Obesity can drive hearts to fail and weaken their structure, new research into heart failure suggests.
The largest study of its kind on 490,000 people found that those with a higher body mass index (BMI) and waist-to-hip ratio, key signs of carrying too much fat, had around a 30% increased risk of heart failure.
This risk occurred regardless of other risks for heart failure such as diabetes, high blood pressure and high cholesterol.
To investigate the reasons why, scientists at Queen Mary University of London, in collaboration with the University of Southampton and the University of Oxford, looked at the cardiac magnetic resonance (CMR) scans of over 31,000 of the group.
CMR scans are a type of heart scan used to diagnose and give information on various heart conditions, and the people were chosen at random to have a scan.
The study found that when the heart scans of people with a higher BMI and waist-to-hip ratio were compared with those for people within the healthy range, the hearts of obese people had undergone structural changes.
The heart muscle was found to be thicker, had more signs of scarring and the main pumping chamber was weaker.
All of these changes make it more difficult for the heart to effectively pump blood around the body and could lead to the development of heart failure.
The research, funded by the British Heart Foundation (BHF), was presented at the British Cardiovascular Society conference in Manchester.
Dr Zahra Raisi-Estabragh, from Queen Mary University of London, who supervised the study, said: “We already know that obesity increases the risk of heart and circulatory diseases that can go on to cause heart failure.
“But now we have revealed that obesity itself could be a driver of hearts starting to fail.
“Further research could provide new insights into the biological mechanisms through which obesity leads to poorer heart health.”
Professor James Leiper, associate medical director at the BHF, said: “This research provides new evidence of the link between obesity and heart failure and forms the basis of further research to understand the mechanisms underpinning the connection between obesity and changes to the heart’s anatomy.”