The change of insulin-like growth factor-1 in diabetic patients with neuropathy

Objective To evaluate the possible relationship between insulin-like growth factor-1 (IGF-1) and diabetic neuropathy (DNP). Methods Sixty-nine patients with Type 2 non-insulin-dependent diabetes (54 with peripheral neuropathy and 15 without neuropathy) were observed. Normal controls were 34 non-diabetic persons. Diabetic peripheral neuropathy diag nosis was carried out taking into account results of NS, ND, NC and AF. Aft er an overnight fast, blood was taken for IGF-1, glucose, hemoglobin Alc, C -peptide, and insulin. Plasma IGF-1 was measured by radioimmunoassay (RIA) method. Results The neuropathic group had significantly lower levels for IGF-1 (86. 43 ng/ml +/- 45.18 ng/ml) compared to normal controls (119.68 ng/ml +/- 89. 42 ng/ml) (P < 0.05), and to diabetic patients without neuropathy (113.75 n g/ml +/- 66.58 ng/ml) (P < 0.05). No significant difference was found betwe en diabetic non-neuropathic group and normal control subjects (P > 0.05). I n diabetic subjects there was a positive correlation (gamma = 0.27, P < 0.0 5) between IGF-1 and beat to variation in heart rate. There were negative c orrelation between IGF-1 and postprandial blood glucose (gamma = -0.3, p < 0.05), and aspartic acid translocase (gamma = - 0.27, P < 0.05). Conclusion In diabetic patients with peripheral neuropathy there are abnorm alities of IGF-1 that may contribute to the pathogeneses of diabetic neurop athy.