Trends in Hyperinsulinemia and Insulin Resistance Among Nondiabetic US Adults, NHANES, 1999-2018

Introduction: Hyperinsulinemia and insulin resistance are strong predictors of cardiometabolic diseases, which disproportionately affect individuals across gender, racial/ethnic, and socioeconomic groups. We aim to estimate and test the temporal trends in the prevalence of hyperinsulinemia and insulin resistance (IR) by sociodemographic groups among nondiabetic adults in the United States from 1999 to 2018. Methods: We used data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018. We fitted linear and joinpoint logistic regression models to test the sample weighted and age-standardized time trends for linear and nonlinear trends in the prevalence of hyperinsulinemia and IR, respectively. Results: We included 17,310 nondiabetic men and nonpregnant women aged 20 years or older. The age-standardized prevalence of hyperinsulinemia increased from 28.2% in 1999-2000 to 41.4% in 2017-2018, with IR prevalence similarly rising from 24.8% in 1999-2000 to 38.4% in 2017-2018. Across the entire period examined, individuals who were male; non-Hispanic Black; Hispanic; or had a lower educational level or lower family income consistently had a higher prevalence of hyperinsulinemia and IR than other groups. We found increasing temporal trends in the prevalence of hyperinsulinemia and IR for all the sociodemographic subgroups, at least in some periods from 1999 to 2018. Conclusions: There was an increased age-standardized prevalence of hyperinsulinemia and IR among nondiabetic adults in the US across each defined sociodemographic group from 1999 to 2018. The difference in prevalence across subgroups underscores the need for designing personalized and targeted interventions to address disparities.