Comparison of tests used to detect obese and non-obese individuals with prediabetes

Diabetes mellitus (DM) has morbidity and mortality risks. Prediabetes indicates high blood glucose levels that aren't high enough to diagnose as diabetes. Early diagnosis of DM is important in preventing complications. Superiority of other glycosylated proteins (glycated albumin (GA), fructosamine) over HbA1c have been discussed in prediabetes diagnosis. Obesity, a risk factor for diabetes, influences the diagnostic and follow-up tests for prediabetes. We aimed to assess the value of glycated albumin and HbA1c values in obese and non-obese individuals in prediabetes diagnosis. Individuals (126; 72 females, 54 males), admitted to the Endocrinology Clinic of AEAH (June 2017- June 2018), were included in this study. Groups (prediabetes, diabetes and insulin resistance) were sub-divided as obese and non-obese, according to their body mass index (BMI). GA levels were determined spectrophotometrically. HbA1c measurements were performed with (1) ion exchange chromatographic HPLC method (Agilent 1100 Series), (2) Abbott c8000 and (3) Roche Cobas 501 instruments. Glycated albumin levels in diabetic patients were significantly higher than other groups (p <0.001). Glycated albumin values were similar between insulin resistance and prediabetes groups (p> 0.05). There was positive correlation between BMI and HbA1c values (0.065) and negative correlation between BMI and glycated albumin values (-0.129). For HbA1c, the fit coefficients for Roche Cobas-Abbott, Roche Cobas-HPLC, and Abbott-HPLC were 0.826, 0.916 and 0.773, respectively. In evaluation of glycated protein results for diagnosis of prediabetes BMI should be considered. ROCHE Cobas instrument was found to have better concordance with the gold standard HPLC test, compared to the Abbott analyser for HbA1c analysis. Keywords: Diabetes mellitus, glycated albumin, obesity,prediabetes