The ‘good’ cholesterol not always good for the heart

The widespread belief among doctors and ordinary people that the “good” cholesterol (HDL) is always good for the heart, it seems that there is a doctrine that applies in each case.
A new international scientific research -with the participation of a Greek scientist of the dispersion – revealed for the first time that, in some people, to whom the “lipoprotein high density (HDL) is increased for genetic reasons, this high level is actually bad for the heart.
The “good” cholesterol usually compensates for the detrimental presence of “bad” cholesterol (LDL). But some people have a specific gene mutation, which -despite the parallel presence of a high “good” cholesterol – increases the risk of coronary heart disease and heart attack, as about and smoking. This discovery raises some doubts as to whether drugs that increase “good” cholesterol, is appropriate for all patients, if there has been a genetic test.
The researchers, who made the relevant publication in the top journal “Science,” analyzed data from the genome of 328 people, with a very high “good” cholesterol, and they did a comparison with 1156 other people who had lower levels in their blood, in order to identify the genetic causes of high HDL.
Previous studies have indicated that HDL may not always be protective for heart disease, as people think of cardiologists. The suspicion was reinforced after a series of clinical trials of drugs that increase the HDL, but finally reduce little or no risk for the heart, according to the Athenian Agency.
“The perception of the HDL tends to develop last, as it appears that it may not always protect from any heart disease,” said Ράντερ. “Our findings show that some (genetic) causes of increased HDL actually increase the cardiovascular risk. It’s the first time identified a mutation, which increases HDL and at the same time increases the risk for heart disease,” he added.
The mutation concerns the gene SCARB1, which regulates the function of a protein, which is the main receptor of HDL on the surface of the cell. Because of the mutation, the protein ceases to function properly, and cholesterol is not transported in the liver, thus paradoxically increasing the risk for the heart, although the “good” cholesterol is at high levels in the blood of the patient.
This mutation, however, is rare in the population and usually appears in people of jewish origin, but the researchers intend to check if there are other mutations that may have a similar paradoxical result (i.e., high HDL and high cardiovascular risk).
The researcher proposed to develop eventually a genetic test will control the people with high HDL are dangerous mutations in the DNA, which can transform it into a “boomerang” high good cholesterol. In any case, as he said, “we still have a lot to learn about the function of HDL and the risk of heart disease”.
In the investigation participated the Greek origin Panos Δελούκας, professor of cardiovascular genomics at Queen Mary University of London and a research fellow of the british Institute of Genetics Wellcome Trust Sanger Institute.