Osteoporosis is characterized by bone loss with microarchitectural deterioration, reduced bone strength, and increased risk of fracture (Kanis et al., J Bone Miner Res 9:1137–41, 1994; NIH Consensus Development Panel on Osteoporosis Prevention, South Med J 94:569–73, 2001). It is, in part, a disorder of the aging skeleton and, thus, as the world population ages, it is inevitable that the incidence of this disease will also increase. For example, in the USA during the first quarter of this century, the population greater than 50 years old will increase by 60 % (Day, Population projections of the USA by age, sex, race, and hispanic origin: 1995 to 2050. US Bureau of the Census, Current Population Reports, US Government Printing Office, Washington, DC, P25-1130, 1996; Cummings and Melton, Lancet 359:1761–7, 2002). With that increase in the older population will come a greater incidence of osteoporosis. This disease has traditionally been considered to be a disease of postmenopausal women but men now constitute nearly 1/4 of all osteoporotic patients (Burge et al., J Bone Miner Res 22(3):465–75, 2007; Center et al., JAMA 297:387–94, 2007). Hip fracture, which accounts for at least 1/3 of all fractures in men (Gullberg et al., Osteoporos Int 7:407–13, 1997), is associated with a threefold higher mortality rate in men than in women (Center et al., Lancet 353:878–82, 1999). Data from Trombetti et al. (Osteoporos Int. 13:731–7, 2002) show that more years of life are lost in men than in women after a hip fracture. This may be due, at least in part, to the impression that men are typically older when they sustain a hip fracture and are, therefore, more likely to suffer from serious comorbid events when they fracture. Data from the classic study of Johnell and Kanis (Osteoporos Int 17:1726–33, 2006), however, indicates that worldwide, the peak number of hip fractures occurs at a similar age for men and women, between the ages of 75 and 79.