title: Gonadotropin-releasing hormone agonists and fracture risk: a claims-based cohort study of men with nonmetastatic prostate cancer.
abstract: OBJECTIVE
  Gonadotropin-releasing hormone (GnRH) agonists decrease bone mineral density, a surrogate for fracture risk, in men with prostate cancer. We conducted a claims-based cohort study to characterize the relationship between GnRH agonists and risk for clinical fractures in men with nonmetastatic prostate cancer.
  
  
  METHODS
  Using medical claims data from a 5% national random sample of Medicare beneficiaries, we identified a study group of men with nonmetastatic prostate cancer who initiated GnRH agonist treatment from 1992 to 1994 (n = 3,887). A comparison group of men with nonmetastatic prostate cancer who did not receive GnRH agonist treatment during the study period (n = 7,774) was matched for age, race, geographic location, and comorbidity. Clinical fractures were identified using inpatient, outpatient, and physician claims during 7 years of follow-up.
  
  
  RESULTS
  In men with nonmetastatic prostate cancer, GnRH agonists significantly increased fracture risk. The rate of any clinical fracture was 7.88 per 100 person-years at risk in men receiving a GnRH agonist compared with 6.51 per 100 person-years in matched controls (relative risk, 1.21; 95% CI, 1.14 to 1.29; P < .001). Rates of vertebral fractures (relative risk, 1.45; 95% CI, 1.19 to 1.75; P < .001) and hip/femur fractures (relative risk, 1.30; 95% CI, 1.10 to 1.53; P = .002) were also significantly higher in men who received a GnRH agonist. GnRH agonist treatment independently predicted fracture risk in multivariate analyses. Longer duration of treatment conferred greater fracture risk.
  
  
  CONCLUSIONS
  GnRH agonists significantly increase risk for any clinical fracture, hip fractures, and vertebral fractures in men with prostate cancer.
authors.affiliation: Massachusetts General Hospital, Boston, 02114, USA. smith.matthew@mgh.harvard.edu
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Smith
authors.forename: Won Chan
authors.initials: WC
authors.lastname: Lee
authors.forename: Jane
authors.initials: J
authors.lastname: Brandman
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.forename: Marc
authors.initials: M
authors.lastname: Botteman
authors.forename: Chris L
authors.initials: CL
authors.lastname: Pashos
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000187:drug effects*; D015331:Cohort Studies; D050723:Fractures, Bone / Q000453:epidemiology*; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists* / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D007345:Insurance Claim Review; D008297:Male; D010024:Osteoporosis / Q000139:chemically induced; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
chemical_list: D007987:Gonadotropin-Releasing Hormone