OBJECTIVE To assess the association between serum bicarbonate concentration and cause-specific mortality in the US general population. METHODS A total of 31,195 individuals enrolled in the National Health and Nutrition Examination Survey between 1999 and 2010 were followed for a median 6.7 (interquartile range, 3.7-9.8) years. Cause-specific mortality was defined as cardiovascular, malignancy, and noncardiovascular/nonmalignancy causes. Cox proportional hazards adjusted for demographics, comorbidities, medications, and renal function were used to test the association between baseline serum bicarbonate and the outcomes of interest. RESULTS Of the 2798 participants who died, 722 had a cardiovascular- and 620 had a malignancy-related death. Compared with participants with serum bicarbonate 22 to 26 mEq/L, those with a level below 22 mEq/L had an increased hazard of all-cause and malignancy-related mortality (hazard ratio [HR], 1.54; 95% CI, 1.30-1.83; and HR, 1.46; 95% CI 1.00-2.13, respectively). The hazard for cardiovascular mortality was increased by 8% with each 1 mEq/L increase in serum bicarbonate above 26 mEq/L (HR, 1.08; 95% CI, 1.01-1.15). The findings were consistent in participants with or without chronic kidney disease, with no significant interactions observed. CONCLUSION In a large cohort of US adults, serum bicarbonate concentration level below 22 mEq/L was associated with malignancy-related mortality, whereas a concentration above 26 mEq/L was associated with cardiovascular mortality. Further studies to evaluate potential mechanisms for the differences in cause-specific mortality are warranted.

中文翻译：

---

血清碳酸氢盐浓度和特定原因死亡率：1999-2010 年全国健康和营养调查。

目的 评估美国普通人群中血清碳酸氢盐浓度与死因特异性死亡率之间的关系。方法 对 1999 年至 2010 年间参加全国健康和营养调查的 31,195 人进行了中位随访 6.7 年（四分位距，3.7-9.8）年。原因特异性死亡率被定义为心血管、恶性肿瘤和非心血管/非恶性肿瘤原因。使用针对人口统计学、合并症、药物和肾功能调整的 Cox 比例风险来测试基线血清碳酸氢盐与目标结果之间的关联。结果 在死亡的 2798 名参与者中，722 人死于心血管疾病，620 人死于恶性肿瘤。与血清碳酸氢盐 22 至 26 mEq/L 的参与者相比，水平低于 22 mEq/L 的患者全因死亡率和恶性肿瘤相关死亡率的风险增加（风险比 [HR]，1.54；95% CI，1.30-1.83；HR，1.46；95% CI 1.00-2.13 ， 分别）。血清碳酸氢盐在 26 mEq/L 以上每增加 1 mEq/L，心血管死亡的风险就会增加 8%（HR，1.08；95% CI，1.01-1.15）。在患有或不患有慢性肾病的参与者中，这些发现是一致的，没有观察到显着的相互作用。结论 在美国成年人的大型队列中，血清碳酸氢盐浓度水平低于 22 mEq/L 与恶性肿瘤相关死亡率相关，而高于 26 mEq/L 的浓度与心血管死亡率相关。有必要进行进一步的研究来评估特定原因死亡率差异的潜在机制。