Associations of objectively measured moderate-to-vigorous-intensity physical activity and sedentary time with all-cause mortality in a population of adults at high risk of type 2 diabetes mellitus
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.