Endurance exercise-induced changes in BNP concentrations in cardiovascular patients versus healthy controls.

Background: Healthy athletes demonstrated increased B-type natriuretic peptide (BNP) concentrations following exercise, but it is unknown whether these responses are exaggerated in individuals with cardiovascular risk factors (CVRF) or disease (CVD). We compared exercise-induced increases in BNP between healthy controls (CON) and individuals with CVRF or CVD. Furthermore, we aimed to identify predictors for BNP responses.

Methods: Serum BNP concentrations were measured in 191 participants (60±12yrs) of the Nijmegen Marches before (baseline) and immediately after 4 consecutive days of walking exercise (30-50km/day). CVRF (n=54) was defined as hypertension, hypercholesterolemia, obesity or smoking and CVD (n=55) was defined as a history of myocardial infarction, heart failure, atrial fibrillation or angina pectoris.

Results: Individuals walked 487±79min/day at 65±10% of their maximum heart rate. Baseline BNP concentrations were higher for CVD (median: 28.1pg/ml; interquartile range: 13-50, p<0.001) compared to CVRF (3.9pg/ml; 0-14) and CON (5.5pg/ml; 0-14). Post-exercise BNP concentrations were elevated in CVD (35.7pg/ml, 17-67, p=0.01), but not in CVRF participants (p=0.11) or CON (p=0.07). No cumulative effect in BNP concentrations was observed across the consecutive walking days (p>0.05). Predictors for post-exercise BNP (R=0.77) were baseline BNP, beta-blocker use and age.

Conclusion: Prolonged moderate-intensity walking exercise increases BNP concentrations in CVD participants, but not in CVRF and CON. BNP increases were small, and did not accumulate across consecutive days of exercise. These findings suggest that prolonged walking exercise for multiple consecutive days is feasible with minimal effect on myocardial stretch, even for participants with CVD.