title: Independent elevations of N-terminal pro-brain natriuretic peptide and cardiac troponins in endurance athletes after prolonged strenuous exercise.
abstract: BACKGROUND
  Although elevated resting brain natriuretic peptide (BNP) concentrations reflect heart disease, the meaning of exercise-induced increases is poorly understood and has been examined in small groups only. Therefore, the present study aimed to examine the increase in N-terminal pro-brain natriuretic peptide (NT-proBNP) and relations to cardiac troponin I and T (cTnI, cTnT) elevations after prolonged strenuous exercise in a large cohort of athletes.
  
  
  METHODS
  We examined exercise-induced changes in NT-proBNP, cTnI, and cTnT in 105 obviously healthy endurance athletes (40 +/- 8 years) before and after prolonged strenuous exercise. Blood samples were taken before, 15 minutes, and 3 hours after a marathon (n = 46), a 100-km run (n = 14), and a mountain bike marathon (n = 45).
  
  
  RESULTS
  Eighty-one of 105 athletes exceeded the upper reference limit of NT-proBNP (males/females 88:153 ng/L) after exercise. NT-proBNP increased in all 3 events (P < .001) with the highest increase in the 100-km runners (median increase 200 ng/L; 25th/75th percentile 115/770 ng/L), which differed from the increase in the marathon (97 ng/L; 36/254 ng/L) or the mountain bike marathon (78 ng/L; 37/196 ng/L) (P < .01). Cardiac troponin I exceeded 0.04 microg/L in 74%; cTnT exceeded 0.01 microg/L in 47% of athletes after exercise. NT-proBNP was not related to exercise-induced increases in cTnI or cTnT, but correlated with exercise time (r = 0.55, P < .001).
  
  
  CONCLUSIONS
  Increases in NT-proBNP can be found in a major part of obviously healthy athletes after prolonged strenuous exercise. The release of BNP during and after exercise may not result from myocardial damage but may have cytoprotective and growth-regulating effects. The different nature of exercise-induced increases in BNP and cardiac troponins has to be elucidated in the future.
authors.affiliation: Institute of Sports and Preventive Medicine, University of Saarland, Saarbrücken/Homburg, Germany. j.scharhag@mx.uni-saarland.de
authors.forename: Jürgen
authors.initials: J
authors.lastname: Scharhag
authors.forename: Markus
authors.initials: M
authors.lastname: Herrmann
authors.forename: Axel
authors.initials: A
authors.lastname: Urhausen
authors.forename: Michaela
authors.initials: M
authors.lastname: Haschke
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Herrmann
authors.forename: Wilfried
authors.initials: W
authors.lastname: Kindermann
mesh_terms: D000328:Adult; D003402:Creatine Kinase / Q000097:blood; D003404:Creatinine / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D012420:Running; D012907:Smoking; D013177:Sports; D019210:Troponin I / Q000097:blood*; D020107:Troponin T / Q000097:blood*
chemical_list: D010446:Peptide Fragments; D019210:Troponin I; D020107:Troponin T; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D003404:Creatinine; D003402:Creatine Kinase