Association between reduced sleep and weight gain in women

Elevated ghrelin predicts food intake during experimental sleep restriction

OBJECTIVE

Sleep curtailment has been linked to obesity, but underlying mechanisms remain to be elucidated. This study assessed whether sleep restriction alters 24-h profiles of appetite-regulating hormones ghrelin, leptin, and pancreatic polypeptide during a standardized diet and whether these hormonal alterations predict food intake during ad libitum feeding.

METHODS

Nineteen healthy, lean men were studied under normal sleep and sleep restriction in a randomized crossover design. Blood samples were collected for 24 h during standardized meals. Subsequently, participants had an ad libitum feeding opportunity (buffet meals and snacks) and caloric intake was measured.

RESULTS

Ghrelin levels were increased after sleep restriction as compared with normal sleep (P < 0.01). Overall, sleep restriction did not alter leptin or pancreatic polypeptide profiles. Sleep restriction was associated with an increase in total calories from snacks by 328 ± 140 kcal (P = 0.03), primarily from carbohydrates (P = 0.02). The increase in evening ghrelin during sleep restriction was correlated with higher consumption of calories from sweets (r = 0.48, P = 0.04).

CONCLUSIONS

Sleep restriction as compared with normal sleep significantly increases ghrelin levels. The increase in ghrelin is associated with higher consumption of calories. Elevated ghrelin may be a mechanism by which sleep loss leads to increased food intake and the development of obesity.

Cumulative exposure to short sleep and body mass outcomes: a prospective study

Short sleep duration is associated with excess body mass among adolescents and young adults. The mechanisms theorized to drive that association suggest that persistent exposure to short sleep should be associated with greater accumulations of body mass. We use prospective cohort data from four waves of the National Longitudinal Study of Adolescent to Adult Health (1994-2009; n = 14 800) to examine associations between cumulative exposure to short sleep throughout adolescence and early adulthood and obesity and elevated waist circumference outcomes. We compare several clinical and distribution-based standards of short sleep to assess which measures are associated most strongly with body mass. Cumulative exposure to short sleep exhibits dose-response associations with obesity and elevated waist circumference. Relative to respondents with no instances of short sleep, those who slept -0.50 standard deviations or less than the age and sex-specific average sleep hours in all four waves had 1.45 [95% confidence interval (CI): 1.03, 2.04] times the odds of being obese and 1.45 (95% CI: 1.02, 2.06) times the odds of having an elevated waist circumference. Our findings suggest that cumulative exposure to short sleep during adolescence and young adulthood may play an important role in the etiology of obesity and elevated waist circumference during this important developmental period.

[Sleep duration and metabolism]

Sleep duration has gradually diminished during the last decade while obesity and type 2 diabetes have become epidemics. Experimental sleep curtailment leads to increased appetite, hormonal disturbances and, especially, insulin resistance. Numerous epidemiological studies have therefore examined whether habitual short sleep is associated with obesity and type 2 diabetes. A large majority of cross-sectional studies have confirmed an association between short, and also long sleep duration and obesity in adults more than in the elderly. Short sleep is strongly associated to obesity in children and adolescents. Prospective studies, including studies in children, are not conclusive with regard to the effect of short sleep on the incidence of obesity. Both short and long sleep durations are associated with diabetes, but only short sleep duration seems predictive of future diabetes. Insomnia seems to be a strong contributor to short sleep duration but the association of insomnia with obesity is not clear. Insomnia is associated with type 2 diabetes and also predictive of a higher incidence. Other studies have shown that short sleep duration and insomnia are associated with, and sometime predictive of, other components of the metabolic syndrome, especially hypertension and the risk of coronary disease. The treatment of short sleep duration and insomnia with regard to their effects on the metabolic syndrome merits further study.

Short sleep duration and dietary intake: epidemiologic evidence, mechanisms, and health implications

Links between short sleep duration and obesity, type 2 diabetes, hypertension, and cardiovascular disease may be mediated through changes in dietary intake. This review provides an overview of recent epidemiologic studies on the relations between habitual short sleep duration and dietary intake in adults from 16 cross-sectional studies. The studies have observed consistent associations between short sleep duration and higher total energy intake and higher total fat intake, and limited evidence for lower fruit intake, and lower quality diets. Evidence also suggests that short sleepers may have irregular eating behavior deviating from the traditional 3 meals/d to fewer main meals and more frequent, smaller, energy-dense, and highly palatable snacks at night. Although the impact of short sleep duration on dietary intake tends to be small, if chronic, it may contribute to an increased risk of obesity and related chronic disease. Mechanisms mediating the associations between sleep duration and dietary intake are likely to be multifactorial and include differences in the appetite-related hormones leptin and ghrelin, hedonic pathways, extended hours for intake, and altered time of intake. Taking into account these epidemiologic relations and the evidence for causal relations between sleep loss and metabolism and cardiovascular function, health promotion strategies should emphasize improved sleep as an additional factor in health and weight management. Moreover, future sleep interventions in controlled studies and sleep extension trials in chronic short sleepers are imperative for establishing whether there is a causal relation between short sleep duration and changes in dietary intake.

Sleep duration and timing in relation to osteoporosis in an elderly Chinese population: a cross-sectional analysis in the Dongfeng-Tongji cohort study

This population-based cross-sectional study in an older Chinese population shows a link between sleep duration, sleep timing, and osteoporosis risk, suggesting that sleep may have a role in osteoporosis development. These findings may help to identify contributing mechanisms and provide new opportunities for sleep-focused interventions to prevent osteoporosis.

INTRODUCTION

Accumulated evidence suggests that sleep pattern disruption may lead to alterations in physiology, potentially triggering the development of osteoporosis. The present study sought to examine whether sleep duration or sleep timing is associated with osteoporosis.

METHODS

A total of 31,769 participants (aged 45-86 years) were recruited from the Dongfeng-Tongji cohort study. All participants completed questionnaires and medical examinations and provided blood samples. The presence of osteoporosis was determined using calcaneal quantitative ultrasonography. Logistic regression models were used to evaluate the association of sleep duration and timing with osteoporosis, after adjusting for potential confounders.

RESULTS

The prevalence of osteoporosis was 14.2 % in men and 23.9 % in women. After controlling for potential confounders, the adjusted odds ratio (OR) [95 % confidence interval (CI)] for osteoporosis comparing sleep duration of 9 h or longer with the reference (7-8 h) was 1.40 (1.22-1.62) in men and 1.20 (1.07-1.33) in women. Men with early sleep timing (going to sleep before 21:00 h) were more likely to have osteoporosis (OR, 1.43; 95 % CI, 1.16-1.78) than those with normal sleep timing (going to sleep between 21:00 and 23:00 h). In the interaction analysis, participants with long sleep duration and early sleep timing had the highest risk of osteoporosis both in men (OR, 1.79; 95 % CI, 1.48-2.16) and women (OR, 1.41; 95 % CI, 1.19-1.66).

CONCLUSIONS

Long sleep duration (≥9 h) and early sleep timing were independently and interactively associated with an increased risk of osteoporosis in this older Chinese population.

Successful physical exercise-induced weight loss is modulated by habitual sleep duration in the elderly: results of a pilot study

Although it is widely accepted that physical exercise promotes weight loss, physical exercise alone had been found to result in only marginal weight loss compared to no treatment. Interestingly, both subjective and objective sleep duration have been shown to be negatively correlated to the body mass index (BMI). Despite this growing evidence of a relation between sleep duration and body weight, the role of habitual sleep duration in physical exercise-induced weight loss has not been studied so far. Twenty-two healthy elderly good sleepers aged 61-76 years (mean 68.36 years, 55 % female, BMI mean 25.15 kg/m²) either took part in a 12-week aerobic endurance training (3 × 30 min/week) or in a relaxation control (2 × 45 min/week). The BMI was assessed prior to and after intervention. Subjects maintained sleep logs every morning/evening during the training period, allowing for calculation of habitual sleep duration. Besides a significant main effect of the type of training, a significant interaction of type of training and habitual sleep duration was observed: while after treadmill training subjects who slept less than 7.5 h/night during intervention reduced their BMI by nearly 4 %, a comparable decrease in the BMI was found neither in subjects who slept more than 7.5 h nor after relaxation training independent of sleep duration. Sleep duration itself did not change in any group. Although results should be interpreted with caution due to the small sample size, this is the first study to indicate that physical exercise might compensate for disturbed body weight regulation associated with short sleep duration.

Development of the National Healthy Sleep Awareness Project Sleep Health Surveillance Questions

OBJECTIVES

For the first time ever, as emphasized by inclusion in the Healthy People 2020 goals, sleep health is an emphasis of national health aims. The National Healthy Sleep Awareness Project (NHSAP) was tasked to propose questions for inclusion in the next Behavioral Risk Factor Surveillance System (BRFSS), a survey that includes a number of questions that target behaviors thought to impact health, as a means to measure community sleep health. The total number of questions could not exceed five, and had to include an assessment of the risk for obstructive sleep apnea (OSA).

METHODS

An appointed workgroup met via teleconference and face-to-face venues to develop an inventory of published survey questions being used to identify sleep health, to develop a framework on which to analyze the strengths and weaknesses of current survey questions concerning sleep, and to develop recommendations for sleep health and disease surveillance questions going forward.

RESULTS

The recommendation was to focus on certain existing BRFSS questions pertaining to sleep duration, quality, satisfaction, daytime alertness, and to add to these other BRFSS existing questions to make a modified STOP-BANG questionnaire (minus the N for neck circumference) to assess for risk of OSA.

CONCLUSIONS

Sleep health is an important dimension of health that has previously received less attention in national health surveys. We believe that 5 questions recommended for the upcoming BRFSS question banks will assist as important measures of sleep health, and may help to evaluate the effectiveness of interventions to improve sleep health in our nation.

Impact of inflammatory markers on the relationship between sleep quality and incident cardiovascular events in type 2 diabetes

AIMS

To analyze relevance of sleep quality with CVD in T2D patients and determine whether inflammation prompted by poor sleep has impact on the CVD.

METHODS

332 T2D patients were recruited and their sleep qualities were evaluated by PSQI. The patients with PSQI score >7 were in the poor sleep group, and the others were in the good sleep group. Plasma samples of the patients were obtained to measure inflammatory markers. Correlation analyses and regression analyses were performed to examine the cross-sectional relationships among the poor sleep, inflammatory markers and CVD.

RESULTS

The morbidity of CVD was significantly higher in the poor sleep patients compared to the good sleep patients (P=0.000). PSQI score ORs were both >1 for CVD in model 1 and model 2 (P<0.05). PSQI score were positively related to IL-6 and ICAM-1(P<0.05), negatively to FBI (P<0.05), but not related to CRP in linear regression models. Multiple logistic regression analysis showed IL-6 and ICAM-1, but not FBI and CRP, were related to CVD (P<0.05).

CONCLUSIONS

Poor sleep is regarded as a plausible risk factor for CVD in T2D patients, and may be mediated by certain inflammatory markers.

Reproducibility of a Standardized Actigraphy Scoring Algorithm for Sleep in a US Hispanic/Latino Population

STUDY OBJECTIVES

While actigraphy is considered objective, the process of setting rest intervals to calculate sleep variables is subjective. We sought to evaluate the reproducibility of actigraphy-derived measures of sleep using a standardized algorithm for setting rest intervals.

DESIGN

Observational study.

SETTING

Community-based.

PARTICIPANTS

A random sample of 50 adults aged 18-64 years free of severe sleep apnea participating in the Sueño sleep ancillary study to the Hispanic Community Health Study/Study of Latinos.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Participants underwent 7 days of continuous wrist actigraphy and completed daily sleep diaries. Studies were scored twice by each of two scorers. Rest intervals were set using a standardized hierarchical approach based on event marker, diary, light, and activity data. Sleep/wake status was then determined for each 30-sec epoch using a validated algorithm, and this was used to generate 11 variables: mean nightly sleep duration, nap duration, 24-h sleep duration, sleep latency, sleep maintenance efficiency, sleep fragmentation index, sleep onset time, sleep offset time, sleep midpoint time, standard deviation of sleep duration, and standard deviation of sleep midpoint. Intra-scorer intraclass correlation coefficients (ICCs) were high, ranging from 0.911 to 0.995 across all 11 variables. Similarly, inter-scorer ICCs were high, also ranging from 0.911 to 0.995, and mean inter-scorer differences were small. Bland-Altman plots did not reveal any systematic disagreement in scoring.

CONCLUSIONS

With use of a standardized algorithm to set rest intervals, scoring of actigraphy for the purpose of generating a wide array of sleep variables is highly reproducible.

Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society on the Recommended Amount of Sleep for a Healthy Adult: Methodology and Discussion

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

Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society on the Recommended Amount of Sleep for a Healthy Adult: Methodology and Discussion

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

Sleep disturbances, body fat distribution, food intake and/or energy expenditure: pathophysiological aspects

Data from cross-sectional and longitudinal studies have illustrated a relationship between short sleep duration (SSD) and weight gain. Individuals with SSD are heavier and gain more weight over time than normal-duration sleepers. This sleep-obesity relationship may have consequences for obesity treatments, as it appears that short sleepers have reduced ability to lose weight. Laboratory-based clinical studies found that experimental sleep restriction affects energy expenditure and intake, possibly providing a mechanistic explanation for the weight gain observed in chronic short sleepers. Specifically, compared to normal sleep duration, sleep restriction increases food intake beyond the energetic costs of increased time spent awake. Reasons for this increased energy intake after sleep restriction are unclear but may include disrupted appetite-regulating hormones, altered brain mechanisms involved in the hedonic aspects of appetite, and/or changes in sleep quality and architecture. Obstructive sleep apnea (OSA) is a disorder at the intersection of sleep and obesity, and the characteristics of the disorder illustrate many of the effects of sleep disturbances on body weight and vice versa. Specifically, while obesity is among the main risk factors for OSA, the disorder itself and its associated disturbances in sleep quality and architecture seem to alter energy balance parameters and may induce further weight gain. Several intervention trials have shown that weight loss is associated with reduced OSA severity. Thus, weight loss may improve sleep, and these improvements may promote further weight loss. Future studies should establish whether increasing sleep duration/improving sleep quality can induce weight loss.

Circadian clocks, feeding time, and metabolic homeostasis

Metabolic processes exhibit diurnal variation from cyanobacteria to humans. The circadian clock is thought to have evolved as a time keeping system for the cell to optimize the timing of metabolic events according to physiological needs and environmental conditions. Circadian rhythms temporally separate incompatible cellular processes and optimize cellular and organismal fitness. A modern 24 h lifestyle can run at odds with the circadian rhythm dictated by our molecular clocks and create desynchrony between internal and external timing. It has been suggested that this desynchrony compromises metabolic homeostasis and may promote the development of obesity (Morris et al., 2012). Here we review the evidence supporting the association between circadian misalignment and metabolic homeostasis and discuss the role of feeding time.

Relative Contribution of Obesity, Sedentary Behaviors and Dietary Habits to Sleep Duration Among Kuwaiti Adolescents

The aim of this study was to investigate whether body mass index (BMI), eating habits and sedentary behaviours were associated with sleep duration among Kuwaiti adolescents. The study is part of the Arab Teens Lifestyle Study (ATLS), which is a school-based cross-sectional multi-center collaborative study. A sample of 906 adolescents (boys and girls) aged 14-19 years was randomly selected from 6 Kuwaiti Governances using a multistage stratified cluster sampling technique. The findings revealed that the prevalence of overweight and obesity was 50.5% in boys and 46.5% in girls. The majority of boys (76%) and of girls (74%) fell into the short sleep duration category (6 hours/day or less). Sleep duration were found to be negatively associated with BMI (girls only). Watching television (boys and girls) and working on computers (boys only) were also negatively associated with sleep duration. While the consumption of breakfast (both genders) and milk (boys only) was positively associated with sleep duration (p<0.05). In contrast, the consumption of fast foods (both genders), sugar-sweetened drinks and sweets (boys only) potatoes (girls only) were negatively associated with sleep duration (p<0.05). It can be concluded that the majority of Kuwaiti adolescents exhibit insufficient sleep duration which was associated with obesity measure, a combination of poor eating habits and more sedentary behaviors. The findings also suggest gender differences in these associations. Therefore, adequate sleep is an important modifiable risk factor to prevent obesity and was positively associated with some unhealthy lifestyle habits.

Onset of impaired sleep as a predictor of change in health-related behaviours; analysing observational data as a series of non-randomized pseudo-trials

BACKGROUND

Changes in health-related behaviour may be a key mechanism linking impaired sleep to poor health, but evidence on this is limited. In this study, we analysed observational data to determine whether onset of impaired sleep is followed by changes in health-related behaviours.

METHODS

We used data from 37,508 adults from the longitudinal Finnish Public Sector Study. In analysis of 59 152 person-observations on duration and quality of sleep and health-related behaviours (alcohol consumption, smoking, physical activity and weight control), data were treated as a series of non-randomized pseudo-trials with strict predefined criteria for data inclusion and temporality.

RESULTS

Smokers who experienced onset of short sleep were less likely to quit smoking than those with persistent normal sleep [odds ratio (OR) = 0.78, 95% confidence interval (CI): 0.64-0.97]. Onset of short sleep also predicted initiating high-risk alcohol consumption (OR = 1.17, 95% CI: 1.00-1.37). Onset of disturbed sleep was associated with changes in all assessed health-related behaviours: initiation of high-risk alcohol consumption (OR = 1.23, 95% CI: 1.05-1.45), quitting smoking (OR = 0.80, 95% CI: 0.63-1.00), becoming physically inactive (OR = 1.17, 95% CI: 1.06-1.30) and becoming overweight or obese (OR = 1.12, 95% CI: 1.01-1.23).

CONCLUSIONS

Findings suggest that the onset of short or disturbed sleep are risk factors for adverse changes in health-related behaviours. These findings highlight potential pathways linking impaired sleep to the development of lifestyle-related morbidity and mortality.

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.

Healthy time use in the encore years: do work, resources, relations, and gender matter?

Social engagement is theorized to promote health, with ages 55 to 75-what some call "encore" adulthood-potentially being a time for ongoing engagement or social isolation. We use the American Time Use Survey (N = 11,952) and a life course perspective to examine associations between paid work, resources, relations, and healthy time use for men and women in the first (55-64) and second (65-74) halves of the encore years. Work limits sufficient sleep (full-time working men) and television watching (all workers) but also time spent in physical activity (full-time workers). College-educated and healthy encore adults-across age and gender divides-are more likely to exercise and watch less television. Marriage and caregiving encourage socializing and limit television watching, despite differential effects on physical activity and sleep. These findings fit well with a gendered life course perspective suggesting socially patterned (by work, resources, relationships, gender, age) health behaviors.

Shorter sleep duration is associated with decreased insulin sensitivity in healthy white men

STUDY OBJECTIVES

Short sleep has been linked to increased risk for type 2 diabetes and incident cardiovascular disease and acute sleep restriction impairs insulin-mediated glucose disposal. Here, we examined whether indices of glucose metabolism vary with naturally occurring differences in sleep duration.

DESIGN AND MEASURES

Subjects were midlife, nondiabetic community volunteers (N = 224; mean age 44.5 ± 6.6 y [range: 30-54]; 52% female; 89% white). Laboratory measures of insulin sensitivity (Si) and acute secretion (AIRg), glucose effectiveness (Sg), and disposition index (Di) were obtained from a 180-min, intravenous glucose tolerance test.

RESULTS

Shorter self-reported sleep duration (in hours) was associated with lower Si (P = 0.043), although an interaction of sleep duration with participant race (β = -0.81, P = 0.002) showed this association significant only in whites. Moreover, sex-stratified analyses revealed that shorter sleep duration predicted lower Si in white men (β = 0.29, P = 0.003) but not in white women (P = 0.22). Findings were similar for AIRg. The relationship between sleep duration and AIRg was moderated by race as well as sex, such that shorter sleep duration associated with greater insulin release only in white men (β = -0.28, P = 0.004). Sleep duration was unrelated to Sg and Di (P's > 0.05).

CONCLUSIONS

Our findings suggest that shorter sleep duration may impair insulin sensitivity and beta-cell function in nondiabetic white men, possibly contributing to later type 2 diabetes and cardiovascular disease.

[Nutritional damages and disturbances in the sleep pattern of nursing workers]

This article presents an integrative review of national and international scientific publications that investigate the sleep habits, the feed intake and nutritional status of nursing professionals. It was analyzed articles published in national and international journals in the period 2002 to 2014 and made available in the database PubMed / MEDLINE (USA National Library of Medicine), Lilacs / SciELO (Scientific Eletronic Library Online) and Google Scholar. Thirty one articles met the criteria. In the analysis of these studies it has been found a high prevalence of overweight and obesity, a negative change in the eating habits, as well as losses in the sleep patterns of nursing professionals.

Sleep habits, daytime sleepiness and working conditions in short-distance bus drivers

Purpose

– Driving needs high levels of alertness. Increased somnolence is the most important negative influence to maintain proper watchfulness and vigilance. Drowsiness, working conditions and their affective impact must be taken into account to determine driving safety. The purpose of this paper is to assess excessive daytime sleepiness, sleep habits, quality of sleep, stress-related symptoms, and working conditions in a large sample of short-distance bus drivers in the city of Buenos Aires.

Design/methodology/approach

– This was a cross-sectional study performed to evaluate sleep habits and obstructive apnea risk in short-distance bus drivers of the Metropolitan Area of Buenos Aires, Argentina. Questionnaires regarding anthropometric data, sleep habits, snoring, daytime sleepiness (Epworth Sleepiness Scale), quality of sleep (Pittsburgh Quality of Sleep Index, PQSI), working conditions and fatigue and anxiety related to work were administered to professional short-distance bus drivers (n=1023).

Findings

– A prevalence of 34.6 percent of obesity and 80 percent of snoring was observed. Mean sleep time during workdays was 6.5±0.1 h and bad sleep quality was reported by 54.6 percent of the subjects. Excessive daytime sleepiness had a prevalence of 48.8 percent and was independently associated with reduced sleep time, increased sleep debt, long time to wake up, snoring, and short resting time along the working day (p<0.05).

Originality/value

– Short-distance drivers in Buenos Aires, the largest urban area of Argentina, are a partially sleep-deprived, overweighted population, showing a high daytime somnolence, poor work-rest conditions and high levels of anxiety and fatigue. This association can be very harmful in view of the demanding working conditions considered.

Impact of menstrual cycle phase on endocrine effects of partial sleep restriction in healthy women

There is extensive evidence that sleep restriction alters endocrine function in healthy young men, increasing afternoon cortisol levels and modifying levels of other hormones that regulate metabolism. Recent studies have confirmed these effects in young women, but have not investigated whether menstrual cycle phase influences these responses. The effects on cortisol levels of limiting sleep to 3h for one night were assessed in two groups of women at different points in their menstrual cycles: mid-follicular and mid-luteal. Eighteen healthy, young women, not taking oral contraceptives (age: 21.8±0.53; BMI: 22.5±0.58 [mean±SEM]), were studied. Baseline sleep durations, eating habits and menstrual cycles were monitored. Salivary samples were collected at six times of day (08:00, 08:30, 11:00, 14:00, 17:00, 20:00) during two consecutive days: first after a 10h overnight sleep opportunity (Baseline) and then after a night with a 3h sleep opportunity (Post-sleep restriction). All were awakened at the same time of day. Women in the follicular phase showed a significant decrease (p=0.004) in their cortisol awakening responses (CAR) after sleep restriction and a sustained elevation in afternoon/evening cortisol levels (p=0.008), as has been reported for men. Women in the luteal phase showed neither a depressed CAR, nor an increase in afternoon/evening cortisol levels. Secondary analyses examined the impact of sleep restriction on self-reported hunger and mood. Menstrual cycle phase dramatically altered the cortisol responses of healthy, young women to a single night of sleep restriction, implicating effects of spontaneous changes in endocrine status on adrenal responses to sleep loss.

Sleep deprivation and obesity in shift workers in southern Brazil

OBJECTIVE

The objective of our study was to explore the association between sleep deprivation and obesity among shift workers.

DESIGN

A cross-sectional study was conducted. Obesity was defined as BMI ≥30 kg/m2. Time of sleep was categorized as: >5 h of continuous sleep/d; ≤5 h of continuous sleep/d with some additional rest (sleep deprivation level I); and ≤5 h of continuous sleep/d without any additional rest (sleep deprivation level II). Sociodemographic, parental and behavioural variables were evaluated by means of a standardized pre-tested questionnaire. Potential confounding factors were controlled for in the multivariable model.

SETTING

A poultry-processing plant in southern Brazil.

SUBJECTS

Nine hundred and five shift workers (63 % female).

RESULTS

Obesity was more prevalent in the participants who were female, aged 40 years and older, who had less schooling and reported excess weight in both parents. Sleep deprivation levels I and II were associated with increased income, number of meals consumed throughout the day and nightshift work. All of the workers who exhibited a degree of sleep deprivation worked the night shift. After controlling for potential confounding factors, the prevalence ratios of obesity were 1·4 (95 % CI 0·8, 2·2) and 4·4 (95 % CI 2·4, 8·0) in the workers with sleep deprivation levels I and II, respectively, compared with the reference group.

CONCLUSIONS

These results show a strong association between sleep deprivation and obesity in shift workers and that sleep deprivation may be a direct consequence of working at night.

An integrative review of sleep for nutrition professionals

Sleep is an essential lifestyle factor that contributes to overall health. The inverse relation between sleep duration and weight status has revealed the importance of sleep in nutritional health. This integrative review builds foundational knowledge with regard to sleep vis-à-vis nutrition by summarizing the importance and process of sleep, current sleep recommendations and trends, as well as lifestyle contributors to poor sleep. Additionally, it details the association between sleep and obesity and potential mechanisms for this association. Furthermore, guidance is offered regarding the incorporation of sleep considerations in nutrition counseling, communication, and research. Like many other lifestyle factors that contribute to nutritional health, sleep needs to be considered when examining weight management and health promotion.

Sleep duration and cardiometabolic risk factors among individuals with type 2 diabetes

OBJECTIVE

To examine the association between sleep duration and cardiometabolic risk factors among individuals with recently diagnosed type 2 diabetes (n = 391).

METHODS

Sleep duration was derived using a combination of questionnaire and objective heart rate and movement sensing in the UK ADDITION-Plus study (2002-2007). Adjusted means were estimated for individual cardiometabolic risk factors and clustered cardiometabolic risk (CCMR) by five categories of sleep duration.

RESULTS

We observed a J-shaped association between sleep duration and CCMR - individuals sleeping 7 to <8 h had a significantly better CCMR profile than those sleeping ≥9 h. Independent of physical activity and sedentary time, individuals sleeping 7 to <8 h had lower triacylglycerol (0.62 mmol/l (0.29, 1.06)) and higher high-density lipoprotein (HDL)-cholesterol levels (0.23 mmol/l (0.16, 0.30)) compared with those sleeping ≥9 h, and a lower waist circumference (7.87 cm (6.06, 9.68)) and body mass index (BMI) (3.47 kg/m(2) (2.69, 4.25)) than those sleeping <6 h. Although sleeping 7 to <8 h was associated with lower levels of systolic and diastolic blood pressure, HbA1c, total cholesterol, and low-density lipoprotein (LDL)-cholesterol, these associations were not statistically significant.

CONCLUSIONS

Sleep duration has a J-shaped association with CCMR in individuals with diabetes, independent of potential confounding. Health promotion interventions might highlight the importance of adequate sleep in this high-risk population.

Sleep to lower elevated blood pressure: study protocol for a randomized controlled trial

Background

Sleep is an essential component of good physical and mental health. Previous studies have reported that poor quality sleep is associated with an increased risk of hypertension and cardiovascular disease. Hypertension is the most common and important risk factor for cardiovascular disease, and even modest reductions in blood pressure can result in significant reductions in the risk of stroke and myocardial infarction. In this trial, we will determine the efficacy of an online sleep intervention in improving blood pressure, in participants with hypertension and poor sleep quality.

Methods

Trial design: Randomized-controlled, two-group, parallel, blinded, single-center, Phase II trial of 134 participants. Population and recruitment: Primary prevention population of participants with hypertension (systolic blood pressure, 130 to 160 mm Hg; diastolic blood pressure, <110 mm Hg) and poor sleep quality in a community setting. Intervention: Multicomponent online sleep intervention consisting of sleep information, sleep hygiene education, and cognitive behavioral therapy. Comparator: Standardized cardiovascular risk factor and lifestyle-education session (usual care). Primary outcome: Change in mean 24-hour ambulatory systolic blood pressure between baseline and 8-week follow-up. Hypertension has been selected as the primary outcome measure because of its robust association with both poor sleep quality and cardiovascular disease. Statistical analyses: Intention-to-treat analysis by using a linear mixed model.

Trial registration

ClinicalTrials.gov: NCT01809821, registered March 8, 2013.

Association between combined lifestyle factors and non-restorative sleep in Japan: a cross-sectional study based on a Japanese health database

BACKGROUND

Although lifestyle factors such as cigarette smoking, excessive drinking, obesity, low or no exercise, and unhealthy dietary habits have each been associated with inadequate sleep, little is known about their combined effect. The aim of this study was to quantify the overall impact of lifestyle-related factors on non-restorative sleep in the general Japanese population.

METHODS AND FINDINGS

A cross-sectional study of 243,767 participants (men, 39.8%) was performed using the Specific Health Check and Guidance System in Japan. A healthy lifestyle score was calculated by adding up the number of low-risk lifestyle factors for each participant. Low risk was defined as (1) not smoking, (2) body mass index<25 kg/m², (3) moderate or less alcohol consumption, (4) regular exercise, and (5) better eating patterns. Logistic regression analysis was used to examine the relationship between the score and the prevalence of non-restorative sleep, which was determined from questionnaire responses. Among 97,062 men (mean age, 63.9 years) and 146,705 women (mean age, 63.7 years), 18,678 (19.2%) and 38,539 (26.3%) reported non-restorative sleep, respectively. The prevalence of non-restorative sleep decreased with age for both sexes. Compared to participants with a healthy lifestyle score of 5 (most healthy), those with a score of 0 (least healthy) had a higher prevalence of non-restorative sleep (odds ratio, 1.59 [95% confidence interval, 1.29-1.97] for men and 2.88 [1.74-4.76] for women), independently of hypertension, hypercholesterolemia, diabetes, and chronic kidney disease. The main limitation of the study was the cross-sectional design, which limited causal inferences for the identified associations.

CONCLUSIONS

A combination of several unhealthy lifestyle factors was associated with non-restorative sleep among the general Japanese population. Further studies are needed to establish whether general lifestyle modification improves restorative sleep.

Impact of conjoint trajectories of body mass index and marijuana use on short sleep duration

BACKGROUND AND OBJECTIVES

We examined the association between the conjoint developmental trajectories of body mass index (BMI) and marijuana use from age 24 to age 32 and short sleep duration.

METHODS

The participants included 158 African American male, 267 African American female, 166 Puerto Rican male, and 225 Puerto Rican female young adults (N=816). Using Mplus, we obtained the conjoint trajectories of BMI and marijuana use. Logistic regression analyses examined the association between the conjoint trajectories and short sleep duration.

RESULTS

Five conjoint trajectory groups were extracted: normal BMI and no or low marijuana use, obese and no or low marijuana use, morbidly obese and some marijuana use, normal BMI and high marijuana use, and obese and high marijuana use. Those in the obese and no or low marijuana use group, the morbidly obese and some marijuana use group, and the obese and high marijuana use group were more likely to report shorter sleep duration than those with normal BMI and no or low marijuana use group.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

This study highlights the significance of examining joint trajectories over several developmental stages. In treating short sleep duration, we propose focusing on treating obesity, and also treating marijuana use if applicable.

Night-time sleep duration and the incidence of obesity and type 2 diabetes. Findings from the prospective Pizarra study

BACKGROUND

Several recent studies have related short sleep duration with different health problems, though the results related with the risk of obesity and type 2 diabetes (T2D) are far from conclusive. The aim of this study was to investigate the association between night-time sleep duration and the incidence of obesity and T2D in a prospective study with a follow-up of 11 years.

MATERIAL AND METHODS

The study comprised 1145 people evaluated in 1997-1998 and re-evaluated after 6 years and 11 years. At the three study points, subjects without known diabetes mellitus (KDM) were given an oral glucose tolerance test (OGTT). Anthropometric and biochemical variables were measured. The subjects were asked about their number of hours of night-time sleep.

RESULTS

After adjustment, the OR of becoming obese was significantly higher in subjects who slept ≤ 7 hours per night, at both the 6-year follow-up (OR = 1.99; 95% CI = 1.12-3.55) and the 11-year follow-up (OR = 2.73; 95% CI = 1.47-5.04). The incidence of T2D at the 6-year follow-up in subjects without T2D at baseline was higher in those who slept ≤ 7 hours per night (OR = 1.96; 95% CI = 1.10-3.50). However, this association was not independent of obesity, weight gain or abnormal glucose regulation at baseline. At the 11-year follow-up however there was no association between night-time sleep duration and the incidence of T2D.

CONCLUSIONS

The incidence of obesity over the 11-year follow-up increased in subjects with fewer hours of night-time sleep. The incidence of T2D according to the hours of night-time sleep depended on obesity and the carbohydrate metabolism phenotype.

Metabolic effects of sleep disruption, links to obesity and diabetes

PURPOSE OF REVIEW

To highlight the adverse metabolic effects of sleep disruption and to open ground for research aimed at preventive measures. This area of research is especially relevant given the increasing prevalence of voluntary sleep curtailment, sleep disorders, diabetes, and obesity.

RECENT FINDINGS

Epidemiological studies have established an association between decreased self-reported sleep duration and an increased incidence of type 2 diabetes (T2D), obesity, and cardiovascular disease. Experimental laboratory studies have demonstrated that decreasing either the amount or quality of sleep decreases insulin sensitivity and decreases glucose tolerance. Experimental sleep restriction also causes physiological and behavioral changes that promote a positive energy balance. Although sleep restriction increases energy expenditure because of increased wakefulness, it can lead to a disproportionate increase in food intake, decrease in physical activity, and weight gain.

SUMMARY

Sleep disruption has detrimental effects on metabolic health. These insights may help in the development of new preventive and therapeutic approaches against obesity and T2D based on increasing the quality and/or quantity of sleep.

A biobehavioral model of weight loss associated with meditative movement practice among breast cancer survivors

Women with breast cancer often experience weight gain during and after treatment, significantly increasing risk for recurrence as well as all-cause mortality. Based on a growing body of evidence, meditative movement practices may be effective for weight management. First, we describe the effects of stress on factors associated with weight gain for breast cancer survivors. Then, a model is proposed that utilizes existing evidence to suggest how meditative movement supports behavioral, psychological, and neurohormonal changes that may explain weight loss. Application of the model suggests how a novel "mindful-body-wisdom" approach may work to help reduce weight for this at-risk group.

Physical factors, personal characteristics, and substance use: associations with obesity

BACKGROUND

Because obesity has become a major public health problem, attention to a range of its predictors is needed. This study examined the association of physical factors, personal characteristics, and substance use with obesity in a sample (N = 815) of African American and Puerto Rican young adults with a mean age of 32.

METHODS

Body mass index (BMI) was calculated to assess obesity. Bivariate and multivariate logistic regression analyses were conducted.

RESULTS

Bivariate analyses showed that protective factors such as physical activity (adjusted odds ratio [AOR] = .82, 95% confidence interval [CI] = .74-.91), healthy diet (AOR = .96, 95% CI = .93-.99), self-control (AOR = .93, 95% CI = .87-.98), and life satisfaction (AOR = .97, 95% CI = .95-.99) were associated with a reduced probability of being obese. Marijuana use was also associated with a decreased probability of obesity (AOR = .89, 95% CI = .80-.99), but was not considered a protective factor. Risk factors such as short sleep duration (AOR = 1.70, 95% CI = 1.24-2.33) and depressive mood (AOR = 1.05, 95% CI = 1.01-1.09) were associated with an increased probability of being obese.

CONCLUSIONS

For African Americans and Puerto Ricans, programs to treat obesity should focus on increasing sleep, physical activity, and life satisfaction.

Association of short sleep duration with impaired glucose tolerance or diabetes mellitus

Aims/Introduction:  To examine the cross‐sectional relationship between sleep duration and impaired glucose tolerance (IGT), including diabetes mellitus (DM), we analyzed a large‐scale healthy workers database in Japan.

Materials and Methods:  We examined the baseline database of 4143 participants (3415 men and 728 women) aged 19–69 years. Sleep duration of participants was categorized into four groups: <6, 6 to <7, 7 to <8 and ≥8 h. The physical activity of each participant was classified according to the International Physical Activity Questionnaire (IPAQ). We defined IGT including DM (IGT/DM) in the present study according to previous studies as follows: fasting blood sugar level ≥110 mg/dL, or if <8 h after meals ≥140 mg/dL, or on medication for diabetes mellitus, or those diagnosed as having DM. Logistic regression was applied to estimate the odds ratio (OR) to examine the relationship between IGT/DM, sleep duration and other related factors.

Results:  The number of participants with IGT/DM was 402 (9.7%). The factors that significantly associated with IGT/DM were age (OR 1.08, 95% confidence interval [CI] 1.07–1.10, P < 0.001), high blood pressure (OR 1.94, CI 1.52–2.47, P < 0.001), and <6 h of sleep duration in comparison with 6 to <7 h sleep (OR 2.32, CI 1.18–4.55, P = 0.015). The associations of difficulty in sleep initiation, IPAQ classification, current smoking and alcohol intake with IGT/DM were not statistically significant.

Conclusions:  Our results showed that shorter sleep duration (<6 h of sleep duration per night) was associated with a risk of IGT/DM independent of other lifestyle habits and metabolic risk factors. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00114.x, 2011)

Timing and intensity of light correlate with body weight in adults

Light exposure can influence sleep and circadian timing, both of which have been shown to influence weight regulation. The goal of this study was to evaluate the relationship between ambient light, sleep and body mass index. Participants included 54 individuals (26 males, mean age 30.6, SD = 11.7 years). Light levels, sleep midpoint and duration were measured with wrist actigraphy (Actiwatch-L) for 7 days. BMI was derived from self-reported height and weight. Caloric intake was determined from 7 days of food logs. For each participant, light and activity data were output in 2 minute epochs, smoothed using a 5 point (10 minute) moving average and then aggregated over 24 hours. The mean light timing above 500 lux (MLiT⁵⁰⁰) was defined as the average clock time of all aggregated data points above 500 lux. MLiT⁵⁰⁰ was positively correlated with BMI (r = 0.51, p<0.001), and midpoint of sleep (r = 0.47, p<0.01). In a multivariable linear regression model including MLiT⁵⁰⁰ and midpoint of sleep, MLiT⁵⁰⁰ was a significant predictor of BMI (B = 1.26 SE = 0.34, β = 0.53 p = 0.001, r²_Δ = 0.22). Adjusting for covariates, MLiT⁵⁰⁰ remained an independent predictor of BMI (B = 1.28 SE = 0.36, β = 0.54, p = 0.002, r²_Δ = 0.20). The full model accounted for 34.7% of the variance in BMI (p = 0.01). Exposure to moderate levels of light at biologically appropriate times can influence weight, independent of sleep timing and duration.

Sleep, obesity, and weight loss in adults: is there a rationale for providing sleep interventions in the treatment of obesity?

Rates of obesity and sleep disturbances are substantial in adults. A number of cross-sectional, longitudinal, and experimental studies have found that insufficient sleep and possibly longer sleep are associated with obesity and related eating patterns. Methodological discrepancies and limitations in the literature create ambiguity about the nature and potential mechanisms underlying these relationships. Insomnia and circadian patterns in eating and sleeping have also been examined in relation to weight. Although these studies are not as extensive as those examining sleep duration, the extant literature suggests possible associations between obesity and both insomnia (particularly when combined with short sleep duration) and circadian eating behaviours. However, research has only just begun to examine the benefits of combining sleep interventions with obesity treatment. The goal of the current review is to summarize research examining behavioural sleep patterns and disorders in relation to obesity, to discuss methodological considerations, and to provide an overview of studies examining whether addressing sleep disturbances can augment weight loss treatment effects. We conclude that future studies are needed that take into account sleep duration, sleep disorder co-morbidity, and chronobiology to explore the impact of sleep interventions on weight loss.

Disordered eating partly mediates the relationship between poor sleep quality and high body mass index

OBJECTIVE

We evaluated the relationship between poor sleep quality and high body mass index (BMI) in a community-derived sample. In addition, we explored the premise that disordered eating (i.e. eating late at night and/or binge eating, which can occur at night) may partly explain the relationship.

METHOD

An online survey asked 330 participants about their height and weight, recent sleep quality, and recent experiences of binge-eating and night-time eating.

RESULTS

Using multiple regression analyses, high BMI was shown to be related to shorter sleep duration, increased sleep latency, use of sleeping medications and worse binge-eating, whereas worse sleep quality was related to worse night-eating, after controlling for depression and demographics. Using mediational analyses, binge-eating was shown to partly mediate the relationship between worse sleep quality to higher BMI, whereas night-eating mediated the reverse association of high BMI to worse sleep quality.

DISCUSSION

The results suggest that night- and/or binge-eating may partly explain the observed relationship between worse sleep quality and overweight/obesity. Thus, the relationship may simply reflect that overweight people are more likely to binge-eat while they wait for sleep to come, and this may contribute to weight gain over time. In addition, the results may indicate that eating rather than weight gain or obesity may be responsible for causing the sleep deficits in overweight people.

Short sleep duration is associated with higher energy intake and expenditure among African-American and non-Hispanic white adults

Habitual short sleep duration appears to increase the risk of obesity. The objective of this paper is to investigate the association of habitual sleep duration with objective measures of energy balance. One hundred twelve African-American and 111 non-Hispanic whites aged 21-69 y participated in a cross-sectional study of dietary assessment and biomarkers. Participants reported the mean number of hours per day spent sleeping over the past year. Short sleep duration was defined as ≤6 h/d of sleep. Energy intake (kilocalories) was objectively assessed using the 2-point doubly labeled water technique to determine total energy expenditure, which is approximately equal to energy intake. Physical activity energy expenditure (kilocalories) was estimated as total energy expenditure minus each participant's calculated basal metabolic rate and the thermogenic effect of food. Compared with participants who slept ≤6 h, individuals who slept 8 h were significantly less likely to be obese (OR: 0.33; 95% CI: 0.14, 0.79). However, this association was not linear across 6-9 h of sleep (P-trend = 0.16). There was an inverse association between sleep and energy intake (P-trend = 0.07): compared with ≤6 h/d, adults who reported ≥9 h sleep consumed 178 fewer kcal/d. There was also an inverse association between sleep and physical activity (P-trend = 0.05): compared with ≤6 h/d of sleep, adults who reported 9 h of usual sleep expended 113 fewer kcal/d in physical activity. These data indicate that, compared with longer sleep duration, adults who report habitual short sleep duration have somewhat higher physical activity energy expenditure but considerably higher energy intake. Habitual short sleep duration appears to be 1 of the facets of modern life leading to a mismatch between energy intake and physical activity.

Association between sleep quality and C-reactive protein: results from national health and nutrition examination survey, 2005-2008

Objective

Our objective was to explore the association between poor sleep quality and hs_CRP in an adult U.S. population.

Methods

This study focused on 9,317 participants in the National Health and Nutrition Examination Survey (NHANES) from 2005–2008 who were aged 20–85 years, completed a sleep disorder questionnaire, and had available information on serum hs_CRP. Sleep quality was classified into three categories (good, moderate, poor) based on the responses of participants to the NHANES sleep disorder questionnaire. High CRP was defined as hs-CRP >1 md/dL. Linear regression model was applied to investigate the association between poor sleep quality and log-transformed hs_CRP. And logistic regression model was fitted to evaluate the association between sleep quality and the risk of high CRP.

Results

Females were more likely to report poor sleep quality than males (26% vs. 19%, p<0.0001). Each sleep disorder was significantly associated with increased hs_CRP and correlative to other sleep disorders. In fully-adjusted linear regression model, poor sleep quality was significantly associated with elevated hs_CRP (log transformed) among the overall sample and in females only (β = 0.10, se = 0.03, p<0.01 and β = 0.13, se = 0.04, p<0.01, respectively). In fully-adjusted logistics regression model, poor sleep quality was linked with risk of high CRP(OR: 1.42, 95%CI: 1.15–1.76 in overall sample and OR: 1.59, 95%CI: 1.18–2.14 in females, respectively).

Conclusion

We found that poor sleep quality was independently associated with elevated hs_CRP in females but not in males in a U.S. adult population.