Glomerular hyperfiltration in microalbuminuric NIDDM patients

Area of Science:

• Nephrology
• Diabetology
• Internal Medicine

Background:

• Diabetic nephropathy is a major complication of diabetes mellitus.
• Microalbuminuria and glomerular hyperfiltration are recognized risk factors for diabetic nephropathy.
• Limited data exists on glomerular hyperfiltration in microalbuminuric non-insulin-dependent diabetes mellitus (NIDDM) patients.

Purpose of the Study:

• To investigate the prevalence of glomerular hyperfiltration in microalbuminuric NIDDM patients.
• To compare glomerular filtration rates (GFR) between microalbuminuric NIDDM patients, normoalbuminuric NIDDM patients, and non-diabetic controls.

Main Methods:

• Cross-sectional study involving 158 microalbuminuric NIDDM patients, 39 normoalbuminuric NIDDM patients, and 20 non-diabetic controls.
• Glomerular filtration rate was measured using 51Cr-EDTA single intravenous bolus injection and 4-hour plasma clearance.
• Groups were matched for sex, age, and body mass index.

Main Results:

• Glomerular filtration rate was significantly elevated in microalbuminuric NIDDM patients compared to normoalbuminuric NIDDM patients and controls (p < 0.001).
• Glomerular hyperfiltration was identified in 37% of microalbuminuric NIDDM patients.
• HbA1c, 24-hour urinary sodium excretion, age, and diabetes duration correlated with GFR in microalbuminuric NIDDM patients (r2 = 0.21, p < 0.01).

Conclusions:

• Microalbuminuric NIDDM patients exhibit a high prevalence of glomerular hyperfiltration.
• Glomerular hyperfiltration represents an additional risk factor for diabetic nephropathy progression in NIDDM patients.
• Further research is warranted to explore the clinical implications of hyperfiltration in NIDDM.