Increased risk of osteoporosis with hysterectomy: A longitudinal follow-up study using a national sample cohort

BACKGROUND: Premenopausal hysterectomy is associated with a decreased ovarian reserve, follicular atresia, and subsequently reduced long-term estrogen secretion. Therefore, women who undergo hysterectomy will experience greater gradual bone mineral loss than women with an intact uterus and have an increased risk of osteoporosis. OBJECTIVE: This study aimed to evaluate the association between hysterectomy without/with bilateral oophorectomy and the occurrence of osteoporosis using a national sample cohort from South Korea. STUDY DESIGN: Using the national cohort study from the Korean National Health Insurance Service, we extracted data for patients who had undergone hysterectomy (n=9082) and for a 1:4 matched control group (n=36,328) and then analyzed the occurrence of osteoporosis. The patients were matched according to age, sex, income, region of residence, and medical history. A Cox proportional hazards model was used to analyze the hazard ratios and 95% confidence intervals. Subgroup analyses were performed based on age and bilateral oophorectomy status. The age of the participants was defined as the age at the time of hysterectomy. RESULTS: The adjusted hazard ratio for osteoporosis was 1.45 (95% confidence interval, 1.37-1.53, P<.001) in the hysterectomy group. The adjusted hazard ratios for osteoporosis in the different age subgroups of this group were 1.84 (95% confidence interval, 1.61-2.10) for ages 40-44 years, 1.52 (95% confidence interval, 1.39-1.66) for ages 45-49 years, 1.44 (95% confidence interval, 1.28-1.62) for ages 50-54 years, 1.61 (95% confidence interval, 1.33-1.96, all P<.001) for ages 55-59 years, and 1.08 (95% confidence interval, 0.95-1.23, P=.223) for ages >= 60 years. The adjusted hazard ratios for osteoporosis according to hysterectomy/oophorectomy status were 1.43 (95% confidence interval, 1.34-1.51) in the hysterectomy without bilateral oophorectomy group and 1.57 (95% confidence interval, 1.37-1.79) in the hysterectomy with bilateral oophorectomy group. CONCLUSION: The occurrence of osteoporosis was increased in patients who had undergone hysterectomy compared with that in matched control subjects regardless of bilateral oophorectomy status.