Researchers have been telling us for some time now that telomere length is a marker of age-related chronic diseases, such as heart disease, Alzheimer’s disease, and cancer, among others. It’s not clear, however, if there is an association between telomere length and cardiovascular risk. This uncertainty was the focus of a study published in BMJ by a team of researchers in the United Kingdom.
What are telomeres?
Telomeres are the similar to the lids or caps on the end of a shoestring, except these caps are positioned on the ends of DNA strands. The purpose of telomeres is to protect our chromosomes from damage, because damaged cells are unable to fulfill their purpose or function. Telomeres become shorter every time cells divide, so they are a reflection of the amount of cellular turnover going on in an individual.
Telomere length can vary significantly between people of the same chronological age, and one reason is that everyone is exposed to different levels of factors that can have an impact on their length, such as exposure to environmental pollutants, stress, and inflammation.
The bottom line is, telomeres play a critical role in how our cells age and, therefore, our aging process as well.
Telomere length and cardiovascular risk study
In this review, the authors evaluated 24 studies that involved 43,725 participants and 8,400 patients who had cardiovascular disease 5,566 with coronary heart disease and 2,834 with cerebrovascular disease). The studies analyzed the telomere length of leucocytes, which are white blood cells that play a critical role in counteracting foreign invaders and disease.
When the shortest and the longest third of leucocyte telomere length were compared, the reviewers noted an increased risk for coronary heart disease associated with the shorter length independent of conventional vascular risk factors, such as age, sex, history of diabetes, blood pressure, lipid levels, and smoking. However, shorter telomeres were not significantly associated with cerebrovascular disease risk overall.
This study helped show an inverse relationship between shorter telomere length of white blood cells and the risk of coronary heart disease independent of traditional risk factors for vascular health. For now, any association between telomere length and cerebrovascular disease is less defined.
Haycock PC et al. Leucocyte telomere length and risk of cardiovascular disease: systematic review and meta-analysis. BMJ 2014; 349:g4227