Adverse Effects of Recombinant Human Insulin-like Growth Factor I in Obese Insulin-Resistant Type II Diabetic Patients

Data from studies in diabetic rodents and evidence from clinical situations of severe resistance to insulin suggest that insulin-like growth factor I (IGF-I) is able to at least partly overcome insulin resistance. To assess the efficacy of recombinant human IGF-I in subjects with the most common form of insulin resistance, e.g., obese, type II diabetic patients, we administered recombinant human IGF-I (rhIGF) in doses of 120 and 160 μg/kg twice daily for 4–52 days to seven such individuals who had been treated previously with high doses of insulin (> 0.7 U·kg⁻¹ · day⁻¹). Four patients exhibited comparable or enhanced, whereas three had diminished, blood glucose control on rhIGF-I relative to that while on twice daily NPH insulin during the six-week control period. The occurrence of adverse effects in all patients compelled us to discontinue rhIGF-I administration before completing the 8-week treatment period. These adverse effects included edema primarily on the face and hands, mild weight gain, occasional dyspnea, bilateral jaw tenderness, arthralgias and myalgias, fatigue, tachycardia, flushing, orthostatic hypotension, and local burning at the injection site. We conclude that the frequency and severity of side effects associated with administering high-dose subcutaneous rhIGF-I to obese insulin-resistant diabetic patients make it an unacceptable therapeutic agent for these patients despite its ability to produce reasonable blood glucose control in ∼50% of them.