title: Bone mineral density changes over two years in first-time users of depot medroxyprogesterone acetate.
abstract: OBJECTIVE
  To compare longitudinal changes in bone mineral density (BMD) among first-time depot medroxyprogesterone acetate (DMPA) users to women using no hormonal contraception, and evaluate user characteristics associated with that BMD change.
  
  
  METHODS
  Prospective longitudinal study.
  
  
  METHODS
  Healthy volunteers in an academic research environment.
  
  
  METHODS
  Women, aged 18 to 35, choosing DMPA for contraception (n = 178) and women using no hormonal contraception (n = 145).
  
  
  METHODS
  Hip and spine BMD measured, at three-month intervals for 24 months, by dual energy x-ray absorptiometry.
  
  
  RESULTS
  Mean hip BMD declined 2.8% (SE = 0.034) 12 months following DMPA initiation and 5.8% (SE = 0.096) after 24 months. Mean spine (L1-L3) BMD declined 3.5% (SE = 0.022) and 5.7% (SE = 0.034), respectively, after one and two years of DMPA use. Mean hip and spine BMD of control participants changed less than 0.9% over the same period. Among DMPA users, body mass index (BMI) change was inversely associated with BMD change at the hip, but not at the spine. Calcium intake, physical activity, and smoking did not influence BMD change in either group.
  
  
  CONCLUSIONS
  Hip and spine BMD declined after one DMPA injection and this decline continued with each subsequent injection for 24 months. With the exception of increasing BMI among DMPA users, no user characteristics offered protection against DMPA-related BMD loss.
authors.affiliation: College of Nursing, University of Iowa, Iowa City, Iowa 52242, USA. mary-clark@uiowa.edu
authors.forename: M Kathleen
authors.initials: MK
authors.lastname: Clark
authors.forename: Maryfran R
authors.initials: MR
authors.lastname: Sowers
authors.forename: Sara
authors.initials: S
authors.lastname: Nichols
authors.forename: Barcey
authors.initials: B
authors.lastname: Levy
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D015992:Body Mass Index; D015519:Bone Density / Q000187:drug effects*; D015331:Cohort Studies; D003271:Contraceptive Agents, Female / Q000008:administration & dosage* / Q000009:adverse effects*; D003692:Delayed-Action Preparations; D005260:Female; D006621:Hip Joint / Q000378:metabolism; D006801:Humans; D008137:Longitudinal Studies; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage* / Q000009:adverse effects*; D011446:Prospective Studies; D013131:Spine / Q000378:metabolism
chemical_list: D003271:Contraceptive Agents, Female; D003692:Delayed-Action Preparations; D017258:Medroxyprogesterone Acetate