What 28 Years of Danish Data Tell Us About Type 1 Diabetes Trends

A major new study tracking diabetes across an entire country reveals shifting patterns in who gets Type 1 diabetes and when—with important implications for understanding the disease.

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Key takeaways

Type 1 diabetes rates have been declining overall since 1996, dropping by about 1.1% each year on average
More children and young adults under 40 are developing Type 1 diabetes, even as rates fall in older age groups
Type 1 diabetes remains relatively rare: only 8.2% of Denmark's diabetes cases are Type 1; the rest are Type 2
Denmark's national health registers allow researchers to track disease patterns across an entire population over decades

A 28-Year Snapshot of Type 1 Diabetes in Denmark

Researchers at Danish health institutions have completed the most comprehensive long-term analysis of Type 1 diabetes trends in the country, examining data from 1996 through 2024. As of early 2025, approximately 30,000 Danes have Type 1 diabetes—making up 8.2% of all diabetes cases in the nation. The remaining cases are Type 2 diabetes, which has surged dramatically over the past three decades.

This study is notable for its scope and precision. Rather than relying on surveys or estimates, researchers used Denmark's integrated national health registers—which combine hospital records, prescription data, clinical notes, and laboratory results—to identify every person with diabetes and when they were diagnosed. This allowed them to track real population-level trends with unusual accuracy.

Type 1 Diabetes Rates Are Declining, But the Pattern Is Complex

The headline finding: Type 1 diabetes incidence (the number of new diagnoses) has declined by an average of 1.1% per year since 1996. In other words, fewer people are developing Type 1 diabetes now than in the mid-1990s.

However, the decline is not uniform across all age groups. While Type 1 diabetes rates are falling in older adults, they are actually rising in children and people under 40. This shift suggests that the disease's age of onset may be changing, though researchers did not investigate the reasons why in this study.

Why This Data Matters

Population-level surveillance—tracking disease patterns across entire countries—is crucial for understanding how diseases evolve and where resources should be directed. Denmark's ability to monitor diabetes through its national health system provides a model that few countries can match.

These trends help researchers and clinicians ask better questions: Why are overall Type 1 diabetes diagnoses declining? What factors might explain why young people are a growing share of new diagnoses? Understanding these patterns can guide research into the causes of Type 1 diabetes and help health systems prepare for future needs.

Evidence label

Source: BMJ open diabetes research & care. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.

Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.

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