Background Participation of amateur runners in endurance races continues to
increase. Previous studies of marathon runners have raised concerns about
exercise-induced myocardial and renal dysfunction and damage. In our pooled
analysis, we aimed to characterize changes of cardiac and renal function after
marathon running in a large cohort of mostly elderly amateur marathon runners.
Methods A total of 167 participants of the BERLIN-MARATHON (female n = 89,
male n = 78; age = 50.3 ± 11.4 years) were included and cardiac and renal
function was analyzed prior to, immediately after and 2 weeks following the
race by echocardiography and blood tests (including cardiac troponin T, NT-
proBNP and cystatin C). Results Among the runners, 58% exhibited a significant
increase in cardiac biomarkers after completion of the marathon. Overall, the
changes in echocardiographic parameters for systolic or diastolic left and
right ventricular function did not indicate relevant myocardial dysfunction.
Notably, 30% of all participants showed >25% decrease in cystatin C-estimated
glomerular filtration rate (GFR) from baseline directly after the marathon; in
8%, we observed a decline of more than 50%. All cardiac and renal parameters
returned to baseline ranges within 2 weeks after the marathon. Conclusions The
increase in cardiac biomarkers after completing a marathon was not accompanied
by relevant cardiac dysfunction as assessed by echocardiography. After the
race, a high proportion of runners experienced a decrease in cystatin
C-estimated GFR, which is suggestive of transient, exercise-related alteration
of renal function. However, we did not observe persistent detrimental effects
on renal function