MedWire News: Fat levels around the heart may predict a person's risk of a heart attack more accurately than their body mass index or waist circumference, research suggests.

"Obesity or excess amount of body fat is a well-established risk factor for coronary heart disease," said Dr Jingzhong Ding, from Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.

But he added: "The distribution of body fat may be as important as the amount of body fat in determining risk of heart attacks... Even a thin person can have fat around the heart."

Dr Ding explained that pericardial fat (fat surrounding the heart) produces inflammatory proteins that may, with long-term exposure, increase the risk of heart disease and heart attacks by promoting the build up calcified plaques in blood vessels.

To investigate, the researchers measured pericardial fat levels in 159 participants, aged between 55 and 74 years, who did not have a history of coronary artery disease.

Imaging scans showed that 58% of the participants had identifiable levels of calcified coronary plaque.

Analysis revealed that higher levels of pericardial fat were associated with increased levels of calcified coronary plaque.

Indeed, participants in the group with the highest levels of pericardial fat were nearly five times more likely to have calcified coronary plaque than those in the group with the lowest levels of heart fat.

However, the team found no evidence of an association between body mass index or waist circumference and calcified coronary plaque levels.

Although conceding that further research is needed to confirm the findings, Dr Ding and team conclude: "Our data indicate that pericardial fat may be more relevant to calcified coronary plaque than either body mass index or waist circumference."

They add: "Given the public health importance of coronary heart disease, enhanced research in this area which may yield new therapeutic targets is imperative."

The research is published in the journal Obesity.