Gender Differences in Skin Aging and the Changing Profile of the Sex Hormones with Age

Abstract

ABSTRACTThe sex steroids modulate skin structure and function, but their serum concentration profiles differ in aging men and women. Dehydroepiandrosterone and its sulfate form decline dramatically with age, with consistently lower serum concentrations in women. Dehydroepiandrosterone is the predominant source of both androgen and estrogen synthesis following menopause. Supplementation has been shown to increase skin thickness, hydration and sebum production. Serum concentrations of androgens decline slowly with age in men, yet remain higher than in postmenopausal women. Wound healing, reportedly depressed by androgens, is compromised to a greater degree in aging men. Estradiol levels are unaffected by age in men, but in women, postmenopausal estrogen deficiency results in thinner, drier skin with a lower collagen content and reduced elasticity. Local synthesis of the sex steroids affects the eccrine sweat glands and hair follicles. Thermoregulation by sweating appears to be compromised with age in both sexes. Senile sebaceous gland hyperplasia, whereby the sebaceous gland compensates for the reduction of its lipogenesis, is more prominent and occurs earlier in females. Dihydrotestosterone miniaturizes and reduces the number of anagen hair follicles in genetically susceptible men, leading to male-pattern baldness (androgenetic alopecia). Its impact is limited in women because their scalp hair follicles express lower levels of 5a-reductase and androgen receptor and higher levels of aromatase. Hence circulating sex hormones as well as the expression of key steroidogenic enzymes and receptors within the skin itself influence certain gender differences in aging skin.