title: Nephrolithiasis and Risk of Incident Bone Fracture.
abstract: OBJECTIVE
  Higher urine calcium is a common feature of calcium nephrolithiasis and may be associated with lower bone mineral density in individuals with kidney stones. However previous population based studies of kidney stones and the risk of bone fracture demonstrate conflicting results. We examined independent associations between a history of kidney stones and incident fracture.
  
  
  METHODS
  We performed prospective studies using data from the Nurses' Health Study of 107,001 women with 32 years of followup and the Health Professionals Follow-up Study of 50,982 men with 26 years of followup. We excluded premenopausal women, men younger than 45 years and individuals who reported osteoporosis at baseline. Study outcomes were incident wrist (distal radius) or incident hip (proximal femur) fracture due to low or moderate trauma. Cox proportional hazards regression was used to adjust for multiple factors, including age, race, body mass index, thiazide use, supplemental calcium and dietary intakes.
  
  
  RESULTS
  There were 4,940 wrist and 2,391 hip fractures in women, and 862 wrist and 747 hip fractures in men. All fractures were incident. The multivariable adjusted relative risk of incident wrist fracture in participants with a history of kidney stones compared to participants without kidney stones was 1.18 (95% CI 1.04-1.34) in women and 1.21 (95% CI 1.00-1.47) in men. The pooled multivariable adjusted relative risk of wrist fracture was 1.20 (95% CI 1.08-1.33). The multivariable adjusted relative risk of incident hip fracture in participants with kidney stones was 0.96 (95% CI 0.80-1.14) in women and 0.92 (95% CI 0.74-1.14) in men. The pooled multivariable adjusted relative risk of hip fracture was 0.94 (95% CI 0.82-1.08).
  
  
  CONCLUSIONS
  Nephrolithiasis is associated with a significantly higher risk of incident wrist but not hip fracture in women and men.
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts; Division of Nephrology and Transplantation, Maine Medical Center, Portland, Maine. Electronic address: entaylor@partners.org.
authors.forename: Eric N
authors.initials: EN
authors.lastname: Taylor
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Diane
authors.initials: D
authors.lastname: Feskanich
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts; Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts; Department of Epidemiology, Harvard T.H. Chan School of Public Health, Portland, Maine.
authors.forename: Julie M
authors.initials: JM
authors.lastname: Paik
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts; Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts; Department of Epidemiology, Harvard T.H. Chan School of Public Health, Portland, Maine.
authors.forename: Gary C
authors.initials: GC
authors.lastname: Curhan
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D050723:Fractures, Bone / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D007669:Kidney Calculi / Q000150:complications* / Q000453:epidemiology; D008875:Middle Aged; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology
keywords: bone; fractures; hip; kidney calculi; osteoporosis; wrist