Can we really prevent type 2 diabetes?

Posted by jchoules

14 February 2017

The UK is making a serious attempt to prevent type 2 diabetes. We know that the development of type 2 diabetes is strongly driven by excess weight and low levels of physical activity. High quality trials have shown that this process is reversible through lifestyle change. The NHS England “One You ” national diabetes prevention programme aims to tackle this problem by offering support to help people who are at risk of developing type 2 diabetes to lose weight and get more physically active.

In theory this sounds like a great idea and one that is very welcome in a service delivery landscape where prevention services that support healthy lifestyles (weight management, exercise on referral, smoking cessation) are being decimated as local authorities (who host public health services) respond to massive funding cuts.

However, as always, the devil is in the detail. NHSE have tried to specify programmes based on evidence about what works or doesn’t work. However, evidence to date has shown that real world diabetes prevention programmes deliver only around a third to a half of the weight loss achieved in clinical trials and reduce diabetes incidence by around 25%. This may reflect differences in the populations treated (less motivated, higher deprivation, lower education levels, more barriers to change). Or it may reflect differences in quality of delivery and monitoring of quality when moving from highly monitored and expert-led clinical trial settings to real world delivery in a diverse range of community settings.

The results from our ComPoD study (a multi-site trial of a prototype for the Living Well Taking Control programme – which is one of four programmes being used in the One You national programme) and the Norfolk Diabetes Prevention Study – will provide further evidence on the effectiveness of real world programme and help to understand the challenges of real world delivery in more detail. In the meantime the Let’s Prevent study (a trial of another One You programme prototype developed by the Leicester Diabetes Research Centre ) found significant changes in risk markers, despite no significant weight loss. This may have been driven by changes in physical activity or changes in dietary composition.

So overall, the picture is mixed – is the glass half full or half empty? Critics could argue that we may be flogging a dead horse – “One You” might work for a quarter of the 60% of those treated who would have gone on to get diabetes. At a population level, with an uptake of the offered treatment of around 20%, this amounts to an absolute reduction in diabetes incidence of only around 3%. Add to this concerns about the accuracy of methods being used to identify risk and the picture starts to look pretty bleak. On the other hand, it can be argued that a) there is potential to improve performance – delivery methods and delivery quality will evolve over time IF the right drivers and incentives are put in place by NHSE b) as the programme matures and awareness is raised about the benefits of diabetes prevention, uptake rates could increase c) even reducing diabetes incidence by just 3% could save the NHS around £240 million per year (the annual cost of treating type 2 diabetes is around £8 billion). Doubling or trebling this number through efficiency gains certainly seems possible.

More work is needed to establish the “business case” or health economics of diabetes prevention based on the actual performance of the programme, as well as to optimize programme performance. More work is also needed to develop ways to engage the 80% of people who are at risk and are not engaging with the offered programme, as well as to treat people who enter the programme but do not succeed in making lifestyle changes. We need population level as well as individual level approaches.
Overall my view is that cup is half full and worth topping up. This is a much needed world-leading initiative to try to reduce the harm to our people and our economy of a major, preventable illness. It is not good enough, but it is a start. The alternative is to just sit back and wait for the tsunami of expensive and life-affecting type 2 diabetes to hit us and overwhelm the capacity of the NHS to manage it.

** If you are concerned about your own risk of developing diabetes, more information is available at http://medicine.exeter.ac.uk/research/healthresearch/primarycare/projects/recentlycompletedstudies/wakeup/

** You can find out if you are at risk of type 2 diabetes at http://www.nhs.uk/Tools/Pages/Diabetes.aspx

Colin Greaves
Associate Professor in Psychology Applied to Health
Primary Care Research Group, UEMS