Impact of moderate physical activity on the longitudinal trajectory of a cardiac specific biomarker of injury: Results from a randomized pilot study of exercise intervention

In animal models, physical activity (PA) prevents cardiac myocyte cell death. Data for PA mitigating myocyte injury in humans are limited to observational studies. Using a randomized controlled trial design, we sought to determine if introducing moderate PA to previously sedentary older adults could reduce the trajectory of myocardial injury as measured by the high-sensitive cardiac troponin T (hs-cTnT) assay. Methods Participants (age ≥70 years) were assigned to a 1-year intervention of moderate PA or health education control. High-sensitive cTnT was measured at baseline and 1 year in the 307 of 424 subjects who had available stored serum. Changes in hs-cTnT within 1 year were compared between PA and control groups, as were differences in the proportion of subjects with a significant rise in hs-cTnT (prospectively defined as a>50% increase at follow-up from baseline). Moderate to vigorous PA in kcal/wk was estimated with the CHAMPS questionnaire. Results Baseline hs-cTnT levels and PA kcal/wk were similar for both groups. Activity kcal/wk increased in the PA, but not in the control group at 1 year. The median increase in hs-cTnT level from baseline was >3 times larger in the control (0.73 ng/L, interquartile range −0.64 to 2.59) vs the PA group (0.19ng/L, interquartile range −1.10 to 1.93) (P=.02). The proportion with a>50% increase in hs-cTnT was larger in the control group than in the PA group (9.3% vs 5.1%), but this difference was not statistically significant (P=.16). Conclusions Initiation of moderate PA in sedentary older adults may favorably modify subclinical myocardial injury.