Health outcomes following oophorectomy during benign hysterectomy in those who are in postmenopausal ages: a population-based study

BACKGROUND: While postmenopausal bilateral salpingo-oophorectomy during benign hysterectomy may reduce the likelihood of adnexal surgeries and the risk of ovarian cancer, more evidence is needed to evaluate the health impacts of this procedure. Given the role of residual hormone secretion by postmenopausal ovaries, we hypothesize that performing bilateral oophorectomy at the time of benign hysterectomy among postmenopausal people may impact the risk of cardiovascular diseases and accelerated bone loss, both of which can significantly affect the quality of life in aging women. OBJECTIVE: To evaluate cardiovascular and bone health outcomes in people aged 50 to 60 years who did and did not undergo bilateral salpingo-oophorectomy at the time of hysterectomy. STUDY DESIGN: Retrospective population-based study using linked administrative data from British Columbia, Canada between Janaury 1, 1996 and September 30, 2019 with follow-up until December 31st, 2020. Multivariate Cox Proportional hazards models were used, adjusting for age at surgery, year of surgery, systemic menopausal hormone therapy use after surgery, and presence of baseline cardiovascular or bone health conditions up to 5 years before surgery, indication, and route of surgery. Subgroup analyses were conducted by stratifying individuals into early postmenopausal ages (50-55 years) and later postmenopausal ages (56-60 years). Statistical analyses were performed in R software version 4.0.3, STATA 16.1 (StataCorp) and SAS 9.4 (SAS Institute, Cary, NC) software. RESULTS: Of the 18,676 patients who remained in the study after applying exclusion criteria, 46.3% (n=8653) had hysterectomy with bilateral salpingo-oophorectomy. We observed no statistically significant difference in cardiovascular composite event outcomes (congestive heart failure, myocardial infarction, cerebral vascular disease, and ischemic heart disease) and cardiovascular procedure outcomes (percutaneous coronary intervention, coronary artery bypass, or cardiac catheterization) across the groups. Nevertheless, patients who had concurrent oophorectomy were at a higher risk of being diagnosed with conditions that predispose them to cardiovascular diseases, such as diabetes and hypertension (adjusted hazard ratio, 1.16; 95% confidence interval, 1.08-1.25), and were also more likely to be prescribed cardiovascular medications (adjusted hazard ratio, 1.07; 95% confidence interval, 1.00-1.15). No significant differences were observed between the groups in terms of osteoporosis, fractures, or initiating osteoporosis medication after adjustment for covariates. The likelihood of starting menopausal hormone therapy after surgery was significantly higher for those who had hysterectomy with bilateral oophorectomy compared to hysterectomy with ovarian conservation (adjusted hazard ratio, 2.04; 95% confidence interval, 1.92-2.17). Results mostly remained consistent in the subgroup analyses, especially among participants aged 50 to 55 years. CONCLUSION: Our study revealed that although removing postmenopausal ovaries at the time of benign hysterectomy is not associated with an increased risk of adverse cardiovascular or bone health-related outcomes, it might be associated with an increased risk of cardiovascular disease predisposing conditions and the need for prescribing medications for those conditions and hormone therapy. This could indicate a benefit for retaining postmenopausal ovaries at the time of benign hysterectomy among postmenopausal patients. Given the existing variation in practice, pragmatic trials are recommended to inform the decisions on performing oophorectomy in an average-risk population.