Influence of two different GH dosage regimens on final height, bone geometry and bone strength in GH-deficient children

Objective: The aim was to investigate the effects of two different GH dosage regimens on growth, bone geometry and bone strength. Subjects and methods: Final height; parentally adjusted final height; the metacarpal index (MI) SDS, the inner and outer diameters; and the total cross-sectional area (CSA), cortical CSA, medullary CSA and bone strength (Bending Breaking Resistance Index (BBRI)) were evaluated at the metacarpal site in two cohorts of GH-deficient children, treated with two different doses of GH. Group 1 (38 patients) was treated with 0.16 mg/kg body weight per week of GH and group 2 (37 patients) with 0.3 mg/kg per week. Results: At the end of treatment, with group 1 vs group 2, height SDS was -0.84±1.07 vs -0.46±0.76, and parentally adjusted height SDS was 0.14±1.08 vs 0.27±0.82. Parentally adjusted relative height gain was 1.14±0.89 vs 2.14±0.72 SDS (P <0.0001). MI SDS was 0.58±1.31 vs -0.42±1.54 (P <0.005). MI SDS gain was 0.07±1.41 vs -0.35±1.85. There was no difference between groups in the outer and inner diameter, in the total and cortical CSAs, whereas medullary CSA was higher in group 2 (P <0.05). BBRI was 10.02±5.37 vs 11.52±5.49 cm³, and BBRI gain was 3.33±5.06 vs 6.88±6.65 (P = 0.01). P values were assessed using student's t-test. Conclusion: Higher GH doses result in a greater height gain and improved bone strength.