Glomerular structural changes in type 1 (insulin-dependent) diabetes mellitus: causes, consequences, and prevention

Area of Science:

• Nephrology
• Diabetology
• Pathology

Background:

• Diabetic nephropathy is a major complication of diabetes, driven by diabetic glomerulopathy, the kidney's manifestation of diabetic microangiopathy.
• Structural changes in the glomeruli, including basement membrane thickening and mesangial matrix expansion, are key features.

Purpose of the Study:

• To quantitatively describe structural changes in diabetic glomerulopathy using stereological methods.
• To establish the correlation between structural alterations and the stage of renal function in diabetic patients.

Main Methods:

• Stereological methods were employed to quantitatively assess structural changes in the glomeruli.
• Analysis focused on basement membrane thickness, mesangial volume, and glomerular filtration rate relative to structural parameters.

Main Results:

• Diabetic glomerulopathy progresses with diabetes duration, showing normal parameters at onset, mild changes in normoalbuminuria, moderate in microalbuminuria, and advanced lesions in overt nephropathy.
• Changes in peripheral basement membrane and mesangial matrix occur concurrently, contributing to early glomerulopathy in microalbuminuric patients.
• Deviations in glomerular filtration rate align with filtration surface area estimates, increasing in early hyperfunction and decreasing in advanced nephropathy.

Conclusions:

• Structural parameters of diabetic glomerulopathy correlate with renal function stages and can be valuable in clinical trials for preventing diabetic nephropathy.
• While the diabetic state is necessary for glomerulopathy, glomerular hyperfunction or hypertrophy were not found to be contributing causes.
• Further research is needed to clarify the mechanism of albuminuria in relation to early structural changes.