The Dilemma of Diagnosing Type-2 Diabetes Mellitus [T2DM] in Overweight Children and Adolescents

Abstract

American Diabetes Association [ADA] has recommended that diabetes should be diagnosed when HbA_1c is ?6.5%. Subjects with HbA_1c of 6.0 to < 6.5% were at the highest-risk for developing diabetes. Objectives: To determine the sensitivity and specificity of HbA_1c ? 6.5% to diagnose Type 2 Diabetes Mellitus [T2DM] in overweight children and the adolescents as compared to an oral glucose tolerance test. Retrospective chart review was done from January 2004-December 2008, and search criteria included overweight children who had OGTT and HbA_1c done. Based on OGGT we divided the data into normal, impaired and diabetic groups.

The results shows that HbA_1c cut-off of ? 6.5% had a specificity of 96% and a sensitivity of 40% in accurately diagnosing patients with T2DM. Sixty percent of T2DM and 44.60% of impaired OGTT subjects would show a normal glycemic status if only HbA_1c is used to diagnose them. Homeostasis Model of Assessment - Insulin Resistance [HOMA-IR], Quantitative Insulin Sensitivity Check Index [QUICKI] and HbA_1c levels were statistically significant between normal versus diabetic and normal versus impaired groups [p<0.05]. Due to the low sensitivity of the HbA_1c test in diagnosing diabetes, it may result in missed or delayed diagnosis of T2DM if used exclusively to diagnose diabetes.