Feb. 14, 2011 -- Obesity is a risk factor for fatal heart attacks even for people who do not have the conditions normally associated with cardiovascular disease, such as diabetes and high blood pressure, a study shows.
According to researchers at the University of Glasgow in Scotland, it appears that obesity in its own right is associated with an increased risk of fatal heart attacks.
Inflammation is apparently a strong factor in fatal cardiovascular disease, the researchers say, and obesity is now increasingly being recognized as an inflammatory condition.
“We already knew that being obese meant you had a higher chance of having a heart attack,” study researcher Jennifer Logue, MD, of the University of Glasgow, tells WebMD via email. “We also already knew that obese people were more likely to have high cholesterol, high blood pressure, and diabetes.”
She says it was thought that high cholesterol and blood pressure were the reasons obese people had more heart attacks, and that medications can treat those conditions.
But she says the study has shown “two news things: obese, middle-aged men have a 60% increased risk of dying from a heart attack than non-obese middle-aged men, even after we cancel out any of the effects of cholesterol, blood pressure, and other cardiovascular risk factors.”
This means, she says, that “obesity itself may be causing fatal heart attacks through a factor that we have not yet identified.”
Link to Fatal Heart Attacks
Logue notes that the study found that the increased risk is for fatal heart attacks, not nonfatal heart attacks.
“We do not know why this is,” she says. “Possible reasons include particular chemicals that the fat cells are releasing, or perhaps it is related to the fact that obese people tend to have larger hearts to cope with the additional stress of their larger size, and this already stressed heart does not manage to continue to work during a heart attack.”
She and her research team tracked the health of more than 6,000 middle-aged men with high cholesterol but no history of diabetes or cardiovascular disease for about 15 years.
During that time, 214 fatal heart attacks and 1,027 non-fatal heart attacks or strokes were recorded.
The study began 20 years ago, the researchers say, when the prevalence of obesity was lower. Therefore, says Logue, the death risk associated with obesity may be even greater for men now than the study suggests.
She says that the clinical implications of the study are “difficult” and that “the main message should be that further research is urgently required to confirm these findings.”
However, she adds, “it certainly makes me think that we cannot just treat cholesterol, blood pressure, and diabetes in obese men without also considering their weight. We need to find easier and more effective ways to help people lose weight and see if losing weight can help reduce the risk of fatal heart attacks.”
Logue also says that health providers and public officials “need to dedicate far more resources to preventing obesity.”
Markers of obesity-induced inflammation are more strongly associated with fatal than non-fatal heart attacks, the researchers say.
Therefore, treating conventional risk factors alone may not be enough to counteract the risk of death from coronary heart disease in obese men, the study suggests.
The study is published online in the journal Heart.