Cognitive function across the life course and the menopausal transition in a British birth cohort

Abstract

Despite biological plausibility, relationships between menopause and cognitive function are inconsistent. We investigated whether menopause status and menopause age were associated with general cognitive ability, verbal memory, and visual search speed and concentration in a large cohort of women while considering vasomotor and psychological symptoms, previous childhood and adult measures of cognitive function, lifetime socioeconomic circumstances, educational attainment, lifestyle factors, and chronic diseases. A nationally representative British cohort of 1261 women born in March 1946 and all aged 53 years at cognitive testing, with prospective information on previous cognitive function, menopausal characteristics, and potential confounders. There was only weak evidence of the effect of natural menopause on cognitive function and no evidence of any effects of hormone therapy use or hysterectomy status. There was a trend across the phases of the natural menopausal transition (pre-, peri-, and postmenopause) for the National Adult Reading Test (P = 0.005) and search speed and concentration (P = 0.042), with postmenopausal women having the lowest cognitive function, but there was no trend in verbal memory. Variation in vasomotor and psychological symptoms did not explain these trends. In postmenopausal women, there was a positive trend across menopause age for verbal memory (P = 0.004) and a weak positive trend for the National Adult Reading Test (P = 0.052), with women who reached menopause later having higher cognitive function. Previous cognitive function generally explained the associations, which were further weakened by adjusting for socioeconomic and educational confounders. One exception was the association between the natural menopause transition and search speed and concentration, which remained after adjustment for these factors. Menopause adversely affects cognitive function, but this effect may be largely explained by premenopausal cognitive function. These findings suggest that common environmental or genetic factors, operating through long-term or lifelong hormonal mechanisms, may influence the timing of natural menopause and lifetime cognitive function.