The relationship between serum uric acid and chronic kidney disease among Appalachian adults

Background. Higher serum uric acid (SUA) levels have been shown to be associated with cardiovascular disease. SUA levels are also associated with hypertension, a strong risk factor for chronic kidney disease (CKD). However, it is unclear whether SUA is independently associated with CKD. We examined the hypothesis that higher SUA levels are positively associated with CKD. Methods. We analysed data from the C8 Health Study, a population-based study of Appalachian adults aged >= 18 years and free of cardiovascular disease (n = 49,295, 53% women). SUA was examined as gender-specific quartiles. The outcome of interest was CKD (n = 2,980), defined as an estimated glomerular filtration rate of <60 mL/min/1.73 m(2) from serum creatinine. Results. Overall, we observed a clear positive association between increasing quartiles of SUA and CKD, independent of confounders. Compared with the lowest quartile of SUA (referent), the multivariable odds ratios (95% confidence interval) for quartiles 2-4, respectively, of CKD were 1.53 (1.31, 1.78), 2.16 (1.86 2.50) and 4.67 (4.07, 5.36); P-trend < 0.0001. This observed positive association persisted in separate analysis among men (P-trend < 0.0001) and women (P-trend < 0.0001). Conclusions. In conclusion, higher SUA levels are positively associated with CKD, suggesting that at least part of the reported association between SUA and cardiovascular disease may be mediated by CKD.