OUP user menu

Cardiac Biomarkers, Electrolytes, and Other Analytes in Collapsed Marathon Runners
Implications for the Evaluation of Runners Following Competition

Arthur J. Siegel MD, James Januzzi MD, Patrick Sluss PhD, Elizabeth Lee-Lewandrowski MPH, PhD, Malissa Wood MD, Terry Shirey PhD, Kent B. Lewandrowski MD
DOI: http://dx.doi.org/10.1309/4L0M60MGAQBCHMV7 948-951 First published online: 1 June 2008


We measured analytes in collapsed Boston Marathon runners to compare with changes in asymptomatic runners. Of collapsed runners at the 2007 marathon, 18.2% had a measurable cardiac troponin T (cTnT) value with a mean postrace level of 0.017 ng/mL (0.017 μg/L; SD, 0.02 ng/mL [0.02 μg/L]). Three subjects had cTnT values above the cutoff (0.10 ng/mL [0.10 μg/L]) typically used for the diagnosis of acute myocardial infarction. The mean and median N-terminal pro-B-type natriuretic peptide levels were 73 ng/L (SD, 77.3 ng/L) and 54.3 ng/L (interquartile range, 22.8-87.3 ng/L), respectively, in collapsed runners. Only 4.9% had values more than the age-specific normal value (<125 ng/L for subjects younger than 75 years). In collapsed subjects at the 2006 marathon, 18.0% had an abnormal sodium value, including 18 cases of hypernatremia and 7 cases of hyponatremia. The ionized calcium level was low in 49% of subjects, and the ionized magnesium level was low in 19.5% and elevated in 1 subject. The blood lactate level was elevated in 95% of subjects.

The frequency of elevated postrace cTnT levels in collapsed athletes after endurance exercise is similar to that in asymptomatic runners. Other metabolic abnormalities, including hypernatremia, hyponatremia, low ionized calcium and magnesium levels, and lactic acidosis may contribute to muscle fatigue and collapse.

Key Words:
  • Cardiac troponin T
  • B-type natriuretic peptide
  • N-terminal pro-B-type natriuretic peptide
  • Lactic acidosis
  • Ionized magnesium
  • Acute coronary syndrome
  • Sudden cardiac death
  • Marathon