Background: Diabetic nephropathy is a common chronic complication in type 2 diabetes mellitus (T2DM) at the time of diagnosis or later on and to progress with longer duration of the disease. Microalbuminuria (MIC) heralds diabetic nephropathy and precedes proteinuria and is an important risk factor for cardiovascular disease (CVD).Once proteinuria develops after microalbuminuria, progression to end-stage kidney disease occurs rapidly over ~5 years.Objective: To identify the relative importance of glycemic control status and some oxidative stress markers in the discrimination between patients with and without MIC so that the more important ones may be a priority targets in the prevention or treatment of diabetic nephropathy.Subjects and methods: One hundred female T2DM patients and 50 apparently healthy aged-matched women as a control group were enrolled in the study. Diabetic patients comprised two groups; group A: DM patients without MIC; group B: DM with MIC. For each study subject, clinical characteristics were recorded and the following parameters were measured: Urinary Albumin: Creatinine ratio (A:C ratio), and serum levels of fasting glucose , HbA1C, uric acid, thiobarbituric acid-reactive substances (TBARS), and α-tocopherol.Results: Group B patients were found to have a significantly higher mean value of BMI, blood pressure, and longer duration of disease. The mean ratio of HbA1C of group B was significantly higher than in group A (8.7 ± 1.4% vs. 7.1 ± 1%, P < 0.001). On comparison of oxidative stress markers then group B had higher serum TBARS (8±1 vs. 5.9±1 µmol/L, P<0.001), and uric acid (5.8±1vs. 4.9±1.1 mg/dl, P<0.001) than in group A but the two groups showed no significant difference in α-tocopherol. The results revealed that there is a high significant positive correlation between serum TBARS levels and uric acid levels in group B (r = 0.565, p <0.001), while it showed a statistically significant negative correlation between TBARS levels and α-tocopherol levels (r = - 0.837, p<0.001).Receiver operator characteristic (ROC) curve was used to discriminate between group B and A. The area under the curve was highest for serum TBARS (ROC area =0.909) followed by HbA1C (0.814) and their diagnostic accuracy were 85% and 77% respectively.Conclusion: Poor glycemic control and oxidative stress are interrelated states that characterize T2DM patients. Among study analytes, serum levels of TBARS and HbA1c have the highest relative importance in discrimination between patients with and without MIC so that may be, in sequence, a priority targets in the prevention and treatment of diabetic nephropathy.

Microalbuminuria --- Diabetic nephropathy --- Oxidative stress --- TBARS --- MDA --- α-tocopherol