They measured low-density lipoprotein cholesterol (LDL-C, bad cholesterol), high-density lipoprotein cholesterol (HDL-C, good cholesterol), triglycerides and blood levels of CETP before and after treatment with statin drugs. They then compared activity levels of CETP with changes in LDL-C, HDL-C and triglyceride levels after treatment.
For reference DNA, researchers determined the variations of the CETP gene in a group of Caucasian, African-American, Asian and Hispanic-Latino people.
They examined the relationship of each persons CETP gene SNPs and haplotype to his or her response to statin therapy (as measured by changes in HDL-C, LDL-C and triglyceride levels).
The researchers found that, in general, the individual SNPs had little effect on the amount of protein, the activity of the protein, or the persons response to statin therapy. However, when they looked at haplotypes, individuals had very different responses to statin treatment.
People with two copies of a particular CETP haplotype showed at least three times the increase in HDL-C levels compared to those with one or no copies of this haplotype.
Haplotype analysis may allow for highly individualized treatment of patients with lipid disorders, Ruano says.
Ruanos team has launched a larger study of about 800 patients in the United States to further test the association of certain genetic haplotypes with the efficacy and safety of statin treatment.
Sometime in the next five years we would expect genetic testing like this to be as common as cholesterol screening, with as little as a 30-minute wait for test results, says Ruano.