The Cause of High Cholesterol, Discovered Within the Human Body
A recent discovery by Canadian researchers could change the way doctors treat high cholesterol
-- by Alexia Severson
Resistin, a protein secreted by fat tissue, not only raises cholesterol, but works against the effects of statins, the main cholesterol-reducing drug used in the treatment and prevention of cardiovascular disease, according to new research presented at the Canadian Cardiovascular Congress.
Canadian scientists discovered that resistin increases the production of low-density lipoprotein (LDL), or “bad” cholesterol, in human liver cells. It also degrades LDL receptors in the liver, making it harder to clear "bad" cholesterol from the body and increasing a person’s risk of heart disease.
According to Statistics Canada, heart disease was the second leading cause of death, next to cancer, in every province and territory in 2008, except Nunavut where suicide ranked second. And according to CBC/Radio-Canada, “about eight out of every 10 Canadians are at risk of developing cardiovascular disease -an illness that 74,000 die from each year.”
The Expert Take
Forty percent of people taking statins to reduce high levels of cholesterol are actually resistant to their impact, researchers said.
"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," said Shirya Rashid, senior author of the study and assistant professor in the department of medicine at McMaster University.
The results of this study could also lead to new therapeutic drugs that specifically target and inhibit resistin, increasing the effectiveness of statins, she said.
"The possibilities for improved therapy for the causes of cardiovascular disease are very important," says Heart and Stroke Foundation spokesperson, Beth Abramson. "About 40 per cent of Canadians have high blood cholesterol levels: it's a significant health concern in Canada."
The Take Away
Heart disease affects Americans too. While cardiovascular disease (CVD) death rates declined about 31 percent, CVD is still the leading cause of death in the U.S., according to the American Heart Association Heart Disease and Stroke Statistics 2012 Update. Stroke is the fourth leading cause of death.
According to these same statistics, about 34 million people over the age of 20 will have total serum cholesterol levels greater than, or equal to, 240 mg/ dL. Desired levels of total blood cholesterol are less than 200.
Fortunately, there are things you can do to maintain a healthy weight and cholesterol level, therebyh preventing heart disease and stroke.
Abramson recommends these tips to keeping your heart healthy:
- visit the doctor on a regular basis
- monitor weight and waist size
- eat a variety of nutritious, low-fat foods
- stay physically active
- take medications as directed by your doctor
In a similar study published in Postgrad Medical Journal in 2011, researchers assessed serum resistin, known to have a possible link to coronary heart disease, in patients with acute ST segment elevation myocardial infraction (STEMI)--a type of heart attack--with and without type 2 diabetes. The results showed that serum resistin concentrations were elevated in patients with acute STEMI and that this increase was more prominent in patients with type 2 diabetes than those without, suggesting that serum resistin concentration might be used as a diagnostic biomarker for heart attacks.
Another study published in Medical Science Monitor, researcher evaluated the value of resistin in patients with stable multivessel coronary artery disease (MCAD). In stable patients with MCAD, the team found that elevated plasma resistin was a strong, independent predictive factor for the occurrence of major adverse cardiac and cerebrovascular events over a 1 year follow-up.
Researchers also found a correlation between resistin levels and cardiovascular risk factors and severity of coronary heart disease in acute coronary syndrome in a study published Chinese Medical Sciences Journal in 2009.