A team of researchers report finding evidence linking obesity to prolonged inflammation of heart tissue and subsequent damage leading to heart failure.
The study tracked an ethnically diverse group of nearly 7,000 men and women. Of the 79 people in the Multiethnic Study of Atherosclerosis who have developed congestive heart failure so far, 35 (44%) were physically obese, having a BMI of 30 or greater. On average, obese participants were found to have higher blood levels of interleukin 6, C-reactive protein, and fibrinogen, key immune system proteins involved in inflammation.
A near doubling of average interleukin 6 levels alone accounted for an 84% greater risk of developing heart failure in the study population, report the investigators. Similarly, a near tripling of average levels of C-reactive protein in study participants increased the chance of heart failure by 36%. One-fifth higher than average blood levels of fibrinogen bumped up the risk of heart failure by 37% in obese patients. When these inflammatory protein levels were included in the scientists' statistical analysis, the heightened risk from obesity disappeared.
“What this tells us is that both obesity and the inflammatory markers are closely tied to each other and to heart failure," says lead researcher Hossein Bahrami, M.D., a postdoc fellow at Johns Hopkins School of Medicine. Dr. Bahrami says that the study results also point to inflammation as a possible catalyst in metabolic syndrome.
Besides Johns Hopkins, Institutes involved in the study included the University of Washington, Wake Forest University, Northwestern University, and University of Arizona. The study will be published in the May 6 issue of the Journal of the American College of Cardiology.