Primary osteoporosis in men: role of sex steroid deficiency.

This presentation explores the role of estrogen deficiency in the causation of age-related bone loss in both sexes. Over life, women experience 2 phases of bone loss--an early, rapid postmenopausal phase that classically has been attributed to estrogen deficiency and a subsequent slow phase that previously has been attributed to aging changes. Men have only the slow continuous phase of bone loss. The hypothesis is developed here that most of the slow late phase in aging women and much of the slow continuous phase in aging men both are due to estrogen deficiency.