Association between the serum uric acid-to-creatinine ratio and cardiovascular mortality in maintenance hemodialysis patients.

BACKGROUND

Uric acid is a risk factor for death in hemodialysis patients, but its exact role is still unclear. The serum uric acid-to-serum creatinine (SUA/SCr) ratio is a new indicator. This study aimed to clarify the relationship between this indicator and cardiovascular death in maintenance hemodialysis patients.

METHODS

Kaplan-Meier analysis was used to compare all-cause and cardiovascular mortality. Restricted cubic splines were used to plot the relationships between SUA/SCr and all-cause and cardiovascular mortality. Multivariable Cox regression was used to analyze the relationships between SUA/SCr and the risk of all-cause death or cardiovascular death. The C statistic was calculated to test the model discrimination performance. The net reclassification index was calculated to demonstrate the prediction accuracy of SUA and SUA/SCr.

RESULTS

Kaplan-Meier analysis showed that all-cause and cardiovascular mortality were significantly higher in the highest SUA/SCr quartile ( < 0.001, for both). Restricted cubic splines indicate a nonlinear relationship between SUA/SCr and cardiovascular mortality. Multivariable Cox regression analysis showed that there was no significant difference in all-cause mortality, but patients with the highest SUA/SCr quartile had a higher risk of cardiovascular death (HR = 4.023, 95% CI, 1.979-8.179;  < 0.001; HR = 4.339, 95% CI, 2.091-9.002;  < 0.001; HR = 2.747, 95% CI, 1.170-6.450;  = 0.020). The C-statistic of the SUA/SCr model was greater than those of the SUA and SCr models alone. The NRI demonstrated that the SUA/SCr ratio was superior to SUA alone in the prediction of cardiovascular death.

CONCLUSIONS

In maintenance hemodialysis patients patients, higher levels of SUA/SCr are associated with a greater risk of cardiovascular mortality.