Bone mineral density and body composition in prepubertal and adolescent patients with the classical form of 21-hydroxylase deficiency.

OBJECTIVES: To evaluate bone mineral density (BMD) and body composition in prepubertal and adolescent patients with the classical form of 21-hydroxylase deficiency. MATERIAL AND METHOD: The authors measured height, weight and used dual energy x-ray absorptiometry (DEXA) to evaluate lumbar spine, whole body BMD and body composition in 10 prepubertal and adolescent patients with the classical form of 21-hydroxylase deficiency. Serum hormone concentrations (17-hydroxyprogesterone, dehydroepiandrosterone sulfate) were also measured. Results were compared with those of age- and sex-matched controls. RESULTS: Seven patients were adolescent (4 girls and 3 boys; age range, 9.0-19.6 years) and three patients were prepubertal. (2 girls and 1 boy; age range, 6.5-8.6 years). There were no significant differences in age, height z-score, weight z-score and body mass index between the patients with congenital adrenal hyperplasia (CAH) and controls. DEXA showed no differences between each group in whole body BMD, but showed significantly elevated areal regional BMD at the lumbar spine (L1-L4) in CAH patients. However four of the 10 CAH patients and 6 of the 10 controls had osteopenia. The BMD z-score at the lumbar spine was significantly correlated with increasing weight z-score in both CAH patients and controls. When CAH patients with osteopenia were compared with those with normal BMD, there was a trend toward lower weight z-score, higher dose of glucocorticoids and longer duration of treatment among the osteopenic patients, but it did not reach statistical significance. CONCLUSION: Classical 21-hydroxylase deficiency patients treated with long-term glucocorticoids did not have impaired bone mineral density compared with healthy, age and sex-matched controls. However, the reference data for BMD in the Thai pediatric population is lacking and the number of studied participants was limited so we need further studies.

Bone mineral density and body composition in Thai Precocious Puberty girls treated with GnRH agonist.

Treatment of true Precocious Puberty (PP) with GnRH agonist can improve final adult height by suppressing gonadotropin and sex hormone levels that delays the fusion of long bone epiphyseal growth plates. However, deprivation of estrogen may affect the acquisition of peak bone mass, especially in individuals with low calcium intake. Ten Thai girls with idiopathic true PP were evaluated for Bone Mineral Density (BMD) and body composition by DXA scanner (Hologic, Inc) before and after GnRH agonist therapy for 1 year. During treatment, all children were allowed to consume a normal diet without extra calcium supplementation. In addition, serum calcium, phosphate, alkaline phosphatase and osteocalcin were also measured. The results showed that GnRH agonist could improve predicted adult height from 149.4 +/- 5.4 to 153.6 +/- 6.8 cm (p < 0.001). Serum osteocalcin, representing the bone marker formation, decreased from 184.2 +/- 66.7 to 108.6 +/- 35.3 ng/mL (p = 0.012) However, the treatment had no negative effects on BMD lumbar spine and total BMD but increased percentage of fat mass from 25.7 +/- 5.2 to 31.6 +/- 5.5%. (p =0.007). In conclusion, treatment with GnRH agonist in Thai girls with true PP for 1 year can improve PAH without negative effects on BMD but a longer period of treatment needs to be studied.