Department of Nephrology, Hypertension, Glickman Urological and Kidney Institute, and Cleveland Clinic Lerner College of Medicine of CWRU, Cleveland, OH 44195, USA.
Clin J Am Soc Nephrol. 2011 Oct;6(10):2395-402. doi: 10.2215/CJN.03730411. Epub 2011 Sep 1.
The incidence and prevalence of metabolic acidosis increase with declining kidney function. We studied the associations of both low and high serum bicarbonate levels with all-cause mortality among stage 3 and 4 chronic kidney disease (CKD) patients.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We examined factors associated with low (<23 mmol/L) and high (>32 mmol/L) serum bicarbonate levels using logistic regression models and associations between bicarbonate and all-cause mortality using Cox-proportional hazard models, Kaplan-Meier survival curves, and time-dependent analysis.
Out of 41,749 patients, 13.9% (n = 5796) had low and 1.6% (n = 652) had high serum bicarbonate levels. After adjusting for relevant covariates, there was a significant association between low serum bicarbonate and all-cause mortality (hazard ratio [HR] 1.23, 95% CI 1.16, 1.31). This association was not statistically significant among patients with stage 4 CKD and diabetes. The time-dependent analysis demonstrated a significant mortality risk associated with a decline from normal to low bicarbonate level (HR 1.59, 95% CI 1.49, 1.69). High serum bicarbonate levels were associated with death irrespective of the level of kidney function (HR 1.74, 95% CI 1.52, 2.00). When serum bicarbonate was examined as a continuous variable, a J-shaped relationship was noted between serum bicarbonate and mortality.
Low serum bicarbonate levels are associated with increased mortality among stage 3 CKD patients and patients without diabetes. High serum bicarbonate levels are associated with mortality in both stage 3 and stage 4 CKD patients.
代谢性酸中毒的发病率和患病率随着肾功能下降而增加。我们研究了低血清碳酸氢盐和高血清碳酸氢盐水平与 3 期和 4 期慢性肾脏病（CKD）患者全因死亡率的相关性。
设计、设置、参与者和测量：我们使用逻辑回归模型研究了低（<23mmol/L）和高（>32mmol/L）血清碳酸氢盐水平相关的因素，并使用 Cox 比例风险模型、Kaplan-Meier 生存曲线和时间依赖性分析研究了碳酸氢盐与全因死亡率之间的相关性。
在 41749 名患者中，13.9%（n=5796）有低血清碳酸氢盐，1.6%（n=652）有高血清碳酸氢盐。在调整了相关协变量后，低血清碳酸氢盐与全因死亡率之间存在显著相关性（风险比[HR]1.23，95%置信区间[CI]1.16，1.31）。在 4 期 CKD 合并糖尿病患者中，这种相关性不具有统计学意义。时间依赖性分析显示，正常至低碳酸氢盐水平下降与显著的死亡风险相关（HR 1.59，95% CI 1.49，1.69）。高血清碳酸氢盐水平与肾功能水平无关与死亡相关（HR 1.74，95% CI 1.52，2.00）。当血清碳酸氢盐作为连续变量进行检查时，血清碳酸氢盐与死亡率之间存在 J 形关系。
低血清碳酸氢盐水平与 3 期 CKD 患者和无糖尿病患者的死亡率增加相关。高血清碳酸氢盐水平与 3 期和 4 期 CKD 患者的死亡率相关。
