A systematic review of arterial stiffness, wave reflection and air pollution.

Arterial stiffening is associated with increased cardiovascular risk. Whether exposure to relatively high levels of air pollution is associated with arterial stiffening is unclear. We aimed to assess the association between exposure to major air pollutants and arterial stiffening. PubMed, SCOPUS and Web of Science databases (through 31 January 2017) were searched using a combination of terms related to exposure to gaseous [nitrogen dioxide (NO2), nitrogen oxides (NOx) and sulphur dioxide (SO2)] or particulate matter pollutants (PM2.5, PM10 and PM10-2.5), arterial stiffness (pulse wave velocity) and reflected waves (augmentation index, augmentation pressure). Pertinent information were extracted from selected studies. In this systematic review were included 8 studies with available data on air pollution and arterial stiffness/reflected waves parameters (8 studies explored the effects of exposure to particulate matter pollutants, 3 studies the effects of exposure to gaseous pollutants); seven of them reported increased arterial stiffness/reflected waves after exposure to air pollution (6 of 8 studies after particulate matter pollutants; 2 of 3 studies after gaseous pollutants). Arterial stiffness and reflected waves were increased in the majority of the studies after both short- and long-term exposure to air pollutants. In conclusion, available evidence supports an association of main air pollutants with increased arterial stiffness and reflected waves. This finding may have implications for population-based strategies for the reduction of arterial stiffness, a vascular biomarker and an intermediate endpoint for cardiovascular disease.