Few Kids Eligible for Diabetes Screening Test Positive

By Lisa Rapaport

August 12, 2020

(Reuters Health) - While roughly one in four U.S. youth are eligible for screening for diabetes under current guidelines from the American Diabetes Association, very few children and teens who get screened test positive, a new study suggests.

Until 2018, screening recommendations for patients ages 10 and older only covered high-risk youth who were overweight with at least two other risk factors: non-white race, maternal gestational diabetes, family history of type 2 diabetes, or signs of insulin resistance. Starting in 2018, the ADA revised its recommendations to cover all overweight youth with just one of these other risk factors.

For the current study, researchers examined data on 14,119 youth ages 10 to 19 years old who participated in the National Health and Nutrition Examination Survey between 1999 and 2016 to evaluate both the current screening criteria and the performance of current definitions of prediabetes and diabetes.

Overall, 25.5% of youth in the age range examined would qualify for type 2 diabetes screening under the new recommendations, up from 10% under the previous guidelines, the study found.

However, undiagnosed cases of diabetes detected with screening were rare. More than 85% of the total confirmed diabetes cases in the study population had been diagnosed, while the prevalence of undiagnosed diabetes identified by screening was too small to estimate with precision, at less than 0.5% of youth, the study team writes in Pediatrics.

Criteria for diagnosing diabetes were: hemoglobin A1c (HbA1c) of 6.5% or higher or fasting plasma glucose (FPG) of at least 126 mg/dL.

"We found that there were few children and adolescents in the general U.S. population with undiagnosed diabetes - most cases of diabetes have been identified and diagnosed in clinical practice," said senior study author Elizabeth Selvin, a professor of epidemiology and medicine at Johns Hopkins Bloomberg School of Public Health in Baltimore.

The researchers also found that HbA1c screening may be useful regardless of screening eligibility, particularly to identify high-risk youth who could benefit from lifestyle interventions to prevent diabetes and cardiovascular risk.

That's because the association with cardiometabolic risk factors was stronger and more specific for hyperglycemia defined by HbA1c (specificity = 98.6%; sensitivity = 4.0%) than for hyperglycemia defined by FPG (specificity = 90/1%; sensitivity = 19.4%).

The study also looked at so-called prediabetes and found the prevalence varied from 1.5% to 17.5% in youth eligible for screening, compared with 0.5% to 9.9% in youth who didn't meet screening criteria.

Criteria for prediabetes included: impaired FPG (between 100 and 126 mg/dL), impaired glucose tolerance (IGT) (a 2-hour plasma glucose after a 75 g oral glucose tolerance test of 140–199 mg/dL), or hemoglobin A1c (HbA1c) between 5.7% and 6.4%).

One limitation of the study is the lack of repeat measurements as well as a limited sample size in certain subgroups of youth, the study team notes. Researchers also lacked complete data on all variables currently used in diabetes screening, including maternal history of gestational diabetes, family history of type 2 diabetes, and presence of acanthosis nigricans or polycystic ovarian syndrome.

The NHANES data also does not distinguish between type 1 and type 2 diabetes, the study team points out.

Even so, pediatricians should follow screening recommendations, and consider simple tests like the HbA1c test, said Dr. Tamara Hannon of the Riley Hospital for Children at Indiana University Health in Indianapolis.

That's because screening and education about prediabetes alone can lead to better rates of follow-up for obesity, and because early intervention and education can prevent diabetes, Dr. Hannon, author of a commentary accompanying the study, said by email.

"The pediatric healthcare community should strive to promote policies for the prevention of obesity, prediabetes, and type 2 diabetes when possible, identify type 2 diabetes earlier rather than later, and treat it expediently," Dr. Hannon said.

SOURCE: https://bit.ly/3aeShrC and https://bit.ly/3gIut1L Pediatrics, online August 10, 2020.