Moderating effects of physical activity intensity and sedentary break patterns on the association between sedentary time and cardiometabolic risk in older adults

UNLABELLED: To investigate the moderating role of physical activity intensity and sedentary break patterns on the association between sedentary time (ST) and cardiometabolic risk in older adults. METHODS: This cross-sectional study included 248 community-dwelling older adults without major cardiovascular diseases (66.0 ± 4.6 years; 78% female). Physical activity and ST were measured using a hip-worn accelerometer over seven consecutive days. Cardiometabolic disease risk was assessed using a sex-specific continuous metabolic syndrome score (cMetS). ST was entered as the explanatory variable for cMetS, while moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), and the number of short (1-5 min) and long (>5 min) sedentary breaks were tested as moderators. All analyses were adjusted for traditional cardiometabolic risk factors and accelerometer wear time. RESULTS: MVPA (β = -0.005, p = 0.046), LPA (β = -0.030, p = 0.050), short (β = -0.003, p = 0.070) and long (β = -0.010, p = 0.011) sedentary breaks moderated the association between ST and cMetS. The Johnson-Neyman technique revealed that the association between ST and cMetS became non-significant (p ≥ 0.05) at thresholds of MVPA ≥ 19 min/day, LPA ≥ 5.9 h/day, short breaks ≥ 87/day, and long breaks ≥ 10/day. CONCLUSION: Our findings suggest that specific thresholds of MVPA and LPA, as well as short and long sedentary breaks may offset the deleterious association between ST and cardiometabolic risk in older adults.