Fasting blood sugar test versus HbA1C in assessment of impaired fasting glucose in obese children

Introduction
The available information on risk factors for childhood obesity is scarce compared to that for adults, and the progression of impaired fasting glucose (IFG) to type 2 diabetes in obese children has not been systematically investigated. However, the transition from prediabetes to type 2 diabetes is more rapid in children and adolescents than in adults. The objectives were to assess the prevalence of IFG in obese children using their fasting blood glucose (FBG) levels and to test the validity of the HbA1c level as a measure of IFG.

Material and methods
This cross-sectional study included 412 obese children 6 to 18 years of age from two primary healthcare centers in Baghdad, with a BMI ≥ the 95th percentile according to their gender and age. Data (age, weight, height, BMI, FBG, HbA1c and family history) was collected over two interviews three days apart.

Results
IFG was found in 8.9% of boys and 6.3% of girls, and a significant association was found between gender and IFG (p < 0.001). The HbA1c level of the boys and girls in the cohort with IFG was inconclusive, as the results bordered on normal values.

Conclusions
Obesity is a risk factor for IFG, and fasting blood sugar is the test of choice for the early detection of type 2 diabetes. The HbA1c level was not a valid measure of IFG in this study. Larger samples may be needed to detect reliable results for HbA1c as a valid measure of IFG.