Leukocyte telomere length and its relation to nitric oxide metabolites in a bi-ethnic sample: the SABPA study

Abstract

Aging of the cardiovascular system is associated with cardiovascular morbidity and mortality. One of the measures for biological aging is telomere length. Telomere length is considered to be more closely related to cardiovascular disease than chronological age. If telomere length declines, so does the protective mechanisms of nitric oxide (NO) in the cardiovascular system. Additionally, different population groups also have different telomere lengths and NO bioavailability profiles which may indicate a variation in risk of cardiovascular disease in different populations. NO plays a critical role in the maintenance of a healthy cardiovascular system by counteracting endothelial senescence. It is known that when NO declines, so does telomerase activity. When NO bioavailability decreases, telomere shortening may accelerate, because of the association between telomerase activity and NO. Shortened telomere length is age dependent, but might also indicate declining cardiovascular health, through a cycle of negative impact. This cycle could reduce NO, which decreases telomere length, thus increasing cell senescence that could again decrease NO production. The burden of cardiovascular disease is an enormous challenge worldwide. This is also true for the South African population. The association between telomere length and cardiovascular disease is well known, but minimal studies have been done on the South African population. Globally, studies conducted in black populations on telomere length, NO and telomerase activity have shown contradictory results. To date, there are no publications that focus on the association between telomere length and NO metabolites (NOx) in a South African population. With this study, an attempt was therefore made to increase our understanding of the relationship between telomere length and the cardiovascular system, by investigating associations of telomere length with NOx in a bi-ethnic population.