Certain ethnic groups, such as South Asians, are known to have a higher risk of developing type 2 diabetes. However, there are fewer data on the risks of progressing from prediabetes to type 2 diabetes. The present retrospective study sought to determine whether the risk of progression from prediabetes to type 2 diabetes differed by ethnicity and deprivation, and across different age groups.
Data on 397 853 people in the THIN (The Health Improvement Network) database, covering nearly 800 general practices in the UK, were analysed. Overall, 45.1% of the cohort were white, 3.1% South Asian, 1.6% Black and 0.7% mixed race; ethnicity data were missing in 49.1%. Over a median follow-up of 2.6 years (interquartile range 1.1–5.1 years), the incidence of type 2 diabetes was 53.5 per 1000 person-years.
After adjustment for age, gender, BMI, ethnicity, deprivation, smoking status, and cardiovascular event history, metformin treatment and hypertension at baseline, South Asian (hazard ratio [HR] 1.31) and mixed ethnicity (HR 1.22) was associated with increased risk of progression to type 2 diabetes compared with white ethnicity; however, Black ethnicity was not.
The most deprived quintile was more likely to progress to type 2 diabetes than the least deprived quintile (HR 1.17), and the trend was significant and linear. The trend was largely driven by white individuals and not the other ethnicities.
Compared with people aged 40–65 years at prediabetes diagnosis, those aged 18–30 years (HR 0.63) and ≥65 years (HR 0.85) were less likely to progress to type 2 diabetes.
The authors conclude that South Asian and mixed-race individuals, and people with high socioeconomic deprivation, have a higher risk of progressing from prediabetes to type 2 diabetes. The findings are key to improving referral for the highest-risk individuals to appropriate diabetes prevention initiatives, and they reinforce the need to deliver such interventions in a linguistically and culturally appropriate manner.
Attempts to achieve remission, or at least a substantial improvement in glycaemic control, should be the initial focus at type 2 diabetes diagnosis.
9 May 2024