A novel study has been put forth by experts at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University and Boston University School of Medicine. It suggests that although increasing high-density lipoprotein (HDL) cholesterol levels by inhibition of a protein transfer activity may be seen as potential heart disease therapy, it may not be effective.
The scientists claim to have found an association between low plasma cholesterol ester transfer (CETP) activity and surged risk of heart disease. This was observed in the Framingham Heart Study population. CETP is known to be a protein that transports cholesterol throughout the body. It may thus be able control the amount of HDL, low-density lipoprotein (LDL), and very-low-density lipoprotein (VLDL) in the blood.
“Our findings differ from studies suggesting that inhibiting CETP activity would bring a cardiovascular benefit by raising HDL, the so-called good cholesterol credited with lowering the risk of heart disease,” shares senior author Jose Ordovas, PhD, director of the Nutritional Genomics Laboratory at the USDA HNRCA. “In a clinical trial testing that hypothesis, heart disease unexpectedly advanced in a surprising number of participants.”
On the basis of those results Ordovas along with colleagues investigated the activity of CETP in 1,978 Caucasian men and women. These individuals had a mean age of 51 years and no history of heart disease. Upon analysis of 15 to 18 years of study visits, they looked for first cardiac events including heart failure, heart attack, angina, stroke and peripheral vascular disease.
“By the end of the follow-up period, 320 men and women had experienced their first cardiac event,” adds Ordovas who is also a professor at the Friedman School of Nutrition Science and Policy at Tufts University. “Participants with low CETP activity were 18 percent more likely to develop cardiovascular disease than people with CETP activity above the median.”
On further delving into the models, the experts could leave out the chances that age, sex and common risk factors like smoking, weight, diabetes, and cholesterol levels interfered with the findings. The preliminary nature of their data has been stressed upon by the authors.
“The relationship between CETP activity and HDL levels carries many unknowns, including the influence of genetics,” Ordovas remarked pointing to studies of some Japanese families. “Despite very low levels of CETP activities, they still have high heart disease risk. Other genetic studies question the inhibition of CETP, but there is not enough research to discount the possibility that raising HDL levels through CETP inhibitors may reduce the risk of heart disease.”
The results are published in the December 15 issue of Circulation.