Noise pollution is a major environmental stressor and public health concern across Europe. Road traffic is the leading cause of this noise pollution. Approximately 150 million people in the EU are exposed to harmful noise levels annually. This leads to the development of various health problems, such as mental disorders, cardiovascular diseases (CVDs; 62,600 cases), sleep disturbances, and diabetes (28,100 cases). It accounts for an estimated 1.7 million disability-adjusted life years each year. Although epidemiological studies consistently correlate the long-term transportation noise with increased CVD mortality as well as morbidity. Experimental studies of railway and aircraft noise show impaired sleep, elevation in blood pressure, and acute endothelial dysfunction, as well as elevation in blood pressure (BP), which is potentially mediated through mechanisms of oxidative stress and inflammation. But mechanistic evidence studies in humans remain limited. A recent study published in Cardiovascular Research investigated the acute effects of night-time road traffic noise on sleep, CVD health, proteomic profiles, and endothelial function in healthy adults, and assessed oxidative stress involvement using vitamin C.
In this double-blind, crossover, randomized controlled clinical study, a total of 74 healthy adults (mean age = 26.1±5.6 years, female = 50%, body mass index [BMI] = 23.6±3.6 kg/m2) were included. All participants experienced three conditions: control (30.7 dB), 30 noise events (41.4 dB), and 60 events (44.1 dB; peak to nearly 60 dB). The primary outcome was endothelial function, which was measured by using flow-mediated dilation (FMD) the morning following every night-time. Secondary outcomes included proteomic profiling (Olink panels), electrocardiographic parameters, blood pressure, heart rate, and subjective sleep quality. Statistical analyses were performed using R 4.4.3 and SAS 9.4.
Results showed that mean FMD decreased from 9.35% (95% confidence interval [CI]: 8.61-10.10) under control conditions to 7.73% (6.97-8.48) after 60 noise events and to 8.19% (7.44-8.95) after 30 events. These reductions were statistically significant for both 60 events (∆ = 1.63%, p <0.0001) and 30 events (∆ = 1.16%, p = 0.005) compared with control conditions. The difference between 60 and 30 events was not statistically significant, with p = 0.256. Vitamin C did not significantly modify noise-induced FMD changes, although a trend toward improvements was observed in the 60-event condition with ∆ a value of 1.02% and p = 0.09.
Night-time road traffic noise significantly increased annoyance and worsened all subjective sleep parameters (p <0.05). Both 60 and 30 noise events reduced the sleep quality, recovery, and sleep depth compared to control, whereas both events increased difficulty falling asleep, restlessness, nocturnal movements, stressful sleep, and perception of exhaustion.
Metabolic and inflammatory markers (neutrophils, cortisol, adrenaline, glucose, C-reactive protein, interleukine-6 [IL-6]) and BP did not differ significantly. However, average heart rate was increased in the 60-event condition (∆ = 7.95 bpm, p <0.001) and in the 30-event condition (∆ = 7.38 bpm, p <0.001) when compared with the control. The odds of heart rate peaks were higher during control than noise nights (OR 1.89–2.42; 95% CI 1.59–2.24; p < 0.001).
Proteomic analysis detected a noise-responsive network centered on interleukin signaling and chemotaxis. Subgroup analysis revealed distinct protein expression patterns between individuals with strong vs weak noise included FMD impairment.
This study’s limitations include the relatively small sample size, a crossover design with possible order effects, limited generalizability, modest absolute heart rate changes, and short-term exposure.
In conclusion, this study demonstrated that even a single night of typical urban road traffic noise worsened sleep, impaired endothelial function, and increased the heart rate among healthy adult people. These early cardiovascular changes highlight the clinical relevance that supports the stricter nighttime noise regulations and the importance of combined individual prevention strategies and public health.
Reference: Hahad O, Foos P, Hübner J, et al. A randomized, double-blind, crossover study of acute low-level night-time road traffic noise: effects on vascular function, sleep, and proteomic signatures in healthy adults. Cardiovasc Res. 2026;cvag028. doi:10.1093/cvr/cvag028
