Losing a few kilograms in weight almost halves people’s risk of developing Type 2 diabetes – according to a large scale research study led by the Norfolk and Norwich University Hospital and the University of East Anglia, published in JAMA Internal Medicine.
The study shows how providing support to help people with prediabetes make small changes to their lifestyle, diet and physical activity can almost halve the risk of developing Type 2 diabetes.
The findings come from the Norfolk Diabetes Prevention Study (NDPS) – the largest diabetes prevention research study in the world in the last 30 years. The NDPS clinical trial ran over eight years and involved more than 1,000 people with prediabetes at high risk of developing Type 2 diabetes.
The study found that support to make modest lifestyle changes, including losing two to three kilograms of weight and increased physical activity over two years, reduced the risk of Type 2 diabetes by 40 to 47 per cent for those categorised as having prediabetes.
There are about eight million people with prediabetes in the UK and 4.5 million have already developed Type 2 diabetes.
The NDPS, funded by £2.5m from the National Institute for Health Research (NIHR), and NIHR CRN Eastern, was led by the Norfolk and Norwich University Hospital (NNUH) and University of East Anglia (UEA), together with colleagues from Ipswich Hospital, and the universities of Birmingham and Exeter.
The research trial tested a simple lifestyle intervention, which helped people make small achievable lifestyle changes that led to a modest weight loss, and increases in physical activity.
Importantly these changes were sustained for at least two years and the weight lost was not put back on.
These findings are important as they show that a ‘real-world’ lifestyle programme really can make a difference in helping people reduce their risk of Type 2 (adult onset) diabetes.
Prof Mike Sampson, NDPS Chief Investigator and Consultant in Diabetes at NNUH, said: “We are delighted with the results of this trial, as until now no one was very sure if a real-world lifestyle programme prevented Type 2 diabetes in the prediabetes population we studied, as there have been no clinical trials that had shown this.
“We have now shown a significant effect in Type 2 diabetes prevention, and we can be very optimistic that even a modest weight loss, and an increase in physical activity, in real world programmes like this have a big effect on the risk of getting Type 2 diabetes.
“This is really great news for the eight million people in the UK with a prediabetes diagnosis. The results of this trial, show that diabetes prevention is possible in the same prediabetes populations being treated in the NHS national diabetes prevention programme.
“This is important to know, as the clinical methods for diagnosing diabetes and prediabetes have changed a lot in recent years.”
The Norfolk Diabetes Prevention Study ran between 2011 and 2018 and worked with 135 GP practices in the East of England, and found 144,000 people who were at risk of developing Type 2 diabetes.
In screening sites across the East of England, 13,000 of these people then took a fasting glucose and glycosylated haemoglobin (HbA1c) blood test to detect prediabetes.
More than 1,000 people with prediabetes were then entered into a randomised controlled trial, testing a pragmatic real-world lifestyle intervention, compared to a control group, with average follow-up of just over two years.
Earlier studies have used quite intense and expensive research interventions in different groups of prediabetes participants, but this is the first time a real world group delivered intervention has been shown to reduce the risk of Type 2 diabetes.
NDPS also asked lay members of the public who had Type 2 diabetes themselves, to help support participants with prediabetes in the trial, but for this particular population this did not further reduce the risk of getting Type 2 diabetes.
NDPS co-investigator Prof Bachman, from Norwich Medical School, is part of UEA’s Norwich Institute of Healthy Ageing – a new research centre investigating how we can live longer, healthier, and more satisfying lives.
He said: “The NDPS intervention was delivered in groups which was far less expensive than individual-focused interventions which have previously shown to be effective under optimal conditions.
“For every 11 people who received the NDPS intervention, one person was prevented from getting Type 2 diabetes, which is a real breakthrough.”
Prof Colin Greaves from the University of Birmingham, who jointly led the development of the NDPS intervention, said: “If you have been diagnosed with prediabetes, this approach offers a way to take a different direction in your life – to get off the path to type 2 diabetes and onto the road to a healthier future.”
Dr Jane Smith, NDPS collaborator from the University of Exeter, said: “Type 2 diabetes is a huge health challenge globally. NDPS is an incredibly positive story for individuals and healthcare systems, and underlines the importance of providing national diabetes prevention programmes, which can use our research findings.”
Prof Jonathan Valabhji, National Clinical Director for Diabetes and Obesity for NHS England, said: “This study with similar referral criteria and a similar intensive lifestyle intervention to the NHS Diabetes Prevention Programme has surpassed expectations in preventing Type 2 diabetes. This is hugely encouraging for the NHS Diabetes Prevention Programme, and what participants might expect to achieve in the longer term.”
Dr Elizabeth Robertson, Director of Research at Diabetes UK, said: “We welcome this new research showing that a group-based support programme can help people at high risk of developing type 2 diabetes reduce their risk.
“This trial again highlights how achieving modest weight loss through diet and physical activity changes can lead to huge benefits for people at high risk of developing type 2. Type 2 diabetes is a serious condition, but with the right help many cases can be prevented or delayed.
“Diabetes UK’s Know Your Risk’ tool helps people to determine their risk and take steps to reduce it, including by self-referring on to NHS England’s Diabetes Prevention Programme in their local area.”
Importance Nearly half of the older adult population has diabetes or a high-risk intermediate glycemic category, but we still lack trial evidence for effective type 2 diabetes prevention interventions in most of the current high-risk glycemic categories.
Objective To determine whether a group-based lifestyle intervention (with or without trained volunteers with type 2 diabetes) reduced the risk of progression to type 2 diabetes in populations with a high-risk glycemic category.
Design, Setting, and Participants The Norfolk Diabetes Prevention Study was a parallel, 3-arm, group-based, randomised clinical trial conducted with up to 46 months of follow-up from August 2011 to January 2019 at 135 primary care practices and 8 intervention sites in the East of England. We identified 141 973 people at increased risk of type 2 diabetes, screened 12 778 (9.0%), and randomised those with a high-risk glycemic category, which was either an elevated fasting plasma glucose level alone (≥110 and <126 mg/dL [to convert to millimoles per liter, multiply by 0.0555]) or an elevated glycated haemoglobin level (≥6.0% to <6.5%; nondiabetic hyperglycemia) with an elevated fasting plasma glucose level (≥100 to <110 mg/dL).
Interventions A control arm receiving usual care (CON), a theory-based lifestyle intervention arm of 6 core and up to 15 maintenance sessions (INT), or the same intervention with support from diabetes prevention mentors, trained volunteers with type 2 diabetes (INT-DPM).
Main Outcomes and Measures Type 2 diabetes incidence between arms
Results In this study, 1028 participants were randomised (INT, 424 [41.2%] [166 women (39.2%)]; INT-DPM, 426 [41.4%] [147 women (34.5%)]; CON, 178 [17.3%] [70 women (%39.3)]) between January 1, 2011, and February 24, 2017. The mean (SD) age was 65.3 (10.0) years, mean (SD) body mass index 31.2 (5) (calculated as weight in kilograms divided by height in meters squared), and mean (SD) follow-up 24.7 (13.4) months. A total of 156 participants progressed to type 2 diabetes, which comprised 39 of 171 receiving CON (22.8%), 55 of 403 receiving INT (13.7%), and 62 of 414 receiving INT-DPM (15.0%). There was no significant difference between the intervention arms in the primary outcome (odds ratio [OR], 1.14; 95% CI, 0.77-1.7; P = .51), but each intervention arm had significantly lower odds of type 2 diabetes (INT: OR, 0.54; 95% CI, 0.34-0.85; P = .01; INT-DPM: OR, 0.61; 95% CI, 0.39-0.96; P = .033; combined: OR, 0.57; 95% CI, 0.38-0.87; P = .01). The effect size was similar in all glycemic, age, and social deprivation groups, and intervention costs per participant were low at $153 (£122).
Conclusions and Relevance The Norfolk Diabetes Prevention lifestyle intervention reduced the risk of type 2 diabetes in current high-risk glycemic categories. Enhancing the intervention with DPM did not further reduce diabetes risk. These translatable results are relevant for current diabetes prevention efforts.
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