Thin glomerular basement membrane in diabetic patients with urinary abnormalities

To clarify the clinical and pathological significance of thin glomerular basement membranes (Thin-GBM) appearing in evident diabetics, we examined the renal biopsies from 179 diabetes mellitus (DM) patients with urinary abnormalities in which the number of non insulin dependent diabetes mellitus cases was 140 cases while the remaining 39 cases had insulin dependent diabetes mellitus. In addition, 17 of these cases were found to have either segmental or diffuse Thin-GBM by electron microscopy. The clinical and morphological parameters between the diabetics with Thin-GBM (DM-Thin-GBM) and the diabetics without Thin-GBM (the controls) were significantly different regarding DM duration (DM-Thin-GBM vs control: 5.3 +/- 5.5 vs 9.8 +/- 6.5 years, p < 0.01), Ccr (67.0 +/- 25.5 ml/min vs 45.6 +/- 24.4 ml/min, p < 0.01), the incidence of hematuria (52.9% vs 24.5%, p < 0.05) and hypertension (13.3% vs 51.3%, p < 0.05). The severity of glomerular damage was mild in the DM-Thin-GBM group as compared to the control. The renal survival rate from the onset of urinary abnormalities was higher in the DM-Thin-GBM group than in the control (p < 0.01). In the case of DM-Thin-GBM, the grade of proteinuria correlated with the mean width of the thickened GBM (p < 0.01) and the spread of the thickened GBM which was more than 500 nm in width (p < 0.001). The severity of microscopic hematuria correlated with the spread of the Thin-GBM (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)