Objective: Recent recommendations suggest that HbA1c as a stable and standardised index of chronic glucose exposure over time and could be used as a better biochemical marker for the diagnosis of diabetes and prediabetes. Our aim in this cross-sectional study is to assess the validity of HbA1c as a screening tool for the detection of prediabetes in our patient population.
Methods: The study was done in 265 patients selected among the participants attended in our outpatient clinics. All had fasting plasma glucose (FPG) and 2 h post glucose measurements after 75-g glucose load, HbA1c, fasting insulin levels, lipid profiles and biometric measures. The participants were classified as control and prediabetic group in whom impaired glucose tolerance or impaired glucose tolerance plus impaired fasting glucose. Descriptive statistics were presented as mean±S.D. and percentages. For statistical comparisons, Pearson Correlation and MannWhitney U tests were used.
Results: The control group included 118 and the prediabetic group included 147 according to oral glucose tolerance test. There was no difference for sex, age and body mass index between groups. Mean HbA1c levels were significantly different in control and prediabetic group (5.3±0.4 and 5.7±0.4% respectively) (P<0.001). HbA1c was correlated with waist circumference, plasma fasting glucose levels and basal insulin levels (P<0.001 for all), 2 h post glucose measurements and triglyceride levels (P<0.005). There was no difference in the history of hyperlipidemia, gestational diabetes, family history of diabetes and macrosomic baby except the hypertension history (P<0.005) between two groups.
Conclusions: Our results may prove HbA1c as a valuable screening method for the diagnosis of prediabetic state in our population.