Theodorakopoulou Marieta, Iatridi Fotini, Faitatzidou Danai, Karagiannidis Artemios G, Koutlas Aggelos, Dipla Konstantina, Zafeiridis Andreas, Sarafidis Pantelis
First Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, GRC.
Department of Sports Science at Serres, Exercise Physiology and Biochemistry Laboratory, Aristotle University of Thessaloniki, Serres, GRC.
Cureus. 2025 May 27;17(5):e84913. doi: 10.7759/cureus.84913. eCollection 2025 May.
Introduction Vascular dysfunction is a hallmark of chronic kidney disease (CKD), with previous studies showing progressively deteriorating microvascular reactivity in skeletal muscles with advancing CKD stages. Additionally, cognitive impairment is quite common in CKD patients, as significant determinants of brain activation, i.e., cerebral perfusion and oxygenation, are significantly impaired. The aim of this analysis was to investigate, for the first time, the effects of proteinuria on skeletal muscle and cerebral oxygenation, as well as on muscle microvascular reactivity in patients with pre-dialysis CKD. Methods A total of 56 patients with pre-dialysis CKD were included in this post-hoc, exploratory analysis and stratified based on the presence of proteinuria (urinary protein-to-creatinine ratio > 200 mg/g). Patients with and without proteinuria were matched in a 1:1 ratio for age, sex, and estimated glomerular filtration rate (eGFR). Near-infrared spectroscopy was used to measure muscle and cerebral oxygenation at rest and after stimulation (occlusion-reperfusion and handgrip exercise). Results The two groups were similar in terms of age, eGFR, body mass index, and major comorbidities. Muscle oxygenation did not differ between study groups at rest and during occlusion; however, proteinuric CKD patients presented a trend toward lower tissue saturation index (TSI) during reperfusion (10-second slope: 1.36±0.69 vs. 1.67±0.83, p=0.143) and hyperemic response (7.26±3.98 vs. 8.47±4.52, p=0.296). Regarding cerebral oxygenation, proteinuric patients displayed lower average response during exercise (oxygenated hemoglobin [OHb]: 0.92±0.78 vs. 1.49±0.86, p=0.012; hemoglobin difference [Hb]: 1.41±0.96 vs. 1.98±1.12; p=0.044). The average response in total hemoglobin (tHb) (an index of regional blood volume) was also lower (0.43±0.98 vs. 1.00±0.85, p=0.023), but no between-group differences in deoxygenated hemoglobin (HHb) (an index of oxygen extraction capacity) were observed. Conclusions In this exploratory analysis, CKD patients with proteinuria showed signs of attenuated cerebral oxygenation during a mild physical task and a possible trend toward modest impairments in skeletal muscle oxidative capacity and microvascular reactivity.
引言 血管功能障碍是慢性肾脏病（CKD）的一个标志，先前的研究表明，随着CKD分期的进展，骨骼肌中的微血管反应性会逐渐恶化。此外，认知障碍在CKD患者中相当常见，因为大脑激活的重要决定因素，即脑灌注和氧合，会受到显著损害。本分析的目的是首次研究蛋白尿对透析前CKD患者骨骼肌和脑氧合以及肌肉微血管反应性的影响。
方法 本事后探索性分析共纳入56例透析前CKD患者，并根据蛋白尿情况（尿蛋白与肌酐比值>200mg/g）进行分层。有蛋白尿和无蛋白尿的患者在年龄、性别和估计肾小球滤过率（eGFR）方面按1:1的比例进行匹配。使用近红外光谱法测量静息状态和刺激后（闭塞-再灌注和握力运动）的肌肉和脑氧合。
结果 两组在年龄、eGFR、体重指数和主要合并症方面相似。静息状态和闭塞期间，研究组之间的肌肉氧合没有差异；然而，有蛋白尿的CKD患者在再灌注期间组织饱和度指数（TSI）有降低的趋势（10秒斜率：1.36±0.69 vs. 1.67±0.83，p=0.143）和充血反应（7.26±3.98 vs. 8.47±4.52，p=0.296）。关于脑氧合，有蛋白尿的患者在运动期间的平均反应较低（氧合血红蛋白[OHb]：0.92±0.78 vs. 1.49±0.86，p=0.012；血红蛋白差值[Hb]：1.41±0.96 vs. 1.98±1.12；p=0.044）。总血红蛋白（tHb）（区域血容量指标）的平均反应也较低（0.43±0.98 vs. 1.00±0.85，p=0.023），但在脱氧血红蛋白（HHb）（氧摄取能力指标）方面未观察到组间差异。
结论 在这项探索性分析中，有蛋白尿的CKD患者在轻度体力任务期间表现出脑氧合减弱的迹象，以及骨骼肌氧化能力和微血管反应性可能有适度受损的趋势。
