Collaborative study of the effects of human growth hormone in growth hormone deficiency: IV. Treatment with low doses of human growth hormone based on body weight.

In order to define the minimum effective dose of human growth hormone (GH) in growth hormone deficient children, GH was administered to three groups of patients based on their body weight. Five children who received 0.01 International Unit (IU) GH/kg three times a week (tiw) failed to respond with a significant increase in their rate of growth. A dose of 0.03 IU GH/kg tiw increased the growth rate of 12 patients from 3.5 +/- 0.4 (SE) cm/year to 6.4 +/- 0.4 (SE) cm/year (P less than 0.001) during the first 12 months of therapy. Eight children (67%) larger than or equal to 6.0 cm/year. A similar increase growth rate from 3.6 +/- 0.4 (SE) cm/year to 7.3 +/- 0.4 (SE) cm/year (P less than 0.001) was observed over the first 12 months of therapy in 16 growth hormone deficient children who were given 0.06 IU GH/kg tiw. Thirteen children (81%) grew larger than or equal to 6.0 cm/year. During a second year of treatment, children receiving either 0.03 or 0.06 UI GH/kg tiw again showed a significant increase in their rate of growth. However, the response was significantly less than that observed during the first year of treatment. Comparison of these results with those available in the literature suggests that the most efficient, although not necessarily the optimal, initial dose of GH in children with growth hormone deficiency is 0.06 IU GH/kg administered three times a week.