In the Mayo Clinic Cohort Study of Oophorectomy and Aging, women who had both ovaries removed before reaching natural menopause experienced a long-term increased risk of parkinsonism, cognitive impairment or dementia, and depressive and anxiety symptoms. Here, we discuss five possible mechanistic interpretations of the observed associations; first, the associations may be non-causal because they result from the confounding effect of genetic variants or of other risk factors; second, the associations may be mediated by an abrupt reduction in levels of circulating estrogen; third, the associations may be mediated by an abrupt reduction in levels of circulating progesterone or testosterone; fourth, the associations may be mediated by an increased release of gonadotropins by the pituitary gland; and fifth, genetic variants may modify the hormonal effects of bilateral oophorectomy through simple or more complex interactions. Results from other studies are cited as evidence for or against each possible mechanism. These putative causal mechanisms are probably intertwined, and their clarification is a research priority.
Prophylactic oophorectomy in premenopausal women and long-term health
Objective To review the data on long-term outcomes in women who underwent prophylactic bilateral oophorectomy, a common surgical procedure that has more than doubled in frequency since the 1960s. Study design Literature review of the published data on the consequences of prophylactic bilateral oophorectomy. Special emphasis was given to the Mayo Clinic Cohort Study of Oophorectomy and Aging. Main outcome measures Overall mortality, cardiovascular disease, cognitive impairment and dementia, parkinsonism, osteoporosis, psychological wellbeing and sexual function. Results There is a growing body of evidence suggesting that the premature loss of ovarian function caused by bilateral oophorectomy performed before natural menopause is associated with several negative outcomes. In particular, studies have revealed an increased risk of premature death, cardiovascular disease, cognitive impairment or dementia, parkinsonism, osteoporosis and bone fractures, decline in psychological wellbeing and decline in sexual function. The effects involve different organs (e.g. heart, bone, or brain), and different functions within organs (e.g. cognitive, motor, or emotional brain functions). Estrogen treatment may prevent some but not all of these negative outcomes. Conclusion The potential adverse effects of prophylactic bilateral oophorectomy on heart health, neurological health, bone health and quality of life should be carefully weighed against its potential benefits for cancer risk reduction in women at average risk of ovarian cancer.
Novel Use of Kaplan–Meier Methods to Explain Age and Gender Differences in Hypertension Control Rates
Despite 40 years of research demonstrating the efficacy of antihypertensive medications for lowering blood pressure and decreasing cardiovascular disease, hypertension control rates worldwide remain low. We explored here how both medication efficacy rates and patient/physician decision-making (discontinuation rates) affect overall hypertension control rates. To do this we introduced the use of Kaplan–Meier methodology to predict hypertension control rates separately within age strata. An important aspect of our analysis is the use of a “treatment intensity score,” including both the number of agent(s) and the percentage of maximal dose of agent(s). We investigated how blood pressure control rates vary with age, gender, and treatment intensity. Our analysis found that both efficacy and discontinuation rates at different treatment intensities vary with age and gender, so that for each increase in age by 1 decade, the log hazard of achieving controlled blood pressure at any given intensity decreases by 0.10 in men and 0.20 in women. Overall hypertension control rates ranged from 80.8% for persons age 15 to 39 years to only 42.1% for persons age ≥80 years. Our analysis more accurately represents achievable hypertension control rates, with differences by gender, than previous work, because we investigated the contributions of efficacy and treatment aggressiveness in the control of hypertension.
Increased risk of parkinsonism in women who underwent oophorectomy before menopause