The association between physical activity, sedentary behavior and the occurrence of falls in asymptomatic adults over 40 years old

Abstract

Introduction: Sedentary behavior (SB) has been described as an independent risk factor for health, regardless of the recommended amount of moderate-to-vigorous physical activity (MVPA). However, SB and MVPA as predictors of falls have been poorly investigated. Objective: We aimed to compare the associations between SB and MVPA, and the occurrence of falls in middle-aged and older adults. Method: The participants wore a triaxial accelerometer over the dominant hip for 7 days to measure SB and MVPA. The occurrence of falls and cardiovascular risk factors were assessed by self-report. We also assessed isokinetic peak torque (PT) of knee extension, peak oxygen uptake (V’O2) in a ramp treadmill protocol, and lean (LBM) and fat (FBM) body masses (bioelectrical impedance). We compared critical roles of SB and MVPA on the occurrence of falls by multiple logistic regression adjusted for age, sex, cardiovascular risk factors, LBM, peak V’O2, and PT of knee extension. Results: We evaluated 379 participants aged 40-80 years. 48 participants reported at least one fall in the previous 12 months (14.5%). Fallers presented lower SB and higher MVPA. They were predominantly women and older with lower physical fitness. After multivariate analysis, MVPA, but not SB, was selected as an independent predictor of falls, increasing the odds ratio of having a fall (1.184, 95% confidence interval, 1.016 - 1.378). Conclusion: Episodes of falls in predominantly middle-aged and women subjects were associated with a higher amount of MVPA, not the opposite, indicating an adverse effect of MVPA in these subjects.