Supplementary Material for: Hyperuricemia Is an Independent Risk Factor for Mortality Only if Chronic Kidney Disease Is Present

<b><i>Background/Aims:</i></b> Hyperuricemia has been considered a risk factor for renal disease and cardiovascular disease. However, the potential contribution of hyperuricemia to mortality remains uncertain, and the results in the available literature vary according to kidney function. The aim of this study was to determine the association between hyperuricemia and mortality in patients undergoing percutaneous coronary intervention (PCI) across the interaction of kidney function. <b><i>Method:</i></b> We retrospectively reviewed patients who underwent PCI from 2003 to 2009. Propensity scores for hyperuricemia (&gt;7 mg/dl for males and &gt;6 mg/dl for females) were used to assemble a matched cohort of 693 pairs of patients with and without hyperuricemia for analysis from the 3,201 patients who fulfilled the inclusion criteria among the 4,842 patients who underwent PCI. <b><i>Results:</i></b> Of the 3,201 patients who underwent PCI and for whom data were available regarding their baseline serum uric acid level, 763 (23.8%) had hyperuricemia. The hyperuricemia-associated hazard ratios (HRs) [95% confidence intervals (CIs)] for all-cause mortality were 1.780 (1.270-2.495) in the unmatched cohort and 1.655 (1.109-2.468) in the matched cohort. The HRs (95% CI) for all-cause mortality among those with and without chronic kidney disease (CKD) were 2.080 (1.318-3.283) and 1.592 (0.778-3.256), respectively (p for interaction, 0.001). <b><i>Conclusions:</i></b> Hyperuricemia is an independent risk factor for all-cause mortality in those patients with CKD but not in those without CKD.

**背景与目的：** 高尿酸血症（hyperuricemia）被认为是肾病与心血管疾病的危险因素。然而，高尿酸血症对死亡率的潜在贡献仍不明确，现有文献的研究结果因肾功能水平而异。本研究旨在探讨接受经皮冠状动脉介入治疗（percutaneous coronary intervention, PCI）的患者中，高尿酸血症与死亡率的关联，并分析肾功能的交互作用。
**方法：** 本研究回顾性分析了2003年至2009年接受PCI的患者。从4842例行PCI的患者中筛选出符合纳入标准的3201例，基于高尿酸血症诊断标准（男性血清尿酸＞7mg/dl，女性＞6mg/dl）的倾向得分进行匹配，最终纳入693对伴高尿酸血症与不伴高尿酸血症的患者队列开展分析。
**结果：** 在3201例具备基线血清尿酸水平数据的PCI患者中，763例（23.8%）存在高尿酸血症。未匹配队列中，高尿酸血症相关的全因死亡率风险比（hazard ratios, HR）及95%置信区间（95% confidence intervals, 95%CI）为1.780（1.270~2.495）；匹配队列中该值为1.655（1.109~2.468）。在伴与不伴慢性肾脏病（chronic kidney disease, CKD）的患者亚组中，全因死亡率的HR（95%CI）分别为2.080（1.318~3.283）与1.592（0.778~3.256），交互作用检验p值为0.001。
**结论：** 高尿酸血症是伴慢性肾脏病患者全因死亡率的独立危险因素，但在不伴慢性肾脏病的患者中未观察到该关联。