On Nov. 4, 2020, scientists at the University of Oxford announced they had discovered that obesity can increase the chances of someone developing kidney disease. Funded by Kidney Research UK and the Medical Research Council, this new study has found that fat all over the body increases risk, not just fat around the middle (tummy fat), and suggests controlling weight could be a new way to manage kidney disease risk. This research was published in the Journal of the American Society of Nephrology.

Previous studies have found that obesity is linked with an increased risk of kidney disease. But it wasn’t clear whether obesity directly caused kidney disease or whether other factors were involved, such as more salt in people’s diet.

In this latest research, the team studied almost 300,000 DNA samples from the UK Biobank. They searched over 1,000 genetic variations known to predispose people to a higher overall body mass index (BMI) or more abdominal fat deposition (fat around the middle). People with these gene variations are more likely to become overweight or obese because they inherit these genes.

Professor Will Herrington, from the Medical Research Council Population Health Research Unit at the University of Oxford, who co-led the research explains: ‘In this study, we found these genetic variants were consistently linked to kidney disease – each 5 kg/m2 increase in BMI caused roughly a 50% increased risk in chronic kidney disease. Using a genetic approach meant we could be more rigorous than with a conventional approach and rule out other factors.’

The team found kidney disease risk didn’t change based on fat location – it increased by the same amount regardless of whether fat was deposited centrally (around the organs) or across the body generally (such as around the legs and arms).