Heart disease health centre

Obesity is heart disease killer ‘in own right’

15^th February 2011 - Obesity is a cause of heart disease in its own right, irrespective of a range of other health conditions that piling on the pounds can trigger, according to new research.

A study published in the online edition of the journal Heart, examined to what extent obesity contributed to coronary heart disease independently of diabetes, high blood pressure and cholesterol frequently associated with people who have a high body mass index (BMI).

Scottish heart disease study

Researchers from the Faculty of Medicine at the University of Glasgow tracked the health of 6,082 middle aged men from the West of Scotland Coronary Prevention Study who had high cholesterol, but no history of diabetes or cardiovascular disease, for nearly15 years.

214 deaths and 1,027 non-fatal heart attacks or strokes occurred during this period.

The risk of having a heart attack was then compared across the participants who were graded according to their BMI.

Two different approaches were taken in comparing the risks. One simply corrected for any differences in age or whether the men smoked; the second corrected for cardiovascular risk factors such as high cholesterol and blood pressure, deprivation and any medications the men were taking.

The researchers found that the heavier a man was the more likely he was to have risk factors for heart disease.

The results

Although there was no increase in risk of non-fatal heart attack from having a higher BMI, the risk of dying was significantly higher in men who were obese - a BMI of 30 to 39.9 kg/m².

The extent of the risk of dying from a heart attack depended on which method the researchers had used to assess the risk. In the model which took into account age and smoking, the risk was 75% higher. In the model which corrected for cardiovascular risk factors, medication and deprivation, the risk was 60% higher.

Inflammation

The authors say the explanation for why obesity is an independent risk factor for heart disease is that inflammation is a strong factor in fatal cardiovascular disease, and obesity is increasingly being recognised as an inflammatory state.

Cathy Ross, senior cardiac nurse at the British Heart Foundation said in an emailed statement “We’ve known for some time that being overweight or obese can increase your risk of heart disease. But this study now strengthens the argument that obesity - in its own right - increases the risk of dying from a heart attack, irrespective of other risk factors.

“There is already strong evidence to show that inflammation increases the risk of death from heart disease. This study suggests that fatty ‘adipose’ tissue releases inflammatory substances in the body, which could be contributing to fatal cardiac events.