Collaborative study of the effects of human growth hormone in growth hormone deficiency. V. Treatment with growth hormone administered once a week.

Twenty-two GH-deficient patients received 6 IU GH weekly for 6 months. They increased their growth rate from 1.0 +/- 0.2 to 2.9 +/- 0.3 (SE) cm/6 months (P less than 0.01). However, their rate of growth was significantly less (P less than 0.05) than the rate [4.1 +/- 0.5 (SE) cm/6 months] observed earlier when they had received 2 IU GH three times a week. Seven patients received weekly GH for 18 months and they also grew significantly less (P less than 0.01) than when they had received GH divided over the week. These results suggest that once a week GH does not provide the most effective therapy for GH deficiency.