Massive study assesses benefits of lifestyle changes on diabetes risk

Noah Baker

This is an extract from the Nature Podcast. In this clip, you’re going to hear reporter Benjamin Thompson speaking with Nature editor George Caputa all about a new study investigating behavioural changes and diabetes.

Benjamin Thompson

Type 2 diabetes is a leading cause of morbidity and mortality. Estimates suggest that type 2 diabetes affects hundreds of millions of people around the world, significantly burdening health systems. But behaviour change programmes – also known as lifestyle interventions – could potentially play a large role in preventing people from developing type 2 diabetes. And this week in Nature, there is a paper assessing just how effective this kind of intervention might be. Joining me to talk about the work is George Caputa, a senior editor for the journal Nature who handles a lot of papers involving metabolism and physiology. George, thank you so much for being on the show.

George Caputa

No, it's really great to be here, Ben.

Benjamin Thompson

So, we've got this new paper then focusing on lifestyle behaviours and clinical trials have shown that behavioural interventions can make a difference in preventing folk from going from being pre-diabetic, where someone has elevated blood sugar, to full type 2 diabetes.

George Caputa

Yeah, this is not the first epidemiological study or even just a scientific study in general, showing that behavioural interventions can help individuals lose weight or even prevent the development of full type 2 diabetes. I think that something that we have gotten to, especially at this point in time, is that we do we have access to huge amounts of data. And so we can start to make potentially more definitive conclusions. And these are important, obviously, because a lot of these studies are the basis for public policy, public health, governments, they decide about what to fund depending on these types of studies.

Benjamin Thompson

And in this case, then the researchers behind the paper and looked at a data set gathered from health data from folk who referred to different interventions, but primarily England's NHS Diabetes Prevention Pprogramme. What do we know about that?

George Caputa

Yeah, so the NHS Diabetes Prevention Programme is a behavioural change programme with weight loss, diet, physical activity goals, and this consists of 13 group sessions over the course of nine months.

Benjamin Thompson

And overall, what was the big question that the researchers wanted to answer in this paper?

George Caputa

Yeah, so the question is, if an individual is diagnosed with pre-diabetes, if they are provided with a behavioural change programme, can we prevent them developing full diabetes? Can we kind of stop the progression.

Benjamin Thompson

And so in this work, then they take the anonymized patient records from about 2 million people to analyse the effectiveness of behavioural change programmes. And they've done a lot of statistics, in particular, something called a regression discontinuity design. So broadly, what have they done to show the effectiveness of behavioural programmes?

George Caputa

Obviously, in an epidemiological study, you have to be looking apples to apples, because you have to make sure that the groups that you're looking at are being intervened in the same way that they all qualify the same, because then you start to get behavioural and environmental factors that can confound your analysis. And regression discontinuity design, very generally, it is a way to within this population be able to make potentially statistically significant claims about the changes that they see, and that they are very much influenced specifically by the intervention of this programme. And not because the individuals that they're looking at are different groups or influenced in different ways. And one of the reasons that we considered this paper is because it is using state-of-the-art statistical analyses. So this is something that was very appreciated by the reviewers that what was being done here was using some very new and modern techniques.

Benjamin Thompson

And what's the headlines of what they saw then in terms of folk taking part in these programmes?

George Caputa

So, I think to say that they saw a very dramatic results is not the case. But what they did see is that there was statistically significant changes in the measures that they were using to qualify these individuals for pre-diabetes. They're looking at HbA1c which is a blood marker for how high your blood sugar has been basically over the past month, and so it's a good indication of whether your body over the past month has been able to properly maintain its blood glucose, which is a measure of how pre-diabetic you are. And what they saw was a decrease in the levels of HbA1c in the individuals who participate in this programme, they also saw a decrease in body weight, and they also saw a slight decrease in blood pressure and these associated metabolic measures. And I think what the researchers were able to definitively say is that this intervention had an effect. Obviously, in a situation like this, for some individuals, it probably was a big effect. And for some individuals, it probably was quite small. That's why when you get the average, it tends to be more modest.

Benjamin Thompson

And as someone who is an editor who looks at science papers then, what is this paper done maybe differently to things you've seen before?

George Caputa

What I tend to see as an editor is a lot of proposed pharmacological treatments. So like new drugs, new targets, new potential pills that people can take. And so to see a study that's really looking at another type of intervention, that can be just as powerful as putting someone on another drug, or even combined can be very powerful. That is something as an editor, that's really important, because this is a space that we don't talk about enough in terms of public health, in terms of these types of behavioural interventions. I think that as a society, we're kind of very focused, and we associate the most effectiveness with a drug.

Benjamin Thompson

I'm sure, though, that it's not the case that this is kind of everything sort of wrapped up with a neat little bow, there are those who doubt the effectiveness of behavioural intervention programmes. And I'm sure there are questions that remain to be asked when other people get their eyes on this paper.

George Caputa

Yeah, I mean, you know, I think there are people who will look at this paper and say, we're not seeing the same dramatic changes in blood glucose levels in this HbA1c that we would see if we were to immediately put these people on, we would consider frontline, first choice, diabetes drugs. The truth is, the individuals that they're looking at in this study aren't diabetic, they're pre diabetic. And usually, in many countries, the clinical intervention here is that your doctor says you have pre-diabetes, you need to change your behaviour, maybe gives them access to some information, but that's probably it. You know, this is like a full programme. I think the critics of the paper would say that this change is not so big. But when you're looking at the numbers of people who have diabetes, if you can reduce maybe 2% of those cases, that is a huge amount of savings for a public health programme, and for people's lives.

Benjamin Thompson

Nature's George Caputa there, to read the paper we chatted about by Lemp et al. and an associated News and Views article. Look out for links in the show notes.