Effects of prolonged strenuous exercise on plasma levels of atrial natriuretic peptide and brain natriuretic peptide in healthy men

Background Now that marathon racing is growing in popularity, many thousand s of enthusiastic athletes are participating in various ultramarathons all over the world each year. However, it remains controversial whether such a sport contributes to the promotion of health. The occurrence of transient c ardiac dysfunction and irreversible myocardial injury has been reported in association with such exercise in healthy individuals. Brain natriuretic pe ptide (BNP) is a cardiac hormone, as is atrial natriuretic peptide (ANP), a nd its measurement has been widely used for clinical evaluation of cardiac dysfunction. However, little is known about the response of plasma BNP to p rolonged strenuous exercise. We hypothesized that confirmation of minimal c ardiac dysfunction or myocardial injury may be made by measurements of plas ma BNP. Methods levels of plasma ANP, BNP, catecholamines, blood lactate, and serum cardiac troponin T (cTnT) were determined before and after a 100-km ultram arathon in 10 healthy men to examine the effects of the exercise on levels of ANP and BNP and correlations between the natriuretic peptides and cTnT a s a marker for myocardial damage. Results Whereas all variables significantly increased after the race, incre ased levels of ANP and BNP were most strongly correlated with increases in cTnT levels. The cTnT level after the race was greater than the upper refer ence limit in 9 of 10 men. Conclusions such exercise significantly increased ANP and BNP levels in hea lthy men, and the increases could be partially attributed to myocardial dam age during the race.