
B2 Gene Mutation Helps Men Live
By Judy McBride May 31, 2000Two-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. The study, published in the May issue of Arteriosclerosis, Thrombosis and Vascular
Biology, was funded by the Agricultural Research Service,
USDAs chief scientific agency. 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. Ordovas and colleagues collaborated with researchers from
Boston University,
North Carolina State University and
The Framingham
Heart Study. 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, [email protected]. U.S. Department of Agriculture |