Association between sleeping hours and siesta and the risk of obesity: the SUN Mediterranean Cohort

Napping and Obesity in Adults - What do we Know?

PURPOSE OF REVIEW

To review the evidence on the relationship between daytime napping and obesity.

RECENT FINDINGS

There is concern that napping may be harmful to metabolic health. Prospective studies have shown long time daytime napping (> 1 h) is associated with increased diabetes risk which may be partly associated with obesity. Evidence from numerous cross-sectional studies and meta-analyses of cross-sectional studies have shown that long time napping (> 1 h) but not short time napping is associated with increased risk of obesity, and this is seen worldwide. Inference regarding the nature of association from cross-sectional studies is limited; it is suggested the association is bidirectional. Prospective studies on the association between daytime napping and obesity are few and results unclear. Large longitudinal studies integrating daytime napping duration and night-time sleep behaviour and detailed information on lifestyle influences is needed to help elucidate further the associations of long time napping with obesity.

Sex differences in the association between short sleep duration and obesity: A systematic-review and meta-analysis

AIMS

Obesity is a leading contributor to global morbidity and mortality. Short sleep duration is significantly associated with the incidence of obesity, however, it remains unclear whether this relationship is influenced by sex. The purpose of this meta-analysis was to systematically evaluate the evidence of whether the association between short sleep duration and obesity differs between males and females.

DATA SYNTHESIS

The protocol was registered with PROSPERO (CRD42023374205). From inception through June 2023, Medline, Embase and Web of Science databases were searched for longitudinal cohort studies with minimum 12 months of observation. The quality of studies was assessed using the Newcastle-Ottawa Quality Assessment for Cohort Studies. Results were pooled using a random effects model. Results are expressed as ratio of odds ratios (ROR) with 95% confidence interval (CI). ROR directly estimates the relative strength of the association of interest (measured as odds ratio [OR] between females and males). Sensitivity analysis was performed and inconsistency between studies was assessed using I2 statistics. A total of 4582 articles were retrieved with the search strategy, of which 6 were included. The meta-analysis indicated that the association between short sleep duration and obesity incidence was statistically significant in both men [OR 1.26 (95% CI 1.13-1.40)] and women [OR 1.36 (95% CI 1.16-1.59)]. However, it did not differ significantly between sexes ROR (women/men) 1.04 (95%CI 0.79-1.36; I2 20.1%).

CONCLUSIONS

This meta-analysis indicates that women and men who subjectively report short sleep duration have similarly increased risks of incident obesity.

Reciprocal and Differential Influences of Mediterranean Diet and Physical Activity on Adiposity in a Cohort of Young and Older than 40 Years Adults

Translational research has documented the conjoint beneficial relationships between dietary and physical activity habits concerning weight maintenance. However, the precise interplay between diet and exercise impacting body composition remains unclear, challenging personalized interventions. This study aimed to explore potential interactions and effect modifications of these factors affecting the body mass index (BMI) within an online adult cohort. Data from 11,883 NUTRiMDEA cohort participants were analyzed in this cross-sectional study, categorizing individuals by age, sex, and BMI using linear regression models to assess the interactions between lifestyle factors and adiposity. Significant differences emerged in anthropometry, lifestyle, and health-related quality of life (HRQoL) across categories. The combined effect of diet and physical activity had a greater impact on BMI than physical activity or Mediterranean diet adherence alone, with lower BMI as physical activity levels increased (β: -0.5) and adherence to the Mediterranean diet decreased, where a modification effect between them was identified (β: -0.28). Participants with lower Mediterranean diet adherence displayed superior BMI when physical activity was low, but when activity levels were higher, their BMI aligned with those with healthier dietary habits. An interaction link between lifestyle factors and BMI was found, showing the differential effects of the Mediterranean diet and physical activity combination concerning adiposity.

Association of daytime napping and nighttime sleep with all-cause mortality: A prospective cohort study of China Health and Retirement Longitudinal Study

STUDY OBJECTIVES

The correlation of daytime napping and nighttime sleep duration on mortality was inconsistent. We aimed to explore their separate links to all-cause/premature mortality, and evaluate their combined impact on all-cause mortality risk.

METHODS

All of 20617 (mean age: 56.90 ± 10.19, 52.18 % females) participants from China Health and Retirement Longitudinal Study were followed for a median of 7 years (interquartile range: 4-7) to detect death status. Baseline self-reported napping and sleep duration was categorized: napping as none, <60 min, 60-90 min, and ≥90 min, sleep as <6 h/night, 6-8 h/night, and ≥8 h/night. Death event was tracked, and premature death was defined using 2015 China's average life expectancy (73.64 years for men, and 79.43 years for women). Cox regression models analyzed the data.

RESULTS

During follow-up, 1621 participants (7.86 %) died, including 985 (4.78 %) premature deaths. Compared to none nappers, napping ≥90 min associated with a higher risk of all-cause mortality (Hazard ratio, [HR] 1.23, 95 % confidence interval [CI] 1.06-1.42) and premature mortality (HR 1.23, 95 % CI 1.02-1.49), while napping <60 min correlated with a lower risk of premature mortality (HR 0.71, 95 % CI 0.54-0.95), after adjustment. Compared to sleep 6-8 h/night, nighttime sleep ≥8 h was associated with an increased risk of all-cause mortality (HR 1.20, 95 % CI 1.04-1.37) and premature mortality (HR 1.28, 95 % CI 1.08-1.52). Participants napping ≥90 min and sleeping ≥8 h had a multi-adjusted HR (95%CI) of 1.50 (95 % CI 1.17-1.92) for all-cause mortality, versus no napping and 6-8 h/night sleep.

CONCLUSIONS

Prolonged napping and extended nighttime sleep linked to increased mortality risk, particularly in combination. Optimizing sleep patterns may have potential implication in mortality prevention.

Associations between gut microbiota and sleep: a two-sample, bidirectional Mendelian randomization study

Introduction

Previous research has reported that the gut microbiota performs an essential role in sleep through the microbiome-gut-brain axis. However, the causal association between gut microbiota and sleep remains undetermined.

Methods

We performed a two-sample, bidirectional Mendelian randomization (MR) analysis using genome-wide association study summary data of gut microbiota and self-reported sleep traits from the MiBioGen consortium and UK Biobank to investigate causal relationships between 119 bacterial genera and seven sleep-associated traits. We calculated effect estimates by using the inverse-variance weighted (as the main method), maximum likelihood, simple model, weighted model, weighted median, and MR-Egger methods, whereas heterogeneity and pleiotropy were detected and measured by the MR pleiotropy residual sum and outlier method, Cochran's Q statistics, and MR-Egger regression.

Results

In forward MR analysis, inverse-variance weighted estimates concluded that the genetic forecasts of relative abundance of 42 bacterial genera had causal effects on sleep-associated traits. In the reverse MR analysis, sleep-associated traits had a causal effect on 39 bacterial genera, 13 of which overlapped with the bacterial genera in the forward MR analysis.

Discussion

In conclusion, our research indicates that gut microbiota may be involved in the regulation of sleep, and conversely, changes in sleep-associated traits may also alter the abundance of gut microbiota. These findings suggest an underlying reciprocal causal association between gut microbiota and sleep.

Sex differences in sleep quality and psychological distress: Insights from a middle-aged twin sample from Spain

There is a moderate association between poor sleep and psychological distress. There are marked sex differences in the prevalence of both variables, with females outnumbering males. However, the origin of these sex differences remains unclear. The objectives of this study were to: (1) study genetic and environmental influences on the relationship between poor sleep quality and psychological distress; and (2) test possible sex differences in this relationship. The sample comprised 3544 participants from the Murcia Twin Registry. Univariate and multivariate twin models were fitted to estimate the magnitude of genetic and environmental influences on both individual variance and covariance between poor sleep quality and psychological distress. Sleep quality and psychological distress were measured using the Pittsburgh Sleep Quality Index and the EuroQol five-dimensions questionnaire, respectively. The results reveal a strong genetic association between poor sleep quality and psychological distress, which accounts for 44% (95%CI: 27%-61%) of the association between these two variables. Substantial genetic (rA = 0.50; 95%CI: 0.32, 0.67) and non-shared environmental (rE = 0.41; 95%CI: 0.30, 0.52) correlations were also found, indicating a moderate overlap between genetic (and non-shared environmental) factors influencing both phenotypes. Equating sexes in sex-limitation models did not result in significant decreases in model fit. Despite the remarkable sex differences in the prevalence of both poor sleep quality and psychological distress, there were no sex differences in the genetic and environmental influences on these variables. This suggests that genetic factors play a similar role for men and women in explaining individual differences in both phenotypes and their relationship.

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.

Association between the rs3812316 Single Nucleotide Variant of the MLXIPL Gene and Alpha-Linolenic Acid Intake with Triglycerides in Mexican Mestizo Women

The carbohydrate response element binding protein (ChREBP) is a key transcription factor to understand the gene−diet−nutrient relationship that leads to metabolic diseases. We aimed to analyze the association between the rs17145750 and rs3812316 SNVs (single nucleotide variants) of the MLXIPL gene with dietary, anthropometric, and biochemical variables in Mexican Mestizo subjects. This is a cross-sectional study of 587 individuals. Genotyping was performed by allelic discrimination. In addition, liver and adipose tissue biopsies were obtained from a subgroup of 24 subjects to analyze the expression of the MLXIPL gene. An in silico test of the protein stability and allelic imbalance showed that rs17145750 and rs3812316 showed a high rate of joint heritability in a highly conserved area. The G allele of rs3812316 was associated with lower triglyceride levels (OR = −0.070 ± 0.027, p < 0.011, 95% CI = −0.124 to −0.016), the production of an unstable protein (ΔΔG −0.83 kcal/mol), and probably lower tissue mRNA levels. In addition, we found independent factors that also influence triglyceride levels, such as insulin resistance, HDL-c, and dietary protein intake in women. Our data showed that the association of rs3812316 on triglycerides was only observed in patients with an inadequate alpha-linolenic acid intake (1.97 ± 0.03 vs. 2.11 ± 0.01 log mg/dL, p < 0.001).

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.

Daytime napping and cardiovascular risk factors, cardiovascular disease, and mortality: A systematic review

Associations between night sleep duration and cardiovascular risk factors in adults have been well documented. However, the associations for daytime napping remain unclear. In this review, six databases were searched for eligible publications to April 8, 2022. A total of 11 articles were identified for umbrella review on the association of daytime napping with diabetes, metabolic syndrome (MetS), cardiovascular disease (CVD), and mortality in adults, 97 for systematic review on the association with CVD and several CVD risk factors. Our umbrella review showed that the associations of daytime napping with diabetes, MetS, CVD, and mortality in most meta-analyses were mainly supported by weak or suggestive evidence. Our systematic review showed that long daytime napping (≥1 h/d) was associated with higher odds of several CVD risk factors, CVD, and mortality, but no significant association was found between short daytime napping and most of the abovementioned outcomes. Our dose-response meta-analyses showed that daytime napping <30 min/d was not significantly associated with higher odds of most CVD risk factors and CVD among young and middle-aged adults. However, among older adults aged >60 years, we observed significant dose-response associations of daytime napping with higher odds of diabetes, dyslipidemia, MetS, and mortality starting from 0 min/d.

Association of elevated glycated hemoglobin and obesity with afternoon napping for more than 1 h in young and middle-aged healthy adults

INTRODUCTION

Sleep has different patterns followed worldwide and can be influenced by social, cultural, and environmental factors. Daytime napping is commonly practiced in different parts of the world with controversial results of its effect on glucose metabolism. The current study aims to examine the association of afternoon napping and night sleep duration with metabolic derangements.

METHODS

This is a cross-sectional study involving young adults and middle-aged subjects. Anthropometric measurements were taken for height and weight and hip and waist ratio. Consented subjects were asked to wear actigraphy for 1 week and run their usual daily activities. Home sleep apnea testing was performed to exclude obstructive sleep apnea. Subjects had been asked to come fasting on day seven for blood collection to test for fasting glucose, glycated hemoglobin, lipid profile, and insulin.

RESULTS

A total of 405 subjects were involved to complete the study (52% male, 48% female). The mean age of participants was 32.8 ± 11.5 years. The study indicated that the duration of afternoon napping was significantly associated with abnormal glycated hemoglobin (HbA1c > 5.7%) (p = 0.01) and body mass index (p = 0.046) independent of age, gender, and nocturnal sleep duration. Nocturnal sleep duration was associated with increased insulin level (p = 0.04).

CONCLUSION

Afternoon napping is associated with an increased level of glycated hemoglobin and obesity and that may predispose to the development of type 2 diabetes mellitus.

HRQoL and nutritional well-being dissimilarities between two different online collection methods: Value for digital health implementation

Background

Online health data collection has gained a reputation over the last years to record and process information about health issues for implementing digital health.

Objective

The research aim was to appraise two online methods (open and rewarded) to collect information about HRQoL and nutritional well-being and to compare the results between both surveyed populations.

Methods

This cross-sectional study is framed on the NUTRiMDEA project. Online data through two different web-based methods (open survey and rewarded survey) were retrieved to assemble data related to sociodemographic, lifestyle (diet, physical activity and sleep patterns) and general health aspects, as well as HRQoL by an evidence-based form such as the SF-12 questionnaire, the IPAQ survey, and MEDAS-14, participants were adults (>18 years old).

Results

Overall, 17,332 participants responded to the open survey (OS, n = 11,883) or the rewarded survey (RS, n = 5449). About 65.1% of the participants were female, while the mean age was in the range of 40–70 years. There were significant differences ( p < 0.05) between surveyed populations in sociodemographic, lifestyle (diet and physical activity), health and HRQoL data.

Conclusions

This investigation implemented an evidence-based online questionnaire that collected demographic, lifestyle factors, phenotypic and health-related aspects as well as compared differential outcomes in HRQoL and nutritional/lifestyle well-being depending on the online mode data collection. Findings demonstrated dissimilarities in most aspects of health, HRQoL, dietary intake and physical activity records between both populations. Overall, OS sample was characterized as a healthier population with superior lifestyle habits than RS participants.

Association of CLOCK gene variants with obesity and adiposity-related anthropometric, metabolic, and behavioral parameters

The CLOCK gene is a core component of the circadian clock and regulates various aspects of metabolism. Therefore, any variation that affects the function/expression of the CLOCK gene may contribute to the manifestation of metabolic disorders such as obesity. This study investigated whether the CLOCK variants rs4864548 and rs6843722 are associated with obesity and related traits in Pakistanis. A total of 306 overweight/obese cases and 306 age- and gender-matched control subjects were recruited (males 336 and females 276, age range 12–63 years). Anthropometric and metabolic parameters were taken by standard procedures and biochemical analyses, respectively. Behavior-related information was collected with a questionnaire. The genotypes of the variants were determined by allelic discrimination Taqman assays. Both variants were found to have a significant association with overweight/obesity according to the over-dominant model. The rs4864548 and rs6843722 were observed to escalate the risk of overweight/obesity by 1.611 ( p = 0.004) and 1.657 ( p = 0.002) times, respectively. These variants were also seen to be significantly associated with various other adiposity-related anthropometric parameters ( p < 0.05). However, no association of both variants with metabolic and behavioral parameters was observed ( p > 0.05). Thus, these variants may contribute to increasing the risk of overweight/obesity and related anthropometric traits in Pakistanis.

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

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

Daytime napping is associated with retinal microcirculation: a large population-based study in China

STUDY OBJECTIVES

To investigate the association between daytime napping and retinal microcirculation.

METHODS

This is a cross-sectional study from a prospective population-based cohort. 2,662 participants were recruited after quota sampling. Information on napping was collected through face-to-face interviews. Retinal vascular calibers (RVCs), including central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), and arterio-to-venous ratio (AVR), were obtained from fundus photography. Multivariate regression and restricted cubic spline curve were performed to determine the association between RVCs and daytime napping duration.

RESULTS

56.4% participants reported daytime napping regularly. Compared to no nap, daytime nap was related to higher CRAE, with nap duration of 0.5-1 h showing the most significant association. 0.5-1 h daytime nappers displayed an average of 4.18 µm (95% confidence interval [CI] 2.45-5.91, p < 0.001) wider CRAE than non-nappers after adjustment. No significant association was found between CRVE and daytime napping. Moreover, individuals with 0.5-1 h daytime napping had a lower risk for AVR reduction (odds ratio [OR] 0.70, 95% confidence interval [CI] 0.56-0.86, p = 0.001) than non-nappers. Similar association persisted in non-hypertensive population. Restricted cubic spline indicated a J-shaped relationship between AVR reduction and nap duration.

CONCLUSION

Retinal microcirculation was positively associated with self-reported 0.5-1 h daytime napping. Better indicators of retinal microcirculation were probably related to nap duration in a J-shaped manner. Also, the possibly beneficial role of 0.5-1 h daytime napping on retinal microcirculation might be independent of clinically diagnosed vascular diseases.

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

CONTEXT

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

OBJECTIVE

To analyze the association between sleep duration and obesity.

METHODS

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

RESULTS

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

CONCLUSIONS

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

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42019130143.

Timing of chocolate intake affects hunger, substrate oxidation, and microbiota: A randomized controlled trial

Eating chocolate in the morning or in the evening/at night, may differentially affect energy balance and impact body weight due to changes in energy intake, substrate oxidation, microbiota (composition/function), and circadian-related variables. In a randomized controlled trial, postmenopausal females (n = 19) had 100 g of chocolate in the morning (MC), in the evening/at night (EC), or no chocolate (N) for 2 weeks and ate any other food ad libitum. Our results show that 14 days of chocolate intake did not increase body weight. Chocolate consumption decreased hunger and desire for sweets (P < .005), and reduced ad libitum energy intake by ~300 kcal/day during MC and ~150 kcal/day during EC (P = .01), but did not fully compensate for the extra energy contribution of chocolate (542 kcal/day). EC increased physical activity by +6.9%, heat dissipation after meals +1.3%, and carbohydrate oxidation by +35.3% (P < .05). MC reduced fasting glucose (4.4%) and waist circumference (-1.7%) and increased lipid oxidation (+25.6%). Principal component analyses showed that both timings of chocolate intake resulted in differential microbiota profiles and function (P < .05). Heat map of wrist temperature and sleep records showed that EC induced more regular timing of sleep episodes with lower variability of sleep onset among days than MC (60 min vs 78 min; P = .028). In conclusion, having chocolate in the morning or in the evening/night results in differential effects on hunger and appetite, substrate oxidation, fasting glucose, microbiota (composition and function), and sleep and temperature rhythms. Results highlight that the "when" we eat is a relevant factor to consider in energy balance and metabolism.

Effect of interaction between obesity-promoting genetic variants and behavioral factors on the risk of obese phenotypes

The studies investigating gene-gene and gene-environment (or gene-behavior) interactions provide valuable insight into the pathomechanisms underlying obese phenotypes. The Pakistani population due to its unique characteristics offers numerous advantages for conducting such studies. In this view, the current study was undertaken to examine the effects of gene-gene and gene-environment/behavior interactions on the risk of obesity in a sample of Pakistani population. A total of 578 adult participants including 290 overweight/obese cases and 288 normal-weight controls were involved. The five key obesity-associated genetic variants namely MC4R rs17782313, BDNF rs6265, FTO rs1421085, TMEM18 rs7561317, and NEGR1 rs2815752 were genotyped using the TaqMan allelic discrimination assays. The data related to behavioral factors, such as eating pattern, diet consciousness, the tendency toward fat-dense food (TFDF), sleep duration, sleep-wake cycle (SWC), shift work (SW), and physical activity levels were collected via a questionnaire. Gene-gene and gene-behavior interactions were analyzed by multifactor dimensionality reduction and linear regression, respectively. In our study, only TMEM18 rs7561317 was found to be significantly associated with anthropometric traits with no significant effect of gene-gene interactions were observed on obesity-related phenotypes. However, the genetic variants were found to interact with the behavioral factors to significantly influence various obesity-related anthropometric traits including BMI, waist circumference, hip circumference, waist-to-hip ratio, waist-to-height ratio, and percentage of body fat. In conclusion, the interaction between genetic architecture and behavior/environment determines the outcome of obesity-related anthropometric phenotypes. Thus, gene-environment/behavior interaction studies should be promoted to explore the risk of complex and multifactorial disorders, such as obesity.

A Mediterranean Lifestyle Is Associated With Lower Hypertension Prevalence and Better Aerobic Capacity Among New England Firefighter Recruits

OBJECTIVE

Examine the association between healthy Mediterranean lifestyle practices and cardiovascular disease (CVD) risk factors among New England firefighter recruits.

METHODS

A MEDI-Lifestyle score was used to measure adherence to a Mediterranean lifestyle (not smoking, increased physical activity, high adherence to Mediterranean diet, non-obese body mass index, decreased screen time, adequate nightly sleep, and napping) among the recruits. MEDI-Lifestyle scores were cross-sectionally analyzed with blood pressure, aerobic capacity, and other CVD risk factors.

RESULTS

Among 92 recruits, high adherence to MEDI-Lifestyle was significantly associated with a decreased risk of prevalent hypertension (odds ratio [OR] = 0.14 [0.03-0.71]) and a greater probability of high aerobic capacity (OR = 5.80 [1.05-32.05]) as compared with low adherence in age- and sex-adjusted analyses.

CONCLUSIONS

Increased adherence to MEDI-Lifestyle is associated with a better CVD risk profile in firefighter recruits.

Genetic determinants of daytime napping and effects on cardiometabolic health

Daytime napping is a common, heritable behavior, but its genetic basis and causal relationship with cardiometabolic health remain unclear. Here, we perform a genome-wide association study of self-reported daytime napping in the UK Biobank (n = 452,633) and identify 123 loci of which 61 replicate in the 23andMe research cohort (n = 541,333). Findings include missense variants in established drug targets for sleep disorders (HCRTR1, HCRTR2), genes with roles in arousal (TRPC6, PNOC), and genes suggesting an obesity-hypersomnolence pathway (PNOC, PATJ). Association signals are concordant with accelerometer-measured daytime inactivity duration and 33 loci colocalize with loci for other sleep phenotypes. Cluster analysis identifies three distinct clusters of nap-promoting mechanisms with heterogeneous associations with cardiometabolic outcomes. Mendelian randomization shows potential causal links between more frequent daytime napping and higher blood pressure and waist circumference.

Adiposity-related risks among the middle-aged and elderly Chinese: the role of siesta and nocturnal sleep duration

Introduction

Background: increasingly, research suggests that lack of sleep is linked to adiposity worldwide, but few studies have been conducted in middle-aged and elderly Chinese subjects. The purpose of the present study was to analyze the association of siesta and nocturnal sleep duration with the prevalence of adiposity in middle-aged and elderly Chinese individuals. Methods: a total of 7,891 community dwelling Chinese subjects who had participated in the 2015 China Health and Retirement Longitudinal Study were included. A four-stage random sampling method was used to select participants. Siesta and nocturnal sleep duration was self-reported. Adiposity, including general obesity and abdominal obesity, was assessed. Multiple logistic analyses were conducted to explore the association between siesta, nocturnal sleep duration, and adiposity. Results: people with long siesta durations (≥ 1 hour/day) were significantly associated with an increased risk for abdominal obesity, independently and in all subgroup analyses, when compared to those without regular siesta. ORs after adjustment of confounding factors included: all subjects, OR = 1.45, 95 % CI, 1.23 to 1.70; middle-aged subjects, OR = 1.46, 95 % CI, 1.15 to 1.86; elderly, OR = 1.43, 95 % CI, 1.14 to 1.78. Conclusions: our data show that siesta duration plays a role in the prevalence of age-specific abdominal obesity. Individuals with long siesta durations are more likely to have abdominal obesity among the middle-aged and elderly population when compared to those without regular siesta. The results of this study need to be confirmed by further studies.

The Association Between the Mediterranean Lifestyle Index and All-Cause Mortality in the Seguimiento Universidad de Navarra Cohort

INTRODUCTION

Overall lifestyle patterns rather than individual factors may exert greater reductions on chronic disease risk and mortality. The objective is to study the association between a Mediterranean lifestyle index and all-cause and cause-specific mortality.

METHODS

Investigators analyzed data from 20,494 participants in the Seguimiento Universidad de Navarra cohort in 2019. The Mediterranean lifestyle index is composed of 28 items on food consumption, dietary habits, physical activity, rest, and social interactions that score 0 or 1 point; scores theoretically could range from 0 to 28 points.

RESULTS

After a median follow-up of 12.1 years, 407 deaths were observed. In the multivariable-adjusted model, high adherence (>14 points) to the Mediterranean lifestyle was associated with a 41% relative reduction in all-cause mortality (hazard ratio=0.59, 95% CI=0.42, 0.83) compared with low adherence (3-10 points, p<0.001 for trend). For each additional point, the multivariable hazard ratios for all-cause mortality were 0.95 (95% CI=0.89, 1.02) for food consumption; 1.00 (95% CI=0.92, 1.08) for dietary habits; and 0.73 (95% CI=0.66, 0.80) for physical activity, rest, social habits, and conviviality. Significant interaction with age at last contact (p<0.001) suggested a lower risk for each additional point among participants aged ≥50 years (hazard ratio=0.50, 95% CI=0.34, 0.74), whereas no association was found for participants aged <50 years (hazard ratio=1.15, 95% CI=0.54, 2.44).

CONCLUSIONS

Adherence to a Mediterranean lifestyle may reduce the risk of mortality in a Spanish cohort of university graduates. Inverse associations were found for the overall Mediterranean lifestyle score and lifestyle block, whereas no associations were observed for the dietary blocks. Future research should consider the Mediterranean lifestyle beyond the Mediterranean diet in different populations for the promotion of healthy longevity.

TRIAL REGISTRATION

This study is registered at www.clinicaltrials.gov NCT02669602.

Combined effect of three common lifestyle factors on cognitive impairment among older Chinese adults: a community-based, cross-sectional survey

AIM

Lifestyle factors may influence cognitive function. Therefore, we compared the risk of cognitive impairment (COI) of all possible combinations of three lifestyle factors-tea consumption, physical activity, and siesta (afternoon nap or rest)-to the absence of any of these lifestyle factors.

METHODS

This cross-sectional study consisted of 4579 community-dwelling Chinese individuals aged 60 years or older living in Suzhou. Among the subjects were 3634 participants with normal cognition and 945 who had been diagnosed with COI according to the Abbreviated Mental Test. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated with a multivariate-adjusted model by logistic regression.

RESULTS

Individually, tea consumption and physical activity significantly lowered the risk of COI to 0.66 (95%CI: 0.48-0.90) and 0.79 (95%CI: 0.65-0.96), respectively. In combination, physical activity and siesta reduced the risk of COI to the greatest extent (OR = 0.44, 95%CI: 0.31-0.64). Based on multivariate adjustment, almost all combinations of factors had a significant negative association with COI, but the combination of tea consumption and siesta had an irrelevant correlation with COI. All combinations of lifestyle factors had a lower OR than any single lifestyle factor among the correlations that were significant.

CONCLUSION

Based on our findings, engaging in physical activity in combination with either or both of the other lifestyle factors was associated with a lower OR of having COI than adhering on a single factor in elderly Chinese people.

Lifestyle behavior and the risk of type 2 diabetes in the Seguimiento Universidad de Navarra (SUN) cohort

BACKGROUND AND AIMS

We prospectively assessed the association between a healthy lifestyle score (HLS) and the risk of type 2 diabetes mellitus (T2DM) in a Mediterranean cohort.

METHODS AND RESULTS

We followed up 11,005 participants initially free of diabetes diagnosis in the "Seguimiento Universidad de Navarra" (SUN) cohort. We evaluated the influence of lifestyle-related factors based on a score previously related to a lower risk of cardiovascular disease. Only one incident case of T2DM was found among those with a baseline BMI ≤22 kg/m². Therefore, we excluded the BMI item and restricted the analysis to participants with a baseline BMI >22 kg/m². We measured the baseline adherence of a HLS that included: never smoking, physical activity, Mediterranean diet adherence, moderate alcohol consumption, avoidance of binge drinking, low television exposure, taking a short nap, spending time with friends and working hours. Incident cases of T2DM were self-reported by participants and confirmed by a physician. Cox proportional-hazards regression models were fitted to assess the association between HLS and the incidence of T2DM. After a median follow-up of 12 years, 145 incident cases of T2DM were observed. Among participants with a BMI >22 kg/m², the highest category of HLS adherence (7-9 points) showed a significant 46% relatively decreased hazard of T2DM compared with the lowest category (0-4 points) (multivariable adjusted HR: 0.54; 95% CI: 0.30-0.99).

CONCLUSIONS

Higher adherence to a HLS, including some factors not typically studied, may reduce T2DM risk. Preventive efforts should preferentially focus on weight control. However, this score may promote a comprehensive approach to diabetes prevention beyond weight reduction.

Nutritional Determinants of Quality of Life in a Mediterranean Cohort: The SUN Study

Health related quality of life (HRQoL) is a subjective appreciation of how personal characteristics and health influence well-being. This cross-sectional analysis aimed to quantitatively measure the influence of dietary, lifestyle, and demographic factors on HRQoL. A sub-sample of the Seguimiento Universidad de Navarra (SUN) Project, a Mediterranean cohort, was analyzed (n = 15,674). Through self-administered questionnaires the relationship between HRQoL and dietary patterns (Mediterranean-diet (MedDiet) and provegetarian food pattern (FP) assessment), lifestyles (sleeping hours, physical activity) and demographic characteristics were measured. Multivariate linear regression and flexible regression models were used to estimate the pondered effect of personal factors on Short Form-36 (SF-36) scores. Coefficients for MedDiet and provegetarian scores (β-coefficient for global SF-36 score: 0.32 (0.22, 0.42); 0.09 (0.06, 0.12) respectively for every unit increase), physical activity (β: 0.03 (0.02, 0.03) for every metabolic equivalent of task indexes (MET)-h/week) had a positive association to HRQoL. The female sex (β: −3.28 (−3.68, −2.89)), and pre-existing diseases (diabetes, β: −2.27 (−3.48, −1.06), hypertension β: −1.79 (−2.36, −1.22), hypercholesterolemia β: −1.04 (−1.48, −0.59)) account for lower SF-36 scores. Adherence to MedDiet or provegetarian FP, physical activity and sleep are associated with higher HRQoL, whereas the female sex, “other” (versus married status) and the presence of chronic diseases were associated with lower SF-36 scores in this sample.

Polysomnographic and psychometric correlates of napping in primary insomnia patients

Introduction: This study aims to evaluate napping in patients with insomnia compared with two control groups and to investigate the relationships between psychometric measures and napping habitude.Methods: Sixty-eight adult patients with chronic primary insomnia were enrolled; 27 men and 41 women, mean age 53.6 ± 13. All patients underwent 24 h ambulatory polysomnography (A-PSG). Prevalence of napping behavior in Insomnia Patients (I-group) was compared with Obstructive Sleep Apnea Syndrome (OSAS) patients (OSAS-group) and epilepsy patients (Ep-group). Patients were evaluated with Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and Berlin Questionnaire. Psychometric evaluation included Self-Administered Anxiety Scale (SAS #54), Beck Depression Inventory (BDI), Maudsley's Obsessive Compulsive Inventory (MOCI), Snaith-Hamilton Pleasure Scale (SHAPS), and Eating Attitude Test (EAT-26).Results: No significant differences resulted in prevalence and duration of naps in the three groups. In the comparison between nappers (N+, subject with at least one nap in A-PSG) and non-nappers (N-, subject with no naps in A-PSG) we observed significant differences in PSQI scores (N+ = 14.1 ± 2.7; N- =11.9 ± 3.3; Whitney U-test = 341.0; p = 0.004) and in EAT score (N+ = 9.8 ± 9.7; N- = 4.4 ± 5.6; Whitney U-test = 313.5, p = 0.0.14); no significant differences were measured in other psychometric parameters and in sleep macrostructural indexes.Conclusions: Our data are in accordance with previous findings outlining that N + insomniacs have higher PSQI scores than N-. Our results do not confirm the suggested association between napping and depressive or obsessive-compulsive symptoms. Conversely, we found a statistically significant difference (p = 0.0014) in EAT scores in N + and N-. Hyperarousal and REM sleep instability in insomniac patients may create an unbalance of the neuroendocrine hypothalamic regulation leading to an appetite alteration.

Sleep Patterns and Quality in Omani Adults

BACKGROUND

Sleep patterns have changed continuously worldwide and it can be influenced by social, cultural, and environmental factors. These patterns may be associated with poor sleep quality and daytime sleepiness. The aim of the study was to investigate sleep patterns and quality in Omani adults using actigraphy.

SUBJECTS AND METHODS

This was a cross-sectional study conducted between June 2015 and February 2017. Four hundred subjects agreed to participate in the study (52% male, 48% female). Subjects were randomly selected and enrolled in the study among young adults and middle aged individuals living in the City of Muscat. Subjects were asked to fill-in Epworth sleepiness scale (ESS) and Pittsburgh sleep quality index (PSQI). Actigraphy was used to measure their sleep patterns for one week.

RESULTS

The mean age of participants was 32.80±11.50 years. Four sleep patterns were identified: monophasic, bi-phasic (post-dawn), bi-phasic (afternoon siesta), and polyphasic (three sleep periods/24 hours). The study revealed that 35% of participants had biphasic-siesta sleep pattern, 28% polyphasic, 26% monophasic, and 11% biphasic-dawn. The biphasic siesta pattern was found to be associated with younger age group (25-34 years) (P=0.001). Polyphasic sleep was associated with higher ESS score (P=0.001) but not with poor sleep quality (P=0.24). There was no significant difference in night sleep duration among all the sleep patterns (P=0.07) but the polyphasic sleep pattern had higher total 24-hour day sleep duration (P=0.03). Nearly 90% of participants practiced afternoon siestas with mean duration of 45±43 minutes.

CONCLUSION

The predominant sleep pattern among Omanis was biphasic-siesta and majority of people practiced afternoon siesta. Polyphasic sleep pattern is associated with daytime sleepiness.

Associations between nocturnal sleep duration, midday nap duration and body composition among adults in Southwest China

Objective

We aim to explore the relationship between nocturnal sleep duration (NSD) and midday nap duration (MND) with body composition among Southwest Chinese adults.

Methods

Data on sleep duration of 3145 adults in Southwest China (59.4% women) were obtained between 2014 and 2015 through questionnaires. Height, weight, and waist circumference (WC) were measured to calculate body composition (body mass index (BMI), percentage of body fat (%BF), and fat mass index (FMI)). Linear regression models were used to assess gender-specific associations between NSD and body composition. The relationship between MND with the odds of overweight and central obesity has been evaluated by logistic regression models.

Results

NSD has the inverse relation with males’ BMI, WC, %BF and FMI after adjusting for all covariates (all P <0.0007), exclusive of females’ (all P >0.4). After adjustment for potential confounders, compared to the subjects in the no midday nap group, the subjects who napped 0.1–1 hour were independently associated with a less prevalence of overweight in both women (OR: 0.72, 95%CI: 0.55–0.95) and men (OR: 0.71, 95%CI: 0.52–0.98). MND was not associated with central obesity.

Conclusions

Among Southwest Chinese adults, lower NSD might be related to higher BMI, WC, %BF and FMI among men. Additionally, MND is associated with overweight in adults.

Sleep, Diet, and Cardiometabolic Health Investigations: a Systematic Review of Analytic Strategies

PURPOSE OF REVIEW

Poor sleep is a risk factor for cardiometabolic morbidity. The relationship of sleep and cardiometabolic health could be confounded, mediated, or modified by diet, yet the incorporation of diet in sleep-cardiometabolic health studies is inconsistent. This rapid systematic literature review evaluates the conceptualization of diet as a confounder, mediator, or effect modifier within sleep-cardiometabolic health investigations, and the statistical approaches utilized.

RECENT FINDINGS

Of 4692 studies identified, 60 were retained (28 adult, 32 pediatric). Most studies included diet patterns, quality, or energy intake as confounders, while a few examined these dietary variables as mediators or effect modifiers. There was some evidence, mostly in pediatric studies, that inclusion of diet altered sleep-cardiometabolic health associations. Diet plays a diverse role within sleep-cardiometabolic health associations. Investigators should carefully consider the conceptualization of diet variables in these relationships and utilize contemporary statistical approaches when applicable.

Long Daytime Napping Is Associated with Increased Adiposity and Type 2 Diabetes in an Elderly Population with Metabolic Syndrome

Research examining associations between objectively-measured napping time and type 2 diabetes (T2D) is lacking. This study aimed to evaluate daytime napping in relation to T2D and adiposity measures in elderly individuals from the Mediterranean region. A cross-sectional analysis of baseline data from 2190 elderly participants with overweight/obesity and metabolic syndrome, in the PREDIMED-Plus trial, was carried out. Accelerometer-derived napping was measured. Prevalence ratios (PR) and 95% confidence intervals (CI) for T2D were obtained using multivariable-adjusted Cox regression with constant time. Linear regression models were fitted to examine associations of napping with body mass index (BMI) and waist circumference (WC). Participants napping ≥90 min had a higher prevalence of T2D (PR 1.37 (1.06, 1.78)) compared with those napping 5 to <30 min per day. Significant positive associations with BMI and WC were found in those participants napping ≥30 min as compared to those napping 5 to <30 min per day. The findings of this study suggest that longer daytime napping is associated with higher T2D prevalence and greater adiposity measures in an elderly Spanish population at high cardiovascular risk.

From Mediterranean diet to Mediterranean lifestyle: a narrative review

OBJECTIVE

To summarize the recent scientific evidence regarding the wellness-promoting capacity of the Mediterranean lifestyle (ML), with a special focus on physical, social and environmental wellness.

DESIGN

Narrative review of English-language publications in PubMed, Scopus and Embase, from 1 January 2010 to 31 October 2018.

SETTING

Prospective cohort studies, interventional studies, meta-analyses and reviews of those investigating the effect of at least one component of the ML on wellness parameters.

PARTICIPANTS

General population.

RESULTS

Although an explicit definition of ML is missing, compliance with various combinations of its components improves metabolic health and protects against or ameliorates disease state. However, there is heterogeneity in the healthy behaviours that the ML-focused studies include in their design and the way these are assessed. Also, despite that features of the ML could contribute to other wellness dimensions, there are no studies exploring the effect this healthy lifestyle could confer to them.

CONCLUSIONS

Chronic lifestyle diseases are of multifactorial aetiology and they warrant multifaceted approaches targeting the general way of living. ML, if thoroughly evaluated, can provide a valuable tool to holistically promote health and wellness.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sleep Duration and Excessive Daytime Sleepiness Are Associated with Obesity Independent of Diet and Physical Activity

In the European Union, Czech Republic ranks 3rd and 6th for the incidence of obesity and cardiovascular diseases, respectively. Worldwide, short sleep duration and excessive daytime sleepiness (EDS) characterize obese subjects, which in turn exhibit scarce physical activity and unhealthy diet. We aimed to understand the relationship between irregular sleep patterns, obesity and lifestyle factors, such as diet and physical activity, in a vulnerable Czech population. 1482 members of the Kardiovize cohort, a random sample of the Czech urban population, were included in a cross-sectional study. Exposure variables included self-reported sleep duration and EDS, assessed by the Epworth Sleepiness Scale. Primary outcomes were BMI and waist-to-hip ratio or prevalence of obesity and central obesity. Covariates included physical activity and diet. Associations and interactions between variables were evaluated using logistic regression analyses. After adjustment for covariates, short sleep duration (<7 h) was associated with greater odds of overweight (BMI > 25; OR = 1.42; 95%CI = 1.06⁻1.90; p = 0.020) and obesity (BMI > 30; OR = 1.40; 95%CI = 1.02⁻1.94; p = 0.047), while EDS was associated with greater odds of central obesity (OR = 1.72; 95%CI = 1.06⁻2.79; p = 0.030), independent of diet and physical activity. However, due to the cross-sectional nature of our study, further prospective, large-scale studies are needed to evaluate the etiological link and causality between sleep disturbances and obesity.

Sleep Duration and Excessive Daytime Sleepiness Are Associated with Obesity Independent of Diet and Physical Activity

In the European Union, Czech Republic ranks 3rd and 6th for the incidence of obesity and cardiovascular diseases, respectively. Worldwide, short sleep duration and excessive daytime sleepiness (EDS) characterize obese subjects, which in turn exhibit scarce physical activity and unhealthy diet. We aimed to understand the relationship between irregular sleep patterns, obesity and lifestyle factors, such as diet and physical activity, in a vulnerable Czech population. 1482 members of the Kardiovize cohort, a random sample of the Czech urban population, were included in a cross-sectional study. Exposure variables included self-reported sleep duration and EDS, assessed by the Epworth Sleepiness Scale. Primary outcomes were BMI and waist-to-hip ratio or prevalence of obesity and central obesity. Covariates included physical activity and diet. Associations and interactions between variables were evaluated using logistic regression analyses. After adjustment for covariates, short sleep duration (<7 h) was associated with greater odds of overweight (BMI > 25; OR = 1.42; 95%CI = 1.06⁻1.90; p = 0.020) and obesity (BMI > 30; OR = 1.40; 95%CI = 1.02⁻1.94; p = 0.047), while EDS was associated with greater odds of central obesity (OR = 1.72; 95%CI = 1.06⁻2.79; p = 0.030), independent of diet and physical activity. However, due to the cross-sectional nature of our study, further prospective, large-scale studies are needed to evaluate the etiological link and causality between sleep disturbances and obesity.

Sleep and Obesity

Rising global prevalence and incidence of obesity lead to increased cardiovascular-renal complications and cancers. Epidemiological studies reported a worldwide trend towards suboptimal sleep duration and poor sleep quality in parallel with this obesity epidemic. From rodents and human models, it is highly plausible that abnormalities in sleep, both quantity and quality, impact negatively on energy metabolism. While excess dietary intake and physical inactivity are the known drivers of the obesity epidemic, promotion of healthy sleep habits has emerged as a new target to combat obesity. In this light, present review focuses on the existing literature examining the relationship between sleep physiology and energy homeostasis. Notably, sleep dysregulation perturbs the metabolic milieu via alterations in hormones such as leptin and ghrelin, eating behavior, neuroendocrine and autonomic nervous systems. In addition, shift work and trans-meridian air travel may exert a negative influence on the hypothalamic-pituitary-adrenal axis and trigger circadian misalignment, leading to impaired glucose tolerance and increased fat accumulation. Amassing evidence has also suggested that uncoupling of the circadian clock can increase the risk of adverse metabolic health. Given the importance of sleep in maintaining energy homeostasis and that it is potentially modifiable, promoting good sleep hygiene may create new avenues for obesity prevention and treatment.

Perivascular Adipose Tissue as a Relevant Fat Depot for Cardiovascular Risk in Obesity

Obesity is associated with increased risk of premature death, morbidity, and mortality from several cardiovascular diseases (CVDs), including stroke, coronary heart disease (CHD), myocardial infarction, and congestive heart failure. However, this is not a straightforward relationship. Although several studies have substantiated that obesity confers an independent and additive risk of all-cause and cardiovascular death, there is significant variability in these associations, with some lean individuals developing diseases and others remaining healthy despite severe obesity, the so-called metabolically healthy obese. Part of this variability has been attributed to the heterogeneity in both the distribution of body fat and the intrinsic properties of adipose tissue depots, including developmental origin, adipogenic and proliferative capacity, glucose and lipid metabolism, hormonal control, thermogenic ability, and vascularization. In obesity, these depot-specific differences translate into specific fat distribution patterns, which are closely associated with differential cardiometabolic risks. The adventitial fat layer, also known as perivascular adipose tissue (PVAT), is of major importance. Similar to the visceral adipose tissue, PVAT has a pathophysiological role in CVDs. PVAT influences vascular homeostasis by releasing numerous vasoactive factors, cytokines, and adipokines, which can readily target the underlying smooth muscle cell layers, regulating the vascular tone, distribution of blood flow, as well as angiogenesis, inflammatory processes, and redox status. In this review, we summarize the current knowledge and discuss the role of PVAT within the scope of adipose tissue as a major contributing factor to obesity-associated cardiovascular risk. Relevant clinical studies documenting the relationship between PVAT dysfunction and CVD with a focus on potential mechanisms by which PVAT contributes to obesity-related CVDs are pointed out.

Association Between a Healthy Lifestyle Score and the Risk of Cardiovascular Disease in the SUN Cohort

INTRODUCTION AND OBJECTIVES

A healthy lifestyle (HLS) is essential to attaining optimal cardiovascular health. Our objective was to assess the association between a HLS score and the incidence of hard cardiovascular disease (CVD) events.

METHODS

The SUN project is a dynamic, prospective, multipurpose cohort of Spanish university graduates with a retention proportion of 92%. In 19 336 participants, we calculated a HLS score ranging from 0 to 10 points: never smoking, physical activity (> 20 METs-h/wk), Mediterranean diet adherence (≥ 4/8 points), low body mass index (≤ 22), moderate alcohol intake (women, 0.1-5g/d; men, 0.1-10g/d), low television exposure (≤ 2h/d), no binge drinking (≤ 5 alcoholic drinks anytime), taking a short afternoon nap (< 30min/d), meeting up with friends> 1h/d and working> 40h/wk.

RESULTS

After a median follow-up of 10.4 years, we identified 140 incident cases of CVD. After adjustment for potential confounders, the highest category of HLS score adherence (7-10 points) showed a significant 78% relative reduction in the risk of primary CVD compared with the lowest category (0-3 points) (adjusted HR, 0.22; 95%CI, 0.11-0.46). Each healthy habit was individually associated with a lower risk of CVD.

CONCLUSIONS

A HLS score including several simple healthy habits was associated with a lower risk of developing primary CVD. This index may be useful to reinforce CVD prevention without the need to include traditional risk factors.

Heritability of siesta and night-time sleep as continuously assessed by a circadian-related integrated measure

Siesta is a relevant aspect of sleep due to its posited relationship with health or cognitive function. However, unlike night-time sleep, studies about daytime-sleep determinants and characteristics are scarce, and the genetic/environmental structure of siesta is still unknown. Our aim was to explore the relative contribution of genetic and environmental factors to variation in sleep-wake rhythm, measured by a continuous assessment of temperature-activity-position (TAP), which allows for diurnal sleep analysis. The sample comprised 53 pairs of female twins (28 MZ and 25 DZ), selected from the Murcia Twin Register. Mean age of participants was 52 (SD: 6.03). Zygosity was determined by DNA. We conducted separate univariate analyses to study the sources of variance of daytime and night-time sleep parameters. About 60% of the sample reported to take siesta at least once a week. Heritability of taking siesta and daytime sleep duration was 65 and 61% respectively. Other sleep parameters obtained by TAP showed heritability estimates between 36 and 69%, suggesting a relevant impact of genetic factors on sleep rhythm. This is the first study to investigate the relative contribution of genetic factors to siesta. By using TAP, we introduce a novel approach to the study of diurnal sleep characteristics.

Obesity

Excessive fat deposition in obesity has a multifactorial aetiology, but is widely considered the result of disequilibrium between energy intake and expenditure. Despite specific public health policies and individual treatment efforts to combat the obesity epidemic, >2 billion people worldwide are overweight or obese. The central nervous system circuitry, fuel turnover and metabolism as well as adipose tissue homeostasis are important to comprehend excessive weight gain and associated comorbidities. Obesity has a profound impact on quality of life, even in seemingly healthy individuals. Diet, physical activity or exercise and lifestyle changes are the cornerstones of obesity treatment, but medical treatment and bariatric surgery are becoming important. Family history, food environment, cultural preferences, adverse reactions to food, perinatal nutrition, previous or current diseases and physical activity patterns are relevant aspects for the health care professional to consider when treating the individual with obesity. Clinicians and other health care professionals are often ill-equipped to address the important environmental and socioeconomic drivers of the current obesity epidemic. Finally, understanding the epigenetic and genetic factors as well as metabolic pathways that take advantage of 'omics' technologies could play a very relevant part in combating obesity within a precision approach.

Differences in meal patterns and timing with regard to central obesity in the ANIBES ('Anthropometric data, macronutrients and micronutrients intake, practice of physical activity, socioeconomic data and lifestyles in Spain') Study

Objective

To study the association of meal patterns and timing with central obesity to identify the best dietary strategies to deal with the increasing obesity prevalence.

Design

A cross-sectional study performed on data from a representative sample of the Spanish population. Height and waist circumference were measured using standardized procedures and waist-to-height ratio (WHtR) was calculated. The sample was divided into those without central obesity (WHtR<0·5) and those with central obesity (WHtR≥0·5).

Setting

ANIBES (‘Anthropometric data, macronutrients and micronutrients intake, practice of physical activity, socioeconomic data and lifestyles in Spain’) Study.

Subjects

Adults aged 18–64 years (n 1655; 798 men and 857 women).

Results

A higher percentage of people ate more than four meals daily in the group without central obesity and those with central obesity more frequently skipped the mid-afternoon snack than those without. Breakfasts containing >25 % of total energy intake and lunches containing >35 % of total energy intake were associated with increased likelihood of central obesity (OR=1·874, 95 % CI 1·019, 3·448; P<0·05 and OR=1·693, 95 % CI 1·264, 2·268; P<0·001, respectively). On the contrary, mid-morning snacks and mid-afternoon snacks containing >15 % of total energy were associated with decreased likelihood of central obesity (OR=0·477, 95 % CI 0·313, 0·727; P<0·001 and OR=0·650, 95 % CI 0·453, 0·932; P<0·05, respectively). The variety of cereals, wholegrain cereals and dairy was higher in the population without central obesity.

Conclusions

Our results suggest that ‘what and when we eat’ should be considered dietary strategies to reduce central obesity.

General and Abdominal Obesity Is Related to Physical Activity, Smoking and Sleeping Behaviours and Mediated by the Educational Level: Findings from the ANIBES Study in Spain

The aim of the present study was to analyze the association of socioeconomic (SES) and lifestyle factors, with the conditions of overweight (OW), general (OB) and abdominal obesity (AO) in Spanish adults. A representative sample of 1655 Spanish adults (18 to 65 years) from the ANIBES Study was investigated. Collected data included measured anthropometry (weight, height and waist circumference), demographic and SES data (region and habitant population size, educational level, family income, unemployment rate), physical activity (PA) and other lifestyle factors (sleeping time and frequency of viewing television). OW, OB and AO were determined in each participant. Being male, older than 40 years, and watching television more frequently were associated with higher risk of OB and AO, whereas those with a higher level of education, smokers, and more time in sleeping and in vigorous PA, but not in moderate-vigorous PA, were associated with a lower risk. Living in the Atlantic region and stating no answer to the question regarding family income were also associated with lower risk of AO. Strategies for preventing and reducing OB and AO should consider improving sleeping habits and PA. They should also pay more attention to the most vulnerable groups such as those less educated.

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

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

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

BACKGROUND/OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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