Evaluation of radial bone mineral content in prepubertal children with constitutional delay of growth

Age at onset of puberty predicts bone mass in young adulthood

OBJECTIVE

To determine whether the commencement and length of puberty influences dual x-ray absorptiometry (DXA) values of bone mineral content (BMC) and bone mineral density (BMD) in the axial and appendicular skeleton at skeletal maturity.

STUDY DESIGN

From the Bone Mineral Density in Childhood Study, we identified children who began puberty and completed sexual and skeletal development and examined whether the timing and length of puberty influence DXA values of BMC and BMD at skeletal maturity.

RESULTS

A total of 78 girls and 85 boys began puberty and completed skeletal maturity; 4.4 ± 0.8 and 4.5 ± 0.8 years later, respectively. Multiple linear regression analyses indicated that the age of onset of puberty was a strong negative predictor of DXA bone measurements at skeletal maturity, independent of bone values at the beginning of puberty, and the length of puberty. This negative relation was observed for all BMC and BMD measurements at all skeletal sites, in both boys and girls (all P < .0001). In contrast, length of puberty had no relation to any measures of bone.

CONCLUSIONS

In healthy adolescent males and females, bone mass and bone density at skeletal maturity are inversely related to the timing of puberty.

Sex steroid replacement during and after the induction of puberty

The main aim of sex steroid replacement during induction of puberty is to obtain a balance between healthy psychological and somatic development and optimal final height and peak bone mass (PBM). At present, the age at which it is considered appropriate to begin inducing puberty is younger than it was in the past. This trend aims for optimisation of prepubertal and pubertal growth through earlier onset of growth hormone (GH) therapy and administration of higher doses during puberty as necessary. Adequate initiation of puberty should ensure not only optimal final height and psychological balance, but also normal body proportions, appropriate bone formation and preservation of fertility for children with GH and gonadotropin deficiencies.

Osteoporosis in children and adolescents: diagnosis, risk factors, and prevention

Bone mass acquired during childhood and adolescence is a key determinant of adult bone health. Peak bone mass, which is achieved in late adolescence, is a main determinant of osteoporosis in adulthood. Therefore, any factor adversely impacting on bone acquisition during childhood or adolescence can potentially have long-standing detrimental effects on bone health predisposing to osteoporosis and fracture risk. Thus, osteoporosis can well have its origin in childhood and adolescence. Pediatricians should be playing an active role in osteoporosis diagnosis and prevention. It is increasingly recognized that osteoporosis may occur in some disorders of children and adolescents. In this paper we review the diagnostic criteria of osteopenia/osteoporosis by densitometric assessment of bone mineral density, the contributing factors, and the mechanisms whereby several disorders may affect the acquisition of bone mass in children and adolescents. Finally, some recommendations to optimize peak bone mass in order to prevent osteopenia/osteoporosis are suggested.