Muscle wasting in rheumatoid arthritis:The role of oxidative stress

Rheumatoid arthritis(RA), the commonest inflammatory arthritis, is a debilitating disease leading to functional and social disability. In addition to the joints, RA affects several other tissues of the body including the muscle. RA patients have significantly less muscle mass compared to the general population. Several theories have been proposed to explain this. High grade inflammation, a central component in the pathophysiology of the disease, has long been proposed as the key driver of muscle wasting. More recent findings however, indicate that inflammation on its own cannot fully explain the high prevalence of muscle wasting in RA. Thus, thecontribution of other potential confounders, such as nutrition and physical activity, has also been studied. Results indicate that they play a significant role in muscle wasting in RA, but again neither of these factors seems to be able to fully explain the condition. Oxidative stress is one of the major mechanisms thought to contribute to the development and progression of RA but its potential contribution to muscle wasting in these patients has received limited attention. Oxidative stress has been shown to promote muscle wasting in healthy populations and people with several chronic conditions. Moreover, all of the aforementioned potential contributors to muscle wasting in RA(i.e., inflammation, nutrition, and physical activity) may promote pro- or antioxidative mechanisms. This review aims to highlight the importance of oxidative stress as a driving mechanism for muscle wasting in RA and discusses potential interventions that may promote muscle regeneration via reduction in oxidative stress.

Effects of resistance training on cardiovascular health in non-obese active adolescents

AIM:To determine the benefits of a 10-wk resistance training programme on cardiovascular health in nonobese and active adolescents.METHODS:This is a pragmatic randomised controlled intervention.The study was carried out in a Hong Kong Government secondary school.Thirty-eight lean and active boys and girls were randomised to either the resistance training group or the control group.Students in the resistance training group received in-school 10-wk supervised resistance training twice per week,with each session lasting 70 min.Main outcome measures taken before and after training included brachial endothelial dependent flow-mediated dilation,body composition,fasting serum lipids,fasting glucose and insulin,high sensitive C-reactive protein,24-h ambulatory blood pressure and aerobic fitness.RESULTS:The only training related change was in endothelial dependent flow-mediated dilation which increased from 8.5%to 9.8%.A main effect of time and an interaction(P<0.005) indicated that this improvement was a result of the 10-wk resistance training.Main effects for time(P<0.05) in a number of anthropometric,metabolic and vascular variables were noted;however,there were no significant interactions indicating the change was more likely an outcome of normal growth and development as opposed to a training effect.CONCLUSION:Ten weeks of resistance training in school appears to have some vascular benefit in active,lean children.

体育活动与肥胖儿童(英文)

儿童肥胖正逐渐成为全球性流行病,随之而来的是各种代谢疾病的急剧增长。儿童肥胖的主要原因似乎是能量摄入过多,由此引发的肥胖使得儿童不愿锻炼身体,而并非缺乏运动引起肥胖。目前,对伴随肥胖的身体成分变化对体育活动的影响及其机械基础尚缺乏足够认知。本文概述肥胖儿童的体育活动习惯及身体成分,并主张骨骼肌代谢是身体活动的主要驱动力。骨骼肌的量变和质变对肥胖儿童氧化代谢的作用有待讨论。研究肥胖人群缺乏运动的机械基础十分必要。关于肥胖年轻人运动时骨骼肌代谢作用的信息还十分匮乏,与此同时,新技术在不断涌现,都为今后的相关研究提供了广阔的空间。

Fundamental movement skills training to promote physical activity in children with and without disability： A pilot study

背景:前人研究已报道有关健全和残障儿童基础动作技能和体力活动间存在正相关,本研究尝试探讨这种关系的因果机制。我们假设当基础动作技能熟练度改善时,健全和残障儿童对体力活动的领悟力均会提高其:改善基础动作技能熟练度对残障儿童影响更大。方法:受试者包括典型发育的健全和有脑性麻痹的儿童,分别分配在基础动作技能训练组和对照组。训练组练习5组基础动作技能(跑、跳、踢、扔、抓),每周45 min,练习4周。对照组进行常规的物理治疗或体育活动课程。基础动作技能以过程和产品为导向的措施进行评估,用加速器测量训练前后的体力活动。结果:训练组的基础动作技能提高而对照组未提高。工作日体力活动都没有显著改变。常规物理治疗基础动作技能训练在周末增加了中高强度体力活动,然而常规物理治疗基础动作技能训练组和活动基础动作技能组在周末久坐时间都有减少。参加中高强度体力活动及久坐时变化程度大于可测量最小值(MDC_(90))受试者的百分比在脑瘫患儿中高于健全儿童。结论:周末提高基础动作技能熟练度可能会促进儿童增加体力活动、减少久坐时间。通过提高基础动作技能熟练度增强体力活动对残疾儿童的影响大于健全儿童。本研究的发现应在未来研究中得到进一步检测。

Health through martial arts training: Physical fitness and reaction time in adolescent Taekwondo practitioners

Taekwondo (TKD) is a popular sport among adolescents, but the potential benefits of TKD training to young individuals are not well understood. The objectives of this cross-sectional exploratory study were to compare flexibility, muscular endurance, body composition, and simple reaction time between TKD-trained adolescents and controls. Twenty TKD-trained adolescents aged between 10 and 14 and 20 age-matched healthy controls were asked to perform five physical fitness tests: a sit-and-reach test, leg split test, skinfold measurement, one-minute curl-up test, and ruler-drop reaction time test. The results revealed no significance differences between the two groups in sit-and-reach distance (p = 0.690), leg split angle (p = 0.789), percentage of body fat (p = 0.342), or number of repetitions in the one-minute curl-up test (p = 0.250). However, the TKD group had significantly faster reaction times in the rulerdrop test than the control group (p = 0.005). The results thus suggest that although TKD training may improve reaction times in adolescents, it may have little effect on flexibility, muscular endurance, and body composition (percentage of fat). TKD may be a suitable exercise for improving simple reaction time, but it may not be suitable for improving general physical fitness in adolescents.