title: Cardiovascular fitness in young males and risk of unprovoked venous thromboembolism in adulthood.
abstract: Whether high cardiovascular fitness is associated with reduced risk of venous thromboembolism (VTE) is unknown. The present study aims to determine whether high cardiovascular fitness reduces the risk of VTE.
  
  
  
  A Swedish cohort of male conscripts (n = 773,925) born in 1954-1970 with no history of previous VTE were followed from enlistment (1972-1990) until 2010. Data on cardiovascular fitness using a cycle ergonometric test (maximal aerobic workload in Watt [Wmax]) at conscription were linked with national hospital register data and the Multi-Generation Register. We identified all full-siblings and first-cousin pairs discordant for maximal aerobic workload. This co-relative design allows for adjustment for familial resemblance.
  
  
  
  In total, 3005 (0.39%) males were affected by VTE. Cardiovascular fitness estimated with Wmaxwas not associated with VTE risk when adjusted for body mass index (BMI). However, cardiovascular fitness estimated with Wmax/kg and adjusted for BMI was associated with reduced risk for VTE (Hazard ratio (HR) 0.81, 95% confidence interval (CI) 0.78-0.85 per standard deviation compared with mean Wmax/kg). The association was weaker over time and also when examining discordant first cousins and full-sibling pairs.
  
  
  
  These results suggest that there is a relationship between cardiovascular fitness and weight that is important for future VTE risk. Key messages Whether high cardiovascular fitness is associated with reduced risk of venous thromboembolism (VTE) is unknown. A Swedish cohort of male conscripts (n = 773,925) tested with a cycle ergometric test with no history of previous VTE were followed from enlistment (1972-1990) until 2010. Cardiovascular fitness estimated with Wmax/kg and adjusted for BMI was associated with reduced risk for VTE (HR 0.81, 95% CI 0.78-0.85). These results suggest that there is a relationship between cardiovascular fitness and weight that is important for future VTE risk.
authors.affiliation: a Center for Primary Health Care Research, Lund University , Malmö , Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Zöller
authors.affiliation: a Center for Primary Health Care Research, Lund University , Malmö , Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Ohlsson
authors.affiliation: a Center for Primary Health Care Research, Lund University , Malmö , Sweden.|b Stanford University School of Medicine, Stanford Prevention Research Center , Stanford , CA, USA.
authors.forename: Jan
authors.initials: J
authors.lastname: Sundquist
authors.affiliation: a Center for Primary Health Care Research, Lund University , Malmö , Sweden.
authors.forename: Kristina
authors.initials: K
authors.lastname: Sundquist
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D000072599:Cardiorespiratory Fitness / Q000502:physiology*; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology*; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D054556:Venous Thromboembolism / Q000453:epidemiology* / Q000517:prevention & control; D055815:Young Adult
keywords: Epidemiology; exercise; genetics; venous thromboembolism