Higher Aircraft Noise Exposure Is Linked to Worse Heart Structure and Function by Cardiovascular MRI

Abstract

Background: Aircraft noise is a growing concern for communities living near airports.

Objectives: This study aimed to explore the impact of aircraft noise on heart structure and function.

Methods: Nighttime aircraft noise levels (L_night) and weighted 24-hour day-evening-night aircraft noise levels (L_den) were provided by the UK Civil Aviation Authority for 2011. Health data came from UK Biobank (UKB) participants living near 4 UK major airports (London Heathrow, London Gatwick, Manchester, and Birmingham) who had cardiovascular magnetic resonance (CMR) imaging starting from 2014 and self-reported no hearing difficulties. Generalized linear models investigated the associations between aircraft noise exposure and CMR metrics (derived using a validated convolutional neural network to ensure consistent image segmentations), after adjustment for demographic, socioeconomic, lifestyle, and environmental confounders. Mediation by cardiovascular risk factors was also explored. Downstream associations between CMR metrics and major adverse cardiac events (MACE) were tested in a separate prospective UKB subcohort (n = 21,360), to understand the potential clinical impact of any noise-associated heart remodeling.

Results: Of the 3,635 UKB participants included, 3% experienced higher L_night (≥45 dB) and 8% higher L_den (≥50 dB). Participants exposed to higher L_night had 7% (95% CI: 4%-10%) greater left ventricular (LV) mass and 4% (95% CI: 2%-5%) thicker LV walls with a normal septal-to-lateral wall thickness ratio. This concentric LV remodeling is relevant because a 7% greater LV mass associates with a 32% greater risk of MACE. They also had worse LV myocardial dynamics (eg, an 8% [95% CI: 4%-12%] lower global circumferential strain which associates with a 27% higher risk of MACE). Overall, a hypothetical individual experiencing the typical CMR abnormalities associated with a higher L_night exposure may have a 4 times higher risk of MACE. Findings were clearest for L_night but were broadly similar in analyses using L_den. Body mass index and hypertension appeared to mediate 10% to 50% of the observed associations. Participants who did not move home during follow-up and were continuously exposed to higher aircraft noise levels had the worst CMR phenotype.

Conclusions: Higher aircraft noise exposure associates with adverse LV remodeling, potentially due to noise increasing the risk of obesity and hypertension. Findings are consistent with the existing literature on aircraft noise and cardiovascular disease, and need to be considered by policymakers and the aviation industry.

Keywords: aircraft noise; cardiac hypertrophy; cardiac remodeling; worse systolic function.

Figure 1

Aircraft Noise Contours Around the 4 UK Major International Airports Local authority districts surrounding the 4 UK major airports (London Heathrow, London Gatwick, Manchester, and Birmingham), along with the noise contours provided by the UK Civil Aviation Authority, are presented for (A) nighttime aircraft noise levels (L_night) and (B) 24-hour day-evening-night aircraft noise levels (L_den) in 2011.

Figure 2

Associations Between Higher Aircraft Noise Exposure (L_night ≥45 dB and L_den ≥50 dB) and CMR Heart Structure and Function Metrics Plots are presented for 3,635 UK Biobank participants living near 1 of the 4 UK major airports showing the percentage differences (central dots), along with their 95% CIs (whiskers), in cardiovascular magnetic resonance (CMR) metrics between those exposed and unexposed to higher (A) L_night ≥45 dB and (B) L_den ≥50 dB, after adjusting for demographic, cohort-related, socioeconomic, lifestyle, and environmental confounders. IVST = interventricular septal wall thickness; LV = left ventricular; LVEDV_i = left ventricular end-diastolic volume indexed to height^1.7; LVEF = left ventricular ejection fraction; LVESV_i = left ventricular end-systolic volume indexed to height^1.7; LVmass_i = left ventricular mass indexed to height^1.7; MCF = myocardial contraction fraction; MV = myocardial volume; SLWR = septal-to-lateral wall thickness ratio; WT = wall thickness; $\overline{\text{WT}}$ = mean wall thickness; other abbreviations as in Figure 1.

Figure 3

Associations Between Higher Aircraft Noise Exposure (L_night ≥45 dB and L_den ≥50 dB) and CMR Strain Metrics Plots are presented for 3,635 UK Biobank participants living near 1 of the 4 UK major airports showing the percentage differences (central dots), along with their 95% CIs (whiskers), in CMR absolute strain metrics between those exposed and unexposed to higher (A) L_night ≥45 dB and (B) L_den ≥50 dB, after adjusting for demographic, cohort-related, socioeconomic, lifestyle, and environmental confounders, as well as the use of antihypertensives. All strain metrics were indexed to LVmass_i. (C) The directions of myocardial deformation corresponding to these strain metrics are visually displayed. Abbreviations as in Figures 1 and 2.