The gentleman and the lady with Osteoporosis

Abstract

The purpose of this review is to analyze some differencies in epidemiology, pathophysiology, and clinical features of osteoporosis in men and women. The prevalence of osteoporosis in white men is estimated around 7%. However, osteoporosis is not seen as a problem in men, and most fractures men do not receive proper treatment. The rate of wrist fractures increases dramatically in women during the early postmenopausal years, while it remains low among men of all ages. Also, vertebral fractures increase rapidly after the menopause, and they are more frequent in women than in men, as are hip fractures. Vertebral fractures are common among elderly men; however, incidence rates fall with age, while the contrary occurs in women: rates in males older than 65 years are half the rates in women of the same age range. The LAVOS study showed a 17% global prevalence of vertebral fractures among Argentinean women older than 50 years; there are no comparable studies in men. In 7 studies of hip fracture incidence in Argentina, the mean annual rate was 488/100,000 inhabitants (SD±86), and the average female/male ratio was 2.56. The difference could be explained by biomechanical factors, and by different quality of bone in both sexes. With aging, trabecular bone shows more fenestration in women, and more thinning in men, who tend to have an decrease in bone formation rather than an increase in bone resorption. Men appear to have a better preservation of trabecular number, which could help explain the lower fracture incidence they present throughout life. The impact of the cessation of ovarian function on bone is well known. In men, both bioavailable testosterone and estradiol decline with normal aging, and bone loss correlates better with falls in free estradiol. Among elderly males, the rate of fracture increases as serum gonadal steroid levels fall. Thus, estradiol seems to be a main determinant of bone mass in both sexes. Risk factors for osteoporosis (including vitamin D deficiency) are similar in men and women. Present-day diagnostic criteria and treatment strategies are briefly presented.