title: Changes to the cardiac biomarkers of non-elite athletes completing the 2009 London Marathon.
abstract: BACKGROUND
  Many studies have demonstrated a rise in troponin and brain natriuretic peptide (BNP) levels following prolonged and/or strenuous exercise. Only one study looked at athletes who collapse and this showed no difference in cardiac biomarkers between those who collapsed and those who completed without requiring medical attention. We set out to describe and quantify the changes in troponin and BNP in three groups of non-elite runners at the 2009 London marathon: those with and without known structural heart disease (SHD) and those who collapsed on completion.
  
  
  METHODS
  The first group (recruited group, RG) was recruited at the prerace exhibition. This group had two subsets, runners with SHD and without (non-SHD). A second group was recruited from those who collapsed (collapsed group, CG). Blood was taken for troponin I (TnI), troponin T (TnT), high sensitivity TnT (HSTnT) and BNP.
  
  
  RESULTS
  Cardiac biomarker levels increased in all groups following the marathon. No statistically significant difference was seen between the SHD and non-SHD subgroups. When comparing the RG and CG the number and degree of rise was greater in those who collapsed. A trend for the degree of rise of HSTnT was demonstrated.
  
  
  CONCLUSIONS
  We identified runners with troponin levels that, in other circumstances, would raise concern for myocardial necrosis. However absence of adverse clinical sequelae would suggest this rise is physiological. The cause and clinical significance of the increased HSTnT levels seen in those that collapsed is yet to be fully elucidated.
authors.affiliation: Department of Sports Medicine and Rehabilitation, Defence Medical Rehabilitation Centre, Headley Court, Surrey, UK.
authors.forename: Polly
authors.initials: P
authors.lastname: Baker
authors.affiliation: Department of Sports Medicine, Rheumatology and Rehabilitation, Royal National Orthopaedic Hospital, London, Stanmore, UK.
authors.forename: Sarah Louise
authors.initials: SL
authors.lastname: Davies
authors.affiliation: Institute of Sports, Exercise and Health, University College London, London, UK.
authors.forename: Joanne
authors.initials: J
authors.lastname: Larkin
authors.affiliation: Department of Anaesthesia and Intensive Care Medicine, Kings College London, London, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Moult
authors.affiliation: Department Clinical Biochemistry, Royal London Hospital, Barts and the London NHS Trust, London, UK.
authors.forename: Sally
authors.initials: S
authors.lastname: Benton
authors.affiliation: Department of Research, Defence Medical Rehabilitation Centre, Headley Court, Surrey, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Roberts
authors.affiliation: Department of Emergency Medicine and Research, Queen Marys University London, London, UK.
authors.forename: Timothy
authors.initials: T
authors.lastname: Harris
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D006331:Heart Diseases / Q000097:blood*; D006801:Humans; D008131:London; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology*; D012769:Shock / Q000097:blood*; D014336:Troponin / Q000097:blood*
chemical_list: D015415:Biomarkers; D014336:Troponin; D020097:Natriuretic Peptide, Brain
keywords: cardiac care; clinical assessment