Background: Long-term exposure to road traffic noise is associated with the prevalence of hypertension. To understand more about this exposure-response relationship, it is essential to examine this...Show moreBackground: Long-term exposure to road traffic noise is associated with the prevalence of hypertension. To understand more about this exposure-response relationship, it is essential to examine this association with baseline blood pressure measurements. However, theories of possible mechanisms explaining the chronic physiological effects of road traffic noise exposure are limited. Furthermore, the findings of epidemiological studies investigating this relationship are inconsistent and different factors seem to influence the strength of the relationship. A critical evaluation of these studies seems warranted. Purpose: This study aims to gain more theoretical and empirical insight into the association between road traffic noise and resting blood pressure measurements. Methods: Web of Science, PubMed and reference lists were used. Six articles were included, consisting of information about ten studies. A meta-analysis on the association between road traffic noise and blood pressure among adults was performed. The ten effect size estimates were based on the data of 146,339 subjects in total. Results: A 0.195 mmHg (95% CI: 0.004, 0.386) higher systolic blood pressure per 10 dB increase was found. Road traffic noise was not associated with diastolic blood pressure. However, the sensitivity analysis revealed stronger associations with diastolic blood pressure for high-quality studies and stronger associations with systolic blood pressure for nighttime noise exposure. Conclusion: Long-term exposure to road traffic noise had a significant positive association with systolic blood pressure, perhaps strongest at night, and a nonsignificant positive association with diastolic blood pressure. The significant moderating effect of study quality on diastolic blood pressure is a possible explanation for this inconsistency. Further research is required to get a more comprehensive understanding of the association between road traffic noise and blood pressure.Show less