The prime risk factors for heart disease are well known—obesity, smoking, elevated cholesterol, and high blood pressure. Yet many people with these warning signs develop heart problems, while others don't. This observation indicates that yet-unrecognized factors must also influence risk.
A new study finds that the sequence-repeating sections of DNA called telomeres, which protect the ends of chromosomes, might play a role. Middle-aged men with long telomeres are only half as likely to develop heart disease as are men of the same age with short telomeres, researchers report in the Jan. 13 Lancet.
Telomeres buffer chromosomes' tips much as plastic caps preserve the ends of shoelaces. But telomeres get shorter with each successive division of a cell, and too-short telomeres ultimately leave a cell unable to replicate.
In the new study, Nilesh J. Samani, a cardiologist at the University of Leicester in England, and his colleagues assessed telomere lengt