Trends in Prevalence of Insulin Resistance Among Nondiabetic/Nonprediabetic Adolescents, 1999-2020

Purpose: Insulin resistance (IR)/hyperinsulinemia in young individuals is associated with the subsequent development of diabetes and cardiovascular disease. To assess trends in the prevalence of IR/hyperinsulinemia among nondiabetic/nonprediabetic adolescents in the US from 1999 to 2020. Methods: A total of 6111 adolescents without diabetes and prediabetes were included from ten cycles of National Health and Nutrition Examination Survey (NHANES) between 1999-2000 and 2017-2020. Hyperinsulinemia or IR was defined as fasting insulin or homeostasis model assessment of insulin resistance [HOMA-IR] above the 75th percentile in all participants who underwent blood tests on fasting insulin, glucose, and hemoglobin A1c. Trends in prevalence rates were estimated using joinpoint regressions with heteroscedastic and uncorrelated errors. Results: The overall weighted median fasting insulin level, prevalence of hyperinsulinemia, and IR were 9.9 μU/ml [95% confidence interval (CI): 9.6, 10.1], 17.2% (95% CI: 15.7, 18.6), and 16.4% (95% CI: 15.2, 17.9), respectively. The estimated prevalence of hyperinsulinemia and HOMA-IR increased significantly from 15.2% (95% CI: 12.1, 18.9) and 14.0% (95% CI: 11.1, 17.8) in 1999-2000% to 21.5% (95% CI: 17.1, 26.3) and 20.4% (95% CI: 16.4, 25.6) in 2017-2020, respectively, with a 3.35% (95% CI: 1.74, 4.99) and 3.41% (95% CI: 1.72, 5.12) relative increase per 2-year survey cycle, respectively (p for trend <0.05). Substantial increases were observed in the subgroups of girls, Hispanic, non-Hispanic white, and overweight adolescents. Conclusions: The prevalence of hyperinsulinemia/IR increased substantially among US nondiabetic/nonprediabetic adolescents over the last two decades. Early detection and effective interventions are in dire need to reverse the rising tide.