People who are obese face higher risk of dying from a heart attack, irrespective of whether or not they have other known risk factors for
Increasing weight is associated with a higher prevalence of
known risk factors for coronary artery disease, such as diabetes, high blood
pressure and cholesterol. And it has been assumed that these have been
responsible for the increased risk of heart disease seen in obesity, say the
The 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 around 15 years.
After excluding men who had cardiovascular problems or died
within two years of the start of monitoring, to correct for any bias, 214
deaths and 1,027 non-fatal heart attacks/strokes occurred during the whole
The risk of a heart attack was compared across categories of
increasing body mass index (BMI), using two different approaches.
One simply corrected for any differences in the age or
smoking status of the men, while the second corrected for cardiovascular risk
factors such as high cholesterol and blood pressure, deprivation and any
medications the men were taking.
Not unexpectedly, the results showed that the higher a man's
weight, the higher was his likelihood of having other risk factors for
cardiovascular disease. And there was no increased risk of a non-fatal heart
attack with increasing BMI, (when using either approach)
But the risk of death was significantly higher in men who
were obese - a BMI of 30 to 39.9 kg/m2.
In the model simply correcting for age and smoking, this
risk was 75% higher. And despite correcting for known cardiovascular risk
factors, medication, and deprivation in the second model, the risk was still
Inflammation is a strong factor in fatal cardiovascular
disease, and obesity is increasingly being recognised as an inflammatory state,
which may partly explain how obesity is linked to heart disease, say the
authors. This has implications for treatment and prevention, they add.
In an accompanying podcast, which expands on the findings,
lead author Dr Jennifer Logue, of the British Heart Foundation Cardiovascular
Research Centre, at the University
of Glasgow, cautions that
the number of obese men in the sample was small, so the results need to be
But she says, this is mainly because when the study started
20 years ago, the prevalence of obesity was low. But all that has now changed.
"The obesity generation is coming of age. We are
going to see more and more complications from obesity, and coming at an earlier
age," she warns.