Independent, Stratified, and Joint Associations of Sedentary Time and Physical Activity With Major Adverse Cardiovascular Events in Older Adults: Findings From a Population-Based Cohort.

BACKGROUND: Cardiovascular diseases remain the leading cause of death globally. While physical activity reduces cardiovascular risk, sedentary time (ST) may increase it. However, their independent and combined associations in older adults from middle-income countries remain unclear. AIM: To investigate the independent, stratified, and joint associations of ST and physical activity with major adverse cardiovascular events (MACEs) in community-dwelling older adults. METHODS: A prospective population-based cohort of older adults (≥60 years) from Pelotas, Brazil, was enrolled in 2014. ST and moderate to vigorous physical activity (MVPA) were estimated via raw accelerometer data. Participants were categorized by ST (median: low/high) and MVPA (tertiles: low, medium, high). MACEs were defined as all-cause mortality, heart failure, and ischemia. Cox proportional hazard models were used for independent, stratified, and joint associations. RESULTS: Among 965 participants (median follow-up 2.6 years; 205 MACEs), independent analysis showed ST was not associated with MACEs when adjusted for MVPA (hazard ratio 0.98, 0.68-1.40). In contrast, the highest MVPA tertile was associated with lower MACE risk, even after adjusting for ST and prior nonfatal MACEs (hazard ratio 0.58, 0.34-0.96). Stratified and joint analyses of ST/MVPA were not statistically significant (P > .05). CONCLUSIONS: Higher MVPA is associated with reduced risk of MACEs in older adults, whereas ST appears unrelated. Significance/Implications: These findings highlight the importance of promoting MVPA in older adults, even among those with high ST. Public health strategies in middle-income countries should prioritize increasing MVPA to reduce cardiovascular risk and improve population health outcomes.