Sex differences in bone mass acquisition during growth

Risk of osteoporosis in later life may be determined during adolescence and young adulthood. The present study used longitudinal data to examine the a ccumulation of bone mineral content (BMC) and bone mineral density (BMD) in Caucasian subjects ages 6-36 yr. Growth in BMC and BMD (measured by dual X -ray absorptiometry; Lunar, Madison, WI) of 94 males and 92 females was mon itored for a mean period of 4.29 yr. The main findings were that there were no sex differences in BMC or BMD during the prepubertal stage; however, fe males had significantly higher BMD of the pelvis and BMC and BMD of the spi ne during puberty, and postpubertal males generally had significantly highe r BMC and BMD than their female counterparts. In addition, the longitudinal rate of bone accumulation in both sexes increased rapidly during childhood and adolescence and was nearly complete at the end of puberty. Finally, pe ak BMC and BMD was achieved between the ages of 20 and 25 and occurred earl ier in females than in males. The rates of growth and timing of peak bone m ass as reported here define the crucial period during which intervention pr otocols should be developed for maximizing skeletal mass to prevent the dev elopment of osteoporosis.