Gene variants associated with having an apple-shaped body – one that's larger round the middle - increase risk of heart disease and type 2 diabetes.
A study from Massachusetts General Hospital (MGH) researchers has found that a pattern of gene variants associated with an “apple-shaped” body type, in which weight is deposited around the abdomen, rather than in the hips and thighs, increases the risk for type 2 diabetes and coronary heart disease, as well as the incidence of several cardiovascular risk factors. The report appears in the JAMA.
“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,” says Sekar Kathiresan, MD, associate professor of Medicine at Harvard Medical School, and senior author of the JAMA report. “Abdominal adiposity has been correlated with cardiometabolic disease, but whether it actually has a role in causing those conditions was unknown. 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’.”
While several observational studies have reported greater incidence of type 2 diabetes and heart disease among individuals with abdominal adiposity, they could not rule out the possibility that lifestyle factors – such as diet, smoking and a lack of exercise – were the actual causes of increased disease risk. However, the results clearly indicated that genetic predisposition to abdominal adiposity is associated with significant increases in the incidence of type 2 diabetes and coronary heart disease, along with increases in blood lipids, blood glucose and systolic blood pressure. No association was found between the genetic risk score and lifestyle factors, and testing confirmed that only the abdominal adiposity effects of the identified gene variants were associated with cardiometabolic risk.