Bone mineral status in prepubertal children with constitutional delay of growth and puberty

Abstract

Objective: We wished to clarify whether the osteopenia reported in adult men with a history of constitutional delay of growth and puberty (CDGP) could be due to the delayed puberty or an independent predisposition to osteoporosis in this condition. Design: Short prepubertal children with CDGP and children with familial short stature (FSS) were matched for height and other auxological variables. The FSS children served as a control group. Methods: We measured spinal (L1-L4) bone mineral content (BMC) and bone mineral density (BMD) by dual energy X-ray absorptiometry (Hologic QDR 1000/w) in 56 children aged 5-11 years. All children had height below the 10th percentile for chronological age (CA), and bone age (BA) less than 10 years, 29 of them with clinical diagnosis of possible CDGP and 27 of them with FSS. The BMD standard deviation scores (SDS) relative to the values for normal height children were obtained. Results: The mean (Ϯ S.D.) spinal BMD was significantly lower in the children with CDGP than in the FSS group (0.534 Ϯ 0.059 vs 0.623 Ϯ 0.060 g/cm 2 , P < 0.001). Both groups had negative mean lumbar BMD SDS, but in the CDGP group it was significantly lower than in the FSS group as well when the SDS was based on the CA (¹1.41 Ϯ 0.61 vs ¹0.38 Ϯ 0.51, P < 0.001) and when it was related to BA (¹0.78 Ϯ 0.64 vs ¹0.17 Ϯ 0.52, P < 0.01). BMC was significantly lower in the CDGP than in the FSS group, when multiple regression analysis was performed by using scanned bone area, body weight and height, sex and BA as independent variables (P ¼ 0.0005). Conclusion:The finding of decreased mineralization in prepubertal children with CDGP before the age of puberty suggests that they may have an inherent predisposition to osteopenia.

Delayed puberty and peak bone mass

“…This study did not provide an estimate of bone mineral apparent (volumetric) density (BMAD), as it can be calculated by dividing BMC by a volume derived from the projected area and height of L1-L4. However, multiple regression analysis supports the notion that L1-L4 BMC remains lower even after adjustment for the projected bone area (12). The present study cannot explain what might be the nature of the apparent deficit in the amount of bone within the bone.…”

“…In the current issue of this Journal, Moreira-Andrés and her colleagues (12) provide data in favor of the second model described above, so that in CDGP subjects the low bone mass could be already present before the onset of puberty. In this study BMC, bone area, and aBMD of L1-L4 were measured by DXA in 56 children (28 boys and 28 girls) aged 5-11 years, whose height was below the 10th percentile for chronological age (12).…”

“…In this study BMC, bone area, and aBMD of L1-L4 were measured by DXA in 56 children (28 boys and 28 girls) aged 5-11 years, whose height was below the 10th percentile for chronological age (12). In about half of these children the diagnosis of 'possible CDGP' was made based on a bone age of at least 1.75 years below their chronological age, a family history of CDGP, or midparental height above the 25th percentile.…”

Ascertainment and Treatment of Delayed Puberty

“…In addition, not all patients reach a height appropriate for their family context [27, 28, 29, 30, 31]. Furthermore, body proportions can be modified (adults who do not receive treatment for CDGP have relatively short spinal length compared with leg length) [29, 30, 31, 32, 33, 34]and, although there is no clear consensus in this regard [35, 36, 37, 38], the acquisition of bone mass can be reduced in adulthood [39], promoting the possibility of future fractures.…”

Elevated phthalates' exposure in children with constitutional delay of growth and puberty

“…Children with Constitutional Delay of Growth and Puberty (CDGP) are short for their genetic height potential, and display biological immaturity as determined by a delayed bone age (BA) and sexual delay (Ghai et al, 1995;Moreira-Andrés et al, 1998). CDGP is the most common cause of delayed puberty within the general population, and is most frequently encountered in boys (Sedlmeyer and Palmert, 2002).…”