Clinical considerations in using growth hormone therapy in growth hormone deficiency

Growth hormone (GH) replacement therapy has been the standard medical practice for 50 years in treating GH-deficient patients. When recombinant human GH became available around the mid-1980s, daily GH injections via the subcutaneous route started. The GH dosage corresponds to the daily spontaneous secretion (e.g. 20-30 microg/kg body weight in the prepubertal stage; 2-4 times during puberty). Since the growth process is long, the effects of therapeutic strategies can only be observed many years later. Reports of long-term results show that, over the decades, there is a trend towards diagnosing/treating younger patients and that they are less GH-deficient and not as short as patients in the past. Today about 80-90% of these patients attain normal height. We have proposed that the customary 'fixed-dose wait-and-see' approach should be relinquished in favor of an adaptive strategy of dosing which focuses on the individual responsiveness of each patient. The prediction models derived from observations of large cohorts of patients have become essential in determining the responsiveness. This approach not only optimizes the outcomes but also the cost of treatment. Further efforts are needed to incorporate the existing evidence into the diagnostic procedure and treatment of GH deficiency.