The prevalence and incidence of type 1 diabetes (T1D) vary widely across the US, while the distribution of pediatric endocrinologists shows even greater geographic disparities, new research showed.

“This cross-sectional study provides US state-level incidence and prevalence data for T1D and shows marked variation across the country. The results also demonstrate substantial inequity in the distribution of pediatric endocrinologists,” wrote Fei Wang, PhD, of Breakthrough T1D in St. Leonards, Australia, and colleagues in a research letter published in JAMA Network Open.

The authors added, “Demand for pediatric endocrinologists (and multidisciplinary team members, such as diabetes educators and dietitians) will likely increase as T1D screening identifies more individuals at risk for T1D, new drug interventions are approved, and diabetes technologies advance. Therefore, steps should be taken to address this inequity and prevent it from widening.”

The findings are cause for concern at a time of accelerating progress in T1D management, study co-author David Maahs, MD, professor of pediatrics and chief of pediatric endocrinology at Stanford Medicine in Palo Alto, California, told Medscape Medical News.

“Diabetes technology is a reality now and it’s going to keep getting better and better. Immunomodulation is very exciting, and we’ve actually got treatments now, yet we are only filling about half of the training slots. If it continues, there are just not going to be enough people practicing.”

T1D Rates Vary Across US States

The investigators estimated T1D incidence and prevalence using 2024 data from the T1D Index, the US SEARCH for Diabetes in Youth Study, and publicly available demographic data on age and racial and ethnic composition. Pediatric endocrinology workforce estimates were based on methods from a previous study and updated to 2024 using data from the American Board of Pediatrics dashboard.

T1D incidence and prevalence varied substantially among US states. Among people younger than 20 years, estimated incidence per 100,000 population ranged from 17.0 in Hawaii to 27.8 in West Virginia. Other states with relatively low estimated T1D incidence included New Mexico (20.5) and California (20.6), whereas Maine and Vermont had relatively high incidence (27.4 each).

“These are estimates, but they’re certainly the best data that we’ve got,” Maahs said. “It makes sense that there would be variability across states in the US based on different race and ethnicity. Asians and Hispanics might have slightly lower [T1D rates] than the non-Hispanic White and Black populations.”

However, Tessa Crume, PhD, associate professor of epidemiology at the Colorado School of Public Health in Aurora, Colorado, noted that the epidemiology is changing.

“The multi-state, CDC-funded DiCAYA study, which began after SEARCH concluded, has found climbing incidence in non-Hispanic Black youth since the SEARCH observation window closed. A model calibrated to the older SEARCH-era distribution will not capture that shift,” she told Medscape Medical News.

Also commenting, David Sparling, MD, PhD, chief of pediatric diabetes and endocrinology at the University of Oklahoma in Oklahoma City, questioned whether differences in surveillance might contribute to the reported variation.

“I’m not surprised by a degree of variability in incidence of T1D in the United States, but I do wonder if the state-by-state data is confounded by the reporting and public health infrastructures across each state,” he told Medscape Medical News.

Pediatric Endocrinologist Distribution Raises Concern

The ratio of board-certified pediatric endocrinologists per 1000 people younger than 18 years with T1D also varied substantially by state. At the low end were Idaho (2.7) and Wyoming (3.4), although Nebraska, Mississippi, North Dakota, and New Mexico also had fewer than 5.0 pediatric endocrinologists per 1000 young people with T1D. In contrast, Rhode Island and Massachusetts had ratios of 22.5 and 20.7, respectively. The District of Columbia had the highest ratio, at 46.4.

Aside from the District of Columbia, “these findings indicate the number of pediatric endocrinologists in some states was six to eight times higher than in others. These relative differences are substantially higher than those for primary care physicians (two times as high) and for specialist physicians of all types (two to four times as high),” the authors wrote.

Maahs pointed to previous research showing relatively low lifetime earning potential in pediatrics and its subspecialities as one possible contributor to workforce shortages.

“Peds is at the bottom, and if you go into pediatrics and further specialize in many areas, then it goes even worse,” he said.

Sparling said he was less surprised by the endocrinology workforce findings than by the state-by-state variation in T1D incidence.

“W ith the ongoing workforce and training difficulties and the fact that workload and lifestyle also differ state-to-state, recruiting new faculty into open positions is becoming harder and harder.”

Additionally, the number of board-certified endocrinologists may have overestimated the amount of direct patient care available. In Oklahoma, for example, American Board of Pediatrics (ABP) data contain several board-certified pediatric endocrinologists who no longer practice clinically or spend substantial time in other professional activities, Sparling said.

“I’d imagine the data is even more stark if one looked at clinical [full-time equivalents] of endocrinologists as opposed to simply ‘number’ of ABP-certified doctors,” he said.

Crume similarly cautioned that the numbers may not reflect actual access.

“Board-certified pediatric endocrinologist density is a proxy for access, not access itself. It does not capture cross-border treatment, telehealth, or the role of advanced-practice providers and certified diabetes care and education specialists.”

For Maahs, the pediatric endocrinologist shortage is particularly concerning given the expanding treatment options available to children with T1D.

“There’s never been a more exciting time to be caring for kids with diabetes, but we don’t have enough people, and they’re not allocated [appropriately] across the United States,” he said. “We need more pediatric endos so that children can benefit from all these new wonderful therapies that are out there.”

Maahs reported consulting for Abbott, Sanofi, Eli Lilly, Medtronic, Biospex, Kriya, and Enable Biosciences. Crume and Sparling reported having no relevant disclosures.

Miriam E. Tucker is a freelance journalist based in the Washington, DC, area. She is a regular contributor to Medscape, with other work appearing in the Washington Post, NPR’s Shots blog, and Diatribe. She is on X @MiriamETucker and BlueSky @miriametucker.bsky.social.