Twenty-year trends in ethnicity with type 2 diabetes across age at diagnosis: observational study in 11 million individuals in England

BACKGROUND AND AIMS: To investigate temporal variations in ethnic demography in those with versus without type 2 diabetes across age. METHODS AND RESULTS: We used the Clinical Practice Research Datalink to identify adults with newly-diagnosed type 2 diabetes, matched to ∼5 individuals without diabetes. Between 2000 and 2021, we calculated the proportion of individuals with type 2 diabetes from each ethnic group (Black/South Asian/White/Other) across age groups (18-39/40-59/≥60 years) and compared them to proportions in individuals without type 2 diabetes. We included 2,679,348 individuals with type 2 diabetes and 9,019,351 without. In individuals aged 18-39 years, between 2000 and 2021, proportions of individuals with type 2 diabetes from South Asian, White and other ethnic groups remained stable relative to individuals without diabetes, whilst proportions from Black ethnic groups became more similar over time. In older individuals (40-59/>60 years) with type 2 diabetes, the proportion of individuals from each ethnic group became more similar to the proportions in those without diabetes over time. CONCLUSION: Increases in early-onset type 2 diabetes between 2000 and 2021 are not related to disproportionately increasing risks across ethnicity. Excess risk of type 2 diabetes with ethnicity diminished apart from in individuals from South Asian and other ethnic groups aged 18-39 years.