Abstract Body: Background: Physical activity plays a critical role in cardiovascular health throughout the life course. However, data on its trajectories before and after cardiovascular disease (CVD) are limited. We analyzed a bi-racial U.S. cohort with 35 years of repeated assessments of moderate-to-vigorous-intensity physical activity (MVPA) to examine trends and potential variations by race.
Methods: CARDIA participants (n=5,115) underwent up to 10 MVPA assessments from 1985-6 to 2020-2. MVPA was assessed via a Physical Activity History Questionnaire and scored in exercise units (EU), with 300 EU approximating 150 minutes/week. During follow-up, 332 participants experienced an incident non-fatal CVD event, and 236 (71%) had subsequent MVPA data, forming the case group. Nested controls were matched 1:1 to cases by age, sex, and race using risk set sampling. LOESS regression explored non-linear MVPA trends, while linear mixed-effects models assessed differences in MVPA slopes between groups. Generalized estimating equation (GEE) models evaluated the odds ratio (OR) of low MVPA (<300 EU) post-CVD.
Results: The mean baseline age of the matched sample (n=472) was 26 years; 64% were Black, and 60% were men. The mean age at incident CVD was 49 years. The median (IQR) number of MVPA assessments in cases was 6 (5-8) before and 2 (1-3) after CVD. MVPA levels were consistently higher in controls than in cases, with the gap widening after CVD (Figure), supported by a significant time-by-CVD status interaction (P = .002). The OR for low MVPA post-CVD in cases vs. controls was 2.45 (95% CI: 1.76-3.41) and was stronger in Black (OR = 3.67, 95% CI: 2.36-5.70) than in White (OR = 1.49, 95% CI: 0.90-2.48) participants (P_interaction = .017). No heterogeneity was detected across CVD types (CHD, stroke, heart failure; P = .90).
Conclusions: MVPA levels were consistently lower in cases than controls, with a more pronounced decrease after CVD, perhaps due to physical limitations. The odds of lower-than-recommended MVPA post-CVD were notably higher among Black participants.