[Clinical usefulness of measurement of urine type IV collagen for detection of early phase of nephropathy in type 2 diabetic patients].

Urine type IV collagen concentrations in type 2 diabetic patients were measured by enzyme immunoassay which has crossreactivity with only intact type IV collagen, and the clinical usefulness for estimating the early phase of diabetic nephropathy was evaluated. Precision of the measurement system was satisfactory for clinical use and the value did not influenced by the presence of sediments in urine. In whole type 2 diabetic patients (N=132), urine type IV collagen concentration (microg/g of creatinine) increased with development of nephropathy and showed significantly increase even in normoalbuminuria when compared with that in normal control subjects (N=117). In type 2 diabetic patients (N=100) with mild microalbuminuria (less than 100 mg/g of creatinine), multiple regression analysis revealed that HbA1C was extracted as a significant valuable for urine type IV collagen, while body mass index was extracted as a significant valuable for urine albumin. In these subjects, urine type IV collagen was significantly lower in the patients with good metabolic control (HbA1C<8.0%) than those with poor control (HbA1> or =8.0%), while the urine albumin was not significantly different between those two groups. These results suggest that measurement of urine type IV collagen in type 2 diabetic patients is useful for detection of early phase of diabetic nephropathy.