An epidemiologic study of hip fracture in postmenopausal women.

In this case-control study of the epidemiology of hip fracture in post-menopausal women aged 45-74 years, cases of hip fracture and two control groups were selected from admissions to four general hospitals in Connecticut between September 1977 and May 1979. Fewer cases of hip fracture than controls had been exposed to estrogen replacement therapy, and among those who had been exposed, exposure time was shorter than that for controls. The cases had breastfed their children for shorter durations, and they more often had had both ovaries removed. Also, the cases were found to weigh less than the controls. The negative associations of hip fracture with estrogen replacement therapy, intact ovaries, and weight are consistent with the hypothesis that estrogens protect against hip fracture.