Obese people with high levels of abdominal fat and liver fat may face increased risks for heart disease and other serious health problems, according to research published in Arteriosclerosis, Thrombosis and Vascular Biology: Journal of the American Heart Association.

Obesity is commonly associated with heart disease risk and problems called cardiometabolic abnormalities, including insulin resistance, type 2 diabetes, cholesterol disorders, hypertension and gout.

Researchers in Sweden and Finland found that obese people at the highest risk have increased secretion of liver lipids, more abdominal fat and impaired removal of triglycerides from the blood stream. As such, doctors should routinely check obese patients for intra-abdominal obesity and indications of liver fat, researchers said.

"It is important to recognize that measuring abdominal fat and liver fat can identify the patients at high risk for metabolic abnormalities and heart disease," said Jan Boren, M.D., Ph.D., study senior author and professor of molecular and clinical medicine at the University of Gothenburg in Sweden. "Such exams are important because up to 20 percent of the obese appear to be 'metabolically normal.'"

In the study researchers in Sweden and Finland found that liver fat is strongly associated with increased secretion of very-low-density (VLDL), which contains the highest amount of triclycerides. High level of triglycerides can carry an increased risk of metabolic abnormalities and increased risk of heart disease and premature death.

"Increased liver fat is dangerous, as it is linked with many known heart disease risk factors," said Marja-Riitta Taskinen, M.D., Ph.D. study co-author and professor of medicine at the University of Helsinki in Finland. "Lifestyle modifications such as exercise and weight loss can reduce liver fat and the secretion of lipoproteins."

In the study researchers divided middle-aged men into three groups:

The first group of 14 obese men had high levels of fat found in the blood called triglycerides

The second group of 14 obese men had normal triglycerides

The third group of 10 men who were not obese and had normal triglycerides were used to measure the comparison of the two obese group.

In the study researchers measured how much fat was stored in men's livers using a (proton magnaetic resonance spectroscopy) and how much fat was stored in the body and around their organs using a Magnetic resonance imaging (MRI).

The results showed that triglyceride levels in the obese men were higher as a result of the increased secretion coupled with severely impaired clearance of triglyceride-rich VLDL particles. Researchers also found:

  • The obese men with elevated triglycerides had a liver fat content of 13 percent.
  • The obese men with normal triglycerides had a 6.9 percent liver fat content.
  • The non-obese men had a 2.9 percent liver fat content.

Researchers plan to conduct a similar study in women.

published in Arteriosclerosis, Thrombosis and Vascular Biology: Journal of the American Heart Association.