Human pituitary growth hormone (hGH) therapy in growth hormone deficiency

This review has attempted to answer a number of questions regarding human growth hormone therapy in growth hormone deficiency. I believe that the available data support several conclusions which form a suggested current approach to the clinical use of hGH. While these conclusions are derived from data obtained using pituitary growth hormone, it is likely that they are applicable to growth hormone manufactured by recombinant DNA technology, as well. Treatment should be begun as early as the diagnosis can be made in anticipation of a better initial and long-term response in younger patients. Growth hormone should be administered on the basis of body weight in an initial dose of 0.06-0.10 unit/kg 3 times a week. Growth hormone may be administered either intramuscularly or subcutaneously. Therapy should be continuous whenever possible. Treatment should be given until there is no further response which generally will reflect closure of the epiphyses. Associated hormone deficiencies should be adequately treated, and patients should be periodically evaluated for the development of additional deficiencies. Concomitant therapy is not indicated unless deficiencies are clearly demonstrated. Thyroid replacement should be at full dosage, while glucocorticoid replacement should probably not exceed 10-15 mg/m2 x day. Gonadal steroids should be used at the bone age when puberty is expected, and hGH should be continued during pubertal development. There is no general indication for giving anabolic/androgenic steroid in combination with hGH in prepubertal patients. If a waning effect of therapy is observed, the dose of hGH should be incrementally increased, and/or the addition of anabolic/androgenic steroid therapy should be considered. While most reports have focused on the effect of hGH on linear growth, changes in weight, bone age, body proportions, and body composition have also been observed. The effect on bone age is variable, but there is greater enhancement of linear growth than of epiphyseal development in the majority of treated patients. Bone age must be monitored during hGH administration whether or not anabolic/androgenic steroids are used concurrently. Growth hormone administration is remarkably free of side effects. However, neutralizing antibodies to hGH may develop and they should be sought in patients in whom an unexplained decrease in response is observed. Certainly the available incomplete data allow for different conclusions. The expanding supply of hGH should lead to a more systematic evaluation and provide more definite answers to the questions which this review has considered.