Wednesday February 9, 2000, 7:24 PM ET
Gene boosts athletic performance
NEW YORK, Feb 09 (Reuters Health) -- People who carry the longer version of a particular gene have better endurance, giving them an athletic edge over those who inherit a shorter version of the gene, new research suggests.
The gene, known as the ACE gene, for angiotensin-converting enzyme, is found in muscle. There are two variants of this gene, with one 287 base pairs longer than the other.
In the February 10th issue of Nature, British researchers report that among army recruits they studied, those who had the longer of the two ACE gene variants showed better muscle performance than recruits without the variant. Dr. Hugh Montgomery, of the Centre for Cardiovascular Genetics at London's Rayne Institute, led the study.
Everyone has two ACE genes, Montgomery told Reuters Health. Half of the population has one of each variant, while 25% have two short ACE genes and 25% have two of the long variant. The more long ACE genes a person carries, Montgomery said, the greater the individual's muscle efficiency.
In the study, the researchers examined whether the longer ACE gene helps muscles respond to exertion more efficiently. They asked 58 male army recruits -- 35 with two longer ACEs and 23 with two of the shorter variant -- to pedal on stationary bikes at a constant speed for three 3-minute intervals. Subjects' breathing was monitored and used to calculate how much energy each had to expend to complete the exercise -- a measure of muscle efficiency.
Before exercising, subjects' muscle efficiency showed no relation to their particular ACE variants. During the exercise, however, the long-ACE men clearly had the upper hand in muscle efficiency, by about 9% over the other men. In contrast, men with the shorter gene variant saw their muscle efficiency dip by 0.4% while exercising.
Just why the longer ACE variant boosts muscle performance is unclear. The longer gene seems to create less enzyme activity, which may push muscle cells to become more efficient during exertion, Montgomery suggested.
``When demand is high,'' he said, ``the engine must burn lean and use less fuel to go the same number of miles.'' In this scenario, according to Montgomery, muscle cells are the ''fuel-injection system,'' and the longer ACE variant keeps it running more economically.
These findings also lend some insight into why ACE inhibitor drugs can effectively treat heart disease, the researchers note. ''If heart muscle cells are made more efficient, the heart would have less work to do,'' Montgomery explained. ``And if the heart gets more efficient, then it could do more work on less fuel.''
SOURCE: Nature 2000;403:614.
