Department of Anaesthesia and Intensive Care Medicine, Kralovske Vinohrady University Hospital and The Third Faculty of Medicine, Charles University, Prague, Czech Republic.
2nd Department of Internal Medicine, Kralovske Vinohrady University Hospital and The Third Faculty of Medicine, Charles University, Prague, Czech Republic.
PLoS One. 2019 Mar 1;14(3):e0200228. doi: 10.1371/journal.pone.0200228. eCollection 2019.
Aim of the study was to compare metabolic response of leg skeletal muscle during functional electrical stimulation-driven unloaded cycling (FES) to that seen during volitional supine cycling.
Fourteen healthy volunteers were exposed in random order to supine cycling, either volitional (10-25-50 W, 10 min) or FES assisted (unloaded, 10 min) in a crossover design. Whole body and leg muscle metabolism were assessed by indirect calorimetry with concomitant repeated measurements of femoral venous-arterial differences of blood gases, glucose, lactate and amino acids.
Unloaded FES cycling, but not volitional exercise, led to a significant increase in across-leg lactate production (from -1.1±2.1 to 5.5±7.4 mmol/min, p<0.001) and mild elevation of arterial lactate (from 1.8±0.7 to 2.5±0.8 mM). This occurred without widening of across-leg veno-arterial (VA) O2 and CO2 gaps. Femoral SvO2 difference was directly proportional to VA difference of lactate (R2 = 0.60, p = 0.002). Across-leg glucose uptake did not change with either type of exercise. Systemic oxygen consumption increased with FES cycling to similarly to 25W volitional exercise (138±29% resp. 124±23% of baseline). There was a net uptake of branched-chain amino acids and net release of Alanine from skeletal muscle, which were unaltered by either type of exercise.
Unloaded FES cycling, but not volitional exercise causes significant lactate production without hypoxia in skeletal muscle. This phenomenon can be significant in vulnerable patients' groups.
本研究旨在比较功能性电刺激驱动无负荷踏车运动（FES）与自主仰卧踏车运动时腿部骨骼肌的代谢反应。
14 名健康志愿者以交叉设计的方式随机接受仰卧踏车运动，包括自主（10-25-50W，10 分钟）或 FES 辅助（无负荷，10 分钟）。通过间接测热法评估全身和腿部肌肉代谢，并同时重复测量股静脉-动脉血气、葡萄糖、乳酸和氨基酸的差异。
无负荷 FES 踏车运动，而非自主运动，导致跨腿乳酸生成显著增加（从-1.1±2.1 增加至 5.5±7.4mmol/min，p<0.001），并轻度升高动脉乳酸（从 1.8±0.7 增加至 2.5±0.8mM）。这一现象并未导致跨腿动静脉（VA）O2 和 CO2 间隙扩大。股 SvO2 差异与 VA 乳酸差异呈直接比例关系（R2 = 0.60，p = 0.002）。两种运动方式均未引起跨腿葡萄糖摄取的变化。FES 踏车运动时全身耗氧量增加，与 25W 自主运动相似（分别为基础值的 138±29%和 124±23%）。骨骼肌出现支链氨基酸的净摄取和丙氨酸的净释放，但两种运动方式均未改变这一现象。
无负荷 FES 踏车运动引起骨骼肌显著的乳酸生成，而无缺氧。这一现象在易受影响的患者群体中可能具有重要意义。
