Arefirad Tahereh, Seif Ehsan, Sepidarkish Mahdi, Mohammadian Khonsari Nami, Mousavifar Seyedeh Azam, Yazdani Shahrooz, Rahimi Fatemeh, Einollahi Faezeh, Heshmati Javad, Qorbani Mostafa
Department of Exercise Physiology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran.
Front Physiol. 2022 Oct 4;13:953912. doi: 10.3389/fphys.2022.953912. eCollection 2022.
Exercise and physical activity can improve circulation through various mechanisms, such as the increment of nitric oxide (NO) production, by affecting vascular endothelial nitric oxide synthase, and reducing reactive oxygen species (ROS). Although, theoretically, this mechanism is well known, studies in living subjects have made controversial findings regarding the association of NO production and its metabolites [nitrate/nitrite (NOx)] with physical activity. Hence, this systematic review and meta-analysis was designed to gather all these studies and evaluate the effects of exercise training, and physical activity duration and length on the mean change of serum/plasma NO and NOx. We searched all available bibliographic electronic databases from inception through to May 2022 to include all randomized controlled trials (RCT) and quasi-experimental trials which assessed the effect of exercise and training on NO and NOx levels. Random-effects meta-analysis was used to pool the standardized mean difference (SMD) and 95% confidence interval (CI) of included RCT studies which assessed the effect of training. Stratified meta-analysis was performed according to the type of exercise (high-intensity interval training (HIIT), aerobic training (AT), the duration of exercise (≤8 and > 8 weeks), and length of exercise in each session ≥40 and 40 < minutes). Overall, 15 and 10 studies were included in the systematic review and meta-analysis, respectively. According to the random-effects meta-analysis, exercise significantly increased the mean change of NO and NOx compared to control (SMD: 1.82, 95%CI: 1.14 to 2.49. In the stratified meta-analysis, the mean change of NO and NOx in the intervention group was significantly higher than in the control group in the AT (SMD: 1.36, 95%CI: 0.55-2.18), HIIT (SMD: 2.55, 95%CI: 1.14-3.96), duration of ≤8 (SMD: 2.29, 95%CI: 1.24-3.35) and > 8 weeks (SMD: 1.19, 95%CI: 0.52-1.86), length of ≥40 (SMD: 1.61, 95%CI: 1.04-2.18), and 40 < minutes in each session (SMD: 2.07, 95%CI: 0.79-3.35). The findings of this study indicate that, regardless of exercise duration, length, and type (AT or HIIT), exercise can significantly increase serum NO and NOx levels.
运动和体育活动可通过多种机制改善血液循环，比如通过影响血管内皮一氧化氮合酶增加一氧化氮（NO）生成，并减少活性氧（ROS）。虽然从理论上讲，这一机制广为人知，但针对活体受试者的研究在NO生成及其代谢产物[硝酸盐/亚硝酸盐（NOx）]与体育活动的关联方面得出了有争议的结果。因此，本系统评价和荟萃分析旨在汇总所有这些研究，并评估运动训练、体育活动持续时间和时长对血清/血浆NO和NOx平均变化的影响。我们检索了从数据库建立之初到2022年5月的所有可用书目电子数据库，以纳入所有评估运动和训练对NO和NOx水平影响的随机对照试验（RCT）和准实验性试验。采用随机效应荟萃分析来汇总评估训练效果的纳入RCT研究的标准化平均差（SMD）和95%置信区间（CI）。根据运动类型（高强度间歇训练（HIIT）、有氧训练（AT））、运动持续时间（≤8周和>8周）以及每次运动时长（≥40分钟和<40分钟）进行分层荟萃分析。总体而言，分别有15项和10项研究纳入了系统评价和荟萃分析。根据随机效应荟萃分析，与对照组相比，运动显著增加了NO和NOx的平均变化（SMD：1.82，95%CI：1.14至2.49）。在分层荟萃分析中，干预组中AT（SMD：1.36，95%CI：0.55 - 2.18）、HIIT（SMD：2.55，95%CI：1.14 - 3.96）、持续时间≤8周（SMD：2.29，95%CI：1.24 - 3.35）和>8周（SMD：1.19，95%CI：0.52 - 1.86）、每次运动时长≥40分钟（SMD：1.61，95%CI：1.04 - 2.18）以及<40分钟（SMD：2.07，95%CI：0.79 - 3.35）时，NO和NOx的平均变化均显著高于对照组。本研究结果表明，无论运动持续时间、时长和类型（AT或HIIT）如何，运动均可显著提高血清NO和NOx水平。
