Normal Volumetric Bone Mineral Density and Bone Turnover in Young Men with Histories of Constitutional Delay of Puberty

It has been suggested that an appropriate timing of puberty is necessary for normal bone mineral density (BMD) acquisition, which may not be achievable in children with constitutional delay of puberty (CDP). To assess the effect of pubertal delay on BMD, we measured areal BMD (aBMD) at lumbar spine, by dual-energy x-ray absorptiometry (DEXA), in a group of patients with CDP (n=21; mean age, 21.8+/-1.7 yr) at final height and in healthy controls (n=12; mean age, 19.3+/-1.3 yr). A subset of seven patients (group a) were untreated, whereas six subjects (group b) had received im testosterone depot (100 mg/month, for 6-12 months) and 8 boys (group c) oral oxandrolone (1.25-2.5 mg/daily, for 6-28 months) for their pubertal delay. Volumetric BMD (vBMD) was calculated from DEXA measurements. aBMD was reduced in patients with CDP (1.101+/-0.134 g/cm2), in comparison with controls (1.222+/-0.091 g/cm2; P < 0.009); no significant differences were found among the groups (group a, 1.089+/-0.133 g/cm2; group b, 1.111+/-0.118 g/cm2; group c, 1.103+/-0.160 g/cm2). vBMD was not significantly different in patients with CDP (0.327+/-0.021 g/cm3) and in controls (0.337+/-0.017 g/cm3; P= not significant); no significant differences were found among the groups (group a, 0.326+/-0.016 g/cm3; group b, 0.332+/-0.022 g/cm3; group c, 0.330+/-0.021 g/cm3). No differences were found in mineral metabolism and in bone markers between patients and controls; patients did not report an increased fracture rate, compared with controls. Our data indicate that: 1) men with CDP have normal vBMD; 2) the reduced aBMD may be the result of uncritical use of DEXA measurements in subjects with altered growth pattern; and 3) androgen administration during pubertal years did not improve BMD in young men with a history of CDP.