Rationale
Leucocyte telomere length (LTL) is a biological marker of aging, and shorter LTL is associated with adverse cardiovascular outcomes. Reduced regenerative capacity has been proposed as a mechanism. Bone marrow-derived circulating progenitor cells (PCs) are involved in tissue repair and regeneration.
Objective
To examine the relationship between LTL and PCs, and their impact on adverse cardiovascular outcomes.
Methods and Results
We measured LTL by quantitative PCR in 566 outpatients (age 63±9 years, 76% male) with coronary artery disease (CAD). Circulating PCs were enumerated by flow cytometry. After adjustment for age, gender, race, BMI, smoking and previous myocardial infarction, a shorter LTL was associated with a lower CD34+ cell count: for each 10% shorter LTL, CD34+ levels were 5.2% lower (p<0.001). After adjustment for the aforementioned factors, both short LTL (