title: Cardiac troponin increases among runners in the Boston Marathon.
abstract: OBJECTIVE
  Studies indicate that running a marathon can be associated with increases in serum cardiac troponin levels. The clinical significance of such increases remains unclear. We seek to determine the prevalence of troponin increases and epidemiologic factors associated with these increases in a large and heterogeneous cohort of marathon finishers.
  
  
  METHODS
  Entrants in the 2002 Boston Marathon were recruited 1 to 2 days before the race. Data collected included demographic and training history, symptoms experienced during the run, and postrace troponin T and I levels. Simple descriptive statistics were performed to describe the prevalence of troponin increases and runner characteristics.
  
  
  RESULTS
  Of 766 runners enrolled, 482 had blood analyzed at the finish line. In all, 34% were women, 20% were younger than 30 years, and 92% had run at least 1 previous marathon. Most runners (68%) had some degree of postrace troponin increase (troponin T > or = 0.01 ng/mL or troponin I > or = 0.1 ng/mL), and 55 (11%) had significant increases (troponin T > or = 0.075 ng/mL or troponin I > or = 0.5 ng/mL). Running inexperience (< 5 previous marathons) and young age (< 30 years) were associated with elevated troponins. These correlates were robust throughout a wide range of troponin thresholds considered. Health factors, family history, training, race performance, and symptoms were not associated with increases.
  
  
  CONCLUSIONS
  Troponin increases were relatively common among marathon finishers and can reach levels typically diagnostic for acute myocardial infarction. Less marathon experience and younger age appeared to be associated with troponin increases, whereas race duration and the presence of traditional cardiovascular risk factors were not. Further work is needed to determine the clinical significance of these findings.
authors.affiliation: Department of Cardiology, Children's Hospital Boston and Harvard Medical School, Boston, MA 02115, USA. elizabeth.fortescue@cardio.chboston.org
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Fortescue
authors.forename: Andrew Y
authors.initials: AY
authors.lastname: Shin
authors.forename: David S
authors.initials: DS
authors.lastname: Greenes
authors.forename: Rebekah C
authors.initials: RC
authors.lastname: Mannix
authors.forename: Suneet
authors.initials: S
authors.lastname: Agarwal
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Feldman
authors.forename: Manish I
authors.initials: MI
authors.lastname: Shah
authors.forename: Nader
authors.initials: N
authors.lastname: Rifai
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Landzberg
authors.forename: Jane W
authors.initials: JW
authors.lastname: Newburger
authors.forename: Christopher S D
authors.initials: CS
authors.lastname: Almond
mesh_terms: D000328:Adult; D000886:Anthropometry; D001900:Boston; D005260:Female; D006801:Humans; D008297:Male; D012420:Running; D014336:Troponin / Q000097:blood*
chemical_list: D014336:Troponin