Abstract MP25: Physical Activity And The Progression Of Coronary Artery Calcification

Abstract

Introduction: High volume endurance physical activity (PA) has been shown to associate with increased clinically relevant coronary artery calcification (CAC) but not mortality. A key issue is whether active individuals with CAC have progression of atherosclerosis in the setting of sustained high levels of PA. Hypothesis: We hypothesized that changes in CAC are not related to corresponding changes in PA volume. Further, we hypothesized the rate of CAC progression to ≥100 Agatston units (AU) does not depend on baseline PA level. Methods: The study included 6,525 men and 2,056 women with ≥2 assessments of PA and CAC (EBT scans (1997-2007) or MDCT scans (2007-2019)). All individuals had at least one follow-up visit (mean=1.8). We used mixed linear regression to relate within-person changes in square-root CAC to changes in PA volume, controlling for between-person effects. We used interval-censored proportional hazards regression to test if progression to CAC≥100 AU was related to baseline PA level: ≥3000, 1500-2999, and <1500 MET·minutes/week (MET·min/wk). Covariates included age, smoking, BMI, glucose, cholesterol, systolic blood pressure, and statin use. In addition, the longitudinal analysis was adjusted for time since baseline, while the time-to-CAC-threshold analysis was adjusted for baseline CAC. Results: Mean baseline age was 50 years in men/51 years in women. Mean time to first follow-up was 4.5 years in men/5.1 years in women. PA levels increased by 100 MET·min/wk in men but were stable in women. Cardiorespiratory fitness was stable between visits. Within person changes in CAC were not associated with changes in PA volume (Table). At baseline, 5285 men and 1948 women had CAC<100 AU; at follow-up, 1127 men and 136 women progressed to CAC≥100 AU. Neither PA ≥3000 nor 1500-2999 MET·min/wk exhibited significant risk of CAC progression versus <1500 MET·min/wk. Estimated hazard ratios were ≤1 for both men and women. Conclusions: These results show no apparent risk of increasing CAC with sustained PA in active individuals.