Associations of timing of physical activity with all-cause and cause-specific mortality in a prospective cohort study

Biomarkers of aging: from molecules and surrogates to physiology and function

Many countries face an unprecedented challenge in aging demographics. This has led to an exponential growth in research on aging, which, coupled to a massive financial influx of funding in the private and public sectors, has resulted in seminal insights into the underpinnings of this biological process. However, critical validation in humans has been hampered by the limited translatability of results obtained in model organisms, additionally confined by the need for extremely time-consuming clinical studies in the ostensible absence of robust biomarkers that would allow monitoring in shorter time frames. In the future, molecular parameters might hold great promise in this regard. In contrast, biomarkers centered on function, resilience, and frailty are available at the present time, with proven predictive value for morbidity and mortality. In this review, the current knowledge of molecular and physiological aspects of human aging, potential antiaging strategies, and the basis, evidence, and potential application of physiological biomarkers in human aging are discussed.

Accelerometer-derived "weekend warrior" physical activity, genetic susceptibility, and risk of depression and anxiety: The UK Biobank study

IMPORTANCE

Guidelines recommend 150 min per week (min/wk) or more of moderate to vigorous physical activity (MVPA) for mental health benefits. However, the relative effects of concentrated against more evenly distributed activity patterns remain unclear.

OBJECTIVE

We aimed to examine associations of the accelerometer-derived "weekend warrior (WW)" pattern (MVPA concentrated within 1 to 2 days) vs MVPA spread more evenly with risk of depression and anxiety.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study included 84,570 participants with accelerometer data identified from the UK Biobank.

EXPOSURES

Three MVPA patterns were compared: active WW (MVPA ≥150 min/wk and ≥50 % of total MVPA within 1 to 2 days), active regular (MVPA ≥150 min/wk but not active WW), and inactive (MVPA <150 min/wk).

MAIN OUTCOMES AND MEASURES

Cox regression was used to assess the association of MVPA patterns with depression and anxiety, and whether the association differed by different levels of sedentary time (≤6, 7-12, ≥13 h/day) and light physical activity (≤60, 61-150, ≥151 min/day). We also evaluated the combined impact of MVPA patterns and genetic susceptibility on depression and anxiety.

RESULTS

During the follow-up of up to 9.40 years, 2098 and 2699 cases of depression and anxiety were identified, respectively. Compared with inactive group, active regular and active WW groups exhibited similarly reduced risks of depression (active regular: HR, 0.74 [95 % CI, 0.66-0.84]; active WW: 0.72 [0.65-0.80]) and anxiety (active regular: 0.77 [0.69-0.86]; active WW: 0.72 [0.66-0.79]). The impact of active regular and active WW groups on depression and anxiety was more pronounced among individuals with excessive sedentary time (≥13 h/day) and insufficient light physical activity (≤60 min/day). Individuals with low genetic risk and active regular (depression: 0.64 [0.48-0.87]; anxiety: 0.62 [0.49-0.79]), as well as low genetic risk and active WW groups (depression: 0.60 [0.47-0.77]; anxiety: 0.59 [0.48-0.72]) exhibited the lowest risks of depression and anxiety compared to those with high genetic risk and inactive group.

CONCLUSIONS AND RELEVANCE

Adherence to active physical activity, regardless of physical activity concentrated within 1 to 2 days or more evenly distributed, may help reduce depression and anxiety risks across a population with different genetic risk profiles.

Association Between Volume, Intensity and Rhythm of Physical Activity Measured by Accelerometer and Risk of All-Cause and Cause-Specific Mortality in Individuals With MASLD

BACKGROUND

Individuals with metabolic dysfunction-associated steatotic liver disease (MASLD) have a higher mortality risk, and physical activity is important to MASLD management. However, a comprehensive exploration of associations of volume and intensity of physical activity and rest-activity rhythm (RAR) based on an accelerometer with all-cause and cause-specific mortality in MASLD individuals was scarce.

METHODS

We included 10,143 individuals with MASLD from the UK Biobank. Volume and intensity of physical activity [low-intensity physical activity (LPA), moderate-to-vigorous-intensity physical activity (MVPA) and sedentary time] and RAR (amplitude, mesor, pseudo-F statistics and acrophase) were computed from accelerometer data. The Cox proportional hazards model was used to estimate the relationships of volume and intensity of physical activity and RAR with all-cause, cardiovascular disease (CVD) and cancer mortality risk in individuals with MASLD and further in common subtypes of cardiometabolic abnormalities. The population attributable risk and relative importance of physical activity were estimated.

RESULTS

Higher LPA, MVPA and normal RAR (amplitude and mesor) were associated with decreased risk of all-cause and CVD mortality among individuals with MASLD (HRs: 0.712-0.805), especially of all-cause mortality in those with common subtypes of more than two metabolic abnormalities (overweight/obesity-elevated blood pressure-hyperlipidemia and all the four abnormalities). Furthermore, we found MVPA and amplitude represented relatively important contributors to all-cause and CVD mortality risk in individuals with MASLD.

CONCLUSIONS

In individuals with MASLD, a higher volume and intensity of physical activity, as well as normal RAR supported lower all-cause and CVD mortality risk, which provided insights for management guidelines.

Accelerometer-Derived "Weekend Warrior" Physical Activity and All-Cause and Cause-Specific Mortality

OBJECTIVE

To examine the association of "weekend warrior" (WW) pattern and physical activity distributed throughout the week with mortality risk.

PARTICIPANTS AND METHODS

In this cohort study of 95,468 participants in the UK Biobank from 2013 through 2015, participants were grouped by accelerometer-derived physical activity levels: inactive (moderate to vigorous physical activity [MVPA] <150 min/wk using World Health Organization guidelines), active WW (≥150 minutes of MVPA per week and ≥50% of total MVPA over 1 to 2 days), and active regular (≥150 minutes of MVPA but not active WW). Cox regression analyzed associations of activity patterns with all-cause mortality and 10 categories of cause-specific mortality and whether the association differed by sedentary time (≤6, 7 to 12, or ≥13 hours) and light physical activity (≤60, 61 to 150, or ≥151 min/d).

RESULTS

During the median 7.92 years of follow-up, 3539 deaths occurred. Compared with the inactive participants, the hazard ratio for all-cause mortality was 0.74 (95% CI, 0.68 to 0.82) in active regular participants and 0.72 (95% CI, 0.67 to 0.78) in active WW participants. Similar risk reductions were noted in most cause-specific deaths, especially for those from cancer, cardiovascular disease, and respiratory diseases. These benefits were more profound among participants with 13 or more hours of sedentary time (active regular: 0.58 [0.41 to 0.83]; active WW: 0.70 [0.55 to 0.88]) or 60 min/d or less of light physical activity (active regular: 0.59 [0.42 to 0.83]; active WW: 0.47 [0.35 to 0.63]). A similar reduction in all-cause mortality risk was observed across different age groups regardless of activity frequency and timing.

CONCLUSION

Physical activity evenly distributed throughout the week and concentrated within 1 to 2 days are both associated with similar lower risks of all-cause mortality and most categories of cause-specific mortality.

Association between sleep duration, sleep trouble and all-cause mortality in individuals with hyperuricemia in the United States

Objectives

Despite the crucial role of sleep quality in hyperuricemia onset and progression, there is limited evidence on sleep interventions to improve outcomes for hyperuricemic individuals. This study aims to investigate the effects of sleep duration and sleep difficulties on all-cause mortality in this population.

Materials and methods

We conducted a secondary analysis of the National Health and Nutrition Examination Survey (NHANES) data from 2007 to 2018, including 5,837 participants. We employed weighted multivariable Cox proportional hazard models to evaluate the independent predictive value of sleep duration and trouble for all-cause mortality. Restricted cubic splines and segmented Cox proportional hazard models were used to examine threshold effects.

Results

During a mean follow-up of 6.5 years, 906 participants experienced all-cause mortality. After adjusting for confounders, both short (< 7 h; HR = 1.25; 95%CI: 1.04, 1.51; p = 0.018) and long (>9 h; HR = 1.50; 95%CI: 1.10, 2.04; p = 0.011) sleep durations were associated with increased all-cause mortality. The threshold analysis identified an optimal sleep duration of 7.23 h, and when sleep duration was below 7.23 h, it was inversely related to mortality (HR: 0.879; 95% CI: 0.788, 0.981; p = 0.022). Conversely, when sleep duration exceeded 7.23 h, it was positively associated with mortality (HR: 1.187; 95% CI: 1.066, 1.320; p = 0.002).

Conclusion

Sleep duration is U-shapedly associated with all-cause mortality among individuals with hyperuricemia in the United States. However sleep trouble was not associated with all-cause mortality. Maintaining optimal sleep duration helps improve the prognostic survival rates of those with hyperuricemia.

Light physical activity throughout the day and physical function in older adults: A cross-sectional study

Research has demonstrated that habitual light physical activity (LPA) in later life may contribute to preventing muscle loss and disability in older adults. Given that LPA dominated overall physical activity duration throughout the day, investigating the impact of the timing of LPA on physical function among older adults is essential for optimizing health interventions. This cross-sectional study explored the association between LPA timing and performances in four physical function tests among older adults. This study explored the associations between diurnal patterns of light physical activity and physical function performance. The study involved 200 older adults attending the geriatric outpatient clinic at National Taiwan University Hospital. Participants were on average 76.3 years old (SD = 6.6), with 55.5% being female. We collected LPA data using wrist-worn accelerometers for a continuous 7-day period. Principal component analysis (PCA) was employed to categorize daily periods of LPA. Multivariable-adjusted linear regression analyses were conducted to examine the associations between LPA timing and performance in the following physical function tests: grip strength, basic mobility (Timed Up and Go [TUG] test), walking speed, and lower limb muscle strength (five sit-to-stand test). Adjustments were made for gender, age, moderate-to-vigorous physical activity, and average daily triaxial accelerometer wear time. The findings indicated that higher LPA levels during the morning to noon period (08:00-13:00) were positively associated with improved performance across all four physical function tests. Furthermore, increased LPA in the late afternoon (12:00-17:00) and evening (18:00-24:00) was positively associated with better outcomes in the basic mobility (TUG test), walking speed (6-m walking test), and lower limb muscle strength (five sit-to-stand test), after controlling for relevant confounders. This study underscores the significance of the timing of light physical activity in enhancing various aspects of physical function in older adults independent of MVPA. Timing of LPA plays a crucial role in enhancing physical function in older adults, with morning activity being particularly beneficial. This supports tailored activity recommendations for geriatric care.

Wearable device-measured moderate to vigorous physical activity and risk of degenerative aortic valve stenosis

BACKGROUND AND AIMS

Physical activity has proven effective in preventing atherosclerotic cardiovascular disease, but its role in preventing degenerative valvular heart disease (VHD) remains uncertain. This study aimed to explore the dose-response association between moderate to vigorous physical activity (MVPA) volume and the risk of degenerative VHD among middle-aged adults.

METHODS

A full week of accelerometer-derived MVPA data from 87 248 UK Biobank participants (median age 63.3, female: 56.9%) between 2013 and 2015 were used for primary analysis. Questionnaire-derived MVPA data from 361 681 UK Biobank participants (median age 57.7, female: 52.7%) between 2006 and 2010 were used for secondary analysis. The primary outcome was the diagnosis of incident degenerative VHD, including aortic valve stenosis (AS), aortic valve regurgitation (AR), and mitral valve regurgitation (MR). The secondary outcome was VHD-related intervention or mortality.

RESULTS

In the accelerometer-derived MVPA cohort, 555 incident AS, 201 incident AR, and 655 incident MR occurred during a median follow-up of 8.11 years. Increased MVPA volume showed a steady decline in AS risk and subsequent AS-related intervention or mortality risk, levelling off beyond approximately 300 min/week. In contrast, its association with AR or MR incidence was less apparent. The adjusted rates of AS incidence (95% confidence interval) across MVPA quartiles (Q1-Q4) were 11.60 (10.20, 13.20), 7.82 (6.63, 9.23), 5.74 (4.67, 7.08), and 5.91 (4.73, 7.39) per 10 000 person-years. The corresponding adjusted rates of AS-related intervention or mortality were 4.37 (3.52, 5.43), 2.81 (2.13, 3.71), 1.93 (1.36, 2.75), and 2.14 (1.50, 3.06) per 10 000 person-years, respectively. Aortic valve stenosis risk reduction was also observed with questionnaire-based MVPA data [adjusted absolute difference Q4 vs. Q1: AS incidence, -1.41 (-.67, -2.14) per 10 000 person-years; AS-related intervention or mortality, -.38 (-.04, -.88) per 10 000 person-years]. The beneficial association remained consistent in high-risk populations for AS, including patients with hypertension, obesity, dyslipidaemia, and chronic kidney disease.

CONCLUSIONS

Higher MVPA volume was associated with a lower risk of developing AS and subsequent AS-related intervention or mortality. Future research needs to validate these findings in diverse populations with longer durations and repeated periods of activity monitoring.

Characterizing daily physical activity patterns with unsupervised learning via functional mixture models

Physical inactivity is a significant public health concern. Consideration of inter-individual variations in physical activity (PA) trends can provide additional information about the groups under study to aid intervention design. This study aims to identify latent profiles ("phenotypes") based on daily PA trends among adults living in. This was a secondary analysis of 724 person-level days of accelerometry data from 133 urban-dwelling adults (89% Latinx, age = 19-77 years). We used Actigraph accelerometers and the Actilife software to collect and process 24-hour PA data. We implemented a probabilistic clustering technique based on functional mixture models. Multiple days of data per person were averaged for entry into the models. We evaluated step counts, moderate-intensity PA (MOD), total activity and sedentary minutes as potential model variables. Bayesian Information Criterion (BIC) index was used to select the model that provided the best fit for the data. A 4-cluster resolution provided the best fit for the data (i.e., BIC=-3257, improvements of Δ = 13 and Δ = 7 from 3- and 5-cluster models, respectively). MOD provided the greatest between-cluster discrimination. Phenotype 1 (N = 61) was characterized by a morning peak in PA that declined until bedtime. Later bedtimes and the highest daily PA volume were distinct for phenotype 2 (N = 18), along with a similar peak pattern. Phenotype 3 (N = 29) membership was associated with the lowest PA levels throughout the day. Phenotype 4 was characterized by a more evenly distributed PA during the day, and later waking/bedtimes. Our findings point to distinct, interpretable PA phenotypes based on temporal patterns. Functional clustering of PA data could provide additional actionable points for tailoring behavioral interventions.

Social and health disparities associated with healthy brain ageing in Brazil and in other Latin American countries

BACKGROUND

Latin American countries present major health-related inequities due to historical, cultural, and social aspects. Recent evidence highlights that factors related to social and health disparities outweigh classic demographic factors in determining healthy brain aging in these populations. However, these analyses have not been conducted with the Brazilian population, the largest and most ethnically diverse population in Latin America.

METHODS

Here, we evaluated demographic, social, and health factors for healthy brain ageing using a machine learning model in a Brazilian population-based cohort (n=9412) and in additional cohorts from other Latin American countries, including Colombia (n=23 694), Chile (n=1301), Ecuador (n=5235), and Uruguay (n=1450).

FINDINGS

In the Brazilian population and other Latin American countries, social and health disparities were more influential than demographic factors for cognition and functional ability. Uniquely in Brazil, education emerged as the primary risk factor impacting cognitive outcomes, diverging from other Latin American countries where mental health symptoms played more prominent roles. In terms of functional ability, Brazil displayed a distinct pattern, with mental health symptoms identified as the primary contributing factor.

INTERPRETATION

Our findings indicate that Brazil converges with other Latin American countries to show that heterogeneous factors impacted more than demographic factors, but also showed a unique set of health factors when compared with other Latin American countries. Therefore, our study emphasises that social and health disparity factors are relevant predictors of healthy brain ageing in Latin America, but population-specific analyses are necessary to identify the specific risk profiles of each country.

FUNDING

None.

TRANSLATIONS

For the Portuguese and Spanish translations of the abstract see Supplementary Materials section.

Wearables in Chronomedicine and Interpretation of Circadian Health

Wearable devices have gained increasing attention for use in multifunctional applications related to health monitoring, particularly in research of the circadian rhythms of cognitive functions and metabolic processes. In this comprehensive review, we encompass how wearables can be used to study circadian rhythms in health and disease. We highlight the importance of these rhythms as markers of health and well-being and as potential predictors for health outcomes. We focus on the use of wearable technologies in sleep research, circadian medicine, and chronomedicine beyond the circadian domain and emphasize actigraphy as a validated tool for monitoring sleep, activity, and light exposure. We discuss various mathematical methods currently used to analyze actigraphic data, such as parametric and non-parametric approaches, linear, non-linear, and neural network-based methods applied to quantify circadian and non-circadian variability. We also introduce novel actigraphy-derived markers, which can be used as personalized proxies of health status, assisting in discriminating between health and disease, offering insights into neurobehavioral and metabolic status. We discuss how lifestyle factors such as physical activity and light exposure can modulate brain functions and metabolic health. We emphasize the importance of establishing reference standards for actigraphic measures to further refine data interpretation and improve clinical and research outcomes. The review calls for further research to refine existing tools and methods, deepen our understanding of circadian health, and develop personalized healthcare strategies.

The association of activity patterns on female reproductive diseases: a prospective cohort study of UK biobank

OBJECTIVE

Little is known about the role of timing of physical activity in female reproductive disorders. These disorders include polycystic ovary syndrome (PCOS), heavy menstrual bleeding (HMB), endometriosis, infertility, and pregnancy-related disorders. This study aims to investigate the associations of activity patterns with female reproductive diseases.

METHODS

A total of 49,540 female participants from the UK Biobank with valid accelerometer data were enrolled at baseline. Activity patterns were defined based on the timing of moderate-to-vigorous intensity physical activity (MVPA) throughout the day. Participants were categorized into four groups according to the timing of their MVPA: "morning, evening, mixed, midday-afternoon", with the midday-afternoon group serving as the reference. Cox proportional hazards models were utilized to evaluate the association between activity patterns and female reproductive diseases.

RESULTS

During a median follow-up of 12.6 years, a total of 1044 cases of female reproductive diseases were documented. After adjustment for potential confounders, compared to women with midday-afternoon exercise, women with morning exercise and mixed-timing exercise were associated with lower risks for female reproductive diseases (HRmorning=0.81, 95% CI: 0.67-0.98; HRmixed=0.79, 95% CI: 0.69-0.91, P-trend < 0.05). Moreover, morning exercise and mixed-timing exercise had lower risks of PCOS (HRmorning=0.38, 95% CI: 0.15-0.97; HRmixed=0.27, 95% CI: 0.13-0.57, P-trend<0.001), and mixed-timing exercise was associated with a lower risk for HMB (HRmixed=0.81, 95% CI: 0.70-0.95, P-trend < 0.05), compared with the reference group.

CONCLUSIONS

Compared with midday-afternoon group, morning and mixed MVPA timing groups, but not evening group, were associated with decreased risks for female reproductive diseases and PCOS. In addition, we found that women with mixed MVPA timing exercise had a lower risk of HMB, compared with the reference group.

Physical activity and metabolic syndrome in primary care patients in Spain

PURPOSE

To determine the relationship between self-reported physical activity and the components of premorbid metabolic syndrome in patients treated in primary care according to sex.

METHODS

Cross-sectional descriptive study conducted on a sample of 2,359 patients without cardiovascular disease or diabetes, included in the cohort of the IBERICAN study. Using ANOVA models and adjusting for age, economic status, employment situation, level of education, adherence to a Mediterranean diet, tobacco use and alcohol consumption, we estimated the association of the variables blood pressure, triglycerides, HDL cholesterol, blood glucose and waist circumference with the self-reported level of physical activity (sedentary, moderate, high, very high). The analyses were performed stratifying by sex.

RESULTS

A total of 854 men and 1,505 women with no identified diseases were included. Women were more sedentary than men (p<0.004; OR = 1,35; IC95% = 1,10-1,65) and presented lower values in all the components of the metabolic syndrome, except for HDL-cholesterol, which was higher (p<0.001). The adjusted ANOVA model shows that diastolic blood pressure, triglycerides, fasting blood glucose, and waist circumference were significantly lower the higher the level of physical activity in both men and women (p<0.05).

CONCLUSIONS

Patients served in primary care clinics without diabetes or cardiovascular disease and with high levels of physical activity showed better metabolic syndrome profiles. Given that women are more sedentary, gender approaches are needed in the promotion of physical activity to prevent metabolic syndrome and cardiovascular disease.

Nation-wide cohort of device-measured sedentary time and physical activity in the USA-the Cancer Prevention Study-3 (CPS-3) Accelerometry Substudy: cohort profile

PURPOSE

This paper describes the data collection and management methods for the Cancer Prevention Study-3 (CPS-3) Accelerometry Substudy, a nested cohort of device-based physical activity and sedentary time data.

PARTICIPANTS

US-based CPS-3 participants (initially enrolled 2006-2013) who completed the 2018 follow-up survey and had a valid email address were invited to the Accelerometry Substudy (n=109 780). Among the 23 111 participants who registered and were shipped an ActiGraph GT3X+ accelerometer, 21 219 participants returned the device with a complete wear log (91.8%) and 20 950 (90.6%) provided at least three adherent days of data (eg, days with at least 10 hours of wear).

FINDINGS TO DATE

Participants with ≥3 adherent days were predominantly female (n=16 187, 77.3%), non-Latino white (n=17 977, 85.8%) and had an average age of 58 years (SD=9.8). The median daily wear time was 15.3 hours, which did not vary considerably by wear day. The median time spent in moderate-intensity aerobic physical activity was 29 min/day (IQR=36), and the median time in vigorous physical activity was 3 min/day (IQR=13). Participants were sedentary for 9.4 hours (564 min, IQR=171 min) and accumulated a median of 6474 steps per day (IQR=5348).

FUTURE PLANS

The full CPS-3 cohort will be linked with the National Death Index and state cancer registries biennially. Participants will be sent triennial surveys for the next two decades. Future analyses within the CPS-3 Accelerometry Substudy more specifically aim to identify relationships between physical activity, sedentary time and health outcomes, primarily cancer incidence, survival and survivorship.

Association of accelerometer-derived physical activity with all-cause and cause-specific mortality among individuals with cardiovascular diseases: a prospective cohort study

AIMS

To investigate the association of accelerometer-measured intensity-specific physical activity (PA) with all-cause and cause-specific mortality among individuals with cardiovascular disease (CVD).

METHODS AND RESULTS

In this prospective cohort study, 8024 individuals with pre-existing CVD (mean age: 66.6 years, female: 34.1%) from the UK Biobank had their PA measured using wrist-worn accelerometers over a 7-day period in 2013-2015. All-cause, cancer, and CVD mortality was ascertained from death registries. Cox regression modelling and restricted cubic splines were used to assess the associations. Population-attributable fractions (PAFs) were used to estimate the proportion of preventable deaths if more PA was undertaken. During a median follow-up of 6.8 years, 691 deaths (273 from cancer and 219 from CVD) were recorded. An inverse non-linear association was found between PA duration and all-cause mortality risk, irrespective of PA intensity. The hazard ratio (HR) of all-cause mortality plateaued at 1800 min/week for light-intensity PA (LPA), 320 min/week for moderate-intensity PA (MPA), and 15 min/week for vigorous-intensity PA (VPA). The highest quartile of PA was associated with lower risks for all-cause mortality, with HRs of 0.63 (95% confidence interval [CI]: 0.51-0.79), 0.42 (0.33-0.54), and 0.47 (0.37-0.60) for LPA, MPA, and VPA, respectively. Similar associations were observed for cancer and CVD mortality. Additionally, the highest PAFs were noted for VPA, followed by MPA.

CONCLUSION

We found an inverse non-linear association between all intensities of PA (LPA, MPA, VPA, and MVPA) and mortality risk in CVD patients using accelerometer-derived data, but with a larger magnitude of the associations than that in previous studies based on self-reported PA.

Longitudinal timing of physical activity and associated cardiometabolic and behavioral health outcomes in young adults

BACKGROUND

This is the first study to examine longitudinal associations between self-selected timing of moderate-to-vigorous physical activity (MVPA) and health outcomes in young adults over 18 months.

METHODS

Young adults (N = 434, Mage = 23.9, SDage = 4.6 years) enrolled in a weight management trial recorded 4-7 days of ActiGraph wear time at ≥1 time point (baseline, months 6, 12, and 18). Time-of-day categories were based on quartiles of the temporal distribution of MVPA min/h at baseline: morning (06:00-11:59), afternoon (12:00-15:59), evening (16:00-18:59), and night (19:00-00:59). The proportion of weekly MVPA accumulated during each time category was the predictor in longitudinal linear mixed-effects models predicting body mass index (BMI) and total weekly MVPA. Longitudinal quasibinomial generalized estimating equations models predicted cardiometabolic risk. Interactions were tested, and marginal trend estimates were generated for sex and age subgroups.

RESULTS

The analytic sample was 79% female and 49% non-Hispanic White, with a mean (±SD) weekly MVPA of 311 ± 167 min at baseline. In adjusted models, there were no associations with BMI. Morning MVPA was inversely associated with cardiometabolic risk (OR [95% CI]: 0.99 [0.98-0.99]) for both sex and age groups. Evening MVPA was inversely associated with cardiometabolic risk for 26-35 year olds (0.98 [0.97-0.99]). Morning MVPA was associated with greater total MVPA across subgroups, and afternoon MVPA was associated with less total MVPA in women.

CONCLUSIONS

Over 18 months, incremental health benefits may accrue with optimal activity timing in young adults. Activity-based interventions designed to improve cardiometabolic and behavioral health outcomes in young adults may be optimized by tailoring timing recommendations to demographic factors.

Repetitive Transcranial Magnetic Stimulation and Tai Chi Chuan for Older Adults With Sleep Disorders and Mild Cognitive Impairment: A Randomized Clinical Trial

Importance

Sleep disorders and mild cognitive impairment (MCI) commonly coexist in older adults, increasing their risk of developing dementia. Long-term tai chi chuan has been proven to improve sleep quality in older adults. However, their adherence to extended training regimens can be challenging. Repetitive transcranial magnetic stimulation (rTMS) is a neuromodulation technique that may enhance the benefits of exercise.

Objective

To investigate whether 1-Hz rTMS of the right dorsolateral prefrontal cortex could enhance the clinical benefits of tai chi chuan in improving sleep quality and cognitive function among older adults with sleep disorders and MCI.

Design, Setting, and Participants

This 2-arm, sham-controlled, assessor-masked randomized clinical trial was conducted at a university hospital in China between October 2022 and February 2024. Adults aged 60 to 75 years with sleep disorders and MCI were eligible. Data analysis was performed from February to May 2024.

Intervention

Participants were randomized in a 1:1 ratio to an experimental group (tai chi chuan and 1-Hz rTMS) or a sham group (tai chi chuan and sham rTMS). Each participant received 30 sessions of personalized rTMS targeting the right dorsolateral prefrontal cortex, and the sham group underwent the same procedure. The 2 groups received 30 sessions of 60 minutes of the 24-form simplified tai chi chuan, 5 times per week for 6 weeks.

Main Outcomes and Measures

The primary outcomes were subjective sleep quality assessed by the Pittsburgh Sleep Quality Index (PSQI), in which scores range from 0 to 21, with lower scores indicating a healthier sleep quality, and global cognitive function assessed by the Montreal Cognitive Assessment (MoCA), in which scores range from 0 to 30, with higher scores indicating less cognitive impairment. The secondary outcomes included measures of objective sleep actigraphy, anxiety and depression scales, and other cognitive subdomains. Assessments were performed at baseline, 6 weeks after the intervention, and at the 12-week follow-up.

Results

A total of 110 participants (mean [SD] age, 67.9 [4.6] years; 68 female [61.8%]) were randomized to the experimental group (n = 55) and the sham group (n = 55) and included in the intention-to-treat analysis. At 6 weeks after the intervention, compared with the sham group, the experimental group showed a lower PSQI score (between-group mean difference, -3.1 [95% CI, -4.2 to -2.1]; P < .001) and a higher MoCA score (between-group mean difference, 1.4 [95% CI, 0.7-2.1]; P < .001). The per-protocol dataset analyses and 12-week follow-up showed similar results. The generalized estimated equation model revealed an interaction effect between the PSQI score (mean difference, -2.1 [95% CI, -3.1 to -0.1]; P < .001) and the MoCA total score (mean difference, 0.9 [95% CI, 0.1-1.6]; P = .01). There were 7 nonserious, unrelated adverse events (experimental group: 2; sham group: 5) with no significant difference between the 2 groups.

Conclusions and Relevance

In this randomized clinical trial, the findings suggest that 1-Hz rTMS enhanced the clinical benefits of tai chi chuan in improving sleep quality and cognitive function among older adults with sleep disorders and MCI, which may be related to alterations in neural plasticity. These findings provide novel data on nonpharmacologic strategies for the rehabilitation of sleep disorders and may delay or even prevent MCI.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2200063274.

Fecal microbiota transplantation, a tool to transfer healthy longevity

The complex gut microbiome influences host aging and plays an important role in the manifestation of age-related diseases. Restoring a healthy gut microbiome via Fecal Microbiota Transplantation (FMT) is receiving extensive consideration to therapeutically transfer healthy longevity. Herein, we comprehensively review the benefits of gut microbial rejuvenation - via FMT - to promote healthy aging, with few studies documenting life length properties. This review explores how preconditioning donors via standard - lifestyle and pharmacological - antiaging interventions reshape gut microbiome, with the resulting benefits being also FMT-transferable. Finally, we expose the current clinical uses of FMT in the context of aging therapy and address FMT challenges - regulatory landscape, protocol standardization, and health risks - that require refinement to effectively utilize microbiome interventions in the elderly.

Functional quantile principal component analysis

This paper introduces functional quantile principal component analysis (FQPCA), a dimensionality reduction technique that extends the concept of functional principal components analysis (FPCA) to the examination of participant-specific quantiles curves. Our approach borrows strength across participants to estimate patterns in quantiles, and uses participant-level data to estimate loadings on those patterns. As a result, FQPCA is able to capture shifts in the scale and distribution of data that affect participant-level quantile curves, and is also a robust methodology suitable for dealing with outliers, heteroscedastic data or skewed data. The need for such methodology is exemplified by physical activity data collected using wearable devices. Participants often differ in the timing and intensity of physical activity behaviors, and capturing information beyond the participant-level expected value curves produced by FPCA is necessary for a robust quantification of diurnal patterns of activity. We illustrate our methods using accelerometer data from the National Health and Nutrition Examination Survey, and produce participant-level 10%, 50%, and 90% quantile curves over 24 h of activity. The proposed methodology is supported by simulation results, and is available as an R package.

Circadian disruption and its impact on the cardiovascular system

Circadian rhythms are highly conserved biorhythms of ~24 h that govern many fundamental biological processes, including cardiovascular (CV) homeostasis. Disrupting the timing of cellular oscillators promotes cellular stress, and induction of pathogenic pathways underpins the pathogenesis of many CV diseases (CVDs). Thus, shift work, late eating, sleep disturbances, and other disruptors can result in an elevated risk of heart disease and increased incidence of adverse CV events. Here, we discuss the importance of circadian rhythms for CV homeostasis, recent developments in understanding the impact of disrupted circadian rhythms on CV health and disease progression, and how understanding the interactions between circadian and CV physiology is crucial for improving interventions to mitigate CVD, especially in populations impacted by disrupted circadian rhythms.

More absolute moderate-to-vigorous physical activity is associated with better health-related quality of life in outpatients with an acquired brain injury

Health-related quality of life (HRQoL) is a patient-perceived measure of physical, social, and emotional health. Acquired brain injury (ABI) occurs due to damage to the brain after birth. Individuals with an ABI typically present with reduced HRQoL and require additional support to maintain their HRQoL. Although structured exercise training has been shown to improve HRQoL in individuals with ABI, there is little research on habitual, real-world activity. Most activity research characterizes moderate-to-vigorous physical activity (MVPA) in absolute terms; however, relative physical activity levels have been promoted for research in clinical populations. We tested whether longer MVPA durations, measured in absolute/relative levels, are associated with higher HRQoL in outpatients with ABIs. In total, 26 adults (54 ± 13 years, 16 females) with ABI completed the Quality of Life After Brain Injury questionnaire, a 6-min walk test (a measure of aerobic fitness; 490 ± 105 m), and wore an activPAL device 24 h/day for 7 days. Participants had an average HRQoL score of 53.4 ± 15.0 (out of 100), with 20 of 26 showing impaired HRQoL (score <60). Absolute MVPA (74.6 ± 91.0 min/week, b = 0.09, p = 0.03) was associated with HRQoL, whereas total physical activity (565.7 ± 264.8 min/week, p = 0.47), light physical activity (LPA; 491.1 ± 224.3 min/week, p = 0.98), and step count (5,960 ± 3,037 steps/day, p = 0.24) were not. Neither relative LPA (521.4 ± 244.9) nor relative MVPA (33.5 ± 34.9 min/week) were associated with HRQoL (both p values > 0.14). Targeting more absolute MVPA, but not necessarily relative MVPA, may be an effective strategy for interventions aiming to improve HRQoL in individuals with ABI.

Physical Activity During Pregnancy and Preterm Birth Among Women With Gestational Diabetes

Importance

Physical activity, as a modifiable factor, emerges as a primary intervention strategy for the prevention and management of gestational diabetes (GD). Among women with GD, the association of physical activity during pregnancy with preterm birth remains unclear.

Objective

To examine the association of accelerometer-derived physical activity metrics and patterns with preterm birth among women with GD.

Design, Setting, and Participants

This prospective cohort study recruited pregnant women with GD in Hangzhou, China, from August 2019 to August 2023 as part of the Westlake Precision Birth Cohort study. Statistical analysis was performed between August and November 2023.

Exposures

Wearable accelerometer-derived physical activity metrics and patterns. Measurements of physical activity via wearable accelerometer were performed at a median (IQR) of 25.4 (24.6-26.6) weeks' gestation.

Main Outcomes and Measures

Preterm birth was determined through the examination of delivery records. Incident preterm birth was defined as the delivery of infants before completing 37 weeks of gestation.

Results

Among the 1427 women meeting the inclusion criteria, the mean (SD) age was 31.3 (3.8) years, and there were 80 cases of preterm birth. An increase in moderate-to-vigorous intensity physical activity (MVPA) and the fraction of physical activity energy expenditure derived from MVPA exhibited an inverse association with preterm birth, with an odds ratio per 30 minutes of 0.64 (95% CI, 0.42-0.98) and an odds ratio per SD of 0.69 (95% CI, 0.55-0.88). In the dose-response analysis, there was a progressive decrease in the odds of preterm birth with increasing duration of MVPA per day, reaching a plateau at approximately 74 minutes per day. Furthermore, the findings indicated that active MVPA (MVPA ≥30 minutes per day), whether it was concentrated into a few days or followed a more regular pattern, had similar beneficial association with preterm birth.

Conclusions and Relevance

In this prospective cohort study, MVPA during pregnancy exhibited an inverse association with preterm birth among women with GD. Concentrated physical activity was associated with similar benefits in reducing preterm birth risk as regular physical activity.

Association between physical activity and mortality in patients with osteoporosis: a cohort study of NHANES

We utilized data from the NHANES to investigate the impact of physical activity on mortality in osteoporotic patients. Our study suggests that osteoporotic patients may require higher volumes of physical activity to reduce mortality risk compared to the general population. In osteoporotic patients, the dose-response relationships between physical activity volumes and both all-cause and cardiovascular mortality were linear. In contrast, these relationships were non-linear in participants without osteoporosis.

PURPOSE

To determine the impact of physical activity on mortality in osteoporotic patients.

METHODS

A total of 5606 participants were included in this study, including 716 osteoporosis patients. Physical activity was assessed using standardized questionnaire. Participants were categorized into four groups: inactive (no physical activity), low active (physical activity volumes < 150 min/week), moderate active (≥ 150 min/week but < 300 min/week), and high active (≥ 300 min/week). Multivariable Cox regression models, using the inactive group as the reference and adjusted for potential confounders, were performed to estimate the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Osteoporotic patients demonstrated higher mortality rates attributed to various causes compared to non-osteoporosis participants. Physical activity was associated with lower mortality regardless of osteoporosis status. However, Multivariable Cox regression analysis indicated that among osteoporosis patients, only those engaging in ≥ 300 min/week physical activity experienced a significant decrease in mortality (all-cause mortality, HR (95% CI) 0.453 (0.268, 0.767) and cardiovascular mortality, HR (95% CI) 0.521 (0.259, 1.049)), surpassing the threshold of 150 min observed in non-osteoporosis patients. In sensitivity analysis, or when the proportion of vigorous physical activity was included as a confounder in the multivariate Cox regression analysis, only the high active group still showed a significant reduction in mortality. No significant interactions were observed when the analysis was stratified according to age, sex, and body mass index (P for interaction > 0.05). Restricted cubic spline analysis revealed a linear relationship between physical activity volume and all-cause mortality (P < 0.01 [overall] and P = 0.470 [non-linearity]) and cardiovascular-specific mortality (P = 0.003 [overall] and P = 0.610 [non-linearity]) in patients with osteoporosis. In contrast, these relationships were non-linear in participants without osteoporosis.

CONCLUSION

Patients with osteoporosis need to engage in ≥ 300 min/week physical activity to significantly reduce their mortality risk. And the higher the volume of physical activity, the lower the risk of death.

Associations of temporal patterns of objectively measured moderate-to-vigorous physical activity with mortality in the general population and people with abnormal glucose metabolism or hypertension

To investigate the association between temporal patterns of objectively measured moderate-to-vigorous physical activity (MVPA) and all-cause and cause-specific mortality in the general population and people with abnormal glucose metabolism (AGM) or hypertension. This prospective cohort study collected accelerometer data from the National Health and Nutrition Examination Survey from 2003 to 2006 with linkage to the National Death Index records through 31 December 2019 in the United States. Baseline 7-day accelerometry data were analysed and participants were categorized into 5 groups: morning/midday (05:00-13:59), afternoon (14:00-16:59), evening (17:00-19:59), night (20:00-00:59), and mixed MVPA timing groups. Cox regression analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) between temporal patterns and mortality. A total of 5976 adults (mean [SE] age, 46.4 [0.5] years; 52.1% women) were included and 1371 participants died during a median follow-up of 14.6 years. Compared with the mixed group, the night group had 22% to 77% higher risks of all-cause and cardiovascular mortality in the overall sample and AGM and hypertension subsamples. In people with hypertension, the morning/midday group showed a 31% higher risk of cardiovascular mortality. For those with AGM, the evening group had 90% to 185% higher risks of all-cause and cardiovascular mortality.

Effects of caffeine on accelerometer measured sleep and physical activity among older adults under free-living conditions

BACKGROUND

Adequate sleep and physical activity promote longevity among older adults. Caffeine supplementation could be used to increase activity levels, but its effects have not been examined in real-world settings where potential trade-offs regarding sleep quality are also considered. This study sought to examine associations between caffeine intake and accelerometer-derived sleep and activity among older adults under free-living conditions.

METHODS

Cross-sectional data were gathered from older adults aged 65 + in the 2011-14 National Health and Nutrition Examination Surveys (NHANES). Sleep parameters were derived from accelerometer data using a data-driven machine learning approach. Caffeine consumption was categorized based on weight (in mg/kg: 0, > 0 to 1, > 1 to 2, > 2 to 3, > 3) and absolute consumption (in mg: 0, > 0 to 100, > 100 to 200, > 200 to 300, > 300). Multivariable survey weighted regression models were used to examine associations between caffeine with average total daytime activity, highly active minutes, sleep duration, and sleep efficiency. Covariate adjustments included demographics, body mass index, smoking, alcohol, sleep disorders, sleep parameters (for activity outcomes), and daytime activity (for sleep outcomes).

RESULTS

N = 1,629 NHANES participants were included. Caffeine consumption was highest in the morning. In adjusted models, older adults who consumed > 3 mg/kg were 16.5% more active during the day (95% CI: 9.0, 24.4) and were highly active for 42.8 additional minutes (95% CI: 20.3, 65.4) compared to non-consumers. Similar results were observed for absolute consumption (mg), and significant but lower magnitude effects were observed for lower levels of consumption. Caffeine showed no association with sleep efficiency, while low levels of consumption (≤ 1 mg/kg, ≤ 200 mg) were associated with longer sleep duration.

CONCLUSIONS

Under free-living dietary, sleep, and activity patterns, this study found older adults who consumed caffeine were more active than non-consumers. Overall consumption was not associated with sleep efficiency but was associated with longer sleep duration at ≤ 1 mg/kg and ≤ 200 mg. Future causal studies should determine the effectiveness of caffeine for promoting higher activity in older adult populations.

Comprehensive Symptom Prediction in Inpatients With Acute Psychiatric Disorders Using Wearable-Based Deep Learning Models: Development and Validation Study

BACKGROUND

Assessing the complex and multifaceted symptoms of patients with acute psychiatric disorders proves to be significantly challenging for clinicians. Moreover, the staff in acute psychiatric wards face high work intensity and risk of burnout, yet research on the introduction of digital technologies in this field remains limited. The combination of continuous and objective wearable sensor data acquired from patients with deep learning techniques holds the potential to overcome the limitations of traditional psychiatric assessments and support clinical decision-making.

OBJECTIVE

This study aimed to develop and validate wearable-based deep learning models to comprehensively predict patient symptoms across various acute psychiatric wards in South Korea.

METHODS

Participants diagnosed with schizophrenia and mood disorders were recruited from 4 wards across 3 hospitals and prospectively observed using wrist-worn wearable devices during their admission period. Trained raters conducted periodic clinical assessments using the Brief Psychiatric Rating Scale, Hamilton Anxiety Rating Scale, Montgomery-Asberg Depression Rating Scale, and Young Mania Rating Scale. Wearable devices collected patients' heart rate, accelerometer, and location data. Deep learning models were developed to predict psychiatric symptoms using 2 distinct approaches: single symptoms individually (Single) and multiple symptoms simultaneously via multitask learning (Multi). These models further addressed 2 problems: within-subject relative changes (Deterioration) and between-subject absolute severity (Score). Four configurations were consequently developed for each scale: Single-Deterioration, Single-Score, Multi-Deterioration, and Multi-Score. Data of participants recruited before May 1, 2024, underwent cross-validation, and the resulting fine-tuned models were then externally validated using data from the remaining participants.

RESULTS

Of the 244 enrolled participants, 191 (78.3%; 3954 person-days) were included in the final analysis after applying the exclusion criteria. The demographic and clinical characteristics of participants, as well as the distribution of sensor data, showed considerable variations across wards and hospitals. Data of 139 participants were used for cross-validation, while data of 52 participants were used for external validation. The Single-Deterioration and Multi-Deterioration models achieved similar overall accuracy values of 0.75 in cross-validation and 0.73 in external validation. The Single-Score and Multi-Score models attained overall R² values of 0.78 and 0.83 in cross-validation and 0.66 and 0.74 in external validation, respectively, with the Multi-Score model demonstrating superior performance.

CONCLUSIONS

Deep learning models based on wearable sensor data effectively classified symptom deterioration and predicted symptom severity in participants in acute psychiatric wards. Despite lower computational costs, Multi models demonstrated equivalent or superior performance than Single models, suggesting that multitask learning is a promising approach for comprehensive symptom prediction. However, significant variations were observed across wards, which presents a key challenge for developing clinical decision support systems in acute psychiatric wards. Future studies may benefit from recurring local validation or federated learning to address generalizability issues.

Associations Between Physical Activity Patterns and Cardiovascular Events and Risk Factors: Cross-Sectional and Prospective Studies

Background

Moderate-intensity physical activity (PA) is recommended for health benefits, but optimal PA timing regarding cardiovascular disease (CVD) is debated.

Objectives

The authors assessed the impact of differing PA patterns on CVD risk factors and outcomes.

Methods

Data from 2 surveys (S1 and S2) of the CoLaus-PsyCoLaus study (2,465 and 1,692 participants, respectively; 55.3% [54.3%] females; mean age 61.2 ± 9.7 years [64.4 ± 9.5]), conducted in Lausanne, Switzerland. PA was assessed using a wrist-worn accelerometer, and PA patterns were assessed using K-means clustering.

Results

Morning PA was positively associated with hypertension (multivariable-adjusted OR: 1.36 [95% CI: 1.00-1.84]) in S1, similar trend in S2. No significant association was found between PA clusters and total, HDL-, and LDL-cholesterol or triglycerides. Morning PA was positively associated with hypolipidemic drug treatment: 1.88 (1.07-3.30) in S2. Evenly distributed daily PA was positively associated with diabetes: 1.82 (95% CI: 1.06-3.12) in S2, with a similar trend in S1. In the outcome analysis, the early morning PA cluster (7 am-12 am) and the evenly distributed daily PA cluster led to a higher risk of CVD events (HR: 3.33 [95% CI: 1.08-10.3] and 3.16 [95% CI: 1.04-9.57], respectively).

Conclusions

In a population-based study, we observed a higher risk for cardiovascular events in participants whose daily PA occurred predominantly in the early morning (7 am-12 am) or was evenly distributed throughout the day. No PA pattern was consistently associated with hypertension, blood lipids, or diabetes markers.

Exploring the association between daily distributional patterns of physical activity and cardiovascular mortality risk among older adults in NHANES 2003-2006

PURPOSE

Cardiovascular disease (CVD) is one of the leading causes of death worldwide. Physical activity (PA) has previously been shown to be a prominent risk factor for CVD mortality. Traditionally, measurements of PA have been self-reported and based on various summary metrics. However, recent advances in wearable technology provide continuously monitored and objectively measured physical activity data. This facilitates a more comprehensive interpretation of the implications of PA in the context of CVD mortality by considering its daily patterns and compositions.

METHODS

This study utilized accelerometer data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) on 2816 older adults aged 50-85 and mortality data from the National Death Index (NDI) in December 2019. A novel partially functional distributional analysis method was used to quantify and understand the association between daily distributional patterns of physical activity and cardiovascular mortality risk through a multivariable functional Cox model.

RESULTS

A higher mean intensity of daily PA during the day was associated with a reduced hazard of CVD mortality after adjusting for other higher order distributional summaries of PA and age, gender, race, body mass index (BMI), smoking and coronary heart disease (CHD). A higher daily variability of PA during afternoon was associated with a reduced hazard of CVD mortality, after adjusting for the other predictors, particularly on weekdays. The subjects with a lower variability of PA, despite having same mean PA throughout the day, could have a lower reserve of PA and hence could be at increased risk for CVD mortality.

CONCLUSIONS

Our results demonstrate that not only the mean intensity of daily PA during daytime, but also the variability of PA during afternoon could be an important protective factor against the risk of CVD-mortality. Considering circadian rhythm of PA as well as its daily compositions can be useful for designing time-of-day and intensity-specific PA interventions to protect against the risk of CVD mortality.

Association Between Self-Reported Sitting Time and the Physical Function Domain of the Kihon Checklist Among Community-Dwelling Older Adults

Objective Interventions that reduce sitting time are easier to implement than those that aim to increase physical activity in compliance with the guidelines. There is no consensus on the association between sitting time as assessed by the International Physical Activity Questionnaire (IPAQ) and physical function. We investigated the association between self-reported sitting time and physical function according to the Kihon Checklist (KCL) among community-dwelling older adults. Methods This cross-sectional study included 87 community-dwelling middle-aged and older adults who had participated in a long-term preventive care and health promotion project. The project was conducted three times between March 2023 and March 2024. Sitting time was self-reported using the IPAQ. Physical function was assessed using the KCL. A generalized linear model was used to analyze the association between sitting time and physical function. In the adjusted model, handgrip strength, walking speed, five times sit to stand test, skeletal muscle mass index, living alone, pain, sex, and age were used as covariates to adjust for confounders. Results Eight subjects met the exclusion criteria, leaving a final cohort of 79 community-dwelling older adults (mean age: 75 ± 6 years, 73% female). Our analysis revealed that sitting time was associated with physical function, even after adjusting for covariates (standardized β coefficient = 0.22, p = 0.023). Conclusions Our findings emphasize the usefulness of assessing sitting time to maintain physical function in community-dwelling older adults. Furthermore, it may be important to reduce sitting time to maintain or improve physical function.

Improvements in Walking During Subacute Stroke Rehabilitation Translate to Physical Activity at the Chronic Stage: A Sub-Analysis From the Phys Stroke Trial

Stroke frequently results in mobility impairments, contributing to an increased cardiovascular risk. Despite efforts to promote physical activity, stroke survivors fail to meet recommended levels. This secondary analysis of the 'Physical Fitness in Patients with Subacute Stroke' (Phys-Stroke) trial analyzes physical activity at 6 months post-stroke, and examines the effect of gains in walking capacity during the subacute phase on physical activity in the chronic stage. Phys-Stroke compared aerobic exercise vs relaxation in 200 stroke patients. Data from the 6-minute walk test (6MWT) pre and post intervention as well as accelerometry and questionnaire data at 6 months were used. Data was analyzed using mixed linear models and function-on-scalar regression. At 6 months after stroke, participants exhibited low daily step counts (5,623 ± 2,998 steps/day), with most activity occurring in the morning and midday. Per meter gained in the 6MWT during the intervention period, participants increased daily steps by 8.2 (95% confidence interval, 1.6 to 14.8, p = 0.017) at 6 months. Questionnaire data showed that engagement in sports activities was minimal, basic activities being the primary activity. Stroke survivors demonstrated suboptimal activity levels at 6 months but increases in walking capacity during the subacute stage did result in meaningful increases chronically.

Trial Registration

ClinicalTrials.gov Identifier: NCT01953549.

Diurnal patterns of accelerometer-measured physical activity and sleep and risk of all-cause mortality: a follow-up of the National Health and Nutrition Examination Surveys (NHANES)

BACKGROUND

Physical activity and sleep are established modifiable lifestyle factors, but the optimal time of the day of these behaviours for health is unknown. This study examined the independent and joint associations of diurnal patterns of physical activity and sleep with all-cause mortality.

METHODS

This prospective cohort study included 6,673 participants who have attended the accelerometer assessment in the 2011-2014 National Health and Nutrition Examination Surveys (NHANES). Diurnal patterns of accelerometer-measured physical activity and sleep were identified using K-means clustering analysis. All-cause mortality was ascertained from the accelerometer measurement to December 31, 2019 (median follow-up 6.8 years). Survey-weighted Cox proportional hazard models were performed to estimate the independent and joint associations of diurnal patterns of physical activity and sleep with all-cause mortality.

RESULTS

Diurnal patterns identified were: early-morning (32.4%), midday (42.5%), and late-afternoon (25.1%) for physical activity; and irregular sleep (37.4%), morning lark (33.6%), and night owl (29.0%) for sleep. After adjusting for volume of physical activity, sleep duration and other potential covariates, the early-morning physical activity pattern (hazard ratio 1.36, 95% confidence interval 1.13-1.64) and irregular sleep pattern (1.42, 1.01-1.99) were independently associated with higher risk of all-cause mortality, compared with midday physical activity and morning lark sleep patterns, respectively. In addition, participants with the combined pattern of early-morning physical activity and irregular sleep had higher risk of all-cause mortality compared to those with midday physical activity combined with a morning lark sleep pattern (1.92, 1.33-2.78). Several sociodemographic differences were observed in the strength of these associations.

CONCLUSIONS

Wearable activity-rest monitoring data showed that peak physical activity in the early morning and irregular sleep diurnal patterns are associated with increased mortality risk, and the combination of these patterns further exaggerated the risk. Public health program should acknowledge that the diurnal patterns of physical activity and sleep, in addition to their duration and frequency, may play a crucial role in lifestyle-based health promotion and management strategies.

Physical activity combined with tea consumption could further reduce all-cause and cancer-specific mortality

The study aimed to comprehensively assess the separate and combined effects of physical activity (PA) and tea consumption on all-cause mortality and cancer-specific mortality among 21,350 participants from The National Health and Nutrition Examination Survey (NHANES) between 2009 and 2018. PA and tea consumption were evaluated through self-reported questionnaires and dietary recall interviews at baseline, with mortality data from the National Death Index. Cox regression analyses yielded hazard ratios (HR) and 95% confidence intervals (CI). Results indicated that both tea consumption and PA independently reduced all-cause mortality. In the physically active group, tea consumption further decreased mortality risk, while this effect was not significant in the inactive group. Jointly, the highest tea consumers who exercised the most exhibited the lowest mortality risk compared to non-tea drinkers who exercised the least. Tea consumption alone does not significantly impact cancer-specific mortality; it is only in physically active group that tea consumption significantly lowers the risk of cancer-specific mortality. These findings underscore the potential benefits of regular tea consumption and PA in promoting longevity and reducing premature death risks.

Timing matters: diurnal variation of maximal fat oxidation and substrate oxidation rates in metabolic syndrome-a randomized crossover study

PURPOSE

The aim of this study was to investigate if diurnal oscillation in maximal fat oxidation (MFO) and substrate oxidation rates during exercise exists in subjects with metabolic syndrome (MetS).

METHODS

In a randomized crossover design, 14 MetS patients were assigned to two graded exercise tests conditions performed in the morning (between 7:00 and 9:00 a.m) and in the afternoon (between 4:00 and 5:00 p.m). MFO was defined as the highest absolute value of fat oxidation obtained from the average of last 2-min stages during an indirect calorimetry test.

RESULTS

MFO increased by 20.6% from morning to afternoon (p = 0.0002, Cohen's d = 0.52). There was a significant time of day, (p < 0.0001, η2p = 0.76) and intensity effect (p = 0.002, η2p = 0.32) in fat oxidation (Fatox) rates indicating that Fatox was higher in the afternoon than in the morning.

CONCLUSION

Our study extends previous findings on the existence of diurnal variation in maximal fat oxidation to MetS patients, highlighting the afternoon as a more favorable time for fat utilization during exercise. These findings have practical implications for optimizing training timing in MetS patients.

TRIAL REGISTRATION NUMBER

PACTR202306776991260.

Molecular aspects of the exercise response and training adaptation in skeletal muscle

Skeletal muscle plasticity enables an enormous potential to adapt to various internal and external stimuli and perturbations. Most notably, changes in contractile activity evoke a massive remodeling of biochemical, metabolic and force-generating properties. In recent years, a large number of signals, sensors, regulators and effectors have been implicated in these adaptive processes. Nevertheless, our understanding of the molecular underpinnings of training adaptation remains rudimentary. Specifically, the mechanisms that underlie signal integration, output coordination, functional redundancy and other complex traits of muscle adaptation are unknown. In fact, it is even unclear how stimulus-dependent specification is brought about in endurance or resistance exercise. In this review, we will provide an overview on the events that describe the acute perturbations in single endurance and resistance exercise bouts. Furthermore, we will provide insights into the molecular principles of long-term training adaptation. Finally, current gaps in knowledge will be identified, and strategies for a multi-omic and -cellular analyses of the molecular mechanisms of skeletal muscle plasticity that are engaged in individual, acute exercise bouts and chronic training adaptation discussed.

Diurnal timing of physical activity and risk of colorectal cancer in the UK Biobank

BACKGROUND

Physical activity reduces colorectal cancer risk, yet the diurnal timing of physical activity in colorectal cancer etiology remains unclear.

METHODS

This study used 24-h accelerometry time series from UK Biobank participants aged 42 to 79 years to derive circadian physical activity patterns using functional principal component analysis. Multivariable Cox proportional hazard models were used to examine associations with colorectal cancer risk.

RESULTS

Among 86,252 participants (56% women), 529 colorectal cancer cases occurred during a median 5.3-year follow-up. We identified four physical activity patterns that explained almost 100% of the data variability during the day. A pattern of continuous day-long activity was inversely associated with colorectal cancer risk (hazard ratio (HR) = 0.94, 95% confidence interval (CI) = 0.89-0.99). A second pattern of late-day activity was suggestively inversely related to risk (HR = 0.93, 95% CI = 0.85-1.02). A third pattern of early- plus late-day activity was associated with decreased risk (HR = 0.89, 95% CI = 0.80-0.99). A fourth pattern of mid-day plus night-time activity showed no relation (HR = 1.02, 95% CI = 0.88-1.19). Our results were consistent across various sensitivity analyses, including the restriction to never smokers, the exclusion of the first 2 years of follow-up, and the adjustment for shift work.

CONCLUSIONS

A pattern of early- plus late-day activity is related to reduced colorectal cancer risk, beyond the benefits of overall activity. Further research is needed to confirm the role of activity timing in colorectal cancer prevention.

Association between physical activity level and diabetes incidence among Chinese middle-aged and older adults: a cross-sectional study from the China health and retirement longitudinal study

Background

It has been shown that diabetes is associated with insufficient physical activity among middle-aged and older adults, but the association between different physical activity levels (PAL) and diabetes incidence needs to be further explored.

Objective

This study aims to explore the correlation and dose-response relationship between different PAL and the diabetes incidence in middle-aged and older adults.

Methods

Utilizing data from the 2018 China Health and Retirement Longitudinal Study (CHARLS), this cross-sectional analysis included 17,226 middle-aged and older adults aged 45 and above. Binary logistic regression models and restricted cubic spline (RCS) were used to explore the correlation and dose-response relationship between different PAL and the incidence of diabetes in the total middle-aged and older adults population as well as in subgroups. Sensitivity analyses were also performed to verify the robustness of the findings.

Results

In the entire study population, compared with the lowest PAL, participants in the third and fourth quartiles PAL saw diabetes incidence significantly reduced by 16% (p = 0.005) and 33% (p < 0.001), respectively (p for trend < 0.001). In subgroup analyses, the fourth quartile PAL significantly reduced the diabetes incidence among females, individuals aged 60-69, and rural residents by 25% (p = 0.011), 38% (p < 0.001) and 28% (p < 0.001), respectively. For males, middle-aged (45-59 years), and urban residents, the third quartile PAL reduced diabetes incidence by 22% (p = 0.004), 24% (p = 0.012), 21% (p = 0.013), respectively. When the fourth quartile PAL was reached, the diabetes incidence was significantly reduced in these populations by 41% (p < 0.001), 39% (p < 0.001), and 41% (p < 0.001), respectively. There was a negative dose-response relationship between physical activity and diabetes incidence in specific Chinese middle-aged and older adults population. In addition, sensitivity analyses indicated the robustness of the findings.

Conclusion

Higher PAL was associated with lower diabetes incidence in specific Chinese middle-aged and older adults population. It is feasible to use physical activity to predict diabetes incidence in this demographic, and high PAL may be an effective means of preventing and controlling diabetes.

Intensity-specific physical activity measured by accelerometer and the risk of mortality among individuals with cardiometabolic diseases: A prospective study from the UK Biobank

BACKGROUND

While the health benefits of physical activity for general population are well-recognized, the prospective associations of physical activity volume and intensity with mortality among cardiometabolic disease individuals remain unclear.

OBJECTIVE

The objective of this study was to investigate the associations of accelerometer-measured intensity-specific physical activity with mortality risk among population with cardiometabolic disease.

DESIGN

Prospective cohort study.

SETTING

Participants were recruited from the United Kingdom (UK) across 22 assessment centers from 2006 to 2010.

PARTICIPANTS

A total of 9524 participants from the UK Biobank (median: 67.00 years, interquartile range: 61.00-70.00 years) were included in final study.

METHODS

Accelerometer-measured total volume, moderate-to-vigorous and light intensity physical activity collecting from 2013 to 2015 were quantified using a machine learning model. Multivariable restricted cubic splines and Cox proportional hazard models with hazard ratios (HRs) and 95 % confidence intervals (CIs) were employed to examine the associations of interests.

RESULTS

During the follow-up period (median: 6.87 years; interquartile range: 6.32-7.39 years), there were 659 (6.92 %) death events with 218 (2.29 %) cardiovascular disease-related deaths and 441 (4.63 %) non-cardiovascular disease-related deaths separately. In the fully adjusted models, compared with participants in the lowest quartiles of total volume, moderate-to-vigorous and light physical activities, the adjusted HRs (95 % CIs) of all-cause mortality for those in the highest quartiles were 0.40 (0.31, 0.52), 0.48 (0.37, 0.61), and 0.56 (0.44, 0.71) while those for cardiovascular diseases-related mortality were 0.35 (0.22, 0.55), 0.52 (0.35, 0.78) and 0.59 (0.39, 0.88), and for non-cardiovascular diseases-related mortality, they were 0.42 (0.30, 0.59), 0.40 (0.29, 0.54) and 0.54 (0.40, 0.73), separately. The optimal moderate-to-vigorous-intensity physical activity level for cardiovascular diseases-related mortality reduction was found to be in the third quartile (17.75-35.33 min/day). Furthermore, the observed inverse associations were mainly non-linear.

CONCLUSIONS

Promoting physical activity, regardless of intensity, is essential for individuals with cardiometabolic disease to reduce mortality risk. For both all-cause and cardiovascular disease-related and non-cardiovascular disease-related mortality, the observed decrease in risk seems to level off at a moderate level. The current findings deriving from precise device-based physical activity data provide inference for secondary prevention of cardiometabolic disease.

High-level physical activity provides protection against all-cause mortality among U.S. adults with depression

BACKGROUND

Regular physical activity (PA) offers numerous benefits, decreasing all-cause mortality (ACM) among the general population. However, its impact on individuals with depression remains unknown. The present study aimed to investigate the correlation between various PA levels and ACM among adult patients with depression in the United States.

METHODS

Data from the National Health and Nutrition Examination Survey from 2007 to 2018, as well as relevant mortality data up to December 31, 2018 were extracted. 4850 adults with depression were incorporated into this cohort study. PA level was quantified based on weekly metabolic equivalent of task (MET-min/week) and categorized into four groups according to the Physical Activity Guidelines for Americans. Weighted Cox proportional-hazards models were leveraged to assess the association of different PA levels with ACM among adults with depression, and adjustments were made for various sociodemographic and health factors.

RESULTS

Among the 4850 patients with depression, 503 deaths were noted over a median follow-up of 6.6 years. The weighted Cox regression analysis showed that participants with high-level PA (>1200 MET-min/week) had a markedly lower risk of ACM (HR = 0.48, 95 % CI 0.33 to 0.68) compared to those with no PA (0 MET-min/week). The benefit conferred by the high-level PA group (HR = 0.65, 95CI 0.45 to 0.94) remained significant (p < 0.05) after adjustment for other confounders.

LIMITATIONS

PA and some covariates were assessed through self-reported questionnaires.

CONCLUSION

High-level PA has the most pronounced effect on reducing ACM among adult patients with depression, which should be recognized in clinical and public health guidelines.

Impact of lifestyle moderate-to-vigorous physical activity timing on glycemic control in sedentary adults with overweight/obesity and metabolic impairments

OBJECTIVE

Moderate-to-vigorous physical activity (MVPA) improves glucose levels; however, whether its timing affects daily glycemic control remains unclear. This study aims to investigate the impact of lifestyle MVPA timing on daily glycemic control in sedentary adults with overweight/obesity and metabolic impairments.

METHODS

A total of 186 adults (50% women; age, 46.8 [SD 6.2] years) with overweight/obesity (BMI, 32.9 [SD 3.5] kg/m2) and at least one metabolic impairment participated in this cross-sectional study. MVPA and glucose patterns were simultaneously monitored over a 14-day period using a triaxial accelerometer worn on the nondominant wrist and a continuous glucose-monitoring device, respectively. Each day was classified as "inactive" if no MVPA was accumulated; as "morning," "afternoon," or "evening" if >50% of the MVPA minutes for that day were accumulated between 0600 and 1200, 1200 and 1800, or 1800 and 0000 hours, respectively; or as "mixed" if none of the defined time windows accounted for >50% of the MVPA for that day.

RESULTS

Accumulating >50% of total MVPA during the evening was associated with lower 24-h (mean difference [95% CI], -1.26 mg/dL [95% CI: -2.2 to -0.4]), diurnal (-1.10 mg/dL [95% CI: -2.0 to -0.2]), and nocturnal mean glucose levels (-2.16 mg/dL [95% CI: -3.5 to -0.8]) compared with being inactive. This association was stronger in those participants with impaired glucose regulation. The pattern of these associations was similar in both men and women.

CONCLUSIONS

These findings suggest that timing of lifestyle MVPA is significant. Specifically, accumulating more MVPA during the evening appears to have a beneficial effect on glucose homeostasis in sedentary adults with overweight/obesity and metabolic impairments.

Ambient air pollution, lifestyle, and genetic predisposition on all-cause and cause-specific mortality: A prospective cohort study

BACKGROUND

Although it is widely acknowledged that long-term exposure to ambient air pollution is closely related to the risk of mortality, there were inconsistencies in terms of cause-specific mortality and it is still unknown whether lifestyle and genetic susceptibility could modify the association.

METHODS

This population-based prospective cohort study involved 461,112 participants from the UK Biobank. The land-use regression model was used to estimate the concentrations of particulate matter (PM2.5, PMcoarse, PM10), and nitrogen oxides (NO2 and NOx). The association between air pollution and mortality was evaluated using Cox proportional hazard models. Furthermore, a lifestyle score incorporated with smoking status, physical activity, alcohol consumption, and diet behaviors, and polygenic risk score using 12 genetic variants, were developed to assess the modifying effect of air pollution on mortality outcomes.

RESULTS

During a median follow-up of 14.0 years, 33,903 deaths were recorded, including 17,083 (2835; 14,248), 6970, 2429, and 1287 deaths due to cancer (lung cancer, non-lung cancer), cardiovascular disease (CVD), respiratory and digestive disease, respectively. Each interquartile range (IQR) increase in PM2.5, NO2 and NOx was associated with 7 %, 6 % and 5 % higher risk of all-cause mortality, respectively. Specifically, for cause-specific mortality, each IQR increase in PM2.5, NO2 and NOx was also linked to mortality due to cancer (lung cancer and non-lung cancer), CVD, respiratory and digestive disease. Furthermore, additive and multiplicative interactions were identified between high ambient air pollution and unhealthy lifestyle on mortality. In addition, associations between air pollution and mortality were modified by lifestyle behaviors.

CONCLUSION

Long-term exposure to air pollutants increased the risk of all-cause and cause-specific mortality, which was modified by lifestyle behaviors. In addition, we also revealed a synergistically detrimental effect between air pollution and an unhealthy lifestyle, suggesting the significance of joint air pollution management and adherence to a healthy lifestyle on public health.

Associations of different combinations of moderate-vigorous physical activity and muscle-strengthening activity with mortality among US lung cancer survivors

BACKGROUND

To investigate the associations of different combinations of moderate to vigorous physical activity (MVPA) and muscle strengthening activity (MSA) with all-cause and cancer mortality among lung cancer survivors.

METHODS

This nationwide prospective cohort study used data from the US National Health Interview Survey 2009-2018. A total of 785 lung cancer survivors were included in the study. Participants were linked to the National Death Index through December 31, 2019. Self-reported MVPA and MSA frequency data were used to obtain 4 mutually exclusive exposure categories. Multivariate Cox proportional hazard models were applied to explore the association between exposure categories and outcomes.

RESULTS

The mean (standard deviation [SD]) age of the study population was 69.1 (11.3) years and 429 (54.6%) were female. Among them, 641 (81.7%) were White and 102 (13.0%) were Black. The median follow-up time was 3 years (2526 person-years), and 349 (44.5%) all-cause deaths and 232 (29.6%) cancer deaths occurred. Compared to the MVPA < 60 min/week and MSA < 2 sessions/week group, individuals in the MVPA ≥ 60 min/week and MSA < 2 sessions/week group showed hazard ratios (HRs) of 0.50 (95% CI, 0.36-0.69) for all-cause mortality and 0.37 (95% CI, 0.20-0.67) for cancer mortality after the adjustment of covariates. Those in the MVPA ≥ 60 min/week and MSA ≥ 2 sessions/week group exhibited HRs of 0.52 (95% CI, 0.35-0.77) for all-cause mortality and 0.27 (95% CI, 0.12-0.62) for cancer mortality when compared to the MVPA < 60 min/week and MSA < 2 sessions/week group. We also identified distinct non-linear relationships between MVPA and outcomes risk among two MSA frequency subgroups.

CONCLUSION

This cohort study demonstrated that higher levels of MVPA and MSA combined might be associated with optimal reductions of mortality risk in lung cancer survivors.

Smoking timing, genetic susceptibility and the risk of incident type 2 diabetes: A cohort study from the UK Biobank

AIM

To prospectively assess the association of smoking timing with the risk of type 2 diabetes (T2D) and examine whether smoking amount or genetic susceptibility might modify the relationship.

MATERIALS AND METHODS

A total of 294 815 participants without diabetes from the UK Biobank, including non-smokers and smokers with data on the time from waking to first cigarette, were included. Cox proportional hazards models were used to evaluate the association between smoking timing and the risk of incident T2D.

RESULTS

During a median follow-up time of 12 years, a total of 9937 incident cases of T2D were documented. Compared with non-smokers, a shorter time from waking to first cigarette was significantly associated with a higher risk of incident T2D (P for trend < .001). In the fully adjusted model, the hazard ratios (HRs) (95% confidence interval) associated with smoking timing were 1.46 (1.17-1.81) for more than 2 hours, 1.51 (1.21-1.87) for 1-2 hours, 1.58 (1.34-1.85) for 30-60 minutes, 1.86 (1.57-2.21) for 5-15 minutes and 2.01 (1.60-2.54) for less than 5 minutes. We found that even among those who reported being light smokers, those with the shortest time from waking to first cigarette had a 105% higher risk of T2D with an HR of 2.05 (1.52-2.76), which was comparable with heavy smokers. The genetic risk score for T2D did not modify this association (P-interaction = .51).

CONCLUSIONS

Our findings indicate that shorter time from waking to first cigarette is significantly associated with a higher risk of incident T2D.

Associations between accelerometer-measured circadian rest-activity rhythm, brain structural and genetic mechanisms, and dementia

AIM

Knowledge of how circadian rhythm influences brain health remains limited. We aimed to investigate the associations of accelerometer-measured circadian rest-activity rhythm (CRAR) with incident dementia, cognitive dysfunction, and structural brain abnormalities in the general population and underlying biological mechanisms.

METHODS

Fifty-seven thousand five hundred and two participants aged over 60 years with accelerometer data were included to investigate the association of CRAR with incidental dementia. Non-parametric CRAR parameters were utilized, including activity level during active periods of the day (M10), activity level during rest periods of the day (L5), and the relative difference between the M10 and L5 (relative amplitude, RA). Associations of CRAR with cognitive dysfunction and brain structure were studied in a subset of participants. Neuroimaging-transcriptomics analysis was utilized to identify the underlying molecular mechanisms.

RESULTS

Over 6.86 (4.94-8.78) years of follow-up, 494 participants developed dementia. The risk of incident dementia was associated with decreasing M10 (hazard ratio [HR] 1.45; 95% conference interval [CI], 1.28-1.64) and RA (HR 1.37; 95% CI, 1.28-1.64), increasing L5 (HR 1.14, 95% CI 1.07-1.21) and advanced L5 onset time (HR 1.12; 95% CI, 1.02-1.23). The detrimental associations were exacerbated by APOE ε4 status and age (>65 years). Decreased RA was associated with lower processing speed (Beta -0.04; SE 0.011), predominantly mediated by abnormalities in subcortical regions and white matter microstructure. The genes underlying CRAR-related brain regional structure variation were enriched for synaptic function.

CONCLUSIONS

Our study underscores the potential of intervention targeting at maintaining a healthy CRAR pattern to prevent dementia risk.

The effects of health risk behaviors to excess mortality in the population with depression: A cohort study based on NHANES data

BACKGROUND

The population with depression had a considerable excess mortality risk. This increased mortality may be attributed to the biological consequences of depression or the substantial prevalence of health risk behaviors (HRBs). This study aimed to quantify the combined effects of four major HRBs - smoking, excessive alcohol use, physical inactivity, and an unhealthy diet - on excess mortality among depressed individuals.

METHODS

This study included 35,738 adults from the National Health and Nutrition Examination Survey 2005-06 to 2017-18, with mortality follow-up data censored through 2019. The standardized prevalence of HRBs was calculated for populations with and without depression. Poisson regression models were used to calculate the mortality rate ratio (MRR). Based on model adjusting for socio-demographic factors, the attenuation of MRR was determined after further adjustment for HRBs.

RESULTS

A total of 3147 participants were identified as having depression. All HRBs showed a significantly higher prevalence among the population with depression. After adjusting for socio-demographic factors, depression was associated with 1.7 and 1.8 times higher all-cause and cardiovascular disease mortality rate, respectively. Further adjustment for all current HRBs resulted in a 21.9 % reduction in all-cause mortality rate and a 15.4 % decrease in cardiovascular disease mortality rate.

LIMITATION

HRBs were reported at a single time point, and we are unable to demonstrate a causal effect.

CONCLUSION

At least 1/5 of excess mortality for population with depression was attributable to HRBs. Efforts should be made to address HRBs among population with depression.

Association between time-of-day for eating, exercise, and sleep with blood pressure in adults with elevated blood pressure or hypertension: a systematic review

The purpose of this review is to synthesize results from studies examining the association between time-of-day for eating, exercise, and sleep with blood pressure (BP) in adults with elevated BP or hypertension. Six databases were searched for relevant publications from which 789 were identified. Ten studies met inclusion criteria. Four studies examined time-of-day for eating, five examined time-of-day for exercise, and one examined time-of-day for sleep and their associations with BP. Results suggested that later time-of-day for eating ( n  = 2/4) and later sleep mid-point ( n  = 1/1) were significantly related to higher BP in multivariable models, whereas morning ( n  = 3/5) and evening ( n  = 4/5) exercise were associated with significantly lower BP. Although this small body of work is limited by a lack of prospective, randomized controlled study designs and underutilization of 24 h ambulatory BP assessment, these results provide preliminary, hypothesis-generating support for the independent role of time-of-day for eating, exercise, and sleep with lower BP.

Emerging concern on air pollution and health: Trade-off between air pollution exposure and physical activity

Air pollution is a major contributor to the global disease burden, especially affecting respiratory and cardiovascular health. However, physical activity is associated with improved lung function, a slower decline in lung function, and lower mortality. The public is more likely to be exposed to air pollution during outdoor physical activity. However, studies on how long-term and short-term exposure to air pollution interacts with physical activity yield inconsistent results, and the thresholds for air pollution and physical activity remain unclear. Thus, more studies are needed to provide sufficient evidence to guide the public to safely engage in outdoor physical activity when exposed to air pollution.

Reversal of Soleus Muscle Atrophy in Older Adults: A Non-Volitional Exercise Intervention for a Changing Climate

The World Health Organization recommends that older adults undertake at least 150 minutes of moderate intensity physical activity over the course of each week in order to maintain physical, mental, and social health. This goal turns out to be very difficult for most community dwelling older adults to achieve, due to both actual and perceived barriers. These barriers include personal health limitations, confinement issues, and self-imposed restrictions such as fear of injury. Climate change exacerbates the confinement issues and injury fears among the elderly. To assist older adults in obtaining the benefits of increased physical activity under increasingly challenging climate conditions, we propose a targeted non-volitional intervention which could serve as a complement to volitional physical activity. Exogenous neuro-muscular stimulation of the soleus muscles is a non-invasive intervention capable of significantly increasing cardiac output in sedentary individuals. Long-term daily use has been shown to improve sleep, reduce bone loss, and reverse age-related cognitive decline, all of which are significant health concerns for older adults. These outcomes support the potential benefit of exogenous neuro-muscular stimulation as a complementary form of physical activity which older adults may find convenient to incorporate into their daily life when traditional forms of exercise are difficult to achieve due to barriers to completing traditional physical activities as a result of in-home or in-bed confinement, perceptual risks, or real environmental risks such as those arising from climate change.

Timing of Moderate to Vigorous Physical Activity, Mortality, Cardiovascular Disease, and Microvascular Disease in Adults With Obesity

OBJECTIVE

To assess the association between timing of aerobic moderate to vigorous physical activity (MVPA) and risk of cardiovascular disease (CVD), microvascular disease (MVD), and all-cause mortality in adults with obesity and a subset with obesity and type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

Participants included adults with obesity (BMI ≥30 kg/m2) and a subset of those with T2D from the UK Biobank accelerometry substudy. Aerobic MVPA was defined as bouts of MVPA lasting ≥3 continuous minutes. Participants were categorized into morning, afternoon, or evening MVPA based on when they undertook the majority of their aerobic MVPA. The reference group included participants with an average of less than one aerobic MVPA bout per day. Analyses were adjusted for established and potential confounders.

RESULTS

The core sample included 29,836 adults with obesity, with a mean age of 62.2 (SD 7.7) years. Over a mean follow-up period of 7.9 (SD 0.8) years, 1,425 deaths, 3,980 CVD events, and 2,162 MVD events occurred. Compared with activity in the reference group, evening MVPA was associated with the lowest risk of mortality (hazard ratio [HR] 0.39; 95% CI 0.27, 0.55), whereas afternoon (HR 0.60; 95% CI 0.51, 0.71) and morning MVPA (HR 0.67; 95% CI 0.56, 0.79) demonstrated significant but weaker associations. Similar patterns were observed for CVD and MVD incidence, with evening MVPA associated with the lowest risk of CVD (HR 0.64; 95% CI 0.54, 0.75) and MVD (HR 0.76; 95% CI 0.63, 0.92). Findings were similar in the T2D subset (n = 2,995).

CONCLUSIONS

Aerobic MVPA bouts undertaken in the evening were associated with the lowest risk of mortality, CVD, and MVD. Timing of physical activity may play a role in the future of obesity and T2D management.

Age Is Associated With Dampened Circadian Patterns of Rest and Activity: The Study of Muscle, Mobility, and Aging (SOMMA)

BACKGROUND

The effects of aging on circadian patterns of behavior are insufficiently described. To address this, we characterized age-specific features of rest-activity rhythms (RAR) in community-dwelling older adults both overall, and in relation, to sociodemographic characteristics.

METHODS

We examined cross-sectional associations between RAR and age, sex, race, education, multimorbidity burden, financial, work, martial, health, and smoking status using assessments of older adults with wrist-worn free-living actigraphy data (N = 820, age = 76.4 years, 58.2% women) participating in the Study of Muscle, Mobility, and Aging (SOMMA). RAR parameters were determined by mapping an extension to the traditional cosine curve to activity data. Functional principal component analysis determined variables accounting for variance.

RESULTS

Age was associated with several metrics of dampened RAR; women had stronger and more robust RAR versus men (all p < .05). Total activity (56%) and time of activity (20%) accounted for most of the RAR variance. Compared to the latest decile of acrophase, those in the earliest decile had higher average amplitude (p < .001). Compared to the latest decile of acrophase, those in the earliest and midrange categories had more total activity (p = .02). Being in a married-like relationship and a more stable financial situation were associated with stronger rhythms; higher education was associated with less rhythm strength (all p < .05).

CONCLUSIONS

Older age was associated with dampened circadian behavior; behaviors were sexually dimorphic. Some sociodemographic characteristics were associated with circadian behavior. We identified a behavioral phenotype characterized by early time of day of peak activity, high rhythmic amplitude, and more total activity.

Physical Activity Components that Determine Daily Life Satisfaction Among Older Adults: An Intensive Longitudinal Diary Study

BACKGROUND

Although previous studies have shown that engaging in physical activity can elevate daily life satisfaction, few studies have identified the specific aspects that can result in this. This study examined whether enjoying moderate-to-vigorous intensity exercises with others for a longer time, but not any aspects of non-exercise physical activity, was associated with higher daily life satisfaction among older adults.

METHOD

We conducted an intensive longitudinal diary survey of 182 individuals for 1 week and obtained valid data for 853 person-days. The time spent engaging in light and moderate-to-vigorous physical activity at 8:00-11:59, 12:00-15:59, and 16:00-19:59 h was measured using an accelerometer. Duration, intensity, timing, social context, and enjoyment of the exercises were assessed based on diary entries. Stratified by non-exercise and exercise days, we conducted multilevel models.

RESULTS

On non-exercise days, longer duration of light physical activity from 12:00 to 15:59 at the within-person level was associated with higher daily life satisfaction. On exercise days, longer duration of moderate-to-vigorous physical activity from 12:00 to 15:59 at the within-person level, longer exercise duration at the within-person level, exercising with moderate-to-vigorous intensity, and enjoyment of exercise at both the within- and between-person levels were associated with higher daily life satisfaction.

CONCLUSION

These findings indicate that enjoying moderate-to-vigorous intensity exercise for a longer duration than usual and engaging in non-exercise physical activity in the afternoon are important for elevating older adults' daily life satisfaction.

Association between circadian physical activity trajectories and incident type 2 diabetes in the UK Biobank

Physical activity (PA) is linked to a decreased risk of type 2 diabetes mellitus (T2DM). However, the influence of circadian PA trajectories remains uncertain. This study aims to explore the optimal circadian PA trajectory pattern for reducing the risk of T2DM. Methods: A total of 502,400 participants were recruited from the UK Biobank between 2006 and 2010, and 102,323 participants provided valid accelerometer-captured acceleration data. After excluding individuals with prior T2DM, 99,532 participants were included in the final analysis. We initially investigated the association between PA intensity at 24 hourly time points and T2DM. Subsequently, PA trajectories were identified using K-means cluster analysis. Cox proportional hazard models were employed to estimate hazard ratios (HR). Four distinct PA trajectories were identified: consistently low, single peak, double peak, and intense trajectories. Compared to consistently low, single peak, double peak and intense PA trajectory reduced the risk of T2DM progressively. Sensitivity analyses, further excluding individuals with glycated hemoglobin (HbA1c) ≥ 6.5% or random glucose ≥ 11.1 mmol/L and adjusted for daily average acceleration, yielded consistent results. This confirms that the ideal circadian PA trajectory serves as a protective factor, independently of PA intensity. Subgroup analyses indicated that these effects were more pronounced in men and individuals with eGFR < 60 mL/(min*1.73 m2). In conclusion, ideal circadian PA trajectory patterns (especially intense and then double peak) reduced risk of T2DM.