Abstract 13926: Air Pollution and Pulse Wave Velocity in Patients With Hypertension

Abstract

Introduction: Ambient air pollution has been linked with increased cardiovascular risk, yet the mechanisms of this are incompletely understood. We sought to investigate the linkage between ambient particulate matter (PM 2.5 ) and pulse wave velocity (PWV), a marker of arterial stiffness, in the systolic blood pressure intervention trial (SPRINT). Methods: A subset of SPRINT participants underwent PWV measurements at baseline, and annually through 3 years using the Sphygmocor CPV® system and were linked with ambient PM 2.5 using participant address at study entry. Spearman’s correlations and linear regression analyses were performed to investigate the relationship between PM 2.5 , baseline PWV, and change in PWV through year 3. Results: A total of 517 participants were included (259 to standard BP, and 258 to intensive BP). Mean PM 2.5 was 9.5±1.8 μg/m 3 and mean baseline PWV was 10.7±2.7 m/s. Over 3 years, PWV increased by a mean of 0.27 m/sec from baseline (P<0.001). There was no correlation between PM 2.5 and PWV at baseline (rho=0.01, P=0.84) or year 1 (rho=0.04, P=0.38). PM 2.5 , however, significantly correlated change in PWV between baseline and year 2 (rho=0.23, P<0.001), and between baseline and year 3 [ΔPWV 0-3 ] (rho=0.26, P<0.001). The association between PM 2.5 and ΔPWV 0-3 was similar in the intensive (rho=0.29, P<0.001) and standard BP arms (rho=0.25, P<0.001). After adjusting for age, sex, race, study randomization, Framingham risk score, smoking, prevalent cardiovascular disease, and eGFR, PM 2.5 remained associated with ΔPWV 0-3 (β 0.37 per 1 μg/m 3 of PM 2.5 , standard error 0.06, P<0.001). Among participants living under the national air quality of 12 μg/m 3 , there was no change in PWV over 3 years (ΔPWV 0-3 0.13 m/s, P=0.26) while participants living above the NAAQS threshold experience significantly increased PWV over 3 years (ΔPWV 0-3 1.3 m/s, P<0.001), P=0.001 between PM 2.5 <12 vs ≥12 μg/m 3 . Conclusions: SPRINT participants who live in areas with higher ambient air pollution (PM 2.5 ) levels experienced larger increase in PWV over 3 years, without a significant impact of intensive BP lowering strategy. Arterial stiffness should be investigated as a mediator of air pollution-related cardiovascular risk.