Telomeres and telomerase in the fetal origins of cardiovascular disease: a review.

Telomeres are noncoding functional DNA repeat sequences at the ends of chromosomes that decrease in length by a predictable amount at each cell division. When the telomeres become critically short, the cell is no longer able to replicate and enters cellular senescence. Recent work has shown that within individuals, telomere length tracks with cardiovascular health and aging and is also affected by growth variation, both prenatally and postnatally. Therefore telomere length can be a marker of both growth history (cell division) and tissue function (senescence). Relationships between early growth and later health have emerged as a research focus in the epidemiology of chronic diseases of aging, such as heart disease and diabetes. The "fetal origins" literature has demonstrated that hormonal and nutritional aspects of the intrauterine environment not only affect fetal growth but also can permanently alter the metabolic program of the individual. Smaller infants tend to have a higher risk of developing cardiovascular disease. Much less attention has been paid to possible genetic links between the processes of early growth and later disease. Our aim in this review is to summarize evidence for one such genetic mechanism, telomere attrition, that may underlie the fetal origins of cardiovascular disease and to discuss this mechanism in light of the evolution of senescence.