Exeter scientists to investigate obesity paradox

27 November 2017        

Category: Research

Scientists at the University of Exeter are to explore why some overweight people are less likely to develop heart disease than others. 

Fat cells in the body

Being overweight or obese increases the risk of heart and circulatory disease. But the places in the body where fat is stored also plays an important part. Fat stored under the skin appears to be less harmful than when it is stored around the organs, such as the liver. And previous research has suggested that tiny differences in our DNA may contribute to where the body stores fat.

To establish if this is the case, Professor Tim Frayling has been awarded £234,000 by the BHF to carry out a study into this phenomenon. 

Professor Frayling and his co-investigators professors Jimmy Bell and Alex Blakemore and doctors Hanieh Yaghootkar and Katarina Kos will seek to identify genetic variants linked with ‘favourable fat’ using data from the UK Biobank, a world leading cohort study that is tracking the health of 500,000 volunteers across the UK.

The team will use these data to find out if these variants are associated with a lower risk of type 2 diabetes, high blood pressure and coronary heart disease. They will then analyse MRI images of up to 100,000 people to assess whether or not the ‘favourable fat’ genetic variants result in fat being stored under the skin rather than around the organs. 

Visceral fat

Fat stored around the organs causes more health problems compared to fat stored elsewhere. Known as visceral fat, it can damage the way key organs such as the pancreas and liver and heart function and there is therefore an increased risk of disease.

Professor Tim Frayling, of the University of Exeter Medical School, said: “This study aims to shed more light on an apparent paradox whereby two people with the same BMI can have a very different risk of heart disease. 

“If these genetic variants are shown to be associated with this differing risk, it may help us identify people who may be genetically predisposed to, or protected from, heart disease because of differences in their fat tissue that can’t be picked up using conventional tests like measuring BMI.

“It may then be possible for doctors to target weight loss interventions to those who would benefit the most. Such targeted interventions will be critical in a world of limited health resources, and even more so as the majority of people spend most of their adult lives at unhealthy weights.” 

Target for treatment

Dr Shannon Amoils, Senior Research Adviser at the BHF, said: “Being overweight is a major risk factor for cardiovascular disease and, as population obesity levels increase, it’s vital that we find new ways to address this problem. 

“We’ve known for some time that different types of fat tissue differ in their effects on the risk of heart and circulatory disease. Professor Frayling’s work will make advance our knowledge of the mechanisms that underlie these contrasting effects, which in turn could lead to more targeted anti-obesity strategies. 

“Important projects like this, which aim to answer fundamental questions about how our body works, are only possible thanks to the generosity of the public. And their continued support is vital if we are to make discoveries that can shape treatments and prevent heart disease in the future.”  

In the UK, it is estimated that 63% of the population is overweight or obese. Cardiovascular disease causes more than a quarter of all deaths in the UK – an average of 435 people each day.