Estrogens, the be-all and end-all of male hypogonadal bone loss?

Excerpt

Gender is one of the strongest predictors of osteoporotic fracture risk, second only to ageing. A recent systematic review of worldwide epidemiology revealed that hip fracture incidence is about twofold lower in men compared to women, despite greater than tenfold variation between geographic regions [1]. This lower fracture incidence occurs despite persisting underdiagnosis and undertreatment of osteoporosis in men, which probably explains why hip fracture incidence may be decreasing in women but not men [2‐5]. It is well known that men generally have a more robust body composition; even after correction for an average 10 % greater height and bone length, men at the age of peak bone mass have 25 % greater bone mineral content [6], almost 50 % greater muscle mass and power and half the fat mass of women [7]. Conversely, late-onset male hypogonadism increases the risk of bone loss, muscle atrophy and fat accumulation [3, 8]. Understanding the underlying mechanisms involved in this gender dimorphism in body composition may thus identify additional therapeutic targets not only for osteoporosis, but also for sarcopenia and obesity. …