Early-onset type 2 diabetes, meaning a diagnosis of type 2 diabetes before age 40, is associated with aggressive disease progression, long-term health burden and reduced life expectancy. In a new study published in The Lancet, researchers aimed to uncover a detailed picture of how the rate of new disease cases has changed over time, as one did not currently exist.

The researchers used data from the English National Diabetes Audit, a national clinical project that measures and compares the quality of diabetes care in England and Wales against NICE standards. They measured how many new type 2 diabetes cases appeared each year from 2011 to 2024. They adjusted the data to remove the effect of different age sizes in groups, then broke down the results by age, sex and ethnic background. Poisson regression models were created to study incidence over time and annual change in median BMI within 26 weeks of diagnosis was calculated.

The findings for each age category

• The rate of new type 2 diabetes diagnoses in people aged 20–29 increased every year, with a slightly faster annual increase in women than men.
• Incidence increased minimally in men aged 40–59 years but rose more significantly in women aged 40-59 years.
• Incidence was found to be declining in both men and women aged 60–79 years.

Other important findings

• Increasing incidence in young adults were found in all sex and ethnicity subgroups except Asian men (20–39-years).
• The highest rates of increasing incidence were in White women (30–39-years) and Black women(20–29).
• BMI at diagnosis increased in all subgroups over time, but this was highest in younger adults and higher in women than men.
• The annual change in younger adults was double that of older adults.

Researchers concluded that the incidence of type 2 diabetes has risen significantly in young adults across most ethnic and demographic subgroups since 2011, particularly among women, despite minimal change or even declining incidence at older ages. This trend parallels a steeper rise in BMI at diagnosis among younger patients. The findings point to a shift in disease burden and an urgent need for earlier prevention and targeted obesity interventions earlier in life.