Association of uric acid with all-cause mortality in acute coronary syndrome patients with T2DM

Background: The specific prognostic value of hyperuricemia for all-cause mortality in patients with concurrent type 2 diabetes mellitus (T2DM) and acute coronary syndrome (ACS) remains unclear, particularly regarding the modifying effect of glycemic control status (HbA1c levels). This study elucidated the uric acid (UA)-mortality association in ACS patients with T2DM and examined this relationship across different HbA1c subgroups. Methods and results: The study included 2265 ACS patients with T2DM who were assigned to four groups based on UA quartiles. During a median follow-up period of 4.4 years, 203 all-cause deaths occurred. Significant positive associations were found in patients with HbA1c level above 7 (Quartile 1 group: Hazard Ratio (HR): 3.215, 95 % confidence interval (CI): 1.525-6.780, p = 0.002; Quartile 3 group: HR: 2.725, 95 % CI: 1.308-5.678, p = 0.007; Quartile 4 group: HR: 3.369, 95 % CI: 1.644-6.905, p = 0.001). Interaction analysis between UA quartiles and HbA1c subgroups showed no statistical significance (p-interaction = 0.648). Restricted cubic splines revealed a J-shaped relationship between UA and all-cause mortality. Kaplan-Meier analysis demonstrated higher event-free survival rates in the Quartile 2 group (log-rank test: p < 0.001). Conclusions: A J-shaped curve characterizes the association between UA levels and all-cause mortality in patients with T2DM and ACS. Patients with an appropriate UA level exhibited better prognosis. Post-hoc analyses revealed stronger point estimates for the prognostic effect of UA in patients with suboptimal glycemic control, although interaction testing did not achieve statistical significance. Further studies with larger subgroup samples are warranted.