Trends and Racial/Ethnic Differences in Age at Diagnosis of Adult-Onset Type 1 and Type 2 Diabetes in the United States, 2016–2022

Introduction

Age at diagnosis of diabetes is important for informing public health planning and treatment strategies. This study aimed to estimate trends and racial/ethnic differences in age at diagnosis of adult-onset diabetes by type in the U.S.

Methods

This serial nationwide cross-sectional study used data from the National Health Interview Survey in 2016–2022. Adults aged ≥18 years with self-reported age at diagnosis of adult-onset type 1 diabetes or type 2 diabetes were included. Trends in mean age at diagnosis of type 1 diabetes and type 2 diabetes and in proportions of people with type 1 diabetes or type 2 diabetes diagnosed at different ages were assessed by linear and logistic regressions. Racial/ethnic differences in mean age at diagnosis of type 1 diabetes and type 2 diabetes were determined.

Results

Included were 1,224 type 1 diabetes cases and 14,221 type 2 diabetes cases. From 2016 to 2022, the mean age at diagnosis of type 2 diabetes increased by 0.18 years annually (95% CI=0.05, 0.30 years, p=0.005), but no significant trend was observed for type 1 diabetes. The proportion of type 2 diabetes cases with diagnosis age ≥60 years increased by 3.17% and with diagnosis age in 18–29 years decreased by 5.62% annually (p≤0.01). On average, Hispanic individuals had type 1 diabetes diagnosed 3.2 years older and minority groups had type 2 diabetes diagnosed 2.0–6.1 years younger than non-Hispanic White individuals (p≤0.02).

Conclusions

Among U.S. adults, the mean age at diagnosis of adult-onset type 1 diabetes remained stable, and of adult-onset type 2 diabetes increased significantly from 2016 to 2022. Substantial and opposite differences in mean diagnosis age of type 1 diabetes and type 2 diabetes by race/ethnicity were identified.