Urinary Type IV Collagen as Biochemical Test Marker in Patients with Diabetic Nephropathy In Early Stage

Objective: Our purpose was to investigate the change of urinary type Ⅳ collagen in early stage of diabetic nephropathy(DN) and its possible relationship with the correlated markers. Methods:Urinary type Ⅳ collagen was determined with one-step sandwich enzyme immunoassay (EIA) in 85 diabetic patients, including 31 cases of normal albuminuria(DM1 group),42 of microalbuminuria (DM2 group),12 of overtalbuminuria(DM3 group) and 24 healthy subjects as control.Results:The mean concentration of urinary type Ⅳ collagen in DM1 group(9.43±8.79 μg/g·cr) was significantly higher than that of control(3.44±0.11μg/g·cr,P0.01).The levels of urinary type Ⅳ collagen in patients in DM2 or DM3 group, which were (23.33±16.40) μg/g·cr and (61.23±30.73) μg/g·cr, were significantly higher than that in DM1 group (P0.01). There was a significant correlation between the concentration of urinary type Ⅳ collagen and urinary albumin, as well as diabetic duration. There was no correlation between urinary type IV collagen and TC, TG, SBP, DBP, BMI, and blood sugar. Conclusion:Abnormal collagen metabolism exists in patients with diabetic nephropathy. The level of urinary type Ⅳ collagen has largely increased in early renal lesion stage in diabetic nephropathy.Therefore, it could be an early and sensitive marker of DN.