title: Physical activity reduces breast cancer risk in African American women.
abstract: OBJECTIVE
  To examine the relationship between physical activity and breast cancer in African American women.
  
  
  METHODS
  A population-based case-control study was conducted with 199 women (97 cases and 102 controls) from the Washington, DC metro area. A physical activity questionnaire elicited responses on frequency of walking for exercise and vigorous physical activity (eg, running, aerobics) in the past year. Responses were used to calculate a metabolic equivalent (MET) score (MET-hours/week = hours/week vigorous activity x 7 + hours/week walking x 3). The MET score was categorized into low, medium, and high tertiles. Multivariate logistic regression examined the association between physical activity and breast cancer.
  
  
  RESULTS
  African American women who engaged in vigorous physical activity (> or = 2 hours/week in the past year) had a 64% reduced risk of breast cancer compared to those who did not participate in any vigorous activity (odds ratio, OR = .36; 95% confidence interval, CI = .17-.75). We also found a 64% reduced breast cancer risk in women with a high vs low tertile of total activity (OR = .36; 95% CI = .16-.79). For postmenopausal women, vigorous physical activity and total activity (high vs low tertile) also had an inverse relationship with breast cancer (P<.05).
  
  
  CONCLUSIONS
  Data regarding the association of physical activity and breast cancer have been equivocal and lacking for African American women. This study found that modest levels of physical activity reduced breast cancer risk in this group. Targeted efforts are needed to encourage more African American women to engage in physical activity.
authors.affiliation: Lombardi Comprehensive Cancer Center, Georgetown, University, Washington, DC 20057, USA. vls3@georgetown.edu
authors.forename: Vanessa B
authors.initials: VB
authors.lastname: Sheppard
authors.forename: Kepher
authors.initials: K
authors.lastname: Makambi
authors.forename: Teletia
authors.initials: T
authors.lastname: Taylor
authors.forename: Sherrie Flynt
authors.initials: SF
authors.lastname: Wallington
authors.forename: Jennifer
authors.initials: J
authors.lastname: Sween
authors.forename: Lucile
authors.initials: L
authors.lastname: Adams-Campbell
mesh_terms: D000328:Adult; D001741:Black or African American; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000208:ethnology; D016022:Case-Control Studies; D004219:District of Columbia / Q000453:epidemiology; D015444:Exercise; D005260:Female; D006801:Humans; D016015:Logistic Models; D055686:Metabolic Equivalent; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D017698:Postmenopause; D017697:Premenopause; D012307:Risk Factors; D011795:Surveys and Questionnaires; D016138:Walking