Associations of Mutually Exclusive Categories of Physical Activity and Sedentary Time With Metabolic Syndrome in Older Adults: An Isotemporal Substitution Approach

The aim of this study was to examine, theoretically, how reallocating time between the intensity of mutually exclusive categories of physical activity and sedentary behavior time is associated with metabolic syndrome. Four hundred and six older adults (61.6% women) from the second wave of the EpiFloripa Aging Cohort Study were included in the study (mean age 71.7 ± 5.9 years). Isotemporal substitution analysis showed a decrease of 35% (odds ratio: 0.65; 95% confidence interval [0.45, 0.96]) in the risk for metabolic syndrome when replacing 30 min/day of sedentary behavior with an equivalent amount of moderate to vigorous physical activity. Furthermore, it has been observed that older adults classified as low sedentary behavior and physically active were 57% less likely to have metabolic syndrome than participants classified as high sedentary and physically inactive (odds ratio: 0.43; 95% confidence interval [0.19, 0.97]). This study highlights the importance of behavioral categories that may emerge concerning the interrelationships of physical activity and health in older adults, having important implications for future health intervention programs.