Association between the uric acid-to-albumin ratio and mortality in hyperuricemia: a nationwide cohort study.

BACKGROUND AND AIMS: The prognostic value of uric acid-to-albumin ratio (UAR) for mortality among patients with hyperuricemia remains unclear. This study aimed to investigate its association with all-cause and cardiovascular mortality. METHODS AND RESULTS: We analyzed data from 6437 hyperuricemic patients in NHANES (2007-2018), linked to the National Death Index. Associations between UAR and mortality were assessed using multivariable Cox proportional hazards models and restricted cubic splines (RCS). Subgroup interaction and mediation analyses were performed. During a mean follow-up of 78.61 ± 42.45 months, 982 all-cause deaths and 279 cardiovascular deaths occurred. After multivariable adjustment, participants in the highest UAR quartile had significantly higher risks of all-cause mortality (HR = 2.07, 95% CI: 1.60-2.67; P < 0.0001) and cardiovascular mortality (HR = 1.69, 95% CI: 1.05-2.72; P = 0.0311). Compared with serum uric acid (SUA) alone, UAR showed stronger associations with both outcomes. RCS analysis showed a significant linear association between UAR and all-cause mortality (overall P < 0.001), while an L-shaped association was observed for cardiovascular mortality, with a threshold of 1.66 mg/g (P for non-linearity = 0.010). The associations were stronger in males (P for interaction = 0.0184) and smokers (P for interaction = 0.0173). Mediation analysis indicated that eGFR mediated 9.26% and 12.61% of the associations with all-cause and cardiovascular mortality, respectively. CONCLUSION: UAR is independently associated with all-cause and cardiovascular mortality among patients with hyperuricemia and may serve as a composite index for cardiovascular risk stratification.