A Dose-Response Curve for Human Growth Hormone

Abstract

Although human GH (hGH) has been administered to GH-deficient patients for over 20 yr, there are minimal published data on the relationship of response to dose. We have given hGH on the basis of body weight to 93 prepubertal GHdeficient patients over an initial 12 months of therapy. Their annual growth rate while receiving hGH was 5.58 ± 2.30 (±SD) cm at a dose of 30 mlU/kg, three times a week (tiw; n = 27); 7.31 ± 1.75 (±SD) cm at a dose of 60 mlU/kg, tiw (n = 38); 7.22 ± 3.12 (±SD) cm at a dose of 80 mlU/kg, tiw (n = 12); and 8.94 ± 1.19 cm (±SD) at a dose of 100 mlU/kg, tiw (n = 16). Doubling the dose from 30 to 60 mlU increased the mean rate of growth 1.3 times, and increasing the 30 mlU dose by a factor of 3.3 increased the mean rate of growth 1.6 times. The response (y) as a function of the log-dose (x) is defined by the equation y = −3.12 + 5.80 log x. When the effect of hGH is expressed as the increase in growth rate while receiving therapy, the log-dose relationship is defined by the equation y =-6.09 + 5.67 log x. This doseresponse curve provides data which are useful in choosing the best dose of hGH for an individual patient. It also allows a more accurate projection of the costs and benefits of hGH therapy.