Associations Between Ambient Air Pollution And Mitochondrial Dna Copy Number And Telomere Length In A Panel Of Elderly Residents Of Shanghai, China

Abstract

Introduction: Several previous studies proposed a link between air pollution, especially particulate matter (PM), and mitochondrial DNA copy number (MtDNAcn) and telomere length (TL). However, this knowledge is quite limited, especially on how the particle size affects the associations and on whether there exists such an association with gaseous pollutants. We examined short-term associations of size-fractionated PM and gaseous pollutants with blood MtDNAcn and TL. Methods: We conducted a longitudinal panel study involving 6 repeated measurements among 35 elderly residents in Shanghai, China. Real-time concentrations of size-fractionated PM (0.25~10μm) and criteria gaseous pollutants (SO2, NO2, CO and O3) were measured from April to June 2013. Blood MtDNAcn and TL were measured by a quantitative real-time PCR–based assay. Linear mixed-effect models were used to explore their short-term associations using multiple lag periods from 2 hours to 3 days. Results: In general, there were negative but statistically insignificant associations between all pollutants and MtDNAcn at all lags. The associations between air pollutants and TL were quite weak even null. Coarse PM appears to be more closely linked with MtDNAcn and TL than small PM, although these associations were not statistically significant either. Conclusions: This study did not support short-term associations of PM or gaseous pollutants with blood MtDNAcn and TL in Shanghai, China. Further studies are still needed to evaluate the effects of air pollution on MtDNAcn and TL, and to elucidate the potential roles of abnormal MtDNAcn and TL in the pathophysiology of air pollution.