Long-term exposure to higher road traffic noise is linked to a higher incidence of hypertension particularly if there is higher air pollution
Chinese and UK researchers have observed that long-term exposure to high levels of road traffic noise (RTN) increases the risk for developing hypertension and that this risk is even greater when levels of air pollution are also increased.
Hypertension is the leading cause of cardiovascular disease and premature death worldwide with one estimate suggesting that 349 million in high-income countries are affected by the condition. Although modification of lifestyle factors including a reduction of sodium intake, stopping smoking and increased physical activity are an integral part of the overall management strategy for the disease, it has become recognised that road traffic noise exposure is associated with increased risk of premature arteriosclerosis, coronary artery disease, and stroke. Moreover, the World Health Organisation (WHO) has suggested that there is high quality evidence linking road traffic road and ischaemic heart disease. However, while the WHO has found evidence linking noise from air, road, or rail traffic with hypertension, they considered the quality of the supportive evidence to be ‘very low’. Although some data indicates that exposure to RTN increases both systolic and diastolic blood pressure, it remains uncertain if exposure might actually cause hypertension.
In the current study, researchers examined information held in the UK Biobank to evaluate the association between long-term RTN exposure with incident primary hypertension. The RTN level was estimated with common noise assessment methods and the development of hypertension through linkage with medical records.
Road traffic noise and incident hypertension
A total of 246,447 individuals with mean age of 55 years (54.6%) were included in the analysis. Over a median follow-up period of 8.1 years, there were 21,140 cases of incident primary hypertension recorded.
In fully adjusted models for continuous exposure to RTN, there was 7% increase in newly diagnosed hypertension per 10 dB [A] increment in the mean weighted average 24-hour road traffic noise level (hazard ratio, HR = 1.07, 95% CI 1.02 – 1.13). Interestingly, exposure to the highest level of RTN (> 65 db[A]), and the highest levels of air pollution, based on both fine particles and nitrogen dioxide, posed the greatest risk for incident hypertension (HR = 1.22 for fine particles, HR = 1.18 for nitrogen dioxide).
The authors concluded that long-term exposure to road traffic noise was associated with an increased incidence of primary hypertension and that this effect was stronger in presence of higher air pollution.
Huang J et al. Road Traffic Noise and Incidence of Primary Hypertension: A Prospective Analysis in UK Biobank. JACC Adv 2023