The association between urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) and cardiovascular diseases and blood pressure: a systematic review and meta-analysis of observational studies

Although epidemiological studies have discerned the association between polycyclic aromatic hydrocarbons (PAHs) exposure and hypertension and/or cardiovascular disease in the general population, the possible mechanisms for this association are not well understood. We sought to examine the association between urinary metabolites of PAHs and cardiovascular diseases (CVDs) and blood pressure in adults, by conducting a meta-analysis of observational studies. We searched PubMed, Scopus, Embase, and Web of science, up to July 2021, for observational studies that investigated the association between urinary metabolites of PAHs and CVDs and blood pressure in adults. Nine prospective studies, including 27,280 participants, were included. Based on overall pooled results, there was a significant positive association between all types of urinary metabolites of PAH and blood pressure (OR: 1.32; 95%, CI: 1.19 to 1.48, p < 0.0001) (I² = 62.4%, p < 0.0001). There was no significant association between any urinary metabolite of PAH and CHD (OR: 0.93; 95%, CI: 0.83 to 1.03, p = 0.174) (I² = 0%, p = 0.653). Overall, there was a significant positive association between all urinary metabolites of PAH and CVD (OR: 1.23; 95%, CI: 1.16 to 1.30, p < 0.0001) (I² = 59.7%, p < 0.0001). The results of the present meta-analysis suggest that different metabolites PAHs are associated with an increased risk of CVD and HTN. Further studies, including randomized clinical trials, are needed to confirm the veracity of our findings.