A major population study of type 2 diabetes in England has shown a clear generational divide, with rates of diagnosis rising rapidly among younger adults, particularly in women, although declining in older age groups.
The research, published in Lancet Regional Health Europe, is the first to examine trends in new diagnoses of type 2 diabetes (T2D) across the entire English population, while stratifying analyses by age, sex and ethnicity.
Researchers at Imperial College London analysed the English National Diabetes Audit data and calculated age-standardised incidence rates for adults with type 2 diabetes by age, sex and ethnicity between 2011-2024.
Overall trends in diabetes incidence have usually appeared to be stable or increasing, but the new data shows that while incidence is falling in older adults, who make up the largest proportion of new diagnoses, it is increasing rapidly in people under 40 years of age.
This, say researchers, is especially worrying, given that type 2 diabetes diagnosed at a younger age leads to a longer lifetime exposure to the disease, earlier death and a greater risk of serious complications, , including poor pregnancy outcomes in women. They say current type 2 diabetes prevention strategies may be working less well in younger generations.
In addition, the new analysis shows clearly that younger females (under 40 years) are driving this rising trend.
Discussion of rising levels of type 2 diabetes has tended to focus on ethnic minority populations, but the data shows that the increase in younger people’s early-onset type 2 diabetes is not confined to ethnic minority populations. The analysis shows that the rise is particularly noticeable in White, Asian and Black women aged 20–29 years, and in White women aged 30–39 years.
“Much of the discussion around rising type 2 diabetes in younger people has focused on ethnic minority groups,” said Dr Shivani Misra from the Department of Metabolism, Digestion and Reproduction at Imperial College London, who led the study. “While these ethnic groups are disproportionately affected with early-onset type 2 diabetes, we now see that incidence is also increasing in White populations too, showing that this public health challenge is broadening across the generation.”
The study also identified a dramatic shift in average body weight at the time of diagnosis. While obesity is already well established as the major risk factor for type 2 diabetes, researchers found that body mass index (BMI) at diagnosis has been rising more rapidly in younger adults than in older adults.
The increase in BMI over time among younger people diagnosed with type 2 diabetes was approximately double that seen in older adults. This suggests that successive generations of younger adults are developing type 2 diabetes at increasingly severe levels of obesity.
Among some groups, the figures were particularly striking. White women diagnosed at younger ages had average BMIs approaching 40 kg/m², a level that is classified as severe obesity.
Dr Shivani Misra, Clinical Associate Professor at Imperial College London, explained: “We have known for a long time that obesity is linked to type 2 diabetes, but what is new from this study is the scale of the change occurring in younger adults. We think that the earlier onset of severe obesity in young people is increasing their type 2 diabetes risk in early life and pulling down their age at diagnosis. This is really worrying given the poor health outcomes from early-onset type 2 diabetes and as numbers increase, we need to think about implementing effective treatments as early as possible."
Older adults are not experiencing as large an increase in BMI at diagnosis, but the reasons remain unclear. However, the study did not examine weight trends in the general population and further research is needed.
The authors say the findings highlight an urgent need to rethink approaches to type 2 diabetes and obesity prevention, with greater focus on reaching younger adults. Potential strategies could include earlier identification of people at risk, encouraging greater participation in diabetes prevention programmes at younger ages, earlier use of effective weight-management treatments such as GLP-1 medicines, and targeted weight-management support for people with severe obesity, for example intensive lifestyle or bariatric surgery. However, researchers stress that population-level prevention still remains crucial.
The study was funded by the Wellcome Trust and supported by the NIHR Imperial Biomedical Research Centre, a translational research partnership between Imperial College Healthcare NHS Trust and Imperial College London.
