2003 Volume 12 Issue 2 Pages 99-104
We prospectively investigated the effects of growth hormone (GH) replacement therapy on glucose tolerance and insulin resistance. An oral glucose tolerance test (OGTT) was conducted on 36 prepubertal children with GH deficiency (20 boys and 16 girls, 4.9~12.8 yr old) at 0, 0.5, 1, 1.5, 2 and 3 yr after the start of the therapy. As the parameter of glucose tolerance, the sum of 0, 30, 60, 120, and 180 min plasma glucose (ΣPG) (mg/dl), immunoreactive insulin (ΣIRI) (μU/ml), and C-peptide immunoreactivity (ΣCPR) (ng/ml), were used. The homeostasis model assessment ratio (HOMA-R), an index of insulin resistance, and β-cell function, assessed by the Matthews' formula, was also calculated. ΣPG exhibited a significant increase at 1.5 yr after the start of the therapy. ΣIRI and ΣCPR had increased significantly at 1 yr and thereafter. The blood glucose curve exhibited normal glucose tolerance (NGT) in 33/36, impaired glucose tolerance (IGT) in 3/36, and a diabetic pattern (DM) in 0/36 at the beginning of the therapy. The percentage of subjects exhibiting the IGT increased over time and a DM pattern appeared in some patients. The HOMA-R exhibited a significant increase at 1.5 yr. β-cell function showed a significant increases at 1 and 1.5 yr. In summary, increases in insulin resistance and in insulin secretion, and a tendency to an increased blood glucose level were observed after GH therapy. These results showed that careful observation should be conducted about the possibility of developing glucose intolerance during long-term GH therapy.
