Associations of long-term physical activity trajectories with coronary artery calcium progression and cardiovascular disease events: results from the CARDIA study

The study aimed to assess the associations of physical activity (PA) trajectories across a 25-year span with coronary artery calcium (CAC) progression, and subsequent risk of cardiovascular disease (CVD) events.We included 2497 participants from the Coronary Artery Disease Risk Development in Young Adults study who had computed tomography-assessment of CAC at baseline (year 15: 2000-2001) and follow-up (year 20 or 25) and at least three measures of PA from year 0 to year 25. Long-term PA trajectories were determined by latent class modelling using a validated questionnaire.Among the included participants, 1120 (44.9%) were men, 1418 (56.8%) were white, and the mean (SD) age was 40.4 (3.6) years. We identified three distinct PA trajectories based on PA average levels and change patterns: low (below PA guidelines, n=1332; 53.3%); moderate (meeting and slightly over PA guidelines, n=919; 36.8%) and high (about three times PA guidelines or more, n=246; 9.9%). During a mean (SD) follow-up of 8.9 (2.1) years, 640 (25.6%) participants had CAC progression. Participants in the high PA trajectory group had a higher risk of CAC progression than those in the low PA trajectory group after adjustment for traditional cardiovascular risk factors (HR 1.51; 95% CI 1.18 to 1.94). However, high PA trajectory was not associated with an increased risk of incident CVD events (HR 1.01; 95% CI 0.44 to 2.31) and the incidence of CVD events in participants with CAC progression was similar across all three PA trajectory groups (p=0.736).Long-term PA about three times the guidelines or more is independently associated with CAC progression; however, no additional risk of incident CVD events could be detected.