Sex differences in the acquisition of total bone mineral mass peak assessed through dual-energy X-ray absorptiometry.

Dual energy X-ray absorptiometry evaluation of total body bone mineral content (TBBM), total bone mineral density (TBMD), and regional bone mineral content (BMC) (head, trunk, arms, and legs) was carried out in order to assess sex differences of bone in 120 women and 121 men aged 15-29 years. Subjects from both sexes were divided into 5-year groups (15 through 19, 20 through 24, and 25 through 29 years old, respectively). Significantly higher values for TBBM, TBMD, and regional BMC were observed in males compared with females in the 20 to 24 and 25 to 29-year-old groups (P less than 0.001), but not in the group aged 15-19. After adjusting TBBM for lean body mass (LBM), we observed significantly lower values of TBBM/LBM in the males compared with females in all the age groups. A positive and significant correlation was observed between TBBM and age in the males of all the groups (r = 0.624, P less than 0.001), but not in the females. These data suggest that total bone mass peak acquisition takes place earlier in women than in men, leading to more reduced bone mass value, which in turn may be an osteoporosis predisposing factor.