A Case-Control Study to Evaluate the Predictive Ability of Hba1c in Detecting Type-II Diabetes Mellitus with Nephropathy

Abstract

Objective: To evaluate the predictive ability of HbA1c in detecting type-II diabetes mellitus with nephropathy. Methods: The present case-control study was conducted in the Department of Biochemistry and General Medicine at S.M.M.H. Medical College and Hospital and Maa Vindhyavasini Autonomous State Society Medical College & Hospital Mirzapur, India. Patients with history of diabetes type 2 with nephropathy; history of diabetes without nephropathy; and no history of diabetes and nephropathy were included in the study.  A total of 30 cases and 30 controls were included in the study. HbA1c (glycated hemoglobin) was estimated by commercially available standard kits. Results: HbA1c was significantly (p=0.0001) higher among cases (9.81±1.33) compared to controls (5.88±2.46). HbA1c >8.0 correctly (efficacy) predicted DM2 with DN among 48.3% cases with sensitivity and specificity of 96.7 (95%CI=90.2-103.1) and 80.0 (95%CI=65.7-94.3) respectively. The AUC was also high (AUC=0.85, 95%CI=0.74-0.96). Linear regression analysis showed that lipid biomarkers such as HDL, LDL, VLDL & total cholesterol-to-HDL ratio as well as BMI and WHR were positive predictors of HbA1c, after adjusted for age and sex. In turn, TC and TG level was a negative predictive factor of HbA1c levels. The increase of 1 unit on TC was associated with a reduction of 0.05 in HbA1c levels. However, all the predictors had no statistical significance (p>0.05). Conclusion: HbA1c was found to be significantly higher among cases than controls. There was high sensitivity and specificity of HbA1c in diagnosing DM2 with DN.