An NHS behaviour-change programme has been linked to a significant reduction in the risk of developing type 2 diabetes mellitus in adults with pre-diabetes. The analysis, carried out by University of Manchester researchers shows that when controlling for the characteristics of participants, the risk of diabetes progression was 20% lower in people with pre-diabetes referred to the NHS Diabetes Prevention Program (NDPP) when compared to similar patients not referred to NDPP.
"Our findings show that the NDPP appears to be successful in reducing the progression from non-diabetic hyperglycaemia to type 2 diabetes. Even though we were only able to examine referral to the program, rather than attendance or completion, it still showed a significant reduction in risk of 20%m” explained lead authors, Dr Rathi Ravindrarajah from The University of Manchester. "That suggests the decision to implement program quickly and at scale in England was the right one. And as the results are reproducible, it also supports the continuation of similar programs to Northern Ireland, Scotland and Wales."
The NHS Healthier You Diabetes Prevention Program in England is offered to non-diabetic adults with pre-diabetes providing exercise and dietary advice to help reduce people's risk of developing the disease. For the study, University of Manchester investigators examined the association between referral to the programme and reducing conversion of NDH to T2DM.
A cohort study of patients attending primary care in England using clinical Practice Research Datalink data from April 2016 (NDPP introduction) to March 2020 was used. They matched patients referred to the programme in referring practices to patients in nonreferring practices. Patients were matched based on age (≥3 years), sex, and ≥365 days of NDH diagnosis. Random-effects parametric survival models evaluated the intervention, controlling for numerous covariates.
Across the 2,209 GP practices for which the researchers had data, more than 700,000 people were identified with pre-diabetes and about 100,000 had a code in their health records indicating they were referred to the program.
A total of 18,470 patients referred to NDPP were matched to 51,331 patients not referred to NDPP in the main analysis. Mean follow-up from referral was 482.0 (SD = 317.3) and 472.4 (SD = 309.1) days, for referred to NDPP and not referred to NDPP, respectively. Baseline characteristics in the 2 groups were similar, except referred to NDPP were more likely to have higher BMI and be ever-smokers. The adjusted HR for referred to NDPP, compared to not referred to NDPP, was 0.80 (95% CI: 0.73 to 0.87) (p <0.001).
The probability of converting to type 2 diabetes at 36 months after referral was 12.7% for those referred to the NDPP and 15.4% for those not referred to the NDPP. Using a figure of 1,000 people referred to NDPP and 1,000 not referred to NDPP, by 36 months after referral, the team calculate they would expect 127 conversions to type 2 diabetes in the group referred to the program and 154 in the group not referred.
The mechanism for the difference is likely to be through weight reduction, with previous work showing that people who attended the NHS DPP were associated with a significant reduction in weight - the key factor in reducing risk - of 2.3 kg on average. In addition, prior work also showed levels of HbA1c reduced by a significant 1.26 mmol/mol.
"Type 2 diabetes is a major public health concern which has been rising globally, with over 3 million people in the UK currently diagnosed with it. Previous studies have shown that both lifestyle modifications through diet and physical activity and medication can prevent progression to this condition” said study co-author, Professor Evangelos Kontopantelis from The University Manchester. "This study is good news for the Healthier You Diabetes Prevention Program which we show beyond doubt is a powerful way to protect your health."
NHS national clinical director for diabetes and obesity, Professor Jonathan Valabhji, said, "This important study is further evidence that the NHS is preventing type 2 diabetes and helping hundreds of thousands of people across England to lead healthier lives. We completed roll out of the NHS Diabetes Prevention Program in 2018, and now over 1.2m people have been offered support with lifestyle changes including better quality nutrition, weight loss, and increased physical activity, which this study shows is preventing development of this life-changing condition."
The findings were reported in the paper, ‘Referral to the NHS Diabetes Prevention Programme and conversion from nondiabetic hyperglycaemia to type 2 diabetes mellitus in England: A matched cohort analysis’, published in PLoS Medicine. To access this paper, please click here