Increased urinary fibronectin excretion in type II diabetic patients with microalbuminuria

Area of Science:

• Nephrology
• Endocrinology
• Biochemistry

Background:

• Elevated plasma fibronectin (FN) observed in diabetic patients with retinopathy and nephropathy.
• Limited data exists on urinary FN excretion in diabetic nephropathy, particularly with microalbuminuria.

Purpose of the Study:

• To investigate the association between urinary fibronectin (U-FN) excretion and early diabetic nephropathy.
• To explore the relationship between U-FN and other diabetic complications.

Main Methods:

• Study included 59 Type II diabetic inpatients and 15 age-matched controls.
• Urinary FN (U-FN) was measured in micrograms per gram of creatinine over 24 hours.
• Creatinine clearance was assessed to evaluate kidney function.

Main Results:

• Mean U-FN was significantly higher in diabetic patients (348.1 ± 48.3 µg/g) compared to controls (108.6 ± 22.7 µg/g, p < 0.01).
• U-FN levels tended to be higher in patients with microalbuminuria (262.4 ± 21.9 µg/g) versus those without (188.1 ± 34.3 µg/g, p < 0.08).
• In patients without retinopathy or neuropathy, U-FN was significantly higher in the microalbuminuria group (222.5 ± 28.5 µg/g) compared to the non-microalbuminuria group (116.1 ± 22.6 µg/g, p < 0.01).
• A significant negative correlation was found between U-FN and creatinine clearance in diabetic patients (r = -0.642, p < 0.01).

Conclusions:

• Urinary fibronectin excretion is significantly increased in diabetic patients, indicating potential kidney involvement.
• Elevated U-FN may serve as an early marker for diabetic nephropathy, even in the presence of microalbuminuria.
• Decreased creatinine clearance correlates with higher U-FN levels, suggesting U-FN reflects impaired kidney function in diabetes.