People who are genetically predisposed to storing belly fat, or having an apple-shaped body type, could face a higher risk of type 2 diabetes and heart disease, researchers said yesterday.
According to the study in the Journal of the American Medical Association (JAMA), a person's genetic makeup might cause health problems down the road.
''People vary in their distribution of body fat - some put fat in their belly, which we call abdominal adiposity, and some in their hips and thighs,'' said senior author Sekar Kathiresan, associate professor of Medicine at Harvard Medical School, AFP reported.
''We tested whether genetic predisposition to abdominal adiposity was associated with the risk for Type 2 diabetes and coronary heart disease and found that the answer was a firm 'yes'.''
Observational studies had so far pointed to a link between belly fat and type 2 diabetes and heart disease, but had not been able to prove a cause and effect relationship.
In their investigations, the researchers looked at six studies conducted from 2007 to 2015, including some 400,000 participants whose genomes were analysed.
In earlier research 48 gene variants had been identified that were associated with waist-to-hip ratio, resulting in a genetic risk score.
They found that certain genes predisposed people to higher waist-to-hip ratio, higher lipids, insulin, glucose and systolic blood pressure, as also a higher risk for type 2 diabetes and heart disease.
''The relationship to heart disease and diabetes did not surprise us,'' Kathiresan told TCTMD, a comprehensive on-line resource in interventional cardiology, noting however that he and his colleagues ''were a little surprised'' that the level of triglycerides in the blood could explain the relationship between belly fat and disease risk.
"There are a number of different theories that could clarify this, he said, but ''the abdominal fat cells seem to secrete a lot of bad factors that go into the blood and that actually lead to delayed clearance of the fat from the blood, which [leads] to higher levels of triglyceride-rich lipoproteins.''