Sleep duration and the associated cardiometabolic risk scores in adults

Association of oxidative balance score with blood pressure, all-cause and cardiovascular disease mortality among hypertensive patients: a prospective study

OBJECTIVE

The oxidative balance score (OBS) has emerged as a novel marker for assessing oxidative stress status. This study aimed to investigate the association of OBS with systolic blood pressure (SBP), diastolic blood pressure (DBP), all-cause, and cardiovascular disease mortality in hypertensive patients.

METHODS

We conducted an analysis of data from 7602 hypertensive patients from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Multiple linear regression, Cox proportional hazards models, Kaplan-Meier survival curves, restricted cubic spline, and subgroup analysis were used to examine the association between OBS and SBP, DBP, estimated pulse wave velocity (ePWV), and mortality risk.

RESULTS

The results showed that individuals in the highest OBS quartile (27 ≤ OBS ≤ 40) had a significant 2.41 mmHg reduction in SBP compared to the lowest quartile (5 ≤ OBS ≤ 15) (Ptrend < 0.001). Compared to the lowest quartile, individuals in the highest OBS quartile had a 29% lower risk of all-cause mortality and a 44% lower risk of cardiovascular disease mortality (Ptrend < 0.001). This inverse association persisted irrespective of antihypertensive medication use. OBS is inversely associated with SBP, all-cause, and cardiovascular disease mortality in hypertensive patients.

CONCLUSION

This finding provides new evidence and suggestions for those with poor blood pressure control and low OBS (<15) to adjust their diet and lifestyle reasonably.

Associations between habitual sleep characteristics and cardiometabolic disease risk in corporate executives

OBJECTIVES

Corporate executive job demands may lead to poor sleep habits, increasing their risk for cardiometabolic disease. This study aimed to describe and explore associations between objectively measured habitual sleep characteristics and cardiometabolic disease risk of corporate executives, while accounting for occupational, psychological, and lifestyle factors.

METHODS

Habitual sleep was measured using wrist-worn actigraphy and a sleep diary over seven consecutive days in 61 (68.3% men) corporate executives aged 46.4 ± 8.7years. A composite cardiometabolic disease risk score was determined using body mass index, waist circumference, blood pressure and fasting glucose and lipid concentrations. Prediction models were built using a backward stepwise selection approach to explore associations between sleep characteristics and cardiometabolic disease risk factors adjusting for occupational, psychological, and lifestyle covariates.

RESULTS

Average total sleep time was 6.60 ± 0.75 hours, with 51.7% of participants reporting poor sleep quality and 26.2% extending their weekend sleep. Adjusted models showed that lower sleep efficiency (β = -0.25, 95%CI: -0.43; -0.08, P = .006), shorter weekday total sleep time (β = -1.37, 95% CI: -2.41, -0.32; P = .011) and catch-up sleep (β = 0.84, 95%CI: 0.08, 1.60, P = .002) were associated with higher cardiometabolic disease risk scores. Adjusted models also found that shorter average time-in-bed (ß=-2.00, 95%CI: -3.76; -0.18, P = .031), average total sleep time (ß=1.98, 95%CI: -3.70; -0.25, P = .025) and weekday total sleep time (β = -2.13, 95%CI: -3.56; -0.69, P = .025) as well as catch-up sleep (β = 1.67, 95% CI: 0.52; 2.83; P = .012) were all associated with a higher body mass index.

CONCLUSION

Corporate executives who compromise sleep duration during the working week may increase their risk for obesity and future cardiometabolic disease.

Unintentional fall mortality by place, sex, and age group among older Chinese adults, 2010-21

Background

Unintentional falls are known to be a leading cause of injury mortality among older Chinese adults, yet we lack data on the most recent trends in related mortality. To address this, we used the latest nationally representative data from China to examine trends in elderly unintentional fall mortality by place (urban/rural), sex (men/women), and age group (65-69, 70-74, 75-79, 80-84, and ≥85 years) from 2010 to 2021.

Methods

We retrieved mortality data from the Chinese Health Statistical Yearbook (2010-21) and population data from the Chinese Population Census (2010, 2020). Using line graphs, we examined mortality trends over time. We fitted a joinpoint regression model to detect periods experiencing significant changes and calculated the average and specific annual percentage change of mortality rates to quantify significant changes in the mortality of the elderly due to unintentional falls.

Results

Between 2010 and 2021, the age-standardised mortality rate from unintentional falls increased from 45.7 to 67.8 per 100 000 population among Chinese adults aged 65 years and older. Subgroup analyses by sex and place showed similar changing patterns to the overall mortality trends. The joinpoint regression identified certain recent periods that saw significant increases in mortality among adults aged 65-69, 70-74, 75-79, and 80-84 years. During the study period, men and individuals living in rural areas generally had higher unintentional fall mortality rates than women and people living in urban areas (mortality rate ratios: 1.09-1.21 for men vs. women and 1.01-1.27 for rural areas vs. urban areas). Notably, the differences between urban and rural areas, and those between men and women, were consistent across the three younger age groups (65-69, 70-74, and 75-79 years) studied, but reduced in the two oldest age groups (80-84 and ≥85 years).

Conclusions

The age-standardised mortality rate from unintentional falls increased between 2010 and 2021 among Chinese adults aged 65 years or older, with wide variations across years. Unintentional fall mortality has recently increased among adults aged 65 to 84 years. Differences between urban and rural areas, as well as between men and women, deserve the attention of injury researchers and policymakers.

Sleep onset time as a mediator in the association between screen exposure and aging: a cross-sectional study

Excessive screen exposure has become a significant health concern. This study investigates the impact of screen time on aging in middle-aged and elderly populations. Healthy working adults over 45 years old in Shanghai, China, underwent general and ocular examinations. Questionnaires collected demographics, medical history, and screen exposure details. Aging was assessed using the retinal age gap, defined as the difference between the retinal age predicted by deep learning algorithms based on fundus images and chronological age. Pathway analysis tested the mediation effect of sleep duration and onset time on the relationship between screen usage and retinal age gap. The retinal age gap increased with longer screen exposure, from 0.49 ± 3.51 years in the lowest tertile to 5.13 ± 4.96 years in the highest tertile (Jonckheere-Terpstra test, p < 0.001). Each additional hour of screen exposure accelerated the retinal age gap by 0.087 years (95% CI, 0.027, 0.148, p = 0.005) in the fully adjusted linear model. Sleep onset time mediated the impact of screen usage on the retinal age gap (indirect effect, β = 0.11; 95% CI 0.04-0.24). The impact of screen usage in a light-off environment on the retinal age gap was fully mediated by sleep onset time (indirect effect, β = 0.22; 95% CI 0.07-0.38), with the proportion being 100%. Our study identified a correlation between excessive screen time and a wider retinal age gap in middle-aged and elderly individuals, likely due to delayed sleep onset. To mitigate the adverse effects on the retina and aging, it is important to limit screen usage and avoid screens before bedtime.

Clustering of health behaviors and their associations with cardiometabolic risk factors among adults at high risk for type 2 diabetes in India: A latent class analysis

BACKGROUND

We aimed to identify clusters of health behaviors and study their associations with cardiometabolic risk factors in adults at high risk for type 2 diabetes in India.

METHODS

Baseline data from the Kerala Diabetes Prevention Program (n = 1000; age 30-60 years) were used for this study. Information on physical activity (PA), sedentary behavior, fruit and vegetable intake, sleep, and alcohol and tobacco use was collected using questionnaires. Blood pressure, waist circumference, 2-h plasma glucose, high-density lipoprotein and low-density lipoprotein cholesterol, and triglycerides were measured using standardized protocols. Latent class analysis was used to identify clusters of health behaviors, and multilevel mixed-effects linear regression was employed to examine their associations with cardiometabolic risk factors.

RESULTS

Two classes were identified, with 87.4% of participants in class 1 and 12.6% in class 2. Participants in both classes had a high probability of not engaging in leisure-time PA (0.80 for class 1; 0.73 for class 2) and consuming <5 servings of fruit and vegetables per day (0.70 for class 1; 0.63 for class 2). However, participants in class 1 had a lower probability of sitting for >=3 h per day (0.26 vs 0.42), tobacco use (0.10 vs 0.75), and alcohol use (0.08 vs 1.00) compared to those in class 2. Class 1 had a significantly lower mean systolic blood pressure (β = -3.70 mm Hg, 95% confidence interval [CI] -7.05, -0.36), diastolic blood pressure (β = -2.45 mm Hg, 95% CI -4.74, -0.16), and triglycerides (β = -0.81 mg/dL, 95% CI -0.75, -0.89).

CONCLUSION

Implementing intervention strategies, tailored to cluster-specific health behaviors, is required for the effective prevention of cardiometabolic disorders among high-risk adults for type 2 diabetes.

Interplay of sleep patterns and oxidative balance score on total cardiovascular disease risk: Insights from the National Health and Nutrition Examination Survey 2005-2018

Background

Unhealthy lifestyle and diet may contribute to the development of cardiovascular disease (CVD), but limited evidence exists regarding the association between sleep patterns, oxidative stress-related exposures to diet and lifestyle, and CVD risk.

Methods

We analysed data from 10 212 adults in the National Health and Nutrition Examination Survey (NHANES) database (2005-2018). Self-report questionnaires were used to collect data on sleep duration, sleepiness, and trouble sleeping, classified into three categories: healthy, intermediate, and poor sleep patterns. Healthy sleep was defined as sleeping seven to nine hours per night with no self-reported sleepiness or trouble sleeping, while intermediate and poor sleep patterns indicated one and two to three sleep problems, respectively. The oxidative balance score (OBS) was calculated based on twenty oxidative stress-related exposures to dietary and lifestyle factors, with a higher score indicating greater antioxidant exposure. Survey-based multivariable-adjusted regression analysis was conducted to examine the association of sleep patterns or OBS alone and combined with the total and specific CVD risk.

Results

Participants with poor sleep patterns had a higher likelihood of developing CVD (odds ratio (OR) = 1.76; 95% confidence interval (CI) = 1.26-2.45, P < 0.05), while an inverse association was found between OBS and CVD risk (quartile (Q) 4 vs Q1: OR = 0.67; 95% CI = 0.47-0.94, P = 0.02, P for trend <0.05). There was an interaction between sleep patterns and OBS (P for interaction = 0.03). Participants with unhealthy (intermediate and poor) sleep patterns and pro-oxidant OBS (Q1 and Q2) were significantly associated with increased risk of total CVD (OR = 2.31; 95% CI = 1.42-3.74, P < 0.05), as well as angina and congestive heart failure, but not coronary heart disease (CHD). Stratified analysis showed that among individuals without hyperlipidaemia, participants with both unhealthy sleep patterns and pro-oxidant OBS exhibited a higher risk of CHD compared to those with healthy sleep patterns and antioxidative OBS.

Conclusions

Unhealthy sleep patterns and reduced oxidative balance are positively associated with an increased risk of overall and specific CVD. Interventions that target healthy sleep habits and antioxidant-rich diets and lifestyles may be important for reducing the risk of CVD.

Objective sleep and cardiometabolic biomarkers: results from the community of mine study

Study Objectives

Examining multiple dimensions of sleep health may better capture associations between sleep and health risks, including cardiometabolic disease (CMD). Hispanics have elevated risk for inadequate sleep and CMD biomarkers. Few studies have explored whether associations between sleep and CMD differ by Hispanic ethnicity.

Methods

Leveraging data from the Community of Mine (CoM) study, a cross-sectional investigation of 602 ethnically diverse participants, we derived accelerometer-measured sleep duration and efficiency, and self-reported sleep quality. Accelerometer-measured sleep exposures were analyzed both as continuous and categorical variables. Multivariate and quantile regression models were used to assess associations between sleep and CMD biomarkers (insulin resistance, systolic blood pressure, and low-density-lipoprotein cholesterol), controlling for age, sex, ethnicity, education, smoking status, and body mass index. We examined the potential effect modification of Hispanic ethnicity.

Results

We observed mixed results based on CMD biomarkers and sleep exposure. Increased sleep duration was significantly related to low-density lipoprotein cholesterol in adjusted models (estimate = 0.06; 95% CI: 0.02, 0.11). Poor sleep efficiency was associated with greater insulin resistance in the adjusted quantile (estimate = 0.20; 95% CI: 0.04, 0.36) model at the 90th percentile. Self-reported sleep quality was not associated with CMD outcomes. There was no evidence of effect modification by Hispanic ethnicity.

Conclusions

In this cohort, sleep health measures were found to have mixed and at times opposing effects on CMD outcomes. These effects did not demonstrate an interaction with Hispanic ethnicity.

Longitudinal associations between self-reported sleep duration and cardiometabolic disease risk in corporate executives

OBJECTIVE

This study aimed to determine the longitudinal associations between self-reported sleep duration and cardiometabolic disease (CMD) risk in corporate executives.

METHODS

Self-reported sleep duration and lifestyle, occupational, psychological, and anthropometrical, blood pressure and blood marker variables were obtained from 1512 employees at annual health risk assessments in South Africa between 2016 and 2019. Gender-stratified linear mixed models, adjusting for age, lifestyle, occupational and psychological covariates were used to explore these longitudinal associations.

RESULTS

Among women, shorter sleep duration was associated with higher body mass index (BMI) covarying for age only (ß with 95% confidence intervals: -0.19 [-0.36, -0.03]), age and occupational factors (-0.20 [-0.36, -0.03]) and age and psychological factors (-0.20 [-0.37, -0.03]). Among men, shorter sleep was associated with both BMI and waist circumference (WC) covarying for age only (BMI: -0.15 [-0.22; -0.08]; WC: -0.62 [-0.88; -0.37]); age and lifestyle factors (BMI: -0.12 [-0.21; -0.04]); WC: -0.016 [-0.92; -0.29], age and occupational factors (BMI: -0.20 [-0.22; 0.08]; WC: -0.62 [-0.88; -0.36]), and age and psychological factors (BMI: -0.15 [-0.22; -0.07]; WC: -0.59 [-0.86; -0.33]). Among men, shorter sleep was also longitudinally associated with higher CMD risk scores in models adjusted for age and lifestyle factors (CMD: -0.12 [-0.20; -0.04]) and age and psychological factors (CMD: -0.08 [-0.15; -0.01]).

CONCLUSION

Corporate executives who report shorter sleep durations may present with poorer CMD risk profiles, independent of age, lifestyle, occupational and psychological factors. Addressing sleep health in workplace health programmes may help mitigate the development of CMD in such employees.

An mHealth-Supported antenatal lifestyle intervention may be associated with improved maternal sleep in pregnancy: Secondary analysis from the PEARS trial

OBJECTIVE

To investigate the effect of an antenatal diet and exercise intervention during pregnancy on sleep duration. As a secondary objective, associations between sleep duration and gestational weight gain (GWG), maternal metabolic parameters and pregnancy outcomes were assessed.

DESIGN

Secondary analysis.

SETTING

Large tertiary Maternity Hospital in Dublin, Ireland.

POPULATION

326 women with overweight or obesity who participated in the Pregnancy Exercise And Nutrition Research Study (PEARS) randomised controlled trial between March 2013 and August 2016.

METHODS

Secondary analysis of a randomised trial.

MAIN OUTCOME MEASURES

Impact of the PEARS intervention on sleep duration, and association of sleep duration and maternal metabolic parameters, and pregnancy outcomes.

RESULTS

Participants had a mean age of 32.5 ± 4.5 years and median (interquartile range [IQR]) body mass index of 28.3 (26.6-31.2) kg/m² . The intervention group had a longer sleep duration in late pregnancy (mean difference 17.1 minutes (95% confidence interval [CI] 0.5-33.7) and a higher proportion achieving optimum sleep duration of 7-9 h (54.3 vs. 42.9%, relative risk [RR] 1.28 (95% CI 1.01-1.62). In late pregnancy, sleep duration of <6 h was associated with lower breastfeeding rates on discharge (RR 0.74, 95% CI 0.57-0.95) and higher triglyceride levels (mean difference 0.24, 95% CI 0.10-0.38). There were no significant associations between sleep and incidence of gestational diabetes mellitus or pre-eclampsia/toxaemia, or other metabolic parameters assessed (insulin, fasting glucose, HOMA-IR).

CONCLUSION

A diet and exercise intervention from early pregnancy may promote longer and optimal sleep duration, with maternal benefits such as lower triglyceride levels and higher breastfeeding rates.

Association between self-reported sleep duration and cardiometabolic risk in corporate executives

PURPOSE

This cross-sectional study aimed to compare the association between self-reported sleep duration and cardiometabolic risk among men and women corporate executives and investigate potential lifestyle, work- and stress-related mediators thereof.

METHODS

Self-reported sleep duration and lifestyle, occupational, psychological and measured anthropometrical, blood pressure (BP) and blood marker variables were obtained from health risk assessment data of 3583 corporate executives. Sex-stratified regression analyses investigated the relationships between occupational and psychological variables with self-reported sleep duration, and sleep duration with individual cardiometabolic risk factors. Mediation analyses investigated the effects of work, psychological and lifestyle factors on the relationships between self-reported sleep duration and cardiometabolic risk factors, as well as a continuous cardiometabolic risk score calculated from the sum of sex-stratified z-standardized scores of negative fasting serum HDL, and positive plasma Glu, serum TG, body mass index (BMI), waist circumference, systolic and diastolic BP.

RESULTS

Longer work hours and work commute time, depression, anxiety and stress were associated with shorter sleep duration in both men and women (all p < 0.05). Shorter sleep duration was associated with higher BMI, larger waist circumference and greater cardiometabolic risk scores in both men and women (all p < 0.05), higher diastolic BP in men (p < 0.05) and lower HDL cholesterol in women (p < 0.05). Physical activity, working hours and stress significantly mediated the relationships between self-reported sleep duration and BMI, waist circumference, diastolic BP and cardiometabolic risk score in men only.

CONCLUSION

In these corporate executives, shorter self-reported sleep duration is associated with poorer psychological, occupational and cardiometabolic risk outcomes in both men and women. Given that physical activity, working hours and stress mediate this association among the men, the case for sleep health interventions in workplace health programmes is warranted.

24-h movement behaviors among autistic adults: Differences by sex, age, and level of independence

BACKGROUND

Autistic adults have low levels of physical activity [PA], high levels of sedentary behavior [SB], and insufficient sleep. Not known is the extent to which engagement in these movement behaviors vary by sex, age, and level of independence in activities of daily living (ADLs).

OBJECTIVE

To characterize movement behaviors in a national sample of autistic adults by sex, age, and level of independence in ADLs.

METHODS

A national sample of autistic adults and caregivers of autistic adults self-reported PA, SB and sleep behaviors as well as demographic variables using an electronic survey. Levels of engagement in movement behaviors were described, and compared by sex, age (young-adult versus middle-age), and level of independence in ADLs.

RESULTS

Data were collected on 361 autistic adults (60.3% male, n = 217, mage = 30.82 years, SD = 10.24). Overall, 44% did not meet the PA guideline; PA guideline adherence was lowest among males and those who were dependent on others in ADLs. Overall, the SB guideline was not met by 43% of the sample at weekdays and 48% at weekends. SB guideline adherence was lowest among adults who were middle-aged, and those who were fully independent in ADLs. Overall, 35.2% did not meet the total sleep time (TST) guideline. Middle-aged autistic adults had the lowest adherence to the TST guideline.

CONCLUSIONS

These finding should prompt researchers to consider these demographic differences, and tailor research and programmatic efforts to account for the unique movement behavior profiles of different segments of this heterogenous population.

The Associations Between Objectively Measured Gait Speed and Subjective Sleep Quality in First-Year University Students, According to Gender

PURPOSE

To examine the associations between gait speed and sleep quality in first-year university students, according to gender.

METHODS

In this cross-sectional study, we recruited 193 first-year university students [mean age±standard deviation (SD): 19.6±1.1 years; mean height: 178.0±10.5 cm; mean weight: 74.0±11.0 kg; 26.9% women). Sleep quality was assessed using the Pittsburgh Sleep Quality questionnaire, with a lower score indicating "better" sleep quality. Gait speed was measured using the Zebris pressure platform. The associations were examined with generalized linear models and multiple regression analysis.

RESULTS

In the unadjusted model, faster participants had significantly "better" sleep quality (β=-3.15, 95% CI -3.82 to -2.47, p<0.001). When the model was adjusted for sex, age, body-mass index, self-rated health, smoking status, and psychological distress, faster participants remained having "better" sleep quality (β=-2.88, 95% CI -3.53 to -2.22, p<0.001).

CONCLUSION

This study shows that sleep quality can be predicted by gait speed in the first-year university students.

Sleep and cardiometabolic risk: a cluster analysis of actigraphy-derived sleep profiles in adults and children

STUDY OBJECTIVES

Sleep plays an important role in cardiometabolic health. Although the importance of considering sleep as a multidimensional construct is widely appreciated, studies have largely focused on individual sleep characteristics. The association between actigraphy-derived sleep profiles and cardiometabolic health in healthy adults and children has not been examined.

METHODS

This study used actigraphy-measured sleep data collected between February 2015 and March 2016 in the Child Health CheckPoint study. Participants wore actigraphy monitors (GENEActiv Original, Cambs, UK) on their nondominant wrist for 7 days and sleep characteristics (period, efficiency, timing, and variability) were derived from raw actigraphy data. Actigraphy-derived sleep profiles of 1,043 Australian children aged 11-12 years and 1,337 adults were determined using K-means cluster analysis. The association between cluster membership and biomarkers of cardiometabolic health (blood pressure, body mass index, apolipoproteins, glycoprotein acetyls, composite metabolic syndrome severity score) were assessed using Generalized Estimating Equations, adjusting for geographic clustering, with sex, socioeconomic status, maturity stage (age for adults, pubertal status for children), and season of data collection as covariates.

RESULTS

Four actigraphy-derived sleep profiles were identified in both children and adults: short sleepers, late to bed, long sleepers, and overall good sleepers. The overall good sleeper pattern (characterized by adequate sleep period time, high efficiency, early bedtime, and low day-to-day variability) was associated with better cardiometabolic health in the majority of comparisons (80%).

CONCLUSION

Actigraphy-derived sleep profiles are associated with cardiometabolic health in adults and children. The overall good sleeper pattern is associated with more favorable cardiometabolic health.

How do associations between sleep duration and metabolic health differ with age in the UK general population?

BACKGROUND

Despite a growing body of evidence suggesting that short sleep duration may be linked to adverse metabolic outcomes, how these associations differ between age groups remains unclear. We use eight years of data from the UK National Diet and Nutritional Survey (NDNS) (2008-2016) to analyse cross-sectional relationships between sleep duration and metabolic risk in participants aged 11-70 years.

METHODS

Participants (n = 2008) who provided both metabolic risk and sleep duration data were included. Self-reported sleep duration was standardised by age, to account for differences in age-related sleep requirements. A standardised metabolic risk score was constructed, comprising: waist circumference, blood pressure, serum triglycerides, serum high-density lipoprotein cholesterol, and fasting plasma glucose. Regression models were constructed across four age groups from adolescents to older adults.

RESULTS

Overall, decreased sleep duration (hrs) was associated with an increased metabolic risk (standard deviations) with significant quadratic (B:0.028 [95%CI: 0.007, 0.050]) and linear (B:-0.061 [95%CI: -0.111, -0.011]) sleep duration coefficients. When separated by age group, stronger associations were seen among mid-aged adults (36-50y) (quadratic coefficient: 0.038 [95%CI: 0.002, 0.074]) compared to other age groups (e.g. adolescents (11-18y), quadratic coefficient: -0.009 [95%CI: -0.042, 0.025]). An increased difference between weekend and weekday sleep was only associated with increased metabolic risk in adults aged 51-70 years (B:0.18 [95%CI: 0.005, 0.348]).

CONCLUSIONS

Our results indicate that sleep duration is linked to adverse metabolic risk and suggest heterogeneity between age groups. Longitudinal studies with larger sample sizes are required to explore long-term effects of abnormal sleep and potential remedial benefits.

Eating habits, sleep, and a proxy for circadian disruption are correlated with dyslipidemia in overweight night workers

OBJECTIVE

The aim of this study was to evaluate the relationship between proxy for circadian disruption, eating habits, sleep characteristics, and dyslipidemic parameters.

METHODS

This was a randomized, double-blind, crossover controlled clinical trial, and for this study, only baseline data were used. The sample was composed of 36 overweight female nurses who worked on a fixed night shift (12 × 36 h). Linear regression models were used to assess the relationship between the mentioned variables.

RESULTS

The participants' average age was 39.4 y (Standard error (SE) 1 y) and the average nighttime sleep duration was 5.76 h (SE 0.16 h). The average chronotype indicated a moderate early type (03:03 h; SE 20 min) and the average social jetlag was 03:42 h (SE 10 min). It was found that 1 h less of nighttime sleep increased very-low-density lipoprotein cholesterol levels by 2.75 mg/dL and triacylglyceride levels by 3.62 mg/dL. Additionally, higher social jetlag was associated with higher low-density lipoprotein cholesterol levels. On the other hand, each additional hour in the chronotype increased high-density lipoprotein cholesterol levels by 3.06 mg/dL and a time interval >2 h between the last meal and sleep onset was associated with higher high-density lipoprotein cholesterol levels.

CONCLUSION

Short duration of nighttime sleep and high social jetlag are risk factors for dyslipidemia, whereas the late type and the longer time interval between the last meal and sleep onset appear to be protective factors for dyslipidemia.

Deep Learning to Predict Energy Expenditure and Activity Intensity in Free Living Conditions using Wrist-specific Accelerometry

Wrist-worn accelerometers are more comfortable and yield greater compliance than hip-worn devices, making them attractive for free-living activity assessments. However, intricate wrist movements may require more complex predictive models than those applied to hip-worn devices. This study developed a novel deep learning method that predicts energy expenditure and physical activity intensity of adults using wrist-specific accelerometry. Triaxial accelerometers were worn by 119 participants on their wrist and hip for two weeks during waking hours. A deep learning model was developed from week 1 data of 60 participants and tested using week 2 data for: (i) the remaining 59 participants (Group UT), and (ii) participants used for training (Group TR). Estimates of physical activity were compared to a reference hip-specific method. Moderate-to-vigorous physical activity predicted by the wrist-model was not different to the reference method for participants in Group UT (5.9±3.1vs. 6.3±3.3 hour/week) and Group TR (6.9±3.7 vs. 7.2±4.2 hour/week). At 60-s epoch level, energy expenditure predicted by the wrist-model on Group UT was strongly correlated with the reference method (r=0.86, 95%CI: 0.84-0.87) and closely predicted activity intensity (83.7%, 95%CI: 80.9-86.5%). The deep learning method has application for wrist-worn accelerometry in free-living adults.

Use of Compositional Data Analysis to Show Estimated Changes in Cardiometabolic Health by Reallocating Time to Light-Intensity Physical Activity in Older Adults

BACKGROUND

All physical activity (PA) behaviours undertaken over the day, including sleep, sedentary time, standing time, light-intensity PA (LIPA) and moderate-to-vigorous PA (MVPA) have the potential to influence cardiometabolic health. Since these behaviours are mutually exclusive, standard statistical approaches are unable to account for the impact on time spent in other behaviours.

OBJECTIVE

By employing a compositional data analysis (CoDA) approach, this study examined the associations of objectively measured time spent in sleep, sedentary time, standing time, LIPA and MVPA over a 24-h day on markers of cardiometabolic health in older adults.

METHODS

Participants (n =366; 64.6 years [5.3]; 46% female) from the Mitchelstown Cohort Rescreen Study provided measures of body composition, blood lipid and markers of glucose control. An activPAL3 Micro was used to obtain objective measures of sleep, sedentary time, standing time, LIPA and MVPA, using a 7-day continuous wear protocol. Regression analysis, using geometric means derived from CoDA (based on isometric log-ratio transformed data), was used to examine the relationship between the aforementioned behaviours and markers of cardiometabolic health.

RESULTS

Standing time and LIPA showed diverging associations with markers of body composition. Body mass index (BMI), body mass and fat mass were negatively associated with LIPA (all p <0.05) and positively associated with standing time (all p <0.05). Sedentary time was also associated with higher BMI (p <0.05). No associations between blood markers and any PA behaviours were observed, except for triglycerides, which were negatively associated with standing time (p < 0.05). Reallocating 30 min from sleep, sedentary time or standing time, to LIPA, was associated with significant decreases in BMI, body fat and fat mass.

CONCLUSION

This is the first study to employ CoDA in older adults that has accounted for sleep, sedentary time, standing time, LIPA and MVPA in a 24-h cycle. The findings support engagement in LIPA to improve body composition in older adults. Increased standing time was associated with higher levels of adiposity, with increased LIPA associated with reduced adiposity; therefore, these findings indicate that replacing standing time with LIPA is a strategy to lower adiposity.

Delayed sleep-onset and biological age: late sleep-onset is associated with shorter telomere length

STUDY OBJECTIVES

We evaluated the relationship between leukocyte telomere length (LTL) and sleep duration, insomnia symptoms, and circadian rhythm, to test whether sleep and chronobiological dysregulations are associated with cellular aging.

METHODS

Data from the Netherlands Study of Depression and Anxiety (N = 2,936) were used at two waves 6 years apart, to measure LTL. Telomeres shorten during the life span and are important biomarkers for cellular aging. LTL was assessed by qualitative polymerase chain reaction and converted into base pair number. Sleep parameters were: sleep duration and insomnia symptoms from the Insomnia Rating Scale. Circadian rhythm variables were: indication of Delayed Sleep Phase Syndrome (DSPS), mid-sleep corrected for sleep debt on free days (MSFsc), sleep-onset time, and self-reported chronotype, from the Munich Chronotype Questionnaire. Generalized estimating equations analyzed the associations between LTL, sleep, and chronobiological factors, adjusted for baseline age, sex, North European ancestry, and additionally for current smoking, depression severity, obesity, and childhood trauma.

RESULTS

Indicators of delayed circadian rhythm showed a strong and consistent effect on LTL, after adjustment for sociodemographic and health indicators. Late MSFsc (B = -49.9, p = .004), late sleep-onset time (B = -32.4, p = .001), indication of DSPS (B = -73.8, p = .036), and moderately late chronotype in adulthood (B = -71.6, p = .003) were associated with significantly shorter LTL across both waves; whereas sleep duration and insomnia symptoms were not. Extremely early chronotype showed significantly less LTL shortening than intermediate chronotype (B = 161.40, p = .037). No predictors showed accelerated LTL attrition over 6 years.

CONCLUSIONS

Individuals with delayed circadian rhythm have significantly shorter LTL, but not faster LTL attrition rates.

Associations between self-reported sleep duration and cardiometabolic risk factors in young African-origin adults from the five-country modeling the epidemiologic transition study (METS)

OBJECTIVES

To investigate associations between self-reported sleep duration and cardiometabolic (CM) risk factors in African-origin adults residing in five countries spanning the epidemiologic transition.

DESIGN

Cross-sectional.

SETTING AND PARTICIPANTS

Ghanaian (n = 491), South African (n = 503), Jamaican (n = 508), Seychellois (n = 501) and American (n = 480) men and women.

MEASUREMENTS

Self-reported sleep duration was obtained using questionnaires. Sex- and site-stratified logistic regression analyses investigated relationships between sleep duration, individual CM risk factors and a binary CM risk variable (presence of ≥3 CM risk factors), adjusting for age, physical activity and education.

RESULTS

Sleep duration distributions varied by cohort: 44.5%, 41.4%, 35.9%, 16.8% and 2.5% of American, Jamaican, Seychellois, Ghanaian and South African men reported <7 h sleep per night respectively (p < 0.001). Similarly, 42.6%, 28.6%, 25.2%, 12.8% and 1.5% of American, Jamaican, Seychellois, Ghanaian and South African women reported <7 h sleep respectively (p < 0.001). American men reporting ≤6 h sleep were more likely to be in the elevated CM risk group (OR: 2.52, 95%CI: 1.02, 6.22, p = 0.045) and to have a high waist circumference (OR: 2.44, 95%CI: 1.07, 5.57, p = 0.034) compared to those reporting 8 h sleep. Jamaican women reporting ≤6 h sleep (OR: 2.53, 95%CI: 1.19, 5.36, p = 0.016) and American women reporting 7 h sleep (OR: 2.71, 95%CI: 1.17, 6.26, p = 0.002) were more likely to be obese than those reporting 8 h sleep.

CONCLUSIONS

Associations between short sleep and CM risk factors were only evident in the American men and women and Jamaican women. Future interventions to address CM risk and sleep health may need to be country-specific when targeting high-risk populations.

Gait can reveal sleep quality with machine learning models

Sleep quality is an important health indicator, and the current measurements of sleep rely on questionnaires, polysomnography, etc., which are intrusive, expensive or time consuming. Therefore, a more nonintrusive, inexpensive and convenient method needs to be developed. Use of the Kinect sensor to capture one’s gait pattern can reveal whether his/her sleep quality meets the requirements. Fifty-nine healthy students without disabilities were recruited as participants. The Pittsburgh Sleep Quality Index (PSQI) and Kinect sensors were used to acquire the sleep quality scores and gait data. After data preprocessing, gait features were extracted for training machine learning models that predicted sleep quality scores based on the data. The t-test indicated that the following joints had stronger weightings in the prediction: the Head, Spine Shoulder, Wrist Left, Hand Right, Thumb Left, Thumb Right, Hand Tip Left, Hip Left, and Foot Left. For sleep quality prediction, the best result was achieved by Gaussian processes, with a correlation of 0.78 (p < 0.001). For the subscales, the best result was 0.51 for daytime dysfunction (p < 0.001) by linear regression. Gait can reveal sleep quality quite well. This method is a good supplement to the existing methods in identifying sleep quality more ecologically and less intrusively.

Evaluation of Allostatic Load as a Mediator of Sleep and Kidney Outcomes in Black Americans

Introduction

Poor sleep associates with adverse chronic kidney disease (CKD) outcomes yet the biological mechanisms underlying this relation remain unclear. One proposed mechanism is via allostatic load, a cumulative biologic measure of stress.

Methods

Using data from 5177 Jackson Heart Study participants with sleep measures available, we examined the association of self-reported sleep duration: very short, short, recommended, and long (≤5, 6, 7–8, or ≥9 hours per 24 hours, respectively) and sleep quality (high, moderate, low) with prevalent baseline CKD, and estimated glomerular filtration rate (eGFR) decline and incident CKD at follow-up. CKD was defined as eGFR <60 ml/min per 1.73 m² or urine albumin-to-creatinine ratio ≥30 mg/g. Models were adjusted for demographics, comorbidities, and kidney function. We further evaluated allostatic load (quantified at baseline using 11 biomarkers from neuroendocrine, metabolic, autonomic, and immune domains) as a mediator of these relations using a process analysis approach.

Results

Participants with very short sleep duration (vs. 7–8 hours) had greater odds of prevalent CKD (odds ratio [OR] 1.31, 95% confidence interval [CI] 1.03–1.66). Very short, short, or long sleep duration (vs. 7–8 hours) was not associated with kidney outcomes over a median follow-up of 8 years. Low sleep quality (vs. high) associated with greater odds of prevalent CKD (OR 1.26, 95% CI 1.00–1.60) and 0.18 ml/min per 1.73 m² (95% CI 0.00–0.36) faster eGFR decline per year. Allostatic load did not mediate the associations of sleep duration or sleep quality with kidney outcomes.

Conclusions

Very short sleep duration and low sleep quality were associated with adverse kidney outcomes in this all-black cohort, but allostatic load did not appear to mediate these associations.

Wrist-specific accelerometry methods for estimating free-living physical activity

OBJECTIVES

To compare accelerometry-derived estimates of physical activity from 9 wrist-specific predictive models and a reference hip-specific method.

DESIGN

Prospective cohort repeated measures study.

METHODS

110 participants wore an accelerometer at wrist and hip locations for 1 week of free-living. Accelerometer data from three axes were used to calculate physical activity estimates using existing wrist-specific models (3 linear and 6 artificial neural network models) and a reference hip-specific method. Estimates of physical activity were compared to reference values at both epoch (≤60-s) and weekly levels.

RESULTS

9044h were analysed. Physical activity ranged from 7 to 96min per day of moderate-to-vigorous physical activity (MVPA). Method of analysis influenced determination of sedentary behaviour (<1.5 METs), light physical activity (1.5 to <3 METs) and MVPA (>3 METs) (p<0.001, respectively). All wrist-specific models produced total weekly MVPA values that were different to the reference method. At the epoch level, Hildebrand et al. (2014) produced the strongest correlation (r=0.69, 95%CI: 0.67-0.71) with tightest ratio limits of agreement (95%CI: 0.53-1.30) for MVPA, and highest agreement to predict MVPA (94.1%, 95%CI: 94.0-94.1%) with sensitivity of 63.1% (95%CI: 62.6-63.7%) and specificity of 96.0% (95%CI: 95.9-96.0%).

CONCLUSIONS

Caution is required when comparing results from studies that use inconsistent analysis methods. Although a wrist-specific linear model produced results that were most similar to the hip-specific reference method when estimating total weekly MVPA, modest absolute and relative agreement at the epoch level suggest that additional analysis methods are required to improve estimates of physical activity derived from wrist-worn accelerometers.

Associations of mental health and sleep duration with menstrual cycle irregularity: a population-based study

This study aimed to examine whether the characteristics of mental health and sleep duration, alone or in combination, are associated with menstrual cycle irregularity. This population-based, cross-sectional study analyzed the data from 4445 women aged 19-49 years, who participated in the Korea National Health and Nutrition Examination Survey 2010-2012. A structured questionnaire was used to assess mental health characteristics, sleep duration, and menstrual cycle irregularity. A multivariable logistic regression analysis was performed. High stress, depressive mood, and suicidal ideation were associated with increased risk of menstrual cycle irregularity after adjusting for confounding variables (odds ratio [95% confidence interval] = 1.33 [1.07-1.65], 1.56 [1.17-2.07], and 1.37 [1.01-1.87], respectively). Short sleep duration (≤ 5 h a day) was significantly associated with higher odds of severe menstrual cycle irregularity with menstrual interval of greater than 3 months (2.67 [1.35-5.27]). Participants with sleep duration of ≤ 5 h a day with psychological stress, depressive mood, or suicidal ideation had higher odds of menstrual cycle irregularity (1.96 [1.26-3.05], 2.86 [1.50-5.44], and 2.25 [1.18-4.29]). This study suggests positive associations of mental health problems and short sleep duration with menstrual cycle irregularity among Korean female adults. Therefore, strategies to deal with psychological stress, depressive mood, and sleep duration are needed for improving the reproductive health of women suffering from menstrual disturbances.

Associations between sleep parameters, non-communicable diseases, HIV status and medications in older, rural South Africans

As part of the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI), we investigated sleep habits and their interactions with HIV or non-communicable diseases (NCDs) in 5059 participants (median age: 61, interquartile range: 52—71, 54% females). Self-reported sleep duration was 8.2 ± 1.6h, and bed and rise times were 20:48 ± 1:15 and 05:31 ± 1:05 respectively. Ratings of insufficient sleep were associated with older age, lack of formal education, unemployment, and obesity (p < 0.05). Ratings of restless sleep were associated with being older, female, having more education, being unemployed, and single. Hypertension was associated with shorter self-reported sleep duration, poor sleep quality, restless sleep, and periods of stopping breathing during the night (p < 0.05). HIV positive individuals not on antiretroviral treatment (ART) reported more nocturnal awakenings than those on ART (p = 0.029) and HIV negative individuals (p = 0.024), suggesting a negative net effect of untreated infection, but not of ART, on sleep quality. In this cohort, shorter, poor-quality sleep was associated with hypertension, but average self-reported sleep duration was longer than reported in other regions globally. It remains to be determined whether this is particular to this cohort, South Africa in general, or low- to middle-income countries undergoing transition.

Associations between long self-reported sleep, obesity and insulin resistance in a cohort of premenopausal Black and White South African women

OBJECTIVES

South African women have disproportionately high levels of overweight and obesity, and ethnic differences in obesity and insulin resistance have been observed. We investigated associations between self-reported sleep duration, obesity and insulin resistance in Black and White South African women.

DESIGN

Cross-sectional.

PARTICIPANTS

Black normal-weight (n = 122), Black obese (n = 133), White normal-weight (n = 87) and White obese (n = 63) urban South African women, aged 18 to 45y.

MEASUREMENTS

Participants completed questionnaires capturing self-reported sleep duration, demographic, socioeconomic, medical history and lifestyle information. Body composition and fasting blood glucose and insulin concentrations were measured.

RESULTS

The Black women reported longer sleep than the White women (median: 8 h, interquartile range: 8-10 h v 7(7-8) respectively, P < .001). Adjusted models indicated that women sleeping <7 h sleep were less likely to be obese (P = .035) or insulin resistant (P = .032), while those sleeping >9 h were more likely to be insulin resistant (P = .014) than those sleeping 7 to 9 h. Shorter self-reported sleep was associated with less insulin resistance (<7 h v 7-9 h: P = .018) and longer sleep with more insulin resistance (>9 h v 7-9 h: P = .047) in the Black but not White women.

CONCLUSIONS

Future research that objectively measures sleep duration is needed to confirm these observations and investigate potential factors contributing to the relationship between sleep and risk for non-communicable diseases in different ethnic groups.

Sleep duration and incidence of type 2 diabetes: the Multiethnic Cohort

OBJECTIVES

As an emerging risk factor for the rising incidence of type 2 diabetes, we examined sleep duration in relation to type 2 diabetes and several biomarkers.

DESIGN

Prospective cohort recruited 1993-1996.

SETTING

The Multiethnic Cohort in Hawaii and California.

PARTICIPANTS

A cohort of 151,691 White, African American, Japanese American, Native Hawaiian, and Latino participants; 9695 cohort members had biomarker measurements.

MEASUREMENTS

Sleep duration was self-reported at cohort entry. Diabetes status was obtained from 3 questionnaires and confirmed by 3 administrative data sources. Biomarkers were measured by standard assays 9.6±2.1 years after cohort entry. We estimated diabetes risk as a time-varying outcome using Cox regression adjusted for body mass index assessed at 3 time points and other known confounders and computed adjusted means of biomarkers by sleep hours.

RESULTS

During 7.9±3.5 years of follow-up, 8487 new diabetes cases were diagnosed. Long sleep duration (≥9 hours), as compared with 7-8 hours, was significantly associated with higher incidence (hazard ratio, 1.12; 95% confidence interval 1.04-1.21), but the 4% elevated incidence for short sleep duration (≤6 hours) did not reach significance (95% confidence interval 0.99-1.09). After stratification, the associations appeared stronger in Japanese American than other ethnic groups and in participants without comorbidity. Hours of sleep were positively associated with C-reactive protein and triglycerides and inversely related to high-density lipoprotein cholesterol and adiponectin but not with leptin levels and homeostatic model assessment of insulin resistance.

CONCLUSION

In this multiethnic population, the 12% higher diabetes risk for long sleep hours may be mediated through inflammation, a poor lipid profile, and lower adiponectin levels.