ASSOCIATION OF ESTROGEN REPLACEMENT THERAPY WITH THE RISK OF OSTEOARTHRITIS OF THE HIP IN ELDERLY WHITE WOMEN

Objective: To determine whether postmenopausal estrogen replacement th erapy is associated with a reduced risk of radiographic findings of os teoarthritis (OA) of the hip. Design: Cross-sectional study. Subjects: White women (N=4366; age, greater than or equal to 65 years) who were participants in a cohort study of osteoporotic fractures. Measurement s and Methods: Radiographs of the pelvis that were obtained in all sub jects were assessed for radiographic features of OA of the hip on a su mmary scale of 0 (none) to 4 (severe OA). Postmenopausal estrogen use was assessed by interview. The association of current and past oral es trogen use with OA of the hip was analyzed by using logistic regressio n, adjusting for potential confounding variables (eg, indicators of os teoporosis and correlates of estrogen use). Results: Five hundred thir ty-nine women (12.3%) had mild or greater radiographic findings of OA of the hip in at least 1 hip, and 214 women (4.9%) had moderate to sev ere findings; 17% and 24% of the women were current and past users of oral estrogen, respectively. Women who were currently using oral estro gen had a significantly reduced risk of any OA of the hip (adjusted od ds ratio [OR], 0.62; 95% confidence interval [CI], 0.49-0.86) and mode rate to severe manifestation of disease (OR, 0.54; 95% CI, 0.33-0.88). Current users who had taken estrogen for 10 years or longer had a gre ater reduction in the risk of any OA of the hip (OR, 0.57; 95% CI, 0.4 0-0.82) compared with that of users for less than 10 years (OR, 0.75; 95% CI, 0.47-1.24). Current estrogen use for 10 years or longer was as sociated with a nonsignificant trend for a reduced risk of moderate to severe symptomatic disease (OR, 0.59, 95% CI, 0.28-1.29). Conclusion: Postmenopausal estrogen replacement therapy may protect against OA of the hip in elderly white women.