Canadian scientists claim to have discovered a protein called resistin, secreted by fat tissue, that causes high levels of "bad" cholesterol.

They say their research, presented Sunday at the Canadian Cardiovascular Congress in Toronto, proves that resistin increases the production of "bad" cholestrol (low-density lipoprotein or LDL) in human liver cells, resulting in the liver being ess able to clear "bad" cholesterol from the body. Resistin accelerates the accumulation of LDL in arteries, increasing the risk of heart disease.

Dr. Shirya Rashid, senior author of the study and assistant professor of medicine at Hamilton's McMaster University says a staggering 40% of people taking statins - the main cholesterol-reducing drug used in the treatment and prevention of cardiovascular disease - are resistant to their impact on lowering blood LDL.

"The bigger implication of our results is that high blood resistin levels may be the cause of the inability of statins to lower patients' LDL cholesterol," Dr. Rashid said in a statement issued by the Heart and Stroke Foundation Sunday.

She believes the discovery could lead to revolutionary new therapeutic drugs, especially those that target and inhibit resistin and thereby increase the effectiveness of statins.

"The possibilities for improved therapy for the causes of cardiovascular disease are very important," says Heart and Stroke Foundation spokesperson Dr. Beth Abramson. "About 40 per cent of Canadians have high blood cholesterol levels: it's a significant health concern in Canada."

Dr. Abramson says the research reconfirms the importance of maintaining a healthy weight and cholesterol level, two critical factors in the prevention of heart disease.