.

Insomnia with objective short sleep duration: the most biologically severe phenotype of the disorder

Until recently, the association of chronic insomnia with significant medical morbidity was not established and its diagnosis was based solely on subjective complaints. We present evidence that insomnia with objective short sleep duration is the most biologically severe phenotype of the disorder, as it is associated with cognitive-emotional and cortical arousal, activation of both limbs of the stress system, and a higher risk for hypertension, impaired heart rate variability, diabetes, neurocognitive impairment, and mortality. Also, it appears that objective short sleep duration is a biological marker of genetic predisposition to chronic insomnia. In contrast, insomnia with objective normal sleep duration is associated with cognitive-emotional and cortical arousal and sleep misperception but not with signs of activation of both limbs of the stress system or medical complications. Furthermore, the first phenotype is associated with unremitting course, whereas the latter is more likely to remit. We propose that short sleep duration in insomnia is a reliable marker of the biological severity and medical impact of the disorder. Objective measures of sleep obtained in the home environment of the patient would become part of the routine assessment of insomnia patients in a clinician's office setting. We speculate that insomnia with objective short sleep duration has primarily biological roots and may respond better to biological treatments, whereas insomnia with objective normal sleep duration has primarily psychological roots and may respond better to psychological interventions alone.

Association between physical activity and metabolic syndrome among Malay adults in a developing country, Malaysia

OBJECTIVES

Metabolic syndrome is a highly prevalent health problem within the adult population in developing countries. We aimed to study the association of physical activity levels and metabolic risk factors among Malay adults in Malaysia.

DESIGN

Cross-sectional.

METHODS

Body mass index, waist circumference, and systolic/diastolic blood pressure, fasting blood glucose, fasting triglyceride and high-density lipoprotein cholesterol levels were measured in 686 Malay participants (aged 35-74 years). Self-reported physical activity was obtained with the validated International Physical Activity Questionnaire (Malay version) and categorized into low, moderate or high activity levels.

RESULTS

Individuals who were classified as overweight and obese predominated (65.6%). On the basis of the modified NCEP ATP III criteria, metabolic syndrome was diagnosed in 31.9% of all participants, of whom 46.1% were men and 53.9% were women. The prevalence of metabolic syndrome among participants with low, moderate or high activity levels was 13.3%, 11.7% and 7.0%, respectively (p<0.001). Statistically significant negative associations were found between a number of metabolic risk factors and activity categories (p<0.05). The odds ratios for metabolic syndrome in the moderate and high activity categories were 0.42 (95% CI: 0.27-0.65) and 0.52 (95% CI: 0.35-0.76), respectively, adjusted for gender.

CONCLUSIONS

Moderate and high activity levels were each associated with reduced odds for metabolic syndrome independent of gender. Although a slightly lower prevalence of metabolic syndrome was associated with high activity than with moderate activity, potential health benefits were observed when moderate activity was performed.