Long-term effects of air pollution on ankle-brachial index

Siqi Zhang,Kathrin Wolf,Susanne Breitner,Florian Kronenberg,Massimo Stafoggia,Annette Peters,Alexandra Schneider

doi:10.1016/j.envint.2018.05.025

Siqi Zhang, Kathrin Wolf + Show 5 more

Open Access

https://doi.org/10.1016/j.envint.2018.05.025

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Abstract

BackgroundAnkle-brachial index (ABI) has been linked to the risk of cardiovascular events. However, the association between long-term exposure to air pollution and abnormal ABI has not been fully investigated. MethodsThis cross-sectional study involved 4544 participants from the KORA Study (2004–2008) in the region of Augsburg, Germany. Participants' residential annual mean concentrations of particulate matter (PM) and nitrogen dioxide (NO2) were predicted with land-use regression models, and the traffic information was collected from geographic information systems. We applied multinomial logistic regression models to assess the effects of air pollution on the prevalence of low and high ABI, and quantile regression models to explore the non-monotonic relationship between air pollution and ABI. We also examined effect modification by individual characteristics. ResultsLong-term exposure to PM with an aerodynamic diameter ≤ 10 μm (PM10) and ≤ 2.5 μm (PM2.5) was significantly associated with a higher prevalence of low ABI, with the respective odds ratios (ORs) of 1.82 (95%CI: 1.11–2.97) and 1.59 (95%CI: 1.01–2.51) for a 5th to 95th percentile increment in pollutants. Positive associations with the prevalence of high ABI were observed for PM (e.g., PM10: OR = 1.63, 95%CI: 1.07–2.50) and NO2 (OR = 1.84, 95%CI: 1.15–2.94). Quantile regression analyses revealed similar non-monotonic results. The effects of air pollution on having abnormal ABI were stronger in physically inactive, hypertensive, or non-diabetic participants. ConclusionsLong-term exposure to PM and NO2 was associated with a higher prevalence of both low and high ABI, indicating the adverse effects of air pollution on atherosclerosis and arterial stiffness in the lower extremities.

Highlights

The ankle-brachial index (ABI) is the ratio of systolic blood pressure at the ankle to that at the brachial artery
Participants living in areas with a higher level of air pollution tended to be of lower neighborhood socioeconomic status (SES), have higher prevalence of smokers and more smoking pack years, and do less physical exercise (Supplemental Table S1)
Our result of the association between traffic load and having high ABI is consistent with the Girona Heart Register (REGICOR) Study in Girona, Spain.[15]

Summary

Introduction

The ankle-brachial index (ABI) is the ratio of systolic blood pressure at the ankle to that at the brachial artery. Epidemiological studies have shown that both low and high ABI were associated with increased risk of cardiovascular disease and mortality.[1,2,3] A meta-analysis of 16 population-based cohort studies suggested that ABI could act as an independent risk predictor for coronary heart disease and mortality alongside with traditional risk factors.[4]. PM10 PMcoarse PM2.5 PM2.5abs NO2 intensity load. Live at the same address for ≥ 5 years a Age > 50 years b. PM10 PMcoarse PM2.5 PM2.5abs NO2 Ttraffic intensity Traffic load ABI < 0.9. 2.05 (1.23, 3.42) ** 1.43 (0.88, 2.32) 1.68 (1.05, 2.70) * 1.53 (0.96, 2.42) † 1.69 (0.99, 2.90) † 1.17 (0.88, 1.55) 1.21 (0.84, 1.75) ABI > 1.3

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