Abstract
BACKGROUND: The optimal approach to screening and diagnosis of prediabetes and diabetes in youth is uncertain. METHODS: We conducted a cross-sectional analysis of 14 119 youth aged 10 to 19 years in the 1999-2016 NHANES. First, we examined the performance of American Diabetes Association risk-based screening criteria. Second, we evaluated the performance of current clinical definitions of prediabetes and diabetes based on hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), either HbA1c or FPG, or both HbA1c and FPG (confirmatory definition) to identify youth at high cardiometabolic risk. RESULTS: Overall, 25.5% of US youth (10.6 million in 2016) were eligible for screening. Sensitivity and specificity of the screening criteria for detecting any hyperglycemia were low for both HbA1c ≥5.7% (sensitivity = 55.5%, specificity = 76.3%) and FPG ≥100 mg/dL (sensitivity = 35.8%, specificity = 77.1%). Confirmed undiagnosed diabetes (HbA1c ≥6.5% and FPG ≥126 mg/dL) was rare, <0.5% of youth. Most (>85%) cases of diabetes were diagnosed. Associations with cardiometabolic risk were consistently stronger and more specific for HbA1c-defined hyperglycemia (specificity = 98.6%; sensitivity = 4.0%) than FPG-defined hyperglycemia (specificity = 90.1%; sensitivity = 19.4%). CONCLUSIONS: One-quarter of US youth are eligible for screening for diabetes and prediabetes; however, few will test positive, especially for diabetes. Most cases of diabetes in US youth are diagnosed. Regardless of screening eligibility, we found that HbA1c is a specific and useful nonfasting test to identify high-risk youth who could benefit from lifestyle interventions to prevent diabetes and cardiovascular risk in adulthood.