Third Department of Internal Medicine, Prague, Czech Republic.
Department of Nephrology, First Faculty of Medicine, Charles University in Prague and General University Hospital, Prague, Czech Republic.
Nephron. 2018;139(2):113-119. doi: 10.1159/000487092. Epub 2018 Feb 13.
BACKGROUND/AIMS: High rates of cognitive impairment (CI) are an alarming problem in patients undergoing chronic hemodialysis (HD). Its pathophysiology remains unclear and there are indications that brain ischemia might be one of the key causes. Cerebral tissue oxygenation, as measured by near-infrared spectroscopy, is known to be decreased in HD patients. However, it is unknown whether CI is associated or not associated with lower cerebral oxygenation in these patients. The primary aim of our study was to probe this possible association. Our secondary aim was to assess other factors possibly related to cerebral ischemia and CI.
Thirty-nine patients treated by chronic HD were included in this cross-sectional study. All measurements were performed before the initiation of an HD session. The Montreal Cognitive Assessment (MoCA) was administered according to published recommendations. Regional saturation of oxygen (rSO2) of the left frontal lobe was measured using the INVOS 5100C device. Basic medical history and laboratory data were recorded, and handgrip strength was analyzed. We used the unpaired t test to compare the rSO2 and other variables between cognitively normal patients (MoCA score ≥26) and those who displayed CI (MoCA score <26). Multiple linear regression analysis was used to adjust for principal confounders.
Cognitively impaired patients had lower brain rSO2 values compared to cognitively normal patients (48 ± 9 vs. 57 ± 10%, p = 0.01). Among other variables, higher red cell distribution width (15.8 ± 1.9 vs. 13.8 ± 1.6%, p = 0.01) and lower hand grip strength (49.2 ± 23.3 vs. 99.3 ± 31.4 lbs, p < 0.001) also displayed a significant association with CI. The relation between rSO2 and MoCA score was significant after adjustment for age and gender (p = 0.007).
Decreased brain oxygenation is associated with weaker cognitive performance in patients undergoing chronic HD. Further understanding the causes of cerebral ischemia in HD patients could lead to the prevention of cognitive decline in this population.
背景/目的：认知障碍（CI）发生率高是接受慢性血液透析（HD）患者的一个严重问题。其病理生理学尚不清楚，有迹象表明脑缺血可能是关键原因之一。近红外光谱测量的脑组织氧合已知在 HD 患者中降低。然而，尚不清楚 CI 是否与这些患者的脑氧合降低有关。我们的主要研究目的是探究这种可能的关联。我们的次要目的是评估其他可能与脑缺血和 CI 相关的因素。
本横断面研究纳入了 39 名接受慢性 HD 治疗的患者。所有测量均在 HD 治疗前进行。根据发表的建议进行蒙特利尔认知评估（MoCA）。使用 INVOS 5100C 设备测量左侧额区的局部氧饱和度（rSO2）。记录基本的医学史和实验室数据，并分析握力。我们使用独立样本 t 检验比较认知正常患者（MoCA 评分≥26）和认知障碍患者（MoCA 评分<26）的 rSO2 和其他变量。使用多元线性回归分析调整主要混杂因素。
认知障碍患者的脑 rSO2 值低于认知正常患者（48±9% vs. 57±10%，p=0.01）。在其他变量中，较高的红细胞分布宽度（15.8±1.9% vs. 13.8±1.6%，p=0.01）和较低的握力（49.2±23.3 磅 vs. 99.3±31.4 磅，p<0.001）也与 CI 显著相关。在校正年龄和性别后，rSO2 与 MoCA 评分之间的关系具有统计学意义（p=0.007）。
在接受慢性 HD 治疗的患者中，脑氧合降低与认知功能下降相关。进一步了解 HD 患者脑缺血的原因可能会导致该人群认知能力下降的预防。
