Evidence Lacking to Screen Youth for Prediabetes, Type 2 Diabetes

The Academy is reviewing the USPSTF’s Sept. 13 final recommendation statement (an “I” grade), final evidence review and evidence summary. This is the first time the task force has made a recommendation on screening this particular population for prediabetes and type 2 diabetes; a draft recommendation was posted for comments on Dec. 14, 2021.

“The rate of prediabetes and type 2 diabetes in youth is increasing. The challenge is that we don’t have the evidence to tell us whether or not screening in primary care helps,” task force member Michael Cabana, M.D., M.A., M.P.H., said in a USPSTF bulletin. “It is important that health care professionals be aware of the signs and symptoms of prediabetes and type 2 diabetes and use their judgment when determining whether or not to screen youth.”

The recommendation applies to children and adolescents younger than 18 years who have not been previously diagnosed with prediabetes or diabetes and who do not show any signs or symptoms of either condition. It does not apply to pregnant youth and does not specifically apply to children and adolescents with overweight or obesity, who are at the highest risk for developing prediabetes or type 2 diabetes. The task force has issued separate recommendations on screening for gestational diabetes in people who are pregnant and screening for obesity in youth.

While there is limited evidence on screening for prediabetes and type 2 diabetes in youth, a JAMA Pediatrics study published earlier this year found that between 1999 and 2018, the prevalence of prediabetes in children ages 12 to 19 more than doubled, from 11.6% to 28.2%. The CDC, meanwhile, estimates that more than 80% of adults with prediabetes don’t know that they have it — a number that could be even higher in young people, given the lack of regular screening.

Findings and Future Research

For the final recommendation, the USPSTF considered a fasting plasma glucose level of 126 mg/dL or greater, an HbA1c level of 6.5% or greater or a 2-hour postload glucose level of 200 mg/dL or greater as consistent with the diagnosis of type 2 diabetes, and a fasting plasma glucose level of 100 to 125 mg/dL, an HbA1c level of 5.7% to 6.4% or a 2-hour postload glucose level of 140 to 199 mg/dL as consistent with prediabetes. These levels are in alignment with classifications and diagnosis listed in the American Diabetes Association’s Standards of Medical Care in Diabetes—2020.

A lack of evidence was the USPSTF’s most notable finding.

Since none of the studies in the evidence review examined the direct benefits of screening for prediabetes and type 2 diabetes in asymptomatic children and adolescents, the task force said there was inadequate evidence to show that screening improved health outcomes, that interventions for screen-detected prediabetes or type 2 diabetes improved health outcomes or that interventions for prediabetes delay or prevent progression to type 2 diabetes.

And because none of the reviewed studies addressed the harms of screening the USPSTF said there was inadequate evidence to determine the harms of screening asymptomatic children and adolescents, or of interventions for prediabetes, screen-detected type 2 diabetes or recently diagnosed type 2 diabetes.

The task called for more research on how screening affects health outcomes, especially for racial and ethnic minority youth and those at higher risk, as well as several other topics.