Wagner Sandra, Metzger Marie, Flamant Martin, Houillier Pascal, Haymann Jean-Philippe, Vrtovsnik François, Thervet Eric, Boffa Jean-Jacques, Massy Ziad A, Stengel Bénédicte, Rossignol Patrick
CESP, Inserm U1018, Univ Paris-Saclay, Univ Paris-Sud, UVSQ, Villejuif, France.
FCRIN INI-CRCT, Paris, France.
BMC Nephrol. 2017 Sep 12;18(1):295. doi: 10.1186/s12882-017-0710-7.
Low and high blood potassium levels are common and were both associated with poor outcomes in patients with chronic kidney disease (CKD). Whether such relationships may be altered in CKD patients receiving optimized nephrologist care is unknown.
NephroTest is a hospital-based prospective cohort study that enrolled 2078 nondialysis patients (mean age: 59 ± 15 years, 66% men) in CKD stages 1 to 5 who underwent repeated extensive renal tests including plasma potassium (P) and glomerular filtration rate (GFR) measured (mGFR) by Cr-EDTA renal clearance. Test reports included a reminder of recommended targets for each abnormal value to guide treatment adjustment. Main outcomes were cardiovascular (CV) and all-cause mortality before end-stage kidney disease (ESKD), and ESKD.
At baseline, median mGFR was 38.4 mL/min/1.73m; prevalence of low P (<4 mmol/L) was 26.5%, and of high P (>5 mmol/L) 6.4%; 74.4% of patients used angiotensin converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB). After excluding 137 patients with baseline GFR < 10 mL/min/1.73m or lost to follow-up, 459 ESKD events and 236 deaths before ESKD (83 CV deaths) occurred during a median follow-up of 5 years. Compared to patients with P within [4, 5] mmol/L at baseline, those with low P had hazard ratios (HRs) [95% CI] for all-cause and CV mortality before ESKD, and for ESKD of 0.82 [0.58-1.16], 1.01 [0.52-1.95], and 1.14 [0.89-1.47], respectively, with corresponding figures for those with high P of 0.79 [0.48-1.32], 1.5 [0.69-3.3], and 0.92 [0.70-1.21]. Considering time-varying P did not materially change these findings, except for the HR of ESKD associated with high P, 1.39 [1.09-1.78]. Among 1190 patients with at least two visits, P had normalized at the second visit in 39.9 and 54.1% respectively of those with baseline low and high P. Among those with low P that normalized, ARB or ACEi use increased between the visits (68.3% vs 81.8%, P < .0001), and among those with high P that normalized, potassium-binding resin and bicarbonate use increased (13.0% vs 37.0%, P < .001, and 4.4% vs 17.4%, P = 0.01, respectively) without decreased ACEi or ARB use.
In these patients under nephrology care, neither low nor high P was associated with excess mortality.
低钾血症和高钾血症很常见，且都与慢性肾脏病（CKD）患者的不良预后相关。在接受优化肾脏科医生治疗的CKD患者中，这种关系是否会改变尚不清楚。
NephroTest是一项基于医院的前瞻性队列研究，纳入了2078例1至5期CKD的非透析患者（平均年龄：59±15岁，66%为男性），这些患者接受了包括血浆钾（P）和通过Cr-EDTA肾清除率测量的肾小球滤过率（GFR）[实测GFR（mGFR）]在内的多次广泛肾脏检查。检查报告包括对每个异常值推荐目标的提示，以指导治疗调整。主要结局为终末期肾病（ESKD）前的心血管（CV）和全因死亡率，以及ESKD。
基线时，mGFR中位数为38.4 mL/min/1.73m²；低钾血症（P<4 mmol/L）患病率为26.5%，高钾血症（P>5 mmol/L）患病率为6.4%；74.4%的患者使用血管紧张素转换酶抑制剂（ACEi）或血管紧张素受体阻滞剂（ARB）。排除137例基线GFR<10 mL/min/1.73m²或失访的患者后，在中位随访5年期间发生了459例ESKD事件和236例ESKD前死亡（83例CV死亡）。与基线时P在[4, 5]mmol/L的患者相比，低钾血症患者ESKD前全因和CV死亡率以及ESKD的风险比（HRs）[95%置信区间（CI）]分别为0.82[0.58 - 1.16]、1.01[0.52 - 1.95]和1.14[0.89 - 1.47]，高钾血症患者的相应数值分别为0.79[0.48 - 1.32]、1.5[0.69 - 3.3]和0.92[0.70 - 1.21]。考虑随时间变化的P后，这些结果没有实质性改变，除了与高钾血症相关的ESKD的HR为1.39[1.09 - 1.78]。在1190例至少就诊两次的患者中，基线低钾血症和高钾血症患者在第二次就诊时P分别有39.9%和54.1%恢复正常。在低钾血症恢复正常的患者中，两次就诊期间ARB或ACEi的使用增加（68.3%对81.8%，P<.0001），在高钾血症恢复正常的患者中，钾结合树脂和碳酸氢盐的使用增加（分别为13.0%对37.0%，P<.001，以及4.4%对17.4%，P = 0.01），而ACEi或ARB的使用没有减少。
在这些接受肾脏科治疗的患者中，低钾血症和高钾血症均与额外死亡率无关。
