Abstract
BACKGROUND: To assess the associations of platelet traits and obesity indices with aging biomarkers (telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN)). METHODS: A cross-sectional study was performed among 5091 rural Chinese adults. Obesity indices (waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR)) and platelet traits (plateletcrit (PCT), platelet large cell ratio (P-LCR), mean platelet volume (MPV) and platelet distribution width (PDW)) were collected by physical examination. The aging biomarkers were determined by quantitative real-time polymerase chain reaction. Generalized linear regression models and mediation analysis were applied to explore the relationships between platelet traits, obesity indices, and aging biomarkers. RESULTS: The mean age of the participants was 56 years (range: 18-79). Each one-unit increment in WC, WHR and WHtR were related to a 0.316 (95% confidence interval (CI): -0.437, -0.196), 0.323 (95% CI: -0.513, -0.134) and 0.277 (95% CI: -0.400, -0.153) decrease in relative TL; or a 0.102 (95% CI: -0.197, -0.007), 0.109 (95% CI: -0.258, -0.041) and 0.101 (95% CI: -0.199, -0.004) decrease in relative mtDNA-CN. The proportions of obesity indices with aging biomarkers mediated by platelet indices ranged from 2.85% to 10.10%. CONCLUSIONS: Increased central obesity indices in relation to shortened relative TL or decreased mtDNA-CN were mediated by platelet traits, indicating that obesity in association with the accelerated aging process may be partially attributable to abnormal platelet activity.