Long-term exposure to ambient air pollution and an increased risk of hyperuricemia.

OBJECTIVES: Evidence suggests that ambient air pollution contributes to metabolic dysregulation, including hyperuricemia. However, previous studies were limited to specific groups or regions with relatively high air pollutant concentrations. This study examined the association between long-term exposure to ambient air pollutants and hyperuricemia in a general population exposed to relatively low pollution concentrations. METHOD: This cross-sectional study analyzed 20,117 adults who underwent health screenings in the Republic of Korea (2015-2019). Annual mean concentrations of PM2.5, PM10, NO2, SO2, and CO were estimated at residential addresses using the Community Multiscale Air Quality model. Hyperuricemia was defined as serum uric acid level > 7.0 mg/dL (males) or > 6.0 mg/dL (females). Multivariable logistic regression estimated odds ratios (ORs) per interquartile range (IQR) increase in pollutant exposure, adjusting for confounders including estimated glomerular filtration rate. RESULTS: Among 20,117 participants, 3,078 (15.3%) had hyperuricemia. All five pollutants were significantly associated with hyperuricemia. The ORs (95% CIs) per IQR increase were 1.06 (1.01-1.10) for PM2.5, 1.15 (1.08-1.21) for PM10, 1.07 (1.00-1.14) for NO2, 1.13 (1.07-1.19) for SO2, and 1.06 (1.01-1.11) for CO. Associations were stronger among current smokers, older adults, and individuals with dyslipidemia or central obesity (all P for interaction < 0.05). CONCLUSIONS: Long-term exposure to air pollutants was significantly associated with hyperuricemia, independent of renal function and even at low concentrations. These findings suggest that air pollution is an important environmental risk factor for metabolic disease, emphasizing the need for stricter regulations to protect vulnerable populations. Key Points • Long-term exposure to major ambient air pollutants is significantly associated with an increased risk of hyperuricemia, even at relatively low concentrations. • The association between air pollution and hyperuricemia persists independent of renal function, suggesting a potential role in systemic metabolic dysregulation. • Vulnerable populations, including older adults, current smokers, and individuals with metabolic conditions, exhibit stronger associations between air pollution exposure and hyperuricemia.