Effect of hyperuricemia and treatment for hyperuricemia in Japanese hemodialysis patients: A cohort study

Whether higher serum uric acid (UA) values comprise a risk factor for death and whether treatment for high UA is effective in patients undergoing hemodialysis (HD) are essentially unknown. To determine associations between UA and all-cause or cardiovascular (CV) mortality, interactions between UA or medication and effects on mortality, and significance of treatment for hyperuricemia in patients undergoing hemodialysis (HD). We collected the baseline data of 222,434 patients undergoing three HD sessions per week, extracted from a nationwide dialysis registry at the end of 2011 in Japan. Then we evaluated the interaction between serum uric acid level and all-cause and cardiovascular (CV) mortality by the end of 2012. Univariate and multivariate logistic regression and Cox regression analyses found higher all-cause and CV mortality rates among patients with lower, than higher UA values. Hazard ratios (HR) for all-cause and CV mortality were significantly lower in a group with, than without medication for hyperuricemia (HR, 0.837; 95% confidence interval (CI), 0.789–0.889 and HR, 0.830; 95%CI 0.758–0.909, respectively). Lower UA values remained associated with all-cause and CV mortality rates even when in patients taking medication for hyperuricemia. The chief interacting factors for higher mortality rates due to lower UA were higher BMI and diabetes mellitus. In conclusion, lower UA levels were independently associated with higher all-cause and CV mortality among Japanese patients undergoing HD. Intervention for hyperuricemia is considered to improve patient outcomes.