Exercise Training, Cardiac Biomarkers, and Cardiorespiratory Fitness in Type 2 Diabetes

High-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are cardiac biomarkers commonly detected in adults with type 2 diabetes (T2D) and are associated with heart failure risk. The purpose of this study was to evaluate the effects of exercise training (ET) on hs-cTnT and NT-proBNP and evaluate the associations of these biomarkers with cardiorespiratory fitness among adults with T2D. Participants of the HART-D (Health Benefits of Aerobic and Resistance Training in Individuals with Type 2 Diabetes) trial who were randomly assigned to one of 3 ET groups or a non-exercise control group were included. Cardiac biomarkers and cardiorespiratory fitness (evaluated by peak oxygen uptake [VO2peak]) were assessed at baseline and after 9 months. The effects of ET (3 ET groups pooled) vs non-exercise control on hs-cTnT and NT-proBNP were assessed using separate analysis of covariance models. Multivariable-adjusted linear regression was performed to identify factors associated with follow-up biomarkers and ΔVO2peak. The present study included 166 participants randomized to the ET (n = 135) and non-exercise control (n = 31) groups. Compared with the non-exercise control, ET did not significantly change hs-cTnT or NT-proBNP. In adjusted analysis, each ET group and ΔVO2peak were not significantly associated with hs-cTnT or NT-proBNP levels on follow-up. Among individuals in the ET group, baseline hs-cTnT was inversely associated with ΔVO2peak [per 1 SD higher log (hs-cTnT): β = −0.08 (95% CI = −0.15 to −0.01)]. Among individuals with T2D, ET did not modify cardiac biomarkers. Higher baseline hs-cTnT was associated with blunted cardiorespiratory fitness improvement in response to exercise.