Objectively Measured Physical Activity Reduces the Risk of Mortality among Brazilian Older Adults

Is rest-activity rhythm prospectively associated with all-cause mortality in older people regardless of sleep and physical activity level? The 'Como Vai?' Cohort study

OBJECTIVE

This study aims to test the association of rest-activity rhythm (intradaily variability and interdaily stability) with all-cause mortality in an older adult cohort in Brazil. It also assesses whether the amount of time spent at each intensity level (i.e., physical activity and nocturnal sleep) interferes with this association.

METHODS

This cohort study started in 2014 with older adults (≥60 years). We investigated deaths from all causes that occurred until April 2017. Rest-activity rhythm variables were obtained using accelerometry at baseline. Intradaily variability indicates higher rhythm fragmentation, while interdaily stability indicates higher rhythm stability. Cox proportional-hazard models were used to test the associations controlling for confounders.

RESULTS

Among the 1451 older adults interviewed in 2014, 965 presented valid accelerometry data. During the follow-up period, 80 individuals died. After adjusting the analysis for sociodemographic, smoking, morbidity score, and number of medicines, an increase of one standard deviation in interdaily stability decreased 26% the risk of death. The adjustment for total sleep time and inactivity did not change this association. On the other hand, the association was no longer significant after adjusting for overall physical activity and moderate to vigorous physical activity.

CONCLUSION

Rest-activity rhythm pattern was not associated with mortality when physical activity was considered, possibly because this pattern could be driven by regular exercise. Promoting physical activity remains a relevant strategy to improve population health.

Device-Measured Physical Activity and Sedentary Behavior in Relation to Cardiovascular Diseases and All-Cause Mortality: Systematic Review and Meta-Analysis of Prospective Cohort Studies

Introduction

This review synthesized evidence from prospective cohort studies on the association of device-measured physical activity and sedentary behavior with cardiovascular disease and all-cause mortality among adults.

Methods

Five databases were searched from 2000 through April 29, 2020. Study quality was appraised using the NIH Quality Assessment Tool. Pooled hazard ratio and 95% CI were obtained from random-effects meta-analyses. Subgroup analyses by age and sex were conducted for studies on all-cause mortality.

Results

Of 29 articles included in the systematic review, 5 studies on cardiovascular disease mortality and 15 studies on all-cause mortality were included in meta-analyses. Comparing the highest with the lowest exposure categories, the pooled hazard ratios (95% CIs) for cardiovascular disease mortality were 0.29 (CI=0.18, 0.47) for total physical activity, 0.37 (CI=0.25, 0.55) for moderate-to-vigorous physical activity, 0.62 (0.41-0.93) for light physical activity, and 1.89 (CI=1.09, 3.29) for sedentary behavior. The pooled hazard ratios (95% CIs) for all-cause mortality were 0.42 (CI=0.34, 0.53) for total physical activity, 0.43 (CI=0.35, 0.53) for moderate-to-vigorous physical activity, 0.58 (CI=0.43, 0.80) for light physical activity, and 1.58 (CI=1.19, 2.09) for sedentary behavior. The pooled hazard ratio (95% CI) for all-cause mortality was 0.35 (CI=0.29, 0.42) for steps per day, but the studies available for analysis were conducted in older adults. The results of subgroup analyses were consistent with the main results.

Discussion

Rapidly accumulating evidence suggests that more physical activity and less sedentary behavior are associated with a lower risk of cardiovascular disease and all-cause mortality. Similar beneficial relationships were found for step counts and all-cause mortality among older adults. Future studies employing standardized research methodologies and up-to-date data processing approaches are warranted to recommend specific amounts of physical activity and limits to sedentary behavior.

Historical development of accelerometry measures and methods for physical activity and sedentary behavior research worldwide: A scoping review of observational studies of adults

This scoping review identified observational studies of adults that utilized accelerometry to assess physical activity and sedentary behavior. Key elements on accelerometry data collection were abstracted to describe current practices and completeness of reporting. We searched three databases (PubMed, Web of Science, and SPORTDiscus) on June 1, 2021 for articles published up to that date. We included studies of non-institutionalized adults with an analytic sample size of at least 500. The search returned 5686 unique records. After reviewing 1027 full-text publications, we identified and abstracted accelerometry characteristics on 155 unique observational studies (154 cross-sectional/cohort studies and 1 case control study). The countries with the highest number of studies included the United States, the United Kingdom, and Japan. Fewer studies were identified from the continent of Africa. Five of these studies were distributed donor studies, where participants connected their devices to an application and voluntarily shared data with researchers. Data collection occurred between 1999 to 2019. Most studies used one accelerometer (94.2%), but 8 studies (5.2%) used 2 accelerometers and 1 study (0.6%) used 4 accelerometers. Accelerometers were more commonly worn on the hip (48.4%) as compared to the wrist (22.3%), thigh (5.4%), other locations (14.9%), or not reported (9.0%). Overall, 12.7% of the accelerometers collected raw accelerations and 44.6% were worn for 24 hours/day throughout the collection period. The review identified 155 observational studies of adults that collected accelerometry, utilizing a wide range of accelerometer data processing methods. Researchers inconsistently reported key aspects of the process from collection to analysis, which needs addressing to support accurate comparisons across studies.

Patterns of Accelerometer-Measured Physical Activity and Health Outcomes in Adults: A Systematic Review

PURPOSE

The aim of this study was to systematically review the literature on accelerometer-measured physical activity and health outcomes in adults.

METHODS

Eight electronic databases were searched for relevant articles published up to March 2021. Only population-based studies of adults (age ≥18 yr) that directly compared two or more categories of physical activity (i.e., bout duration, intensity, and daily/weekly frequency) with a health outcome (e.g., mortality, cardiometabolic, healthy aging, depression, sleep, and brain structure) were included.

RESULTS

Of the 15,923 publications retrieved, 52 articles were included. Twenty-eight studies directly compared the associations between physical activity accumulated in different bout durations, 31 studies directly compared the associations between physical activity accumulated in different intensities, and 9 studies directly compared the associations between the effects of varying daily and weekly frequencies of physical activity, with health outcomes. Most showed no differences in relationships with health outcomes when physical activity was accumulated in short (<10-min) or long (≥10-min) bouts. Overall, there were no differences in the relationships with most health outcomes when different intensities and daily/weekly frequencies were compared. However, in most studies, researchers did not adjust their analyses for total volume of physical activity. Moreover, variations in researcher-driven decisions about data collection and processing methods made it difficult to compare study findings.

CONCLUSIONS

These findings suggest that physical activity accumulated in many patterns of bout duration, intensity, or daily/weekly frequency is associated with a range of beneficial health outcomes in adults. Lack of adjustment for total volume of physical activity in most studies and inconsistent methods for defining components of physical activity prevent firm conclusions about which specific patterns of bout duration, intensity, and daily/weekly frequency are most important for health benefits.

The Association of Objectively Measured Physical Activity and Sedentary Behavior with (Instrumental) Activities of Daily Living in Community-Dwelling Older Adults: A Systematic Review

Up to 60% of older adults have a lifestyle characterized by low physical activity (PA) and high sedentary behavior (SB). This can amplify age-related declines in physical and cognitive functions and may therefore affect the ability to complete basic and instrumental activities of daily living (ADL and IADL, respectively), which are essential for independence. This systematic review aims to describe the association of objectively measured PA and SB with ADL and IADL in community-dwelling older adults. Six databases (PubMed, Embase, the Cochrane library, CINAHL, PsychINFO, SPORTDiscuss) were searched from inception to 21/06/2020 for articles meeting our eligibility criteria: 1) observational or experimental study, 2) participants’ mean/median age ≥60 years, 3) community-dwelling older adults, 4) PA and SB were measured with a(n) accelerometer/pedometer, 5) PA and SB were studied in relation to ADL and/or IADL. Risk of bias was assessed in duplicate using modified versions of the Newcastle–Ottawa scale. Effect direction heat maps provided an overview of associations and standardized regression coefficients (βs) were depicted in albatross plots. Thirty articles (6 longitudinal; 24 cross-sectional) were included representing 24,959 (range: 23 to 2749) community-dwelling older adults with mean/median age ranging from 60.0 to 92.3 years (54.6% female). Higher PA and lower SB were associated with better ability to complete ADL and IADL in all longitudinal studies and overall results of cross-sectional studies supported these associations, which underscores the importance of an active lifestyle. The median [interquartile range] of βs for associations of PA/SB with ADL and IADL were, respectively, 0.145 [0.072, 0.280] and 0.135 [0.093, 0.211]. Our strategy to address confounding may have suppressed the true relationship of PA and SB with ADL or IADL because of over-adjustment in some included studies. Future research should aim for standardization in PA and SB assessment to unravel dose–response relationships and inform guidelines.

Independent and joint associations between leisure time physical activity and strength activities with mortality outcomes in older adults ≥65 years-of-age: a prospective cohort study

Scientific evidence regarding the combined effect of both aerobic leisure time physical activity (LTPA) and muscle strengthening activities on all-cause, CVD or cancer mortality in older adults is scant. The aim of the study was to investigate the associations between recommended physical activity and mortality in older adults ≥65 years-of-age. This prospective cohort study used data from the National Health Interview Surveys from 1997-2013 linked with mortality files through December 31, 2015 (n=89,962). The main outcomes included all-cause, cardiovascular disease (CVD) and cancer mortality. The main exposure variables were aerobic leisure time physical activity and guideline-concordant strength training during leisure time. Cox regression models were used to calculate the hazard ratios (HR) and the corresponding 95% confidence intervals (CI). Muscle-strengthening activity at least twice per week were associated with lower hazards of all-cause mortality (HR 0.92; 95% CI 0.88-0.96), CVD mortality (HR 0.90; 95% CI 0.81-0.99) and cancer mortality (HR 0.87; 95% CI 0.79-0.96). Those who reached the recommended weekly amount of LTPA, had lower hazard of all-cause mortality by 35% (HR 0.66; 95% CI 0.63-0.67), the hazard of CVD 38% (HR 0.62; 95% CI 0.58-0.67), and cancer mortality by 22% (HR 0.78; 95% CI 0.73-0.84). The hazard of death among those who were physically active in both leisure time and engaged in muscle-strengthening activities were 0.57 (95% CI 0.54-0.60) for all-cause mortality, 0.53 (95% CI 0.47-0.61) for CVD mortality, and 0.66 (95% CI 0.58-0.75) for cancer mortality. Thus, engaging in muscle-strengthening activity ≥2 times/week may provide additional benefits among physically active older adults.

All-cause mortality over a three-year period among community-dwelling older adults in Southern Brazil

OBJECTIVE

To evaluate all-cause mortality in approximately three years of follow-up and related sociodemographic, behavioral and health factors in community-dwelling older adults in Pelotas, RS.

METHODS

This was a longitudinal observational study that included 1,451 older adults (≥ 60 years) who were interviewed in 2014. Information on mortality was collected from their households in 2016-2017 and confirmed with the Epidemiological Surveillance department of the city and by documents from family members. Associations between mortality and independent variables were assessed by crude and multiple Cox regression, with hazard ratio with respective 95% confidence intervals (95%CI).

RESULTS

Almost 10% (n = 145) of the participants died during an average of 2.5 years of follow-up, with a higher frequency of deaths among males (12.9%), ?80 years (25.2%), widowhood (15.0%), no education (13.8%) and who did not work (10.5%). Factors associated with higher mortality were: being a male (HR = 2.8; 95%CI 1.9 - 4.2), age ?80 years (HR = 3.9; 95%CI 2.4 - 6.2), widowhood (HR = 2.2; 95%CI 1.4 - 3.7), physical inactivity (HR = 2.3; 95%CI 1.1 - 4..6), current smoking (HR = 2.1; 95%CI 1.2 - 3.6), hospitalizations in the previous year (HR = 2.0; 95%CI 1.2 - 3.2), depressive symptoms (HR = 2.0; 95%CI 1.2 - 3,4) and dependence for two or more daily life activities (HR = 3.1; 95%CI 1,7 - 5.7).

CONCLUSION

The identification of factors that increased the risk of early death makes it possible to improve public policies aimed at controlling the modifiable risk factors that can lead to aging with a better quality of life.

Objectively measured physical activity and all cause mortality: A systematic review and meta-analysis

Current physical activity recommendations have been based on evidence from systematic reviews of questionnaire-based data. Questionnaire-based physical activity data are subject to both random and non-random error. If the estimated association between physical activity and health outcomes was different when a more accurate, objective measure was used, this would have important health policy implications for physical activity. We conducted a systematic review and meta-analysis of published cohort studies that investigated the association between an objective measure of physical activity and all cause mortality. We searched PubMed, Scopus, Embase, Cochrane library, and SPORTDiscus for prospective cohort studies that examined the association between objectively measured (accelerometer, pedometer, or doubly labeled water method) physical activity and mortality in adults aged≥18 years, of either sex. Summary hazard ratios and 95% confidence interval [CI]s were computed using random-effects models. Thirty-three articles from 15 cohort studies were identified that together ascertained 3903 deaths. The mean years of follow-up ranged from 2.3-14.2 years. Individuals in the highest category of light, moderate-to-vigorous, and total physical activity had 40% (95%CI 20% to 55%), 56% (95%CI 41% to 67%), and 67% (95%CI 57% to 75%), respectively, lower risk for mortality compared to individuals in the lowest category of light, moderate-to-vigorous, and total physical activity. The summary hazard ratio for objectively measured physical activity and all cause mortality is lower than previously estimated from questionnaire based studies. Current recommendations for physical activity that are based on subjective measurement may underestimate the true reduction in mortality risk associated with physical activity.