title: Risk of recurrent ischaemic events after myocardial infarction in long-distance ski race participants.
abstract: OBJECTIVE
  To study whether a high level of physical activity prior to myocardial infarction (MI) also protects against recurrent MI (re-MI) or death.
  
  
  RESULTS
  A longitudinal study of a primary cohort consisting of 204,038 skiers with a proved substantially high level of physical activity in the world's largest long-distance ski race, Vasaloppet, and 499,543 non-skiers selected from the Swedish population. Individuals with severe diseases at baseline were excluded. In the nationwide clinical register, Swedeheart, we identified 7092 individuals with a first MI incident between 1989 and 2010. Of these, 1039 (0.5%) were skiers and 6053 (1.2%) were non-skiers. One hundred and sixty-three (15.7%) skiers and 1352 (22.3%) non-skiers suffered a re-MI or died during follow-up (median 4.44 years), corresponding to an incidence rate of 38.9 (95% confidence interval (CI) 33.2-45.4)/1000 person-years and 55.6 (95% CI 52.7-58.7)/1000 person-years, respectively. Severity of MI in both groups was the same. For skiers compared to non-skiers the unadjusted hazard ratio (HR) for re-MI was 0.66 (95% CI 0.52-0.82). For death or re-MI, HR was 0.70 (95% CI 0.59-0.82) with consistent results in subgroups based on race year, age, gender, education level, marital status. After adjustment for also smoking, diabetes, hypertension and cardiovascular medication, HR was 0.80 (95% CI 0.67-0.97).
  
  
  CONCLUSIONS
  This large cohort study supports the hypothesis that patients with MI and with prior physical activity and healthy lifestyle, as evidenced by their participation in a long-distance ski race, have a lower risk of subsequent re-MI or death.
authors.affiliation: Department of Medical Sciences, Uppsala University, Sweden Department of Internal Medicine, Mora Hospital, Sweden ulf.hallmarker@ltdalarna.se.
authors.forename: Ulf
authors.initials: U
authors.lastname: Hållmarker
authors.affiliation: Department of Medical Sciences, Uppsala University, Sweden Department of Surgical Sciences, Uppsala University, Sweden.
authors.forename: Karl
authors.initials: K
authors.lastname: Michaëlsson
authors.affiliation: Department of Medical Sciences, Uppsala University, Sweden School of Health and Social Studies, Dalarna University, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Ärnlöv
authors.affiliation: Department of Women's and Children's Health, Uppsala University, Sweden.
authors.forename: Dan
authors.initials: D
authors.lastname: Hellberg
authors.affiliation: Department of Medical Sciences, Uppsala University, Sweden Uppsala Clinical Research Center, Sweden.
authors.forename: Bo
authors.initials: B
authors.lastname: Lagerqvist
authors.affiliation: Uppsala Clinical Research Center, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Lindbäck
authors.affiliation: Department of Medical Sciences, Uppsala University, Sweden Uppsala Clinical Research Center, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: James
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D006304:Health Status; D006801:Humans; D015994:Incidence; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000517:prevention & control*; D010807:Physical Endurance; D016016:Proportional Hazards Models; D065840:Protective Factors; D012008:Recurrence; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D040242:Risk Reduction Behavior; D055502:Secondary Prevention; D012865:Skiing; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors
keywords: Recurrent myocardial infarction; Sweden; cardiovascular disease; cross-country skiing; epidemiology; lifestyle; physical activity; prevention; public health; sports medicine