Fracture risk after bilateral oophorectomy in elderly women.
Elderly women with the lowest serum estrogen levels are at the greatest risk of bone loss and fractures, but it is controversial whether the ovaries contribute to estrogen production after menopause, and therefore, whether bilateral oophorectomy in postmenopausal women might have adverse skeletal effects. To address this potential problem, we estimated long-term fracture risk among 340 postmenopausal Olmsted County, MN, women who underwent bilateral oophorectomy for a benign ovarian condition in 1950-1987. In over 5632 person-years of follow-up (median, 16 years per subject), 194 women experienced 516 fractures (72% from moderate trauma). Compared with expected rates, there was a significant increase in the risk of any osteoporotic fracture (moderate trauma fractures of the hip, spine, or distal forearm; standardized incidence ratio [SIR], 1.54; 95% CI, 1.29-1.82) but almost as large an increase in fractures at other sites (SIR, 1.35; 95% CI, 1.13-1.59). In multivariate analyses, the independent predictors of overall fracture risk were age, anticonvulsant or anticoagulant use for > or = 6 months, and a history of alcoholism or prior osteoporotic fracture; obesity was protective. Estrogen replacement therapy was associated with a 10% reduction in overall fracture risk (hazard ratio [HR], 0.90; 95% CI, 0.64-1.28) and a 20% reduction in osteoporotic fractures (HR, 0.80; 95% CI, 0.52-1.23), but neither was statistically significant. The increase in fracture risk among women who underwent bilateral oophorectomy after natural menopause is consistent with the hypothesis that androgens produced by the postmenopausal ovary are important for endogenous estrogen production that protects against fractures.
Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
L Joseph
LJ
Melton
Sundeep
S
Khosla
George D
GD
Malkasian
Sara J
SJ
Achenbach
Ann L
AL
Oberg
B Lawrence
BL
Riggs
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006620:Hip Fractures / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D010052:Ovariectomy; D016103:Spinal Fractures / Q000150:complications / Q000453:epidemiology*