Assessing the Rising Prevalence of Early-Onset Type 2 Diabetes in the US

Early-onset type 2 diabetes (T2D), diagnosed before age 40, is on the rise in the US, according to a new analysis.1 Researchers found that individuals with early-onset T2D were more likely to come from underserved populations and had a worse cardiometabolic profile compared with those diagnosed later in life.

This retrospective study is published in Diabetes Therapy.

“These data indicate that undiagnosed early-onset T2D has increased in prevalence over time in the USA, suggesting more attention is needed to screen and diagnose younger adults with T2D,” wrote the researchers of the study.

Data reveal a growing burden of early-onset type 2 diabetes, highlighting disparities and increased cardiometabolic risk. | Image credit: andre - stock.adobe.com

Adults with T2D face significantly greater financial hardship compared with those without the disease.2 These financial risks are particularly pronounced among younger adults, women, Black and Hispanic individuals, Medicaid recipients, and those without earned income, according to one study. These findings point to a need for policies and care strategies that address both medical and financial well-being.

The present study used data from the National Health and Nutrition Examination Survey (NHANES), a series of nationally representative, cross-sectional surveys conducted between 1999 and 2020.1 Researchers retrospectively analyzed participants under age 40 with diagnosed or undiagnosed T2D to estimate prevalence trends over time. Early-onset T2D was identified based on self-reported physician diagnosis or laboratory evidence of undiagnosed diabetes.

Demographic factors, socioeconomic indicators, clinical characteristics, and comorbidities were compared between individuals with early-onset T2D and those with later-onset disease.

Between 1999 and 2020, the prevalence of early-onset T2D in the US increased, with diagnosed cases rising from a mean (SE) 1.42% (0.19) in 1999-2000 to 1.72% (024) in 2017-2020, and undiagnosed cases doubling from 0.18% (0.09) to 0.35% (0.06) over the same period.

Compared with those diagnosed after age 40, individuals with early-onset T2D were more likely to be Hispanic, uninsured, and have a lower poverty-income ratio, while being less likely to be non-Hispanic White or to have private or Medicare coverage (all P < .05). Clinically, this group demonstrated a worse cardiometabolic profile, with higher mean glycated hemoglobin, Homeostatic Model Assessment for Insulin Resistance score, fasting insulin and glucose, body mass index, and waist circumference. Despite these elevated risk factors, they were less likely to have established comorbidities such as heart failure, coronary heart disease, stroke, chronic kidney disease, or cancer (all P < .05), even after adjusting for disease duration.

However, the researchers acknowledged several study limitations. Because NHANES provides cross-sectional rather than longitudinal data, causal inferences regarding disease progression or the development of comorbidities were not able to be evaluated. Additionally, the reliance on self-reported information may have resulted in recall bias, and the exclusion of institutionalized populations may have limited generalizability. Furthermore, because data were collected in cycles over 2 to 3 years, temporal changes within each cycle could not be captured.

Despite these limitations, the researchers believe the study underscores the need for earlier detection and targeted interventions to address the rising rates of early-onset T2D among underserved populations in the US.

“Our findings indicate that the prevalence of undiagnosed early-onset T2D has increased over time in the USA,” wrote the researchers. “Early-onset T2D disproportionately affects certain ethnicities, such as Hispanic people and non-Hispanic Black people, as well as underserved populations.”

References

1. Lee CJ, Bergman BK, Gou R, et al. Prevalence, demographic and clinical characteristics of individuals with early-onset type 2 diabetes in the USA: an NHANES analysis 1999-2020. Diabetes Ther. Published September 16, 2025. doi:10.1007/s13300-025-01788-7

2. Steinzor P. Type 2 diabetes linked to poor credit, financial distress. AJMC®. Published August 4, 2025. Accessed September 16, 2025. https://www.ajmc.com/view/type-2-diabetes-linked-to-poor-credit-financial-distress