Fasting blood glucose between 100 and 109 mg/dL versus prediabetes according to glycosylated hemoglobin

Abstract

Introduction: some studies have shown that fasting blood glucose values between 100 and 109 mg/dL are associated with high rates of prediabetes when the classification criteria are HbA1c values. The Argentine Diabetes Society still maintains 110 mg/dL as the value from which a patient is classified as having impaired fasting blood glucose; the frequency of individuals possibly incorrectly classified, according to this criterion, is not yet known in any Argentine population.
Objectives: to establish the frequency in a population without a diagnosis of diabetes mellitus with fasting blood glucose levels between 100 and 109 mg/dL in which prediabetes occurs according to HbA1c, to correlate both variables and to quantify the probability that this predicts with respect to others with fasting blood glucose levels <100 mg/dL.
Materials and methods: 1.002 samples from the same number of subjects from 45 clinical laboratories belonging to ALAC, with local processing of blood glucose and centralized processing of HbA1c by high performance liquid chromatography (HPLC). Statistical analysis: chi square, odds ratio, Pearson correlation coefficient, coefficient of determination and Durbin-Watson serial correlation.
Results: frequency of HbA1c ≥5.7% in the studied population with fasting blood glucose levels between 100 and 109 mg/ dL = 29.7%, chi square test: p<0.001; odds ratio of having HbA1c ≥5.7% between the population with fasting blood glucose levels of 100 to 109 mg/dL vs that one with values <100 mg/dL=4.328 (95% CI 2.922-6.411); r=0.852, r2 =0.727, DurbinWatson=1.152.
Conclusions: prediabetes diagnosed by HbA1c was four times more frequent in the studied population with fasting glucose values between 100 and 109 mg/dL than in that one with values below 100 mg/dL.