title: [Physical activity and breast cancer risk in Mexican women].
abstract: OBJECTIVE
  To evaluate the effect of moderate physical activity (hours per week and METs hours per week) on the risk of breast cancer (BC) in Mexican women.
  
  
  METHODS
  This is the initial stage of a case control multicentric study based in the Federal District, Monterrey and Veracruz, Mexico, during 2004. Fifty eight cases paired to 58 control cases on quinquennium of age, and belonging to the health system were analyzed: three hospitals from the IMSS, three from ISSSTE and three from SS participated.
  
  
  RESULTS
  In postmenopausal women, there was a reduction of the risk in BC by every additional hour per week of moderate physical activity (RM= 0.91; IC95% 0.85-0.97); in premenopausal women, the reduction of the risk was not statistically significant (RM= 0.99; IC95% 0.94-1.05) (p= 0.048, effect modification).
  
  
  CONCLUSIONS
  Moderate physical activity reduces the risk of BC in postmenopausal Mexican women.
authors: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors: Sandra Patricia
authors: SP
authors: Ortiz-Rodríguez
authors: Gabriela
authors: G
authors: Torres-Mejía
authors: Fernando
authors: F
authors: Mainero-Ratchelous
authors: Angélica
authors: A
authors: Angeles-Llerenas
authors: Alma Ethelia
authors: AE
authors: López-Caudana
authors: Eduardo
authors: E
authors: Lazcano-Ponce
authors: Isabelle
authors: I
authors: Romieu
mesh_terms: D001943:Breast Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008800:Mexico; D008875:Middle Aged; D009043:Motor Activity; D012307:Risk Factors