Abstract 15614: Increased Cardiac Distensibility Is Not Associated with Lower Levels of Circulating Biomarkers of Extracellular Matrix Remodeling in Lifelong Exercisers.
Purpose: Increased levels of matrix metelloproteinases (MMP) are observed in the presence of diastolic dysfunction. Healthy aging is associated with cardiac atrophy, decreased cardiac compliance and alterations in diastolic filling. Conversely, lifelong exercise training (>20 yrs) results in an increased LV mass (LVM) and enhanced cardiac compliance and diastolic filling. However, it is unclear whether the improved diastolic function in lifelong exercisers is reflected in lower levels of MMPs.
Methods: MRI assessed measures of left ventricular (LV) mass, invasive (right heart catheterization) measures of LV filling pressure (pulmonary capillary wedge pressure; PCWP) and end-diastolic volume (echocardiography), plasma MMP-1,-2,-3, -7,-9, TIMP-1,-2, -4 levels determined by high sensitivity immunoassays were collected in 92 healthy trained and untrained older (>60 years) individuals. These included 22 untrained subjects who had consistently (>20 years) performed less than 2 sessions/wk (sedentary), 25 subjects who performed 2-3 sessions/wk (casual exercisers), 24 subjects who performed 4-5 sessions/wk (committed exercisers) and 21 Maters Athletes who performed 6 or more sessions/wk plus regular competitors.
Results: LV mass index (g/m2) and cardiac distensibility (ml/m2/mmHg) increased with life-long training volume (p<0.001). MMP and TIMP profiles were not different among the four groups.
Conclusion: Despite large difference in cardiac distensibility, lifelong exercisers had a similar MMP and TIMP profile compared to sedentary, but healthy untrained subjects. Therefore, the improved cardiac compliance and diastolic function in lifelong exercisers does not seem to be associated with significant extracellular matrix remodeling.
- © 2011 by American Heart Association, Inc.