Inflammation and oxidative stress in heart failure: effects of exercise intensity and duration

Although acute exercise is apparently pro-inflammatory and increases oxidative stress, it can promote the necessary stress stimulus to train chronic adaptations in patients with chronic heart failure (CHF). This study aimed to compare the effects of exercise intensity and duration on the inflammatory markers soluble tumor necrosis factor receptor (sTNFR1) and interleukin-6 (IL-6), and on oxidative stress [malondialdehyde (MDA) and antioxidant enzymes: catalase (CAT) and superoxide dismutase (SOD)] in individuals with CHF. Eighteen patients performed three exercise sessions: 30 min of moderate-intensity (M30) exercise, 30 min of low-intensity (L30) exercise, and 45 min of low-intensity (L45) exercise. Blood analysis was performed before exercise (baseline), immediately after each session (after), and 1 h after the end of each session (1h after). Thirty min of M30 exercise promoted a larger stressor stimulus, both pro-inflammatory and pro-oxidative, than that promoted by exercises L30 and L45. This was evidenced by increased sTNFR1 and MDA levels after exercise M30. In response to this stressor stimulus, 1 h after exercise, there was an increase in IL-6 and CAT levels, and a return of sTNFR1 to baseline levels. These findings suggest that compared with the duration of exercise, the exercise intensity was an important factor of physiologic adjustments.

尽管急性运动具有明确的促炎效应并可加剧氧化应激，但它能够为慢性心力衰竭（chronic heart failure, CHF）患者提供必要的应激刺激，以诱导机体产生慢性适应性改变。本研究旨在对比运动强度与运动时长对慢性心力衰竭患者体内炎症标志物可溶性肿瘤坏死因子受体（soluble tumor necrosis factor receptor, sTNFR1）、白细胞介素-6（interleukin-6, IL-6），以及氧化应激相关指标[丙二醛（malondialdehyde, MDA）与抗氧化酶：过氧化氢酶（catalase, CAT）、超氧化物歧化酶（superoxide dismutase, SOD）]的影响。本研究纳入18名慢性心力衰竭患者，令其完成3次运动干预：30分钟中等强度运动（M30）、30分钟低强度运动（L30）以及45分钟低强度运动（L45）。分别于每次运动前（基线状态）、运动结束即刻及运动结束后1小时采集血液样本进行检测分析。与L30和L45运动相比，30分钟中等强度运动可产生更强的促炎与促氧化应激刺激，这一点可通过M30运动后sTNFR1与MDA水平升高得到验证。针对该应激刺激，运动后1小时可观察到IL-6与CAT水平升高，且sTNFR1水平恢复至基线状态。上述研究结果表明，相较于运动时长，运动强度是影响机体生理调节的关键因素。