The effects of objectively-measured, free-living daily ambulatory movement on mortality in a national sample of adults with diabetes

Accelerometer-derived physical activity and mortality in individuals with type 2 diabetes

Physical activity (PA) has been shown to reduce diabetes mortality, but largely based on imprecise self-reported data, which may hinder the development of related recommendations. Here, we perform a prospective cohort study of 19,624 individuals with type 2 diabetes (T2D) from the UK Biobank with a median follow-up of 6.9 years. Duration and intensity of PA are measured by wrist-worn accelerometers over a 7-day period. We observe L-shaped associations of longer duration of PA, regardless of PA intensity, with risks of all-cause and cancer mortality, as well as a negatively linear association with cardiovascular disease mortality. 12.7%, 15.8%, and 22.3% of deaths are attributable to the lowest level of light-intensity, moderate-intensity PA, and vigorous-intensity PA, respectively. Collectively, our findings provide insights for clinical guidelines that should highlight the potential value of adherence to greater intensity and duration of PA for patients with T2D.

Identification of earlier predictors of pregnancy complications through wearable technologies in a Brazilian multicentre cohort: Maternal Actigraphy Exploratory Study I (MAES-I) study protocol

INTRODUCTION

Non-invasive tools capable of identifying predictors of maternal complications would be a step forward for improving maternal and perinatal health. There is an association between modification in physical activity (PA) and sleep-wake patterns and the occurrence of inflammatory, metabolic, pathological conditions related to chronic diseases. The actigraphy device is validated to estimate PA and sleep-wake patterns among pregnant women. In order to extend the window of opportunity to prevent, diagnose and treat specific maternal conditions, would it be possible to use actigraphy data to identify risk factors for the development of adverse maternal outcomes during pregnancy?

METHODS AND ANALYSIS

A cohort will be held in five centres from the Brazilian Network for Studies on Reproductive and Perinatal Health. Maternal Actigraphy Exploratory Study I (MAES-I) will enrol 400 low-risk nulliparous women who will wear the actigraphy device on their wrists day and night (24 hours/day) uninterruptedly from 19 to 21 weeks until childbirth. Changes in PA and sleep-wake patterns will be analysed throughout pregnancy, considering ranges in gestational age in women with and without maternal complications such as pre-eclampsia, preterm birth (spontaneous or provider-initiated), gestational diabetes, maternal haemorrhage during pregnancy, in addition to perinatal outcomes. The plan is to design a predictive model using actigraphy data for screening pregnant women at risk of developing specific adverse maternal and perinatal outcomes.

ETHICS AND DISSEMINATION

MAES-I has been reviewed and approved by each institutional review board and also by the National Council for Ethics in Research. Detailed information about the study is provided in the Brazilian Cohort website (www.medscinet.com/samba) and findings will be published in the scientific literature and institutional webpages.

Effects of Sedentary Behavior, Physical Activity, Frequency of Protein Consumption, Lower Extremity Strength and Lean Mass on All-Cause Mortality

Background

No study has evaluated the potential independent and cumulative effects of physical activity, sedentary behavior, daily frequency of protein consumption, lean mass and muscular strength on mortality risk.

Methods

Data from the 1999–2002 NHANES were utilized (N = 1,079 adults 50–85 yr), with follow-up through 2011. Leg lean mass was estimated from DXA scans. Knee extensor strength was assessed using the Kin Com MP dynamometer. Physical activity and sedentary behavior were assessed via questionnaire, with the number of meals/day of ≥30 g of protein/meal assessed via a “multiple pass” 24-hour dietary interview. An index score was created (range = 0–5) indicating the number of these health characteristics each participant had.

Results

Only less sedentary behavior was independently associated with reduced mortality risk (HR_adjustment = 0.46; 0.32–0.66). After adjustments, and compared to those with an index score of 0, those with an index score of 1, 2 and 3+, respectively, had a 34%, 49%, and 57% reduced risk of all-cause mortality.

Conclusion

While considering physical activity, sedentary behavior, daily protein frequency consumption, lean mass and muscular strength, only sedentary behavior was independently associated with mortality risk among older adults.

Effect of physical activity on mortality risk among Americans with retinopathy

Background: Previous work demonstrates that retinopathy is associated with increased mortality risk, with physical activity inversely associated with retinopathy and all-cause mortality. However, no study has evaluated the effects of physical activity on mortality among those with existing retinopathy, which was this study’s purpose.

Methods: Data from the 2005-2006 National Health and Nutrition Examination Survey were utilized, with follow-up through 2011. Retinopathy was objectively-measured using the Canon Non-Mydriatic Retinal Camera CR6-45NM. Physical activity was objectively-measured via up to 7 days of accelerometry assessment.

Results: Six-hundred and seventy one adults (40-85 years) with complete data on the study variables constituted the analytic sample. During the follow-up period, 91 deaths occurred. In the sample, 35 886 person-months occurred with a mortality incidence rate of 2.5 deaths per1000 person-months. Among participants with mild retinopathy, those who met physical activity guidelines at baseline had a 63% reduced risk of all-cause mortality (HR _adjusted = 0.37; 95% CI:0.18-0.75; P = 0.007). Notably, physical activity was not associated with mortality risk among those with moderate/severe retinopathy (HR _adjusted = 0.371.72; 95% CI: 0.62-4.76; P = 0.27).

Conclusion: Physical activity is associated with reduced mortality risk among those with mild retinopathy, but not among those with moderate/severe retinopathy.

Examining Non-Linear Associations between Accelerometer-Measured Physical Activity, Sedentary Behavior, and All-Cause Mortality Using Segmented Cox Regression

Healthy adults are advised to perform at least 150 min of moderate-intensity physical activity weekly, but this advice is based on studies using self-reports of questionable validity. This study examined the dose-response relationship of accelerometer-measured physical activity and sedentary behaviors on all-cause mortality using segmented Cox regression to empirically determine the break-points of the dose-response relationship. Data from 7006 adult participants aged 18 or above in the National Health and Nutrition Examination Survey waves 2003-2004 and 2005-2006 were included in the analysis and linked with death certificate data using a probabilistic matching approach in the National Death Index through December 31, 2011. Physical activity and sedentary behavior were measured using ActiGraph model 7164 accelerometer over the right hip for 7 consecutive days. Each minute with accelerometer count <100; 1952-5724; and ≥5725 were classified as sedentary, moderate-intensity physical activity, and vigorous-intensity physical activity, respectively. Segmented Cox regression was used to estimate the hazard ratio (HR) of time spent in sedentary behaviors, moderate-intensity physical activity, and vigorous-intensity physical activity and all-cause mortality, adjusted for demographic characteristics, health behaviors, and health conditions. Data were analyzed in 2016. During 47,119 person-year of follow-up, 608 deaths occurred. Each additional hour per day of sedentary behaviors was associated with a HR of 1.15 (95% CI 1.01, 1.31) among participants who spend at least 10.9 h per day on sedentary behaviors, and each additional minute per day spent on moderate-intensity physical activity was associated with a HR of 0.94 (95% CI 0.91, 0.96) among participants with daily moderate-intensity physical activity ≤14.1 min. Associations of moderate physical activity and sedentary behaviors on all-cause mortality were independent of each other. To conclude, evidence from this study supported at least 15 min per day of moderate-intensity physical activity and no more than 10.9 h per day of sedentary behaviors as recommendations to reduce all-cause mortality.

The effects of objectively measured sedentary behavior on all-cause mortality in a national sample of adults with diabetes

BACKGROUND

Diabetes is a highly prevalent chronic disease that has been increasing globally and is the seventh leading cause of death in the United States. Sedentary behavior is associated with increased risk of diabetes and is unfavorably related to all-cause mortality, but there are limited studies examining the sedentary-mortality relationship among those with diabetes, which was the purpose of this study.

METHODS

Using data from the 2003-2006 NHANES, 712 adult participants with evidence of diabetes had complete data on the study variables. A multivariable Cox proportional hazard model was used to examine the association between objectively measured sedentary behavior and all-cause mortality among this diabetic sample.

RESULTS

Results showed that for every 60min/day increase in sedentary behavior, independent of moderate-to-vigorous physical activity (MVPA) and other covariates, adults with diabetes had a 13% increased risk of all-cause mortality (HRadjusted=1.13; 95% CI=1.03-1.24; P=0.01). However, after adjusting for total physical activity (light and MVPA), sedentary behavior was no longer associated with mortality risk (HRadjusted=1.04; 95% CI=0.92-1.16; P=0.46).

CONCLUSION

Among those with diabetes, sedentary behavior may not have increased mortality risk independent of total physical activity behavior.