Estradiol rates of change in relation to the final menstrual period in a population-based cohort of women

Abstract

Context/Objective: The aim was to characterize rates of change in serum estradiol (E2) levels across the menopausal transition and into early postmenopause. Setting/Participants: We studied the Michigan Bone Health and Metabolism Study cohort of 629 women with median age of 38 yr (interquartile range, 7) at the 1992-1993 baseline with annual assessment of E2 levels over the subsequent 15-yr period. Design/Main Outcome Measures: The purpose was to describe patterns of acceleration/deceleration in logE2 rates of change before and after the final menstrual period (FMP) using nonparametric and piecewise regression modeling. Results: Between -10 to -2 yr to the FMP, mean fitted serum E2 population values were relatively stable. The 95% confidence bands around the slight increase in E2 rate of change 5 yr prior to the FMP included the value of no change. The fitted population mean E2 value declined 67% from 64.5 pg/ml (SE = 3.6) to 21 pg/ml (SE = 1.2) in the 4 yr between -2 < FMP