DNA strands' length linked to heart disease risk

Telomeres— strands of DNAat the end of chromosomes— mayserve as indicators of peopleat risk of developing heart disease, suggests a new study byU.K. researchers.

"We have shown that leukocyte telomere length is associated with future coronary heart disease events in middle-aged, high-risk men," Prof. Nilesh Samani of the University of Leicester in England and his team report in Saturday's issue of The Lancet.

The length of telomeres shrinks every time a cell divides, like a chromosomal clock that reflects the aging process.

Scientists suspect that as telomeres shrink, chromosomes become less stable and are therefore more likely to mutate.

The U.K. researchers took blood samples from 484 middle-aged men with moderately high cholesterol levels.

The length of the telomeres in theparticipants'white blood cells or leukocytes were compared to those of 1,058 control subjects, initially and then five years later.

Participants were also randomly assigned to take statins, drugs that breakdown artery-clogging cholesterol, or a placebo.

Among those in the placebo group, the risk of heart disease was almost double among men with short telomeres comparedto those with long telomeres. The protective effect of the drugs was only seen among people with comparatively short telomeres.

Earlier studies have found shorter telomeres among people with heart disease, but it was not known if telomere length could help predict the illness.

A working relationship between telomere length and heart disease risk has not been shown.

Nevertheless, measuring the length of telomeres in middle-aged men may help identify those at greatest risk of heart disease who may benefit from taking statins, the researchers said.