[Isotopic renal study in diabetic nephropathy].

UNLABELLED: This study aimed to evaluate the prognostic value of the kidney split function (KSF), the effective renal plasma flow (ERPF) and glomerular filtration rate (GF) in the evolution of diabetic nephropathy.

MATERIAL AND METHODS: 125 patients (IDDM:10, NIDDM:115), including 62 men, ages 18-84 years, were studied. In all cases GF (Cr 51 EDTA), ERPF (131I-hippuran), kidney split function (obtained from the 99mTc-MAG3 renogram) and basal serum creatinine (SC) were evaluated at the beginning of the study and patients were clinically followed up for 5 years by SC. Ultrasound and/or intravenous digital angiography were performed in 120 patients.

RESULTS: In patients with decreased ERPF (76 patients) the SC increased progresively during the 5 years, in both those with elevated PC (N = 54) as well as in those with normal baseline SC (n = 22). In patients with normal ERPF the SC did not change significantly during the study. An asymethric split function (KSF < 40% in one kidney) was found in the renogram of 42 patients; in 32 of them the ERPF was decreased. Of these, ulttrasonography was normal in 9, and vascular and/or obstructive pathology was demonstrated by ultrasonography or digital angiography in only 6 patients.

CONCLUSION: The ERPF becomes altered earlier than serum creatinine in patients with diabetic nephropaty. ERPF and split function calculation, and FG seems to have higher prognostic value than ultrasounds in the management of diabetic nephropathy. Radionuclides seems to be an accurate test than the ultrasonography to detect renal function abnormalities in patients with diabetic and thus can be an examination of choice in these patients.