- In 2024, the national incidence rate of type I diabetes was 24.0 per 100,000 persons under age 20, but state-level rates ranged from 17.0 to 27.8.
- The ratio of board-certified pediatric endocrinologists to patients with type 1 diabetes also varied widely.
- Three states had fewer than five pediatric endocrinologists per 1,000 patients under age 18; in contrast, Washington, D.C. had 46.4.
Wide variations in the numbers of type 1 diabetes patients and specialists throughout the U.S. may affect care availability as diagnostic and treatment modalities continue to advance, data from a cross-sectional study indicated.
In 2024, the national incidence rate was 24.0 per 100,000 individuals under age 20, but state-level rates ranged from 17.0 to 27.8, reported Fei Wang, PhD, of Breakthrough T1D in St. Leonards, Australia, and colleagues.
“Such data provide vital information for understanding the burden of disease and guide health service delivery and resource allocation to enable equitable access to care irrespective of where individuals live,” the authors wrote in a JAMA Network Open research letter.
“National-level incidence and prevalence estimates may mask within-country variation,” they pointed out.
States with the lowest estimated incidence per 100,000 youth under age 20 were Hawaii (17.0), New Mexico (20.5), and California (20.6). The highest rates were found in West Virginia (27.8), Maine (27.4), and Vermont (27.4).
Overall, 1,476,859 U.S. individuals of all ages were living with type 1 diabetes in 2024. California (154,949) and Texas (123,329) had the highest prevalence, while Wyoming (2,720) and Washington, D.C. (2,810) had the lowest. Among youth under 20, there were 196,778 living with the condition, with California and Texas again showing the highest numbers, and Washington, D.C. and Wyoming the lowest.
Wang’s team also identified marked disparities in access to specialized care, specifically in the ratio of board-certified pediatric endocrinologists to patients with type 1 diabetes.
Nebraska, Mississippi, North Dakota, and New Mexico each had fewer than five pediatric endocrinologists per 1,000 patients younger than 18. In contrast, Washington, D.C. recorded the highest ratio at 46.4, followed by Rhode Island (22.5) and Massachusetts (20.7).
“Demand for pediatric endocrinologists (and multidisciplinary team members, such as diabetes educators and dietitians) will likely increase as type 1 diabetes screening identifies more individuals at risk … new drug interventions are approved, and diabetes technologies advance. Therefore, steps should be taken to address this inequity and prevent it from widening,” they urged.
Wang told MedPage Today that geography functions as “effectively a clinical variable — same disease, very different access.”
Excluding Washington, D.C., the researchers found that the number of pediatric endocrinologists in some states was six to eight times higher than in others. Wang noted that this gap is “far sharper than variation in primary care physicians (about twofold) or specialists generally (two- to fourfold) — and most of the thinnest-staffed states have at or above the national average incidence.”
Ultimately, the researchers hope these state-level estimates serve two practical functions, Wang said.
First, for individuals living with type 1 diabetes, the findings “give a clearer picture of where specialist capacity actually sits — including the option of seeking care across a state line when their own state is thinly served, which is already common along borders and worth planning for deliberately rather than discovering by accident.”
Second, for national policymakers, the data serves as a framework for targeted investment. “It identifies which states need workforce investment, training pipelines, and telehealth or shared-care support most urgently, rather than distributing resources evenly across a population where need clearly is not even,” Wang added.
In this analysis, the researchers applied the Type 1 Diabetes Index model to estimated incidence figures using data from the U.S. SEARCH for Diabetes in Youth Study, alongside adult incidence estimates and publicly available state demographic data regarding age, race, and ethnicity.
Study limitations included gaps in available data and varying diagnostic criteria used for adult populations.
