Steroid Hormones and Aging: Free Testosterone, Testosterone and Androstenedione in Normal Females Aged 20-87 Years

In order to investigate their pattern of change with age, free testosterone concentration (FTC), testosterone (T), androstenedione (A) and testosterone-estrogen­binding globulin (TeBG) were assayed in normal female volunteers aged 20-87. FTC was determined by equilibrium dialysis, serum A and T by radioimmunoassay and TeBG by saturation analysis. Polynomial regression and a method of smoothing grouped medians were used to obtain regression curves for each hormone by age. A declined progressively from the twenties, leveling off after age 60; FTC and T decreased slightly until age 60, tending to rise thereafter. Although TeBG showed no linear change with age, it correlated negatively with FTC in postmenopausal women. Possible relationships of androgens to female physiology and behavior, especially in the aged, are discussed