Efficacy and safety of individualized growth hormone treatment in adult Japanese patients with growth hormone deficiency.

OBJECTIVE: The aim of the study was to evaluate the efficacy and safety of growth hormone (GH) treatment in Japanese adult patients with GH-deficiency. In the extension of the efficacy study, the effect of individualized-dosing (ID), based on insulin-like growth factor-I (IGF-I) levels, and fixed-dose (FD) GH regimens on body composition, were compared in Japanese GH-deficient adults.

DESIGN: Randomized, double-blind (DB), placebo-controlled, 24-week treatment period followed by 48-week, open-label study in 43 endocrinology clinics in Japan. Patients received DB treatment with GH (0.012 mg/kg/day; n=57) or placebo (n=60) followed by open-label GH in an ID (n=75) or FD (0.012 mg/kg/day; n=38) regimen.

SUBJECTS: Adult Japanese GH-deficient patients (peak GH<3 ng/mL).

MEASUREMENTS: Trunk and total body fat (BF), lean body mass (LBM), and adverse events were determined.

RESULTS: Percentage trunk fat was reduced significantly more in GH- than in placebo-treated patients at 24 weeks (-16.2 vs. 1.7%, p<0.0001). Open-label treatment with an ID or FD GH regimen provided similar reductions in percentage trunk fat (-8.12 vs. -9.35%), and total BF (-0.92 vs. -0.70 kg) and a comparable increase in LBM (1.032 vs. 0.97 kg). Mean+/-SD GH doses (mg/kg/day) at 48 weeks were significantly lower with the ID GH regimen (ID, 0.0082+/-0.0050; FD, 0.0095+/-0.0033; p<0.05). The safety profile was comparable between ID and FD groups.

CONCLUSIONS: Treatment with GH was associated with a significant reduction in trunk fat and improvement in serum lipid profile in Japanese adult GH-deficient patients. The improvement in body composition and tolerability were comparable between ID and FD GH regimens despite a significantly lower daily GH dose with the ID regimen.