Gene clues to cholesterol levels

A third of people have genetic variations that cut their risk of heart disease, perhaps by increasing the level of 'good' (HDL) cholesterol in their blood, say UK and Dutch scientists. A new study, published in the Journal of the American Heart Association, shows that individuals with particular versions of the CETP (Cholesteryl Ester Transfer Protein) gene have a five per cent lower risk of having a heart attack.

The researchers combined the results of almost 100 other studies, involving a total of 147,000 people. They looked at six different versions of the CETP gene, and found that the three most common were associated with both a 3-5 per cent rise in the levels of HDL cholesterol and a lower risk of heart disease. High levels of LDL ('bad') cholesterol increase the risk of a heart attack or stroke, as it can build up in the arteries that feed the heart and brain, making them narrower. In contrast, higher levels of HDL cholesterol seem to protect against these conditions, possibly because it is the form in which cholesterol is carried away from the arteries and back to the liver.

The team, based at the universities of Cambridge, Newcastle and Groningen, hope that their findings will lead to new treatments aimed at preventing heart disease, perhaps in the form of drugs that target the CETP gene in order to raise HDL cholesterol levels. Current medicines offered to people at increased risk of heart attacks, such as statins, work by lowering levels of LDL cholesterol. But as Professor Peter Weissberg, of the British Heart Foundation, pointed out, researchers are now questioning 'whether approaches that raise HDL cholesterol could further prevent heart disease'.

Meanwhile, a new study by researchers at Washington University School of Medicine have identified variations in a gene that affect the risk of 'metabolic syndrome', a collection of symptoms that can increase the risk of both Type 2 diabetes and heart disease. The findings, reported in the journal Human Molecular Genetics, show that five versions of the CD36 gene seem to increase the likelihood of these symptoms appearing, while a sixth has a protective effect. Like the CETP gene, CD36 appears to affect levels of HDL cholesterol in the body.