Association of long-term exposure to traffic-related PM; 10; with heart rate variability and heart rate dynamics in healthy subjects

Epidemiological evidence on the influence of long-term exposure to traffic-related particulate matter (TPM; 10; ) on heart rate variability (HRV) is weak.; To evaluate the association of long-term exposure (10 years) with TPM; 10; on the regulation of the autonomic cardiovascular system and heart rate dynamics (HRD) in an aging general population, as well as potential modifying effects by the a priori selected factors sex, smoking status, obesity, and gene variation in selected glutathione S-transferases (GSTs).; We analyzed data from 1593 SAPALDIA cohort participants aged ≥ 50 years. For each participant, various HRV and HRD parameters were derived from 24-hour electrocardiogram recordings. Each parameter obtained was then used as the outcome variable in multivariable mixed linear regression models in order to evaluate the association with TPM; 10; . Potential modifying effects were assessed using interaction terms.; No association between long-term exposure to TPM; 10; and HRV/HRD was observed in the entire study population. However, HRD changes were found in subjects without cardiovascular morbidity and both HRD and HRV changes in non-obese subjects without cardiovascular morbidity. Subjects without cardiovascular morbidity with homozygous GSTM1 gene deletion appeared to be more susceptible to the effects of TPM; 10; .; This study suggests that long-term exposure to TPM; 10; triggers adverse changes in the regulation of the cardiovascular system. These adverse effects were more visible in the subjects without cardiovascular disease, in whom the overall relationship between TPM; 10; and HRV/HRD could not be masked by underlying morbidities and the potential counteracting effects of related drug treatments.