HbA1c predicts diabetes risk in children

Glycated hemoglobin (HbA1c) was a useful predictor of diabetes risk in children and identified prediabetes in children with other diabetes risk factors with the same confidence as fasting plasma glucose (FPG) and two-hour plasma glucose (2hPG), according to the results of a longitudinal study published recently in Diabetes Care.

“With rising prevalence of obesity and extreme obesity among children and adolescents globally, screening for children who are at risk of developing diabetes in the future using an easily administered test is very important,” study author Medhumita Sinha, MD, MHSM, medical officer at the National Institutes of Health, told Medical Economics.

The American Diabetes Association (ADA) recommends using HbA1c to screen for type 2 diabetes or prediabetes in asymptomatic children and adolescents aged 10 or older with a body mass index in the 85th percentile or greater and at least two additional type 2 diabetes risk factors.

“Our findings would validate the ADA screening criteria for children and adolescents at high metabolic risk,” Sinha said. “Child health providers can identify such at-risk patients and implement lifestyle interventions early to mitigate this risk.”

For the study, Sinha and colleagues measured HbA1c, FPG and 2hPG concentrations in an American Indian population to determine their ability to predict incident diabetes. Incident diabetes was defined as a FPG of 126 mg/dL or greater, a 2hPG of 200 mg/dL or greater, or an HbA1c of 6.5% or greater. The study included 2,095 children without diabetes aged 10 to 19 who were monitored through age 39, and 2,005 adults aged 20 to 39 monitored through age 59.

Next: Prediabetes prevalence

The prevalence of prediabetes-defined as an HbA1c of 5.7% or greater-was 3% in children and adolescents and 8.4% in adults. After long-term follow-up, the data showed that an HbA1c of 5.7% or greater was associated with a fourfold increase in the incidence rate of diabetes in boys and a more than sevenfold increased incidence rate in girls compared with participants with an HbA1c of 5.3% or less.

The researchers also estimated the clinical utility of HbA1c in children and adolescents. Using the ADA screening criteria of overweight or obese with two additional risk factors, the 10-year cumulative incidence of diabetes in participants with an HbA1c of 5.7% of greater was 78% (positive predictive value[PPV]) and the 10-year cumulative incidence in those with an HbA1c of less than 5.7% was 23% (negative predictive value [NPV]). Using a threshold of FPG of 100 mg/dL or greater, the PPV was 36% and the NPV was 78%; for 2hPG of 140 mg/dL or greater, the PPV was 52% and the NPV was 80%.

“HbA1c is a useful predictor of future risk for diabetes; in children it is easily administered (does not require a fasting state), reflects chronic glycemia, and can be used not only for screening but also tracking,” Sinha said.  “All these features make it easy for primary care providers to identify prediabetes in children. Since there are currently no long-term data regarding utility of HbA1c in children, this is a very important clinically relevant finding.”