We hypothesized that blood heavy metal levels such as lead, cadmium, and mercury were associated with uric acid level and hyperuricemia, and that this association remains significant after adjustment for other metals. We tested this hypothesis using the Korean National Health and Nutrition Examination Survey data. Beta coefficients and 95% confidence intervals (95% CIs) were calculated using multiple linear regression, and odds ratios (ORs) and 95% CIs were calculated using logistic regression in the cross-sectional study design. Relative to women, men had a higher geometric mean (GM) of lead (1.95 vs. 1.50 μg/dL) and mercury (3.94 vs. 2.77 μg/L), a lower GM of cadmium (0.80 vs. 1.04 μg/L), and a higher arithmetic mean (AM) of uric acid (5.84 vs. 4.40 mg/dL). Women had significant positive associations of log uric acid level with doubling of lead and mercury, and negative association with cadmium. Logistic regression analysis indicated the inverse association of serum hyperuricemia with doubling of blood metals was only significant for cadmium in women (OR = 0.641, 95% CI = 0.463 to 0.886) and the associations of serum hyperuricemia in the highest versus lowest quartiles of heavy metals were only significant for cadmium in women (OR = 0.495, 95% CI = 0.246 to 0.998). For both genders, age and estimated glomerular filtration rate (e-GFR) had negative associations with uric acid, but hypertension and triglycerides had positive associations with uric acid. In conclusion, blood lead and mercury levels were positively associated with uric acid level, but blood cadmium level was inversely associated with uric acid level and hyperuricemia in women.
Keywords: Cadmium; Korean National Health and Nutrition Examination Survey; Lead; Mercury; Uric acid.