The Utility of Hemoglobin A1c in Detecting Prediabetes in Obese Youth

Abstract

Introduction. The incidence and prevalence of Type 2 diabetes mellitus has been steadily increasing over the past ten years, and is currently approximately 4.1 per 1000 12‐19 year olds in the US2. This increase has been linked to obesity and a sedentary lifestyle. Prediabetes, in the pediatric population is defined as having a fasting plasma glucose concentration ≥ 100 to 125 mg/dL or 2‐hour glucose concentration during an oral glucose tolerance test ≥ 140 mg/dL but <200 mg/dL. Aims. The goal of this study is to describe the sensitivity and specificity of hemoglobin A1c at various thresholds to identify prediabetes, as defined by impaired fasting glucose and/or impaired glucose tolerance; the population included in this study consist of obese youth referred to the Division of Endocrinology and Diabetes at Phoenix Children’s Hospital for weight‐related issues. We anticipate describing various levels of sensitivity and specificity of hemoglobin A1c in comparison with gold standard tests, such that it can be used to propel further studies to ultimately reduce the immense patient burden of fasting in the pediatric population. Methods. We conducted a retrospective cross‐sectional chart review and employed receiver operating characteristic (ROC) curve analysis of data including but not limited to hemoglobin A1c, fasting plasma glucose, and 2‐hr post‐prandial plasma glucose. The benefits of this study include the potential of reducing the patient burden of fasting prior to examination. This review will determine, if any, the potential value in being able to use hemoglobin A1c clinically to detect prediabetes in pediatric patients; determining this may provide critical information to improve the monitoring and screening of prediabetes. Conclusions. Compared to the gold standards of fasting plasma glucose and oral glucose tolerance tests, we found that hemoglobin A1c had a low sensitivity and specificity for identifying prediabetes.