Extreme exercise enhances chromogranin A levels correlating with stress levels but not with cardiac burden

Objective: Stress and heart failure are associated with increased systemic levels of chromogranin A (CGA). Here we analyzed the effects of marathon running on systemic CGA levels and the association with cardiac burden and stress. Methods: We recruited 47 lean and obese runners for a 10. week training program aiming at running a marathon. Heart rates, individual fitness and marathon finishing times were monitored. CGA, proBNP and troponin T levels were analyzed by ELISA. Results: We found a significant increase of CGA (+51%; p< 0.01) in lean runners after marathon. The obese group showed the highest troponin T (0.22. ng/ml; p< 0.01) and proBNP (176.6. ng/ml; p< 0.01) levels. There were no correlations between proBNP, troponin T and CGA. An inverse correlation (r= -0.45; p< 0.01) was found between CGA and finishing times. Conclusion: Marathon running is associated with increased CGA levels. However, this does not seem to reflect cardiac burden but rather marathon induced stress.