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B2 Gene Mutation Helps Men LiveBy Judy McBride
May 31, 2000
Two-fifths of the U.S. population may be carrying a gene mutation that reduces risk of heart disease in men--perhaps by as much as 30 percent--according to a study of nearly 3,000 men and women in Framingham, Mass.
This mutation is common in all populations studied, according to study leader Jose Ordovas at the Jean Mayer USDA Human Nutrition Research Center on Aging in Boston. This is the first report that the mutation protects against heart disease.
Next, Ordovas laboratory will study how this mutation influences the way individuals respond to changes in dietary fat and cholesterol.
Known as B2, the mutation keeps blood levels of the good HDL cholesterol high. And it keeps the size of the HDL particles larger, which also reduces risk. Thats because it slows down the transfer of cholesterol from HDL to LDL--the lipoprotein that promotes artery blockage. The mutation occurs in the gene that codes for cholesterol ester transfer protein, or CETP.
About 40 percent of the study volunteers had at least one B2 mutant among the gene pair. The men with even one B2 had higher HDL and larger HDL particles than those with no mutation. HDL averaged 7 percent higher in the men with a single mutant and 10 percent higher in the men carrying two B2s. The finding supports clinical evidence that for every 1 percent increase in HDL, cardiovascular disease and death drop 2 to 3 percent.
Risk of cardiovascular disease among the nearly 3,000 volunteers was 30 percent lower among the men with at least one B2 mutant.
Women carrying the mutant also had higher HDL levels and larger HDL particles. But their risk of cardiovascular disease was not significantly different from women with the more common B1 genes. That may be due to womens natural hormonal protection before menopause.
Scientific contact: Jose M. Ordovas, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington St., Boston, MA 02111; phone (617) 556-3102, fax (617) 556-3103, firstname.lastname@example.org.