Driver Todd H, Shlipak Michael G, Katz Ronit, Goldenstein Leonard, Sarnak Mark J, Hoofnagle Andrew N, Siscovick David S, Kestenbaum Bryan, de Boer Ian H, Ix Joachim H
School of Medicine, University of California, San Francisco.
Department of Medicine, University of California, San Francisco; Department of Epidemiology and Biostatistics, University of California, San Francisco; Department of General Internal Medicine, San Francisco VA Medical Center, San Francisco, CA.
Am J Kidney Dis. 2014 Oct;64(4):534-41. doi: 10.1053/j.ajkd.2014.05.008. Epub 2014 Jun 18.
Among populations with established chronic kidney disease (CKD), metabolic acidosis is associated with more rapid progression of kidney disease. The association of serum bicarbonate concentrations with early declines in kidney function is less clear.
Retrospective cohort study.
SETTING & PARTICIPANTS: 5,810 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) with a baseline estimated glomerular filtration rate (eGFR) > 60mL/min/1.73 m(2) using the CKD-EPI (CKD Epidemiology Collaboration) creatinine-cystatin C equation.
Serum bicarbonate concentrations.
Rapid kidney function decline (eGFR decline > 5% per year) and incident reduced eGFR (eGFR < 60mL/min/1.73 m(2) with minimum rate of eGFR loss of 1 mL/min/1.73 m(2) per year).
Average bicarbonate concentration was 23.2 ± 1.8mEq/L. 1,730 (33%) participants had rapid kidney function decline, and 487 had incident reduced eGFR during follow-up. Each 1-SD lower baseline bicarbonate concentration was associated with 12% higher adjusted odds of rapid kidney function decline (95% CI, 6%-20%) and higher risk of incident reduced eGFR (adjusted incidence rate ratio, 1.11; 95% CI, 1.03-1.20) in models adjusting for demographics, baseline eGFR, albuminuria, and CKD risk factors. The OR for the associations of bicarbonate level < 21 mEq/L relative to 23-24 mEq/L was 1.35 (95% CI, 1.05-1.73) for rapid kidney function decline, and the incidence rate ratio was 1.16 (95% CI, 0.83-1.62) for incident reduced eGFR.
Cause of metabolic acidosis cannot be determined in this study.
Lower serum bicarbonate concentrations are associated independently with rapid kidney function decline independent of eGFR or albuminuria in community-living persons with baseline eGFR > 60 mL/min/1.73 m(2). If confirmed, our findings suggest that metabolic acidosis may indicate either early kidney disease that is not captured by eGFR or albuminuria or may have a causal role in the development of eGFR < 60 mL/min/1.73 m(2).
在已确诊慢性肾脏病（CKD）的人群中，代谢性酸中毒与肾脏疾病进展加速相关。血清碳酸氢盐浓度与肾功能早期下降之间的关联尚不清楚。
回顾性队列研究。
动脉粥样硬化多族裔研究（MESA）中的5810名参与者，使用CKD-EPI（慢性肾脏病流行病学协作组）肌酐-胱抑素C方程得出的基线估计肾小球滤过率（eGFR）>60mL/（min·1.73m²）。
血清碳酸氢盐浓度。
肾功能快速下降（eGFR每年下降>5%）和新发eGFR降低（eGFR<60mL/（min·1.73m²），eGFR最低损失率为每年1mL/（min·1.73m²））。
平均碳酸氢盐浓度为23.2±1.8mEq/L。1730名（33%）参与者出现肾功能快速下降，487名在随访期间出现新发eGFR降低。在对人口统计学、基线eGFR、蛋白尿和CKD危险因素进行校正的模型中，基线碳酸氢盐浓度每降低1个标准差，肾功能快速下降的校正优势比高12%（95%CI，6%-20%），新发eGFR降低的风险更高（校正发病率比，1.11；95%CI，1.03-1.20）。相对于23-24mEq/L，碳酸氢盐水平<21mEq/L与肾功能快速下降的OR为1.35（95%CI，1.05-1.73），与新发eGFR降低的发病率比为1.16（95%CI，0.83-1.62）。
本研究无法确定代谢性酸中毒的病因。
在基线eGFR>60mL/（min·1.73m²）的社区居住人群中，较低的血清碳酸氢盐浓度与肾功能快速下降独立相关，与eGFR或蛋白尿无关。如果得到证实，我们的研究结果表明，代谢性酸中毒可能表明早期肾脏疾病未被eGFR或蛋白尿所捕获，或者可能在eGFR<60mL/（min·1.73m²）的发生中起因果作用。
