A randomized, double-blind, crossover study of acute low-level nighttime road traffic noise: Effects on vascular function, sleep, and proteomic signatures in healthy adults

O. Hahad (Mainz)¹, P. Foos (Mainz)², C. Große-Dresselhaus (Mainz)³, F. Schmidt (Trier)⁴, M. A. Ostad (Mainz)⁵, M. Kuntic (Mainz)⁶, L. Hobohm (Mainz)³, K. Keller (Mainz)⁷, V. Schmitt (Mainz)³, T. Köck (Mainz)⁸, P. S. Wild (Mainz)⁸, I. Schmidtmann (Mainz)⁹, M. Sørensen (Kopenhagen)¹⁰, M. Röösli (Allschwil)¹¹, P. Stamm (Mainz)⁷, A. Von Kriegsheim (Edinburgh)¹², J. Herzog (Mainz)³, P. Lurz (Mainz)⁷, A. Daiber (Mainz)⁶, T. Münzel (Mainz)^7
1Universitätsmedizin der Johannes Gutenberg-Universität Mainz Zentrum für Kardiologie, Kardiologie I Mainz, Deutschland; ²Universitätsmedizin Mainz Zentrum für Kardiologie Mainz, Deutschland; ³Universitätsmedizin der Johannes Gutenberg-Universität Mainz Zentrum für Kardiologie Mainz, Deutschland; ⁴Inneren Medizin 3: Kardiologie, Diabetologie, Angiologie Klinikum Mutterhaus der Borromäerinnen Trier, Deutschland; ⁵Mainz, Deutschland; ⁶Universitätsmedizin der Johannes Gutenberg-Universität Mainz Labor für Molekulare Kardiologie Mainz, Deutschland; ⁷Universitätsmedizin der Johannes Gutenberg-Universität Mainz Kardiologie 1, Zentrum für Kardiologie Mainz, Deutschland; ⁸Universitätsmedizin der Johannes Gutenberg-Universität Mainz Präventive Kardiologie und Medizinische Prävention Mainz, Deutschland; ⁹Universitätsmedizin der Johannes Gutenberg-Universität Mainz Institut für Medizinische Biometrie, Epidemiologie und Informatik Mainz, Deutschland; ¹⁰Danish Cancer Institute Work, Environment and Cancer Kopenhagen, Dänemark; ¹¹Swiss Tropical and Public Health Institute Department Epidemiology and Public Health Allschwil, Deutschland; ¹²Institute for Genetics and Cancer University of Edinburgh Edinburgh, Großbritannien

Aims: Road traffic noise is the dominant source of environmental noise in Europe and a recognized cardiovascular risk factor, yet direct mechanistic evidence from human studies remains limited. This study investigated the acute effects of low-level nighttime road traffic noise exposure on cardiovascular parameters in healthy adults.

Methods and results: In a randomized, double-blind, crossover design, 74 healthy participants were exposed to three overnight conditions: control (no noise, average sound pressure level (LAeq) 30.70 dB), 30 (LAeq 41.36), and 60 (LAeq 44.13) recorded road traffic noise events (peak level ≈60 dB). The primary endpoint was endothelial function assessed by flow-mediated dilation (FMD) the morning after each night; a subgroup received vitamin C to assess oxidative stress involvement. Secondary endpoints included sleep quality (questionnaires), cardiovascular parameters (blood pressure, heart rate, ECG), and targeted proteomic analysis (Olink panels). FMD significantly decreased from 9.35% (control) to 8.19% after 30 noise events (Δ = 1.16%, p=0.005) and 7.73% after 60 events (Δ = 1.63%, p<0.0001) with the strongest FMD improvement by vitamin C in the 60-event condition (Δ = 1.02%). Noise exposure increased heart rate (mean difference Δ = 1.23 bpm, p=0.04; max Δ = 7.95 bpm, p<0.001) and the odds of post-noise heart rate peaks (OR 2.42, 95% CI 2.07-2.83). After noise exposure, self-reported sleep quality and restfulness were significantly impaired across all dimensions. Clinical chemistry blood parameters did not change significantly. Proteomic analysis revealed noise-associated changes in interleukin signaling and chemotaxis in participants with the strongest FMD impairments.

Conclusion: Acute exposure to nighttime road traffic noise leads to measurable changes of cardiovascular health parameters in healthy adults. These effects were linked to activation of molecular pathways of immune signaling. Plasma proteome changes were correlated to FMD changes (responders versus non-responders), highlighting interindividual biological susceptibility to noise.

 

Keywords: Road traffic noise, Endothelial function, Sleep disturbance, Cardiovascular stress response, Proteomics