Long-term exposure to traffic noise and the incidence of hypertension: a systematic review and meta-analysis of prospective cohort studies

Background Hypertension is the major global preventable risk factor in cardiovascular diseases. While traffic noise is a highly disruptive environmental stressor in contemporary cities, its longitudinal causal association with hypertension remains debatable in past research. This study aims to conduct a systematic review and meta-analysis of high-quality cohort studies to evaluate the correlation between long-term traffic noise exposure and the risk of hypertension in adults. Methods PubMed, Embase, and Web of Science databases were systematically searched to identify relevant published literature. Prospective or retrospective cohort studies examining the relationship between long term exposure to traffic noise with the occurrence of hypertension in adults were incorporated. The quality of the research studies was evaluated based on the Newcastle-Ottawa Scale methodologically. The association was estimated by data pooling with fixed-or random-effect models and estimated by calculating the HR and its 95%CI. Results 11 cohort studies with 1,353,481 participants were included into the present research. The results indicated that in cohorts analyzing traffic noise as a binary variable, higher exposure was significantly associated with an increased risk of hypertension (HR = 1.07, 95% CI: 1.01–1.13, P = 0.03). This finding is highly consistent with the meta-analysis results where traffic noise was treated as a continuous variable (HR = 1.03, 95% CI: 1.02–1.04, P 0.00001). While heterogeneity was low in the main analysis, moderate to high heterogeneity was present in specific subgroups, such as night noise, follow-up time, and aircraft noise. Subgroup analyses revealed that the pathogenic effect of traffic noise was robust across different spatial and temporal noise sources, as well as follow-up time, and completely independent of traditional confounding factors such as air pollution. Conclusion Long-term exposure to traffic noise is significantly associated with an increased risk of hypertension in the adult population. Incorporating environmental noise assessment and mitigation measures into public health strategies can contribute to the comprehensive management of hypertension in the population. Systematic Review Registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420251270952 .