Short telomeres are already linked to increased mortality and disease risk, but the rate of change is also important. New research has revealed heart disease patients whose telomeres remain stable or even lengthen have an improved prognosis
The typical measure of an individual's telomere length is their average leukocyte (white blood cell) length, but this measure alone has only emerged as a partial indication of mortality risk. Individuals with longer telomeres generally appear to benefit, but the rate of shortening is possibly a more potent measure of health. After all, mice begin life with much longer telomeres than humans, but experience rapid degradation. Experiments lengthening telomeres in mice have also demonstrated significant health benefits.
Connecting telomere stability to heart disease
In a recent study involving 608 women and men with stable cardiovascular disease, all participants' leukocyte telomere lengths were taken before and after a period of 5 years - the goal being to see if any changes correlated with mortality risk within that period. Unfortunately 1/4 of the patients passed away during the study's duration. When this group was analysed, it was found that 12% of patients with telomeres that actually lengthened during the study had died, in contrast to 39% of those who showed shortening and 22% of those with lengths that remained the same.
When the researchers analysed other factors, such as cholesterol and blood pressure, the 3 groups were very similar. However, shortened telomeres appeared to increase abdominal fat and decrease overall fitness and kidney function. After further statistical analysis, it emerged that individuals with shortening were 32% more likely to die within 4 years than the stable group. Patients who experienced lengthening were 56% less likely to die however - suggesting a reasonable protective influence. It wasn't clear exactly how some patients were able to extend their telomeres over the designated time period, but the team postulated that it was due to healthy lifestyle factors and decreased stress exposure.
"This study goes beyond telomere length as a single measure and shows that the rate of change may also be an important predictive factor. It also shows, rather surprisingly, that a substantial number of people had telomere lengthening, and that this appeared to be protective. While we have observed in several studies that average telomere length can get longer over the period of a year or two, we think the more common process is that a healthy lifestyle protects telomeres and leads to less shortening, more stability, and thus better telomere maintenance over the years"
Read more at MedicalXpress