DCB Newsletter #3/26: DID YOU KNOW… why type 1 diabetes is rising and what projections to 2050 tell us?

Dear Community,

We are happy to provide you with a new episode of our “DID YOU KNOW…” series – this time with a focus on the long‑term rise in type 1 diabetes incidence and what current projections tell us about the coming decades.

For much of the 20th century, type 1 diabetes (T1D) was regarded as a relatively stable autoimmune condition. That picture has changed.

Across North America and Europe, the number of children, adolescents and adults newly diagnosed with T1D has been increasing for decades and the COVID‑19 pandemic appears to have disrupted an already rising curve. With the latest IDF Diabetes Atlas (11th edition, 2025) and the Global Burden of Disease (GBD) 2021 projections to 2050, we now see a clearer, if sobering, outlook.

United States

The SEARCH for Diabetes in Youth study remains the key source for paediatric incidence in the U.S. In 2017–2018, annual T1D incidence among people under 20 years reached 22.2 per 100,000, reflecting an average yearly increase of about 2% since 2002–2003. CDC estimates suggest that in 2025 around 1.7 million U.S. adults are living with T1D, together with roughly 304,000 youth under 20 – an increase in overall T1D prevalence of about 30% since 2017. The steepest relative increases have been observed among Hispanic and Black youth.

Adult trends are more mixed. One large longitudinal analysis from 2001–2015 found a slight decline in adult T1D incidence (−1.3% per year), while youth incidence continued to rise. This divergence hints that the precipitating factors for childhood‑onset and adult‑onset T1D may differ.

Germany and Austria

In Germany, the DPV registry and the North Rhine‑Westphalia (NRW) registry have followed T1D incidence in children under 15 since the 1990s. Over the 2010s, incidence rose by roughly 3–4% per year, with signs of a plateau just before the pandemic. COVID‑19 disrupted that plateau: DPV data show a wave‑like pattern of higher‑than‑expected incidence followed by partial reversion toward the mean between 2020 and 2023. In NRW, 2020 incidence reached about 29.2 per 100,000 person‑years – the highest level reported so far in Germany.

Austria offers one of the longest‑running nationwide paediatric T1D registries, active since 1989. Between 1989 and 2011, incidence in children under 15 increased with an annual percent change of +4.6%. From 2011 to 2020, the trend flattened – only to jump to a record 28.7 per 100,000 person‑years in 2021, closely paralleling the German experience. For the first time, paediatric type 2 diabetes incidence in Austria is also rising in a statistically significant way.

Switzerland

Switzerland does not yet have a single integrated national T1D registry, but health‑claims data and participation in DPV/DIVE allow robust estimates. Approximately 40,000 people are currently living with T1D in Switzerland. Historical analyses from the late 20th century documented an absolute incidence increase of 0.67 cases per 100,000 per year between 1965 and 1996 – a relative annual rise of about 3.4% – with a particularly steep climb among children under five. Recent Swiss data still point to an upward but moderate trend, consistent with patterns in Germany and Austria.

From a Swiss perspective, one conclusion is clear: establishing a fully integrated national paediatric and adult T1D registry remains an important unmet need for epidemiology, health‑system planning and research.

Scandinavia, France, and other high‑incidence countries

The Nordic region remains the global hotspot for childhood‑onset T1D. Finland has historically reported the highest incidence worldwide – around 60 per 100,000 children per year – although this rate appears to have stabilised or slightly declined since the early 2000s. Sweden, Norway and Denmark follow closely, and the IDF Diabetes Atlas 11 still places Finland, Sweden and Norway among the global top ten for published incidence.

A 2024 systematic review of European paediatric data (1994–2022) confirmed that the Nordic countries retain the highest absolute incidence in Europe, even as their rate of increase has slowed relative to the rapid rise in previously low‑incidence Central and Eastern European countries. A Swedish nationwide cohort study of 2.9 million children found that the heritability of childhood‑onset T1D has remained high and stable at around 0.83 over 30 years, implying that known environmental factors explain less than 10% of the observed rise.

In France, Santé publique France reports an annual T1D incidence increase of approximately 4%. Paediatric incidence rose from 15.4 to 19.1 per 100,000 person‑years between 2010 and 2015, with an overall rate of 19.5 per 100,000 in 2015–2017 and substantial regional variation. Sardinia (Italy) now reports the world’s highest published paediatric incidence at 76.3 per 100,000 (2022), having overtaken Finland, while the United Kingdom and Ireland also remain in the global top ten.

Projections to 2050

Two major modelling efforts suggest the same direction of travel. The GBD 2021 study projects that age‑standardised global type 1 diabetes prevalence will rise by about 23.9% between 2021 and 2050, a smaller relative increase than for type 2 diabetes, but a substantial absolute rise given the lifelong management burden of T1D. The IDF Diabetes Atlas 11 projects that overall adult diabetes prevalence (type 1 and type 2) will grow from 589 million in 2024 to around 853 million by 2050, a 46% absolute increase. While most of this growth is driven by type 2 diabetes, T1D contributes meaningfully through sustained or rising incidence in high‑income countries and improved survival, which increases prevalence even if incidence stabilises.

For the U.S., a modelling exercise based on SEARCH data suggests that, under a linear‑increase scenario, the number of young people with T1D could nearly triple by 2050, with the steepest relative growth among Hispanic and Black children.

Why is incidence rising?

T1D is a polygenic autoimmune disease in which environmental triggers act on a susceptible genetic background. Several, often overlapping, hypotheses are under investigation:

• Reduced early‑life exposure to common infections (“hygiene hypothesis”), with mixed evidence.
• Rising childhood adiposity and insulin resistance, which may accelerate the clinical presentation of existing islet autoimmunity (“accelerator hypothesis”).
• Viral triggers such as enteroviruses and, more recently, SARS‑CoV‑2, where meta‑analyses report a 14–27% increase in paediatric T1D incidence during the pandemic.
• Dietary and microbiome‑related factors, including early cow’s‑milk exposure, gluten timing and shifts in the infant gut microbiome.
• Vitamin D status and latitude, endocrine‑disrupting chemicals, pollution and perinatal factors such as higher maternal age, higher birth weight and Caesarean delivery.

The Swedish cohort study mentioned above is a stark reminder of how much remains unexplained: even with population‑wide data on several environmental exposures, less than 10% of the rise in T1D incidence in Sweden could be attributed to known factors. This underscores the need for long‑term birth cohorts, population‑level islet‑autoantibody screening and mechanistic immunology.

Implications for the next decade

Three practical implications stand out for health systems, innovators and the diabetes community:

• Health systems need to prepare for more people living with type 1 diabetes. Even under conservative assumptions, the number of people living with type 1 diabetes will continue to rise. This has practical consequences for insulin and sensor supply, reimbursement for diabetes technology, specialist care and clinical-trial infrastructure.
• Early detection is becoming more relevant. Type 1 diabetes can often be detected before symptoms appear, through markers of early autoimmune activity. With the first therapy now approved to delay clinical onset in people at an early disease stage, screening is no longer only a research question. Programmes such as Fr1da in Germany and the D1Ce trial in Italy show how early identification could inform future intervention strategies.
• We still need to understand why incidence is rising. Many environmental factors are being studied, but no single explanation is sufficient. Until we better understand the drivers behind the increase, true primary prevention will remain out of reach. This makes high-quality registries, long-term cohort studies and coordinated research more important than ever.

At DCB, we see these trends as both a warning and a call to action.

The rising incidence of type 1 diabetes will require sustained collaboration between clinicians, researchers, industry, policymakers and crucially people living with diabetes and their families.

Our work in innovation, clinical research infrastructure and community engagement aims to contribute to that collective effort.

Selected sources

GBD 2021 Diabetes Collaborators. Global, regional, and national burden of diabetes from 1990 to 2021, with projections of prevalence to 2050. The Lancet, 2023. https://www.thelancet.com/article/S0140-6736(23)01301-6/fulltext

International Diabetes Federation. IDF Diabetes Atlas, 11th edition. 2025. https://diabetesatlas.org/

Ogle GD, et al. Global type 1 diabetes prevalence, incidence, and mortality estimates 2025: Results from the IDF Atlas 11 and the T1D Index v3.0. Diabetes Research and Clinical Practice, 2025. https://www.sciencedirect.com/science/article/pii/S0168822725002918

Stahl-Pehe A, et al. Wave in Pediatric Type 1 Diabetes Incidence After the Emergence of COVID-19: Peak and Trough Patterns in German Youth — DPV Registry. Diabetes Care, 2025. https://diabetesjournals.org/care/article/48/4/e47/157803/

Buchmann M, et al. Type 1 diabetes incidence curves differ by age for girls and boys between 1996 and 2022: Results from the North Rhine-Westphalia Diabetes Registry. Diabetes Research and Clinical Practice, 2025. https://www.sciencedirect.com/science/article/pii/S0168822725000105

Nagl K, et al. Ongoing Increase in Incidence of Diabetes in Austrian Children and Adolescents 1989–2021. Pediatric Diabetes, 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12017070/

Schoenle EJ, et al. Epidemiology of Type I diabetes mellitus in Switzerland: Steep rise in incidence in under-5 year old children in the past decade. Diabetologia, 2001. https://www.researchgate.net/publication/12017578

Santé publique France. Diabetes — Data. Updated 2024. https://www.santepubliquefrance.fr/en/diabete/data

Piffaretti C, et al. Trends in childhood type 1 diabetes incidence in France, 2010–2015. Diabetes Research and Clinical Practice, 2018. https://www.sciencedirect.com/science/article/abs/pii/S0168822718304662

Ruiz-Grao MC, et al. Trends in the Incidence of Type 1 Diabetes in European Children and Adolescents from 1994 to 2022: A Systematic Review and Meta-Analysis. Pediatric Diabetes, 2024. https://onlinelibrary.wiley.com/doi/10.1155/2024/2338922

Ji J, et al. Stable heritability of type 1 diabetes in a Swedish Nationwide Cohort Study. Nature Communications, 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12174315/

D’Souza D, et al. Incidence of Diabetes in Children and Adolescents During the COVID-19 Pandemic: A Systematic Review and Meta-Analysis. JAMA Network Open, 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10314307/

Quinn LM, et al. Environmental Determinants of Type 1 Diabetes: From Association to Proving Causality. Frontiers in Immunology, 2021. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8518604/

Esposito S, et al. Changes in the Global Epidemiology of Type 1 Diabetes in an Evolving Landscape of Environmental Factors. International Journal of Molecular Sciences, 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10141720/

Rogers MAM, et al. Fluctuations in the incidence of type 1 diabetes in the United States from 2001 to 2015: a longitudinal study. BMC Medicine, 2017. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5688827/

Imperatore G, et al. Projections of Type 1 and Type 2 Diabetes Burden in the U.S. Population Aged <20 Years Through 2050. Diabetes Care, 2012. https://pmc.ncbi.nlm.nih.gov/articles/PMC3507562/

We hope this overview is helpful for your own work in diabetes care, research or advocacy. As always, we are grateful for your interest in and support of our activities and we look forward to continuing this conversation with you in future editions of our “DID YOU KNOW…” series.

An earlier version of this article was originally published in the private newsletter of our CEO, Derek Brandt here: Diabetes Technology News.