A person with the 'bad' form could try to lower the risk by exercising, eating a low fat diet, not smoking and taking medication to lower cholesterol. Researchers studied African Americans because their cholesterol and other blood fat levels are different from Caucasians and they have a higher incidence of cardiovascular diseases than the white population, says Juo, an associate research scientist at Columbia University Genome Center in New York City. This long-term study at medical centers in Birmingham, Ala., Chicago, Minneapolis, and Oakland, Calif., has collected 10 years of data on more than 4,000 black and white men and women. As part of the study, participants received a complete evaluation of their blood cholesterol every two years. Juo and his colleagues used blood drawn from the men in their study to determine which variation of the MTP gene each carried.
Genes exist in pairs.
One gene is inherited from the mother and the other from the father. A person with the TT variant of the MTP gene inherited a T variant of the gene from each parent. The team examined the lipid data from the men's five examinations over 10 years and found significant differences between the TT and other gene forms. The men with the other variations had very similar lipid levels. However, in the five exams, total cholesterol levels for the TT group ranged from 6 percent to 11 percent higher and LDL cholesterol was 8 percent to 15 percent higher than for the other two groups.