Comparative Resistance Exercise Effects on Knee Osteoarthritis Pain, Functional I

描述(由申请人提供)：骨关节炎(OA)存在于4000万美国人中，其中高达30%的人经历了严重的疼痛和残疾。股四头肌肌力下降和软骨破坏与骨性关节炎相关的功能损害有关。既能提高肌肉力量，又能将软骨损失降至最低的干预措施，对于预防代价高昂、痛苦的慢性残疾的发生将是重要的。阻力运动已被证明可以改善有症状的膝骨性关节炎患者的体能和下膝疼痛；然而，早期的证据充满了主要的方法学局限性。最近令人信服的证据表明，与向心集中阻力运动(CRX)相比，偏心集中阻力运动(ERX)可以在更低的心血管和代谢成本下诱导肌肉质量和腿部功能的显著增加。目前，还没有公开的研究比较纯eRx和CRX对骨性关节炎疼痛、软骨转换和生理功能的影响。使用一种创新的阻力运动设备原型，我们的实验室将严格比较两种阻力运动模式对患有症状性膝骨性关节炎的老年人这些变量的影响。这项研究是一项随机、单盲对照研究，研究两种阻力运动方案对老年膝关节骨性关节炎患者膝关节疼痛、身体功能和软骨转换的相对疗效。这项研究的主要目的是确定四个月的ERx是否比CRX或标准护理(非运动对照；CON)更能减少老年人与骨关节炎相关的膝关节疼痛。主要结果将是建立良好、可靠和有效的安大略省西部大学和麦克马斯特大学骨关节炎指数(WOMAC评分)的膝痛子量表从基线到第四个月的变化。第二个目标1将是确定到第四个月时，eRx是否比CRx和Con更能改善身体功能和习惯性体力活动。功能和习惯性体力活动将通过一系列测试(分级最大步行测试、6分钟步行测试、爬楼梯、7天计步器测试)进行评估。第二个目标将是确定到第四个月时，eRx是否会引起软骨生物标记物周转率比CRx或CON更大的变化。软骨周转将使用软骨形成(II型前胶原C-前肽，[CPII])与软骨破裂(II型胶原C-端肽[CTX-II])的比率来评估。这项研究将招募患有胫股膝骨性关节炎的老年人(N=90；&GT；60岁)。参与者将被随机分配到三个平均分配的研究组中的一个(每组30人)。这三个组将包括非运动对照组(CON)、集中耐力训练组(CRX；一套/练习，每周两次)和偏心集中抵抗力训练组(ERX；一套/锻炼，每周两次)。研究措施将在基线和第四个月收集。协方差的混合模型分析将被应用于主要目标和次要目标的结果变量1。协方差分析将被应用于软骨转换率的变化；皮尔逊相关性将被进行Bonferroni校正，以寻找训练引起的疼痛、身体功能和软骨转换率的变化之间的联系。这项新研究的结果将被用来进一步开发治疗膝骨性关节炎和防止持续软骨破坏的最佳强化处方。 公共卫生相关性：骨性关节炎引起股四头肌肌肉缺陷和软骨破坏，这两种情况都会导致老年人的疼痛和功能障碍。对抗这些疾病过程的一种可能的方法是抵抗运动训练。该项目将检验在老年人中，使用一种新的偏心阻力锻炼计划与同心集中阻力锻炼相比，在骨关节炎症状、损伤和软骨转换方面是否有不同的改善。

DESCRIPTION (provided by applicant): Osteoarthritis (OA) is present in 40 million Americans and up to 30% of these people experience significant pain and disability. Quadricep muscle strength decline and cartilage breakdown are associated with OA related-functional impairment. Interventions that can both improve muscle strength and minimize cartilage loss would be important for preventing onset of costly, painful chronic disability. Resistance exercise has been shown to improve physical abilities and lower knee pain in patients with symptomatic knee OA; however, earlier evidence is fraught with major methodological limitations. Recent, compelling evidence suggests that eccentrically focused resistance exercise (ERX) may induce superior increases in muscle mass and leg function at a lower cardiovascular and metabolic cost compared to concentrically focused resistance exercise (CRX). Currently, there are no published studies comparing pure ERX and CRX on OA pain, cartilage turnover and physical function. Using an innovative prototype of resistance exercise equipment, our laboratory will rigorously compare two modes of resistance exercise on these variables in older adults with symptomatic knee OA. This proposed study is a randomized, single-blind controlled study of the relative efficacy of two resistance exercise protocols on knee pain, physical function and cartilage turnover in older adults with knee OA. The Primary Aim of this study is to determine if four months of ERX will reduce OA-related knee pain in older adults more than CRX or standard care (non-exercise control; CON). The primary outcome will be the change in knee pain subscale of the well-established, reliable and validated Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC Score) from baseline to month four. The Secondary Aim 1 will be to determine if ERX improves physical function and habitual physical activity more than CRX and CON by month four. Function and habitual physical activity will be assessed by a battery of tests (graded maximal walk test, six-minute walk test, stair climbing, 7-day pedometer test). Secondary Aim 2 will be to determine whether ERX will induce greater changes in cartilage biomarker turnover than CRX or CON by month four. Cartilage turnover will be assessed using a ratio of cartilage formation (C-propeptide of type II procollagen, [CPII]) to cartilage breakdown (Collagen Type II C- telopeptide [CTX-II]). Older adults (N=90; >60 years of age) with tibiofemoral knee OA will be recruited for this study. Participants will be randomly assigned to one of three study groups in equal distributions (n=30 per group). The three groups will include a non-exercise control (CON) group, a concentrically focused resistance training group (CRX; one set/ exercise, two sessions/ week) and an eccentrically focused resistance training group (ERX; one set/ exercise, two sessions/ week). Study measures will be collected at baseline and at month four. Mixed model analyses of covariance will be applied to the outcome variables of the Primary Aim and Secondary Aim 1. Analysis of covariance will be applied to the change in cartilage turnover ratios; Pearson correlations adjusted with Bonferroni correction, will be performed to find associations between training induced changes in pain, physical function and cartilage turnover. The findings from this novel study will be used to further develop optimal strengthening prescriptions to treat knee OA and prevent continued cartilage breakdown. PUBLIC HEALTH RELEVANCE: Osteoarthritis elicits quadricep muscle deficits and cartilage breakdown, both of which contribute to pain and functional impairment in the older adult. A possible method to combat these disease processes is resistance exercise training. This project will examine whether there are differential improvements in osteoarthritis symptoms, impairment and cartilage turnover using a novel eccentric resistance exercise program compared with concentric focused resistance exercise in older persons.