Abstract 218: Relationships Between Telomere G-tail Lengths, Inflammation, Oxidative Stress and Endothelial Function in the Patients With Carotid Atherosclerosis

Abstract

Background and Purpose: Telomere length of leukocytes is associated with cardiovascular risk. Recently, telomere G-tails, which are extensions of a guanine-rich single-stranded 3’-overhang, are thought to be key structures that protect telomere DNA from DNA damage. The aim of this study was to investigate the associations between telomere G-tail lengths, total telomere lengths and clinical factors, including biological inflammation and oxidative stress markers. Methods: Patients with history of cerebrovascular diseases and comorbidities were enrolled in this study (n=102; 69 males, 70.1±9.2 years). Total telomere lengths and telomere G-tail lengths were measured by hybridization protection assay (Tahara H et al. Nat Methods. 2005). Serum reactive oxygen species (ROS) levels were measured by using the total ROS assay system (Hayashi I et al. Mutat Res. 2007). Endothelial function was evaluated by ultrasound assessment of brachial flow-mediated dilation (FMD) as an index of endothelium-dependent vasodilation. Results: Telomere G-tail length (13653.0±2787.4 RLU/μg DNA) was positively correlated with total telomere length (176698.3±20308.0 RLU/μg DNA; R2=0.156, P<0.001). In addition, telomere G-tail length was negatively correlated with age (R2=0.075, P<0.001). Telomere G-tail lengths were not associated with the serum ROS levels or hs-CRP levels, although there was a significant association between serum hs-CRP levels and ROS levels (R2=0.336, P<0.001). Telomere G-tail lengths were positively correlated with FMD values (R2=0.074, P=0.006), although total telomere lengths were not correlated with those values (R2=0.026, P=0.105). On multivariate regression analysis, longer telomere G-tail lengths (standardized partial regression coefficient [β] 0.219; P=0.018), higher age (β -0.209; P=0.031), and male (β -0.264; P=0.004) were independently associated with FMD values. Conclusion: Telomere G-tail lengths were independently related to the endothelial function after adjustment for vascular risk factors, chronic inflammation and oxidative stress. Telomere G-tail lengths might be more useful marker for the endothelial function which was evaluated by FMD than total telomere lengths.