title: Recreational physical activity and the risk of adult leukemia in Canada.
abstract: OBJECTIVE
  To examine the association between adult onset leukemia and recreational physical activity.
  
  
  METHODS
  We analysed data obtained from a population-based case-control study conducted in seven Canadian provinces. Risk estimates were generated by applying multivariate logistic regression methods to 653 incident histologically confirmed leukemia cases and 3,106 controls aged 20-74.
  
  
  RESULTS
  We observed a 25% risk reduction for adult leukemia associated with the highest category of vigorous physical activity (adjusted odds ratio (OR) = 0.75; 95% confidence interval [CI] = 0.57-0.99). This reduction was stronger among men (OR = 0.64; 95% CI = 0.41-0.95), than among women (OR = 0.82; 95% CI = 0.52-1.29). For women, reduced risk estimates were observed for all levels of vigorous activity; for men, reduced risk estimates were restricted to the highest category of vigorous activity High levels of vigorous activity were associated with some degree of risk reduction for each of the five histological subtypes except chronic myeloid leukemia. Risk reductions associated with high levels of vigorous activity were more pronounced with higher body mass index (BMI): BMI < 25 (OR 0.93; 95% CI = 0.61-1.40); BMI > 25 to <30 (OR 0.75; 95% CI = 0.40-1.21); BMI > or = 30 (OR = 0.50; 95% CI = 0.28-0.95).
  
  
  CONCLUSIONS
  Our study suggests that higher categories of vigorous physical activity may decrease the risk of adult leukemia.
authors.affiliation: Department of Public Health and Community Medicine, Faculty of Medicine, AlAzhar University, Cairo, Egypt. kasimyhr@yahoo.com
authors.forename: Khaled
authors.initials: K
authors.lastname: Kasim
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Johnson
authors.forename: Patrick
authors.initials: P
authors.lastname: Levallois
authors.forename: Belkacem
authors.initials: B
authors.lastname: Abdous
authors.forename: Pierre
authors.initials: P
authors.lastname: Auger
mesh_terms: D000328:Adult; D000368:Aged; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007938:Leukemia / Q000453:epidemiology* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D011998:Recreation / Q000502:physiology*; D012307:Risk Factors; D040242:Risk Reduction Behavior; D012923:Social Class; D055815:Young Adult