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

The aim was to investigate the effects of two different GH dosage regimens on growth, bone geometry and bone strength.

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.

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 cm(3), 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.

Higher GH doses result in a greater height gain and improved bone strength.