FRIDAY, Jan. 12, 2007 (HealthDay News) -- Size does matter: Men with short telomeres -- strips of DNA at the end of chromosomes -- may have a higher risk of developing coronary heart disease.
And those same men may benefit the most from treatment with cholesterol-lowering drugs known as statins, a new British study found.
Because telomeres get shorter every time a cell divides, they serve as a sort of biological clock. Older cells have shorter telomeres. While previous research had shown that people with coronary heart disease were more likely to have short telomeres, it had been unclear whether this was a result of heart disease or a predictive marker.
"The main implication of the findings is perhaps a better understanding of why some people develop heart disease early and some people, despite having similar risk factors, never develop or develop it later," said study author Dr. Nilesh J. Samani, British Heart Foundation chair of cardiology at the University of Leicester, in the United Kingdom.
For this paper, published in the Jan. 13 issue of The Lancet, the study authors compared telomere length of white blood cells in 484 men who later developed coronary heart disease, with telomere length in 1,058 control subjects who didn't develop coronary artery disease. All the participants were middle-aged men at high risk for heart disease.
The researchers also analyzed whether telomere length had any connection with benefits derived from treatment with statins.
Among men who were not treated with statins, the risk of coronary heart disease was almost double in those with short telomeres compared to long telomeres. But in patients who were taking statins, the risk of heart disease was considerably lower for those with short telomeres.
Shorter telomeres aren't a consequence of having coronary heart disease, the authors concluded. But the scientists still don't know if telomere length is just another marker indicating a higher risk for heart disease, or whether it actually plays a role in development of the disease.
But the fact that men with shorter telomeres who took statins had a benefit suggests that it might be the latter.
There are a number of potential explanations for the finding that people with shorter telomere length responded better to statin therapy, but one is especially intriguing.
"The simple explanation for this could be that statins are simply more effective in people at higher risk for any reason," Samani said. "But the more intriguing possibility is suggested by the fact that we see an interaction between telomere length and statins. We think we're seeing an interaction which suggests that statins may be working through mechanisms that related to retarding the accretion of the telomeres."
To learn more about telomeres, visit Washington University.