U.S. researchers confirm that prediabetes risk, presence can be identified using A1C test with same accuracy as other, less convenient tests.
The prevalence of type 2 diabetes has increased among youth in the U.S. Between 2001 and 2009, there was a 30.5% rise in the overall prevalence of diagnosed diabetes (1,2). Many youth diagnosed with type 2 diabetes have poor glycemic control (2,3) and experience higher rates of cardiovascular disease risk markers, fatty liver disease, and early evidence of microvascular complications (2,4,5). This highlights the need for early detection of prediabetes to prevent the increase in diabetes and its associated cardiometabolic risk factors.
The object of the study was to determine the utility of predicting type 2 diabetes in children using the HbA1c, fasting plasma glucose (FPG), or the 2-hour post-load plasma glucose (2hPG). Incident diabetes (FPG ≥126 mg/dL [7.0 mmol/L], 2hPG ≥200 mg/dL [11.1 mmol/L], HbA1c ≥6.5% [8 mmol/mol], or clinical diagnosis) was determined in 2,095 children without diabetes ages 10–19 years monitored through age 39, and in 2,005 adults ages 20–39 monitored through age 59. Areas under the receiver operating characteristic (ROC) curve for HbA1c, FPG, and 2hPG in predicting diabetes within 10 years were compared.
C0-author Madhumita Sinha, MD, from the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, in Phoenix, Arizona, said that the benefit of the HbA1c test is its convenience. She added that, when assessing an overweight or obese child aged 10 years, “most pediatricians would…do a fasting blood sugar.” However, she noted that ” no kid is fasting at 8 o’clock in the morning.”
The American Diabetes Association (ADA) recommends that asymptomatic children and adolescents be screened for type 2 diabetes if they are aged ≥ 10 years, have a body mass index ≥ 85th percentile for age and sex, and have at least two additional risk factors.
While measuring HbA1c in children is convenient, as it does not require fasting, and a single test can diagnose and monitor glycemic control, there have been few studies examining the association between HbA1c in childhood and the risk of developing diabetes.
Therefore, the researchers measured HbA1c, FPG, and 2hPG concentrations in a longitudinal study of residents in an American Indian community followed from 1965 to 2007. The current analysis included 2,095 children without diabetes ages 10 to 19 years at enrollment, who were monitored to age 39 years, and 2,005 adults ages 20 to 39 years, who were monitored to age 59 years. Of the children and adolescents, 18.8% were overweight and 53.1% were obese, while the equivalent rates in adults were 19.1% and 73.8%, respectively.
The prevalence of prediabetes as assessed by HbA1c ≥ 5.7% was 3.0% in the children and adolescents and 8.4% in the adults, while that assessed by FPG ≥ 100 mg/dL was 9.2% in children and adolescents and 21.1% in adults. Impaired glucose intolerance, as determined by 2hPG ≥ 140 mg/dl, was 8.1% in children and adolescents and 17.3% in adults.
The median time to diabetes diagnosis or the last examination before the onset of diabetes was 5.2 years in the children and adolescents and 4.6 years in the adults. Incidence patterns of diabetes were similar in children and adults, although rates were higher in adults.
The researchers found that male children and adolescents in the highest HbA1c category (5.7% to 6.4%) at baseline had a fourfold higher incidence of diabetes during follow-up vs those in the lowest HbA1c category (≤ 5.3%). Female children and adolescents in the highest HbA1c category had a sevenfold increased incidence of diabetes over those in the lowest category.
“The lack of a significant difference in AUC between HbA1c and the glucose measures suggests that all three tests have the potential to offer the same level of sensitivity and specificity, depending on the threshold chosen,” the authors write.
Among children and adolescents who met the ADA recommended screening criteria for diabetes, the estimated 10-year cumulative incidence of diabetes in those with HbA1c ≥ 5.7% was 78% vs 23% in those with an HbA1c < 5.7%, giving a positive predictive value (PPV) of 78% and a negative predictive value (NPV) of 77%. For FPG ≥ 100 mg/dL, the PPV was 36% and the NPV was 78%, while the PPV and NPV for 2hPG ≥ 140 mg/dL was 52% and 80%, respectively.
The researchers conclude that HbA1c “can be used to assess risk for diabetes in children or to identify children with prediabetes with the same confidence as FPG or 2hPG.”
- The prevalence of type 2 diabetes has increased among youth in the U.S.
- A single HbA1c test can diagnose and monitor glycemic control.
- HbA1c can be used to assess risk for diabetes in children or to identify children with prediabetes with the same confidence as FPG or 2hPG.
Diabetes Care.Jan. 2017;40:16-21. Article