Accelerated Biological Aging Secondary to Cardiometabolic Risk Factors Is a Predictor of Cardiovascular Mortality: A Systematic Review and Meta-analysis

Background: Chronological aging is one of the major risk factors of cardiovascular (CV) disease (CVD); however, the effect of biological aging on CVD and outcomes remain poorly understood. Herein, we evaluated the association between leukocyte telomere length (LTL), a marker of biological age, and CV outcomes. Methods: We searched PubMed, Embase, Ovid Medline, and Web of Science Core Collection for the studies on the association between LTL and myocardial infarction (MI), CV death, and/or CVD risk factors from inception to July 2020. Extracted data were pooled in a random-effects meta-analysis and summarized as risk ratio (RR) and corresponding 95% confidence interval (CI) per LTL tertile. Results:A total of 32 studies (n=144,610 participants) wereincluded. In a pooled analysis of MI and LTL in a multivariate-adjustedmodel, the shortest LTL was associated with a 39% higher risk of MI(RR, 1.39; 95% CI, 1.16-1.67;P < 0.001). After adjusting for chro-nological age and traditional covariance, we showed a 28% increasedrisk of CV death in the shortest tertile of LTL (RR, 1.28; 95% CI, 1.05-1.56;P=0.01). Analysis of the studies that investigated the associ-ation between CV risk factors and LTL (n=7) showed that diabetesmellitus is associated with a 46% increased risk of LTL attrition (RR,1.46; 95% CI, 1.46-2.09;P=0.039). Conclusions:This study shows a strong association between LTL, amarker of biological aging, and the risk of MI and CV death. Car-diometabolic risk factors contribute to telomere attrition and thereforeaccelerates biological aging.