Trends And Disparities In Diabetes Among Adults In The United States, 1999-2018

Introduction: Diabetes (DM) increases cardiovascular disease morbidity and mortality and the risk of severe complications/death among patients with COVID-19. We aimed to estimate the trends of DM over time among adults in the US. Hypothesis: We anticipated an increase in DM and persistent disparities by racial/ethnic and socioecnomic subgroups from 1999 to 2018. Methods: Data were from a nationally representative sample of US adults (≥20 years; NHANES 1999-2018). Diagnosed DM was defined as a self-reported previous diagnosis of DM by a physician or any other health professionals (other than during pregnancy). Undiagnosed DM was defined as elevated levels of fasting plasma glucose (FPG≥126 mg/dL) or HbA1c (≥6.5%). Total DM included those who had either diagnosed or undiagnosed diabetes. Prediabetes was defined as no DM but a HbA1c level of 5.7% - 6.4% or an FPG level of 100 mg/dL-125 mg/dL. All estimates were age-standardized to the 2010 US census population for age groups 20-44, 45-64, and 65+ years. All analyses accounted for the complex survey design. Logistic regressions were conducted to calculate a P-value for trend. Results: Our sample included 53,533 US adults. From 1999 to 2018, the age-adjusted prevalence of total DM increased significantly from 9.05% (95% CI, 7.80%-10.2%) to 13.9% (95% CI, 12.5%-15.4%) and the prevalence of prediabetes increased from 22.5% (20%-25.2%) to 40.2% (37.4%-43.1%) (P-trends<0.001). The rate of increase in prevalence was higher among Mexican Americans but lower among non-Hispanic black individuals compared to non-Hispanic white individuals (all P-trends<0.01, P-interaction=0.003). Trends in total DM by education and income levels were similar to the overall trend but disparities persisted between low- and high-socioeconomic groups (all P-trends<0.001, P-interaction>0.05) ( Figure 1 ). Conclusions: The prevalence of DM increased significantly from 1999 to 2018 among US adults. There are substantial and persistent disparities between racial/ethnic and socioeconomic subgroups.