IGF-I AND DIABETES IN ADOLESCENCE

Adolescents with insulin-dependent diabetes mellitus (IDDM) of ten exp erience difficulties achieving good glycaemic control, and attempts at intensifying insulin therapy may increase the risk of hypoglycaemia a nd weight gain. Abnormalities of the GH/IGF-I axis may contribute to t hese problems. Insulin-like growth factor-l (IGF-II levels and IGF bio activity are invariably reduced despite growth hormone IGH) hypersecre tion, and these abnormalities are only partially corrected by intensif ied insulin therapy. The administration of recombinant human IGF-I (rh IGF-I) as an adjunct to insulin therapy can restore circulating IGF-I levels and thus suppress GH levels and improve insulin sensitivity. Ra ndomised placebo-controlled clinical trials of daily subcutaneous rhlG F-l therapy (40-80 mu g/kg/day) have demonstrated that significant red uctions in HbA1c can be achieved without evidence of toxicity or exace rbation of diabetic complications. RhIGF-I used in conjunction with in sulin may therefore provide an additional approach to the management o f IDDM during adolescence, although further studies are required to de termine the ideal dose regimen and confirm beneficial effects without adverse effects on microvascular complications in these subjects.