Associations Between Size-Fractioned Particulate Matter And Left Ventricular Voltage: A Panel Study Among Healthy Young Adults In Southern China

Exposure to ambient air pollution is consistently associated with increased cardiovascular morbidity and mortality; however, the underlying pathophysiologic mechanisms remain unclear. High left ventricular voltage has been related to cardiac dysfunction. Therefore, this study aimed to investigate the association between longitudinal exposure to size-fractioned particulate matter (PM) and left ventricular voltage (assessed as the sum of the voltages of the R-wave in lead V5 [RV5] and S-wave in lead V1[SV1]) among 88 healthy, young Chinese adults. We collected weekly 12-lead electrocardiogram (ECG) and serum biomarkers from each participant five times over 35 days. The fixed point, real-time, mass concentrations of particles with aerodynamic diameters of <= 2.5 mu m (PM2.5), PM1, PM0.5, and number concentrations of particles with aerodynamic diameters of <= 0.2 mu m (PNC0.2), PNC0.1, and PNC0.03 were monitored in the catchment area, and linear mixed-effect models were used to estimate the associations between the size-fractioned PM exposure and ECG indices. The results showed that there was a significant association between higher size-fractioned PM levels and higher RV5+SV1 voltage within 24 h of exposure. We detected increases in the RV5+SV1 voltage of 0.060, 0.058, 0.090, 0.084, and 0.077 mV per interquartile range (IQR) PM2.5 (45.92 mu g/m(3); 95% confidence interval [CI] = 0.003, 0.117), PM1 (43.51 mu g/m(3); 95% CI = 0.003, 0.113), PNC0.2 (14.92 x 103 particles/cm(3); 95% CI = 0.017, 0.163), PNC0.1 (12.79 x 10(3) particles/cm(3); 95% CI = 0.004, 0.163), and PNC0.03 (5.43 x 10(3) particles/cm(3); 95% CI = 0, 0.153), respectively. The associations between the RV5+SV1 voltage and size-fractioned PM exposure were stronger among participants with greater serum concentrations of monocyte chemoattractant protein-1, soluble CD40 ligand, plasminogen activator inhibitor-1, and total cholesterol, and lower high-density lipoprotein cholesterol levels. Exposure to various PM size fractions (PNC0.03-PNC0.2, and PM0.5-PM2.5) may increase the left ventricular voltage among healthy young adults, and the effects may be modified by inflammation, coagulation, and lipid biomarkers.