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An electron microscopic study of glomeruli in Japanese patients with non-insulin dependent diabetes mellitus
1Department of Medicine (II), Niigata University School of Medicine, Japan.
Abstract:
Renal biopsy specimens of 29 Japanese non-insulin dependent diabetes mellitus (NIDDM) patients were examined by quantitative electron microscopic morphometry. In NIDDM the relative increase of percent total mesangium and mesangial capillary surface density (S/Vb) and the relative decrease of peripheral capillary surface density (S/Va) were compared with disease controls. However, mesangial-GBM-epithelial surface density (S/Vc) was not different between both groups. These results suggest that the increased mesangial matrix expands directly towards the capillary lumen as well as along the inner surface of GBM, and narrows the capillary lumen and filtration surface. The duration of diabetes mellitus (DM) did not correlate with all morphological parameters. The mesangial expansion correlated with urinary protein excretion and decreased creatinine clearance (CCr). GBM thickening correlated with proteinuria, but not with CCr. The degree of these morphological changes could be the indicators of hypertension of NIDDM patients. Areas of thin GBM were occasionally noticed in glomeruli which revealed thick GBM extensively, although the mechanism of GBM thinning is not known at the present time.
Insights
In Japanese patients with non-insulin dependent diabetes mellitus (NIDDM), increased mesangial matrix and decreased peripheral capillary surface density were observed. These changes correlate with kidney function decline and may indicate hypertension.
Area of Science:
- Nephrology
- Diabetology
- Pathology
Background:
- Non-insulin dependent diabetes mellitus (NIDDM) is a growing global health concern.
- Diabetic nephropathy is a major complication of NIDDM, leading to kidney damage.
- Understanding the early morphological changes in NIDDM kidneys is crucial for timely intervention.
Purpose of the Study:
- To investigate the quantitative ultrastructural changes in renal biopsies of Japanese NIDDM patients.
- To correlate these morphological changes with clinical parameters like proteinuria and creatinine clearance.
- To explore potential indicators of hypertension in NIDDM patients.
Main Methods:
- Quantitative electron microscopic morphometry was performed on renal biopsy specimens from 29 Japanese NIDDM patients.
- Morphological parameters including mesangial matrix expansion and capillary surface densities were analyzed.
- Comparisons were made with disease control groups.
Main Results:
- NIDDM kidneys showed a relative increase in total mesangium and mesangial capillary surface density (S/Vb).
- A relative decrease in peripheral capillary surface density (S/Va) was observed in NIDDM.
- Mesangial expansion correlated with urinary protein excretion and decreased creatinine clearance (CCr), while GBM thickening correlated with proteinuria.
Conclusions:
- Increased mesangial matrix in NIDDM expands towards the capillary lumen, narrowing filtration surfaces.
- Mesangial expansion and GBM thickening correlate with declining kidney function and may indicate hypertension in NIDDM.
- The study highlights the importance of ultrastructural analysis in understanding diabetic nephropathy progression.