The Relationship Between Serum or/and Urinary Concentration of Insulin-like Growth Factor-I(IGF-I) and Amount of Urine Protein in Patients with Non-diabetic Nephropathy (NDN)

Objective:To inrestigate the relationship between serum or/and urinary concentration of insulin-like growth factor-Ⅰ (IGF-Ⅰ) and the amount of proteinurine in patients with non-diabetic nephropathy (NDN).Methods:According to the levels of proteinurine above or below 3.5 g/24 h,24 randomly recruited patients with NDN were divided into experimental group 1 and experimental group 2.12 healthy subjects with the same age and sex were selected randomly as control group.After routine examination,such as bilateral renal ECT and color ultrosound B,serum IGF-Ⅰ and insulin-like growth factor binding protein 3 (IGFBP 3),urinary concentration of IGF-Ⅰ,and glomerular proteinuria for 24 h were assayed by RIA,and renal biopsy examination was performed in both the experimental groups.Results:Serum IGF-Ⅰ significantly decreased in the 24 NDN patients with proteinuria ( P 0.001),which was negatively correlated to the amount of protein in the 24 h urine in the 24 patients ( r =-0.876, P 0.001),while urinary IGF-Ⅰ significantly increased in the 24 NDN patients with proteinuria ( P 0.001),which was positively correlated to the amount of protein in the 24 h urine in the 24 patients ( r =0.897, P 0.001).The amount of protein and IGF-Ⅰ in the 24 h urine in patients of experimental group 1 are significantly increased compared with those in control group ( t =7.09, P 0.001),while serum IGF-Ⅰ decreased statistically ( t =3.71, P 0.001).Conclusion:The same as diabetic nephropathy more urinary IGF-Ⅰ is discharged by glomeruli with the increased excretion of serum protein in non-diabetic nephropathy;The increased excretion of serum IGF-Ⅰ is one of the causes of reduced concentration of serum IGF-Ⅰ.