title: The association between oral contraceptive use, bone mineral density and fractures in women aged 50-80 years.
abstract: BACKGROUND
  The associations between oral contraceptive (OC) use, bone mineral density (BMD) and the risk of fractures remain controversial.
  
  
  METHODS
  A cross-sectional study of 491 women aged 50-80 years was performed. We assessed OC use and fractures by questionnaire, and BMD and vertebral deformity by dual-energy x-ray absorptiometry.
  
  
  RESULTS
  Ever use of OC was associated with significantly higher BMD at the total body (6%, p<.001) and spine (4%; p=.05) (but not hip) after adjustment for confounders. There was also a significant association between duration of OC use and total body and spine BMD. Use of OCs for 5-10 years was associated with reduced vertebral deformity (adjusted odds ratio 0.46, 95% confidence interval 0.22-0.94).
  
  
  CONCLUSIONS
  Oral contraceptive use and duration were associated with higher total body and spine BMD and a consistent reduction in vertebral deformities, although most associations did not reach significance.
authors.affiliation: Menzies Research Institute, University of Tasmania, Hobart, TAS 7001, Australia. Shuying.Wei@utas.edu.au
authors.forename: Shuying
authors.initials: S
authors.lastname: Wei
authors.forename: Alison
authors.initials: A
authors.lastname: Venn
authors.forename: Changhai
authors.initials: C
authors.lastname: Ding
authors.forename: Stella
authors.initials: S
authors.lastname: Foley
authors.forename: Laura
authors.initials: L
authors.lastname: Laslett
authors.forename: Graeme
authors.initials: G
authors.lastname: Jones
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D003277:Contraceptives, Oral, Combined / Q000009:adverse effects*; D003430:Cross-Sectional Studies; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology / Q000517:prevention & control; D006615:Hip; D006801:Humans; D008875:Middle Aged; D013131:Spine; D011795:Surveys and Questionnaires; D013648:Tasmania / Q000453:epidemiology
chemical_list: D003277:Contraceptives, Oral, Combined