Kidney morphological changes in relation to long-term renal function and metabolic control in adolescents with IDDM

Area of Science:

• Nephrology
• Endocrinology
• Diabetology

Background:

• Insulin-dependent diabetes mellitus (IDDM) can lead to diabetic nephropathy.
• Early detection of renal changes is crucial for managing diabetic kidney disease.
• Microalbuminuria is a common early marker, but structural changes can precede it.

Purpose of the Study:

• To investigate early structural renal changes in adolescents and young adults with IDDM.
• To correlate these structural changes with renal function parameters and metabolic control.

Main Methods:

• Renal biopsy with light and electron microscopy in 36 patients (13-25 years) with IDDM.
• Assessment of glomerular filtration rate and effective renal plasma flow.
• Analysis of glomerular basement membrane thickness, mesangial matrix volume, and foot process width.
• Correlation with HbA1c levels and filtration fraction.

Main Results:

• Increased glomerular filtration rate and filtration fraction were observed.
• Glomerular basement membrane thickness and mesangial matrix volume were elevated.
• Increased filtration fraction correlated with HbA1c and structural changes.
• Urinary albumin excretion correlated with foot process width.
• Metabolic control was the primary factor for basement membrane thickening, while filtration fraction influenced mesangial matrix volume.

Conclusions:

• Early diabetic structural kidney changes are present even without persistent microalbuminuria.
• Long-standing hyperfiltration and poor metabolic control are associated with these early structural alterations.
• These findings highlight the importance of monitoring renal function and metabolic control in young patients with IDDM.