The effect of gonadotrophin-releasing hormone agonist treatment over 3 years on bone mineral density and body composition in girls with central precocious puberty.

OBJECTIVE: Puberty is a period characterized by growth spurt and rapid change in body composition. The effect of GnRH agonist therapy for central precocious puberty on bone mineral density is unclear. We demonstrated changes in bone mineral density in subjects with central precocious puberty, who were treated with GnRH agonist for more than 3 years. DESIGN: The changes in bone mineral density and body compositions were tested with analysis of variance with repeated measures to identify statistical significance over the treatment period. PATIENTS: One hundred ninety-five Korean girls with central precocious puberty were treated with GnRH agonist, and among these subjects, 39 patients were treated for more than 3 years. MEASUREMENTS: Dual-energy X-ray absorptiometry was performed on the subjects at the initial evaluation and once yearly thereafter while on the treatment. RESULTS: The bone mineral density parameters for chronological age tended to decrease near the mean for the treatment period; however, they increased significantly for bone age excluding bone mineral apparent density. An increment of the BMI was not significant for the chronological age. CONCLUSIONS: Three-year treatment with GnRH agonist in central precocious puberty patients did not impair bone maturation. GnRH agonist could be effectively commenced in girls with precocious puberty from an early age.

Cross-calibration of multi-frequency bioelectrical impedance analysis with eight-point tactile electrodes and dual-energy X-ray absorptiometry for assessment of body composition in healthy children aged 6-18 years.

BACKGROUND: In diagnosis and treatment of obesity, body composition analysis including percent body fat (%BF) is useful in the clinical setting. Because bioelectrical impedance analysis (BIA) could be used quickly, easily and was non-invasive in clinical setting, the purpose of the present study was to evaluate the usefulness of multi-frequency BIA with eight-point tactile electrodes (MF-BIA8; InBody 720, Biospace) compared with dual-energy X-ray absorptiometry (DXA) in healthy children and adolescents. METHODS: A total of 166 children and adolescents under 18 (male, n = 86; female, n = 80) were recruited. Height, weight, body mass index (BMI) and Tanner stage were measured for each subject. The body composition such as fat-free mass (FFM), fat mass (FM), and %BF was measured on BIA and DXA and compared. RESULTS: On linear regression analysis, DXA FFM = 1.006(BIA FFM) + 0.554, R(2) = 0.99 and the standard error of the estimate (SEE) was 1.16 kg; DXA FM = 0.971(BIA FM) - 0.596, R(2) = 0.93; SEE, 1.34 kg; and DXA %BF = 0.940(BIA %BF) - 1.026, R(2) = 0.858; SEE, 3.03%. Limit of agreement in FFM, FM, and %BF was 0.7 +/- 2.3 kg, -0.9 +/- 2.9 kg and -2.2 +/- 6.1%, respectively. CONCLUSIONS: Although the %BF was not interchangeable with DXA, MF-BIA8 (InBody 720; Biospace) could be used to measure body composition of children and adolescents in the clinical field because of its high precision.