The clinical study on the relationship of the levels of insulin-like growth factor-1 with urinary albumin excretion rate in patients with type 2 diabetes

Objective To evaluate the relationship between the level of insulin-like growth factor-1 (IGF-1)in serum and urine and urinary albumin excretion rate in patients with type 2 diabetes.Methods IGF-1 level in serum and urine was determined in 20 healthy subjects (control),and 80 type 2 diabetic patients.Three subgroups included group N-UA1b with UAER20μg/min(n=32),group M-UA1b with UAER 20-200μg/min(n=28) and group L-UA1b with UAER200μg/min(n=20).Results Serum IGF-1 in group N-UA1b,M-UA1b,L-UA1b significantly decreased in comparison with control(P0.01), however,there were no significant difference in serum IGF-1 among group N-UA1b,M-UA1b and L-UA1b. Urinary IGF-1 in group N-UA1b did not differ from that in controls(n=20,P0.05).Urinary IFG-1 level in group M-UA1b and L-UA1b significantly increased in comparison with group N-UA1b (P 0.01). Urinary IGF-1 level was correlated positively with UAER(r=0.519,P0.01) and RBP(r=0.884,P 0.01).Conclusions Urinary IGF-1 increment may suggest the increase of renal tissue IGF-1 synthesis and secretion,this may be involved in the pathogenesis of diabetic nephropathy in type 2 diabetes.