Telomere Shortening, Regenerative Capacity, and Cardiovascular Outcomes

• Authors: Muhammad Hammadah, Emory University; Ibhar Al Mheid, Emory University; Kobina Wilmot, Emory University; Ronnie Ramadan, Emory University; Naser Abdelhadi, Emory University; Ayman Alkhoder, Emory University; Malik Obideen, Emory University; Pratik M. Pimple, Emory University; Oleksiy Levantsevych, Emory University; Heval M. Kelli, Emory University; Amit Shah, Emory University; Yan Sun, Emory University; Bradley Pearce, Emory University; Michael Kutner, Emory University; Qi Long, Emory University; Laura Ward, Emory University; Yi-An Ko, Emory University; Kareem hosny Mohammed, Emory University; Jue Lin, University of California at San Francisco; Jinying Zhao, Tulane University; James Bremner, Emory University; Jinhee Kim, Emory University; Edmund Waller, Emory University; Paolo Raggi, Emory University; David Sheps, University of Florida; Arshed Quyyumi, Emory University; Laura Vaccarino, Emory University
• Journal Title: Circulation Research
• Volume: Volume 120, Number 7
• Publisher: American Heart Association | 2017-03-31, Pages 1130-+
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1161/CIRCRESAHA.116.309421
• Subjects: Health Sciences, Medicine and Surgery; Health Sciences, Epidemiology; Biology, Biostatistics
• Keywords: Science & Technology; Life Sciences & Biomedicine; Cardiac & Cardiovascular Systems; Hematology; Peripheral Vascular Disease; Cardiovascular System & Cardiology; aging; coronary artery disease; risk; stem cells; telomere; ENDOTHELIAL PROGENITOR CELLS; CORONARY-ARTERY-DISEASE; STEM-CELLS; HEMATOPOIETIC STEM; BLOOD-CELLS; LENGTH; ATHEROSCLEROSIS; RISK; POPULATION; NEOVASCULARIZATION

Abstract

Rationale: Leukocyte 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 are involved in tissue repair and regeneration. Objective: Main objective of this study was to examine the relationship between LTL and progenitor cells and their impact on adverse cardiovascular outcomes. Methods and Results: We measured LTL by quantitative polymerase chain reaction in 566 outpatients (age: 63±9 years; 76% men) with coronary artery disease. Circulating progenitor cells were enumerated by flow cytometry. After adjustment for age, sex, race, body mass index, smoking status, 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 ( < Q1) and low CD34+ levels ( < Q1) predicted adverse cardiovascular outcomes (death, myocardial infarction, coronary revascularization, or cerebrovascular events) independently of each other, with a hazard ratio of 1.8 and 95% confidence interval of 1.1 to 2.0, and a hazard ratio of 2.1 and 95% confidence interval of 1.3 to 3.0, respectively, comparing Q1 to Q2-4. Patients who had both short LTL ( < Q1) and low CD34+ cell count ( < Q1) had the greatest risk of adverse outcomes (hazard ratio =3.5; 95% confidence interval, 1.7-7.1). Conclusions: Although shorter LTL is associated with decreased regenerative capacity, both LTL and circulating progenitor cell levels are independent and additive predictors of adverse cardiovascular outcomes in coronary artery disease patients. Our results suggest that both biological aging and reduced regenerative capacity contribute to cardiovascular events, independent of conventional risk factors.