Current Practices Identified for Screening Teenagers for Type 2 Diabetes
Many pediatricians and family practice physicians recently surveyed were unaware that hemoglobin A1c is a recommended diagnostic test for type 2 diabetes; however, education on this recommendation was linked an increased number of physicians who said they would use the test in a hypothetical case involving an adolescent, according to a cross-sectional study in the February Journal of Adolescent Health.
“This potential for increased uptake of A1c could lead to missed cases prediabetes and diabetes in children, and increased costs,” said lead author Joyce M. Lee, MD, MPH, Associate Professor of Pediatrics, University of Michigan School of Public Health, Ann Arbor. Dr. Lee and colleagues cited studies suggesting a lower performance of A1c testing in children than in adults.
ADA Screening/Diagnostic Recommendation
In 2010, the American Diabetes Association (ADA) released updated guidelines that added use of hemoglobin A1c ≥ 6.5% as a screening/diagnostic test for type 1 and type 2 diabetes in children and adults in addition to the previously recommended fasting tests (ie, fasting plasma glucose test and 2-hour plasma glucose test). This change is controversial given recent findings suggesting that the A1c screening tool has a lower test performance in children than in adults.
“While A1c is convenient (no fasting required) and is a good assessment of average blood glucose over 3 months, it has limitations in those who have anemia, cystic fibrosis, thalassemia, or chronic kidney disease,” commented Jane Chiang, MD, Senior Vice President for Medical and Community Affairs at the ADA. “There may also be disparities in ethnic cohorts, although this is controversial. For example, it has been reported that African Americans have higher glycation rates and therefore, higher A1cs compared to Causasians, while in the Asian population, the A1c is reported to be a more accurate assessment (versus blood glucose),” she explained.
In addition, the ADA acknowledges [in the 2014 Standards of Medical Care in Diabetes] that there are limited data in the pediatric population, Dr. Chiang said. “In children, there is variability of age ranges, and we do not have normative data of A1c and how it relates to children as they are developing,” Dr. Chiang said. “It is hard to recruit for pediatric studies; thus, a lot of the information that is currently available is based on expert opinion and smaller studies. However, the ADA still endorses A1c as an option to screen/follow diabetes in children,” she said.
Hypothetical Case Design
The study authors examined survey responses from 604 pediatric and family practice physicians regarding the types of diagnostic tests they would order when presented with a hypothetical case involving an adolescent at risk for type 2 diabetes.
The vast majority (92%) said that they would screen the hypothetical case for diabetes, with most respondents initially ordering a fasting test (63%) or an A1c test (58%) as part of the initial battery of tests. Most physicians who ordered an A1c test ordered it in combination with a nonfasting (15%) or fasting test (15%) and 7% ordered the A1c test alone.
84% of Physicians Would Order an A1c Test to Diagnose Diabetes
Only 38% of respondents were aware of the revised ADA guidelines. After being presented with the revised guidelines, the majority of respondents (67%) reported that they have or will change their screening practices by including A1c in the initial testing battery. The authors estimated that this would increase the percentage of physicians who would initially order an A1c test to 84%.
“If A1c is performed as recommended, it should facilitate the diagnosis,” Dr. Chiang commented. “The ADA recommends testing for type 2 diabetes in asymptomatic children, especially if they are at risk (see Table 5, page S18 of the ADA guidelines),” she said. Risk factors include overweight (BMI >85%) and >2+ risk factors (family history, race/ethnicity, signs of insulin resistance, maternal history or diabetes or GDM). In addition, Dr. Chiang explained that “unless a person is symptomatic (drinking or urinating frequently), ADA recommends that the abnormal test be repeated as soon as feasible.”