Arsenic exposure and hyperuricemia in US adults

Abstract

Background: Both serum uric acid level and arsenic exposure have been recognized as risk factors for cardiovascular and kidney diseases. However, the association between serum uric acid and arsenic exposures has not been evaluated in a population database. Aim: To investigate the association between arsenic exposure and serum uric acid levels in a representative sample of US adults. Methods: Cross-sectional study in 6845 adults aged 20 years or older who participated in the 2003-2010 National Health and Nutrition Examination Survey (NHANES) and had determinations of serum uric acid and urine total arsenic, dimethylarsinate (DMA), and arsenobetaine. Hyperuricemia was defined by serum uric acid level higher than 7.0 mg/dL in men and higher than 6.0 mg/dL in women. Results: In men, the ratio of geometric means of serum uric acid was 5% (95% CI 1.02-1.08), 3% (95% CI 1.00-1.06) and 5% (1.02-1.08) higher per interquartile range (IQR) of total arsenic, DMA and arsenobetaine, respectively, after adjustment for sociodemographic factors, lifestyle characteristics, and comorbidities related to purine metabolism. In men, the odds ratios for hyperuricemia among highest quartiles of urine total arsenic was 1.90 (95% CI, 1.23-2.94) and urine arsenobetaine 1.57 (95% CI, 1.12-2.20). Urine total arsenic increased the odd ratio of hyperuricemia by 46% per IQR increase (95% CI, 1.18-1.80), urine dimethylarsonic acid by 25% per IQR increase (95% CI, 1.06-1.47), and urine arsenobetaine by 45% (95% CI, 1.16-1.82). Exploratory interaction analyses showed significant effect modification by blood lead levels (p value for interaction=0.01) in men with arsenic exposure measured by dimethylarsinate. However, such interactions were not identified in women. Conclusion: Our data suggest that low level exposures of arsenic may increase the risk of hyperuricemia in men. Joint effect between low arsenic and lead exposures significantly increased the risk of hyperuricemia. Future research focusing on establishing the causal relationship between arsenic and serum uric acid are needed.