Extra Tests Help Screen High-Risk Children for Diabetes

Doctors should add an oral glucose tolerance test (OGTT) to their hemoglobin A1C (HbA1C) test, also known as glycated hemoglobin, when they screen high-risk children for prediabetes and diabetes.

Glycated hemoglobin is a form of hemoglobin that is measured primarily to identify the three-month average plasma glucose concentration. The test is limited to a three-month average because the lifespan of a red blood cell is four months (120 days).

Pediatricians at the Korea University College of Medicine reviewed the medical records of 217 obese boys and 172 obese girls who had undergone OGTT and HbA1C testing simultaneously between January 2010 and June 2016 in six University hospitals. The children were diagnosed with prediabetes (fasting glucose 5.6 to 6.9 mmol/L; 2-hour glucose 7.8 to 11.0 mmol/L) or with diabetes (fasting glucose 7.0 mmol/L or higher; 2-hour glucose 11.1 mmol/L or higher).

The scientists detected all children with diabetes using the combined OGTT and HbA1C tests. Roughly half of overweight children at risk had prediabetes or diabetes based on OGTT results and the agreement between OGTT and HbA1C results was moderate. The authors found that the optimal HbA1C cutoff points were 40 mmol/mol (5.8%) for prediabetes and 44 mmol/mol (6.2%) for diabetes. The team recommends the combined use of fasting and 2-hour glucose levels, in addition to HbA1C, for the diagnosis of childhood prediabetes and diabetes.

Hyo-Kyoung Nam, MD, PhD, clinical assistant professor of pediatrics, and lead investigator, said, “The usefulness of adult criteria of HbA1C for the diagnosis of prediabetes and diabetes in children and adolescents remains to be clarified due to disparities between the results of OGTT- and HbA1C-based tests. The trend in the prevalence of type 2 diabetes mellitus in the pediatric population is rising. Early detection of prediabetes and early diabetes is crucial to enable preventive management of cardiovascular disease. Diabetes-related complications and mortality can lead to major financial burden in individuals with diabetes.” The study was presented on April 4, 2017, at the annual scientific meeting of the Endocrine Society, held in in Orlando, FL, USA.