Abstract 16937: Initiation of Moderate Physical Activity Reduces Progression of Subclinical Cardiac Injury in Previously Sedentary Older Adults: Results From a Randomized Pilot Study of Exercise Intervention
Background: In animal models, physical activity (PA) prevents cardiac myocyte cell death. Data to support effects of PA on cardiac injury in humans are limited to an observational study in older adults, in which the assessment of activity levels was limited. We hypothesized that introducing moderate PA to previously sedentary older adults could reduce progression of myocardial injury.
Methods: Older sedentary adult participants (age≥75 years) in the LIFE pilot study were randomly assigned to a one-year intervention of supervised moderate PA or health education control. Cardiac troponin T (cTnT) detected by a high sensitive (hs) assay was measured in stored serum at baseline and 1-year (n=310). A significant rise in hs cTnT level was defined as >50% at follow-up from baseline based on a prior association with increased risk of cardiac events in older adults. Moderate to vigorous PA Kcals/week were estimated with the CHAMPS questionnaire.
Results: Baseline characteristics and hs cTnT findings for both groups are shown in Table. Kcals increased in the PA, but not in the control group. Baseline hs cTnT levels were similar between groups, but the median increase in level from baseline was > 3 times larger in the control versus the PA group; table. The proportion with a >50% increase in hs cTnT was larger in the control than the PA group, but this difference was not significant.
Conclusions: Initiation of only a modest amount of PA in sedentary adults ≥75 years results in a detectable reduction in progression of subclinical myocardial injury compared to those who remain sedentary. The extent of possible reduction of progression of myocardial injury and subsequent cardiovascular events with introducing a PA program in older adults will need to be tested in a larger randomized trial of longer duration and with greater intensity of PA.
- © 2013 by American Heart Association, Inc.