肌少症的定量测量现状及研究进展

肌少症是一种以骨骼肌质量减少及其功能减退为主要临床表现的复杂的老年综合征。在全球其发病率逐年增高,目前已成为威胁老年人健康,影响老年人生活质量的重要危险因素。其诊断标准主要由欧洲老年人肌少症工作组、亚洲肌少症工作组、国际肌少症会议工作组提出的,通过骨骼肌质量、肌肉力量和身体活动能力进行诊断。肌少症前期仅有肌肉质量减少,肌少症期包括肌肉质量减少伴随肌肉力量下降或身体活动能力降低,重度肌少症期肌肉质量以及身体活动能力均会降低。早期对骨骼肌进行定量测量成为诊断肌少症的重要手段之一。骨骼肌定量测量方法主要有计算机X线体层摄影、磁共振成像、双能X线吸收法、生物电阻抗测量、超声等方法。计算机体X线层摄影在骨骼肌质量的研究中主要应用是作为金标准来校准其他方法;磁共振成像在肌肉定量测量中发挥着越来越重要的作用;双能X线吸收测定法和生物电阻抗方法是目前公认筛查肌少症的手段,并且有诊断的阈值,然而精确性欠佳;超声有经济、易携带、高效等优点,但其对体成分的检测价值有限。本文探讨了骨骼肌定量测量研究的现状及其进展。     

肌少症与老年骨质疏松性椎体压缩骨折相关性的研究进展

肌少症和老年骨质疏松性椎体压缩骨折(OVCF)为老年人群中常见的骨骼肌肉系统退行性疾病，表现为与增龄相关的进行性、全身肌量减少和肌肉生理功能减退为特征的综合征，严重影响老年人的生活质量。近年来，肌少症与老年OVCF的相关性受到重视。该文从肌少症与老年OVCF的流行病学研究、为老年OVCF病因的机制和预后3方面进行综述。     

热休克蛋白与老年肌少症关系的研究进展

肌少症（ｓａｒｃｏｐｅｎｉａ）是以骨骼肌量减少、肌肉力量下降和／ 或躯体功能减退为主要表现的进行性、广泛性的全身性疾病, 与老年人跌倒、失能、骨折等不良事件密切相关。肌少症发病机制复杂,目前暂无特异性治疗药物。热休克蛋白（ｈｅａｔ ｓｔｒｅｓｓ ｐｒｏｔｅｉｎ, ＨＳＰ）是一类高度保守的应激蛋白,有研究发现ＨＳＰ 在维持肌肉健康方面具有重要意义。因此,本文拟就老年肌少症 的特点及发病机制、ＨＳＰ 及其与老年肌少症关系和潜在机制进行综述,以期为国内外同行防治老年肌少症提供思路。     

运动防治老年人骨质疏松的研究进展

骨质疏松症（osteoporosis,OP)现已成为世界十大慢性疾病之一,50岁以上的人群中,30%的女性和10%的男性都患有OP。国际上将OP从病因学上简单地分为原发性、继发性、特发性骨质疏松症三大类;原发性骨质疏松是随着年龄增长必然发生的一种生理退行性病变,发病人群主要为老年人,可分为绝经后骨质疏松症和老年性骨质疏松症。绝经后骨质疏松症是指妇女绝经后雌激素迅速减少,骨吸收大于形成,骨量丢失加快;老年性骨质疏松症是指随着年龄增加,人体单位体积骨量低于正常,骨小梁间隙增大、骨基质减少、骨强度降低。OP会使老年人骨结构遭到破坏,骨折风险增加,肌肉力量下降,造成身体不同部位的疼痛和麻木,降低生活质量。目前针对OP的治疗方法主要有药物治疗、营养治疗和运动治疗。其中运动作为OP的一种康复干预手段,因其能改善骨生物力学及有效减少骨量继续流失的特性,准确适度的运动处方已作为一种相对经济、高效、安全的治疗方法,在OP的临床治疗用中备受医务工作人员和患者的关注。在此我们将不同运动疗法对老年人及绝经 后老年妇女骨质疏松症的影响做一综述,希望对今后老年人群OP的预防及治疗有所帮助。     

肌少症患者肌肉质量测评工具的研究进展

肌少症是肌肉质量和肌肉强度呈渐进性减少和下降的衰老综合征,可导致跌倒、骨折和失能等风险增高,对患者机体功能造成严重影响,极大降低了患者的生活质量,甚至导致死亡。为提高肌少症诊断和治疗效果,选择科学有效的测评工具十分重要。目前,各国际组织对肌少症的诊断标准仍未达成统一共识,尤其在肌肉质量测定部分存在较多争议。本文旨在通过复习总结相关国内外文献,阐述肌少症的筛查流程、诊断标准,重点探讨肌肉质量的测评工具及其优势与不足,以期为肌肉质量测评工具的选择及准确评估提供借鉴。     

肌少症患者生存质量评估工具的研究进展

肌少症是以全身肌肉进行性损失增高和机体功能下降为特点的老年综合征，可增加患者失能、骨折和跌倒等风险，严重危害患者的生存质量。目前，我国对于肌少症的研究处于起步阶段，研究重心多倾向于发病机制、诊断评估及康复治疗等方面，生存质量尚未引起广泛重视。该文对肌少症患者生存质量的评估工具、影响因素及未来研究启示进行综述，旨在为肌少症患者生存质量评估工具的本土化发展，临床实践选择合适的评估工具并深入开展相关领域的研究提供依据。     

肌少症、骨质疏松症的关系及研究进展

随着人均寿命的延长,与肌肉骨骼系统相关疾病的发病率随之增长,国内外学者对肌少症、骨质疏松症的关注度也越来越高。肌少症是指与增龄相关的进行性、全身肌量减少和/或肌强度下降或肌肉生理功能减退。骨质疏松症是以骨量减少、骨组织显微结构退化为特征,以至骨的脆性增高及骨折危险性增加的一种全身性骨病。肌少症、骨质疏松症是危害老年人健康的病理状态,使得老年人的生活质量大打折扣,患有肌少症的人群免疫功能、日常生活能力较常人降低,感染风险、跌倒风险、致残率、死亡风险较常人增加,患有骨质疏松症的人群跌倒风险、骨折风险、致残率也较常人高很多。肌少症与骨质疏松症相互影响、紧密关联的机制比较复杂,包括肌肉收缩力学负荷对骨骼机械力的影响,以及肌肉与骨骼间复杂精密内分泌调控的生物学机制。针对两者之间存在的许多共同危险因素及发病机制,进行运动干预、营养指导、药物治疗,有助于延缓肌少症、骨质疏松症的进展,改善不良预后。本文将结合国内外研究对两者概念、发病机制、临床表现、评估标准、干预及治疗等之间的相关关系及研究进展进行一一综述。     

强化营养联合抗阻运动对老年肌少症患者躯体功能和日常生活能力的影响

目的探讨强化营养联合抗阻运动对老年肌少症患者躯体功能和日常生活能力的影响。方法选取老年肌少症患者40例,按照随机数字表法将其分为强化组和普通组,每组20例。普通组仅予肌少症营养和运动宣教;强化组在此基础上,采用每日增加蛋白粉联合抗阻运动训练(相同运动每周3次,共24周)。24周后,收集患者的握力、身体活动功能评分以及ADL评分。结果 24周后强化组握力、身体活动功能得分及ADL评分显著改善,与普通组比较,差异有统计学意义(P0.05,P0.01)。结论强化营养联合抗阻运动训练能改善老年肌少症患者躯体功能和生活质量。     

绝经后女性肌少症和骨质疏松症对平衡能力的影响

摘要：目的 探讨绝经后女性肌少症和骨质疏松症对平衡能力的单独及联合影响。方法 从北京市社区招募符合要求的绝经后女性332人，分为正常组238人、肌少症组27人、骨质疏松症组44人、肌少-骨质疏松症组23人。根据亚洲肌少症工作组（AWGS）的诊断标准诊断肌少症，采用世界卫生组织（WHO）的骨质疏松症诊断标准诊断骨质疏松症，采用闭眼单脚站立时间（SST）评估静态平衡能力，通过定时起立-行走测试（TUGT）评估动态平衡能力，采用二元Logistic回归分析肌少症及骨质疏松症与平衡不良之间的关系。结果 肌少症和肌少-骨质疏松症患者静态和动态平衡不良发生率显著高于骨质疏松症患者和正常人（P<0.05），骨质疏松症患者与正常人静态和动态平衡不良发生率无显著差异（P>0.05）。二元Logistic回归分析结果显示，肌少症和肌少-骨质疏松症是静态平衡不良（OR=5.747, 95% CI: 1.871~17.651, P=0.002；OR=6.989, 95% CI: 1.902~25.685, P=0.003）的独立危险因素，也是动态平衡不良的独立危险因素（OR=6.843, 95% CI: 2.671~17.535, P=0.000；OR=9.779, 95% CI: 3.317~28.836, P=0.000），且患有肌少-骨质疏松症者静态平衡不良和动态平衡不良发生风险显著高于仅患有肌少症者；单独患有骨质疏松症对静态和动态平衡不良发生风险均无显著影响（P>0.05）。结论 患肌少症或肌少-骨质疏松症都会增加绝经后女性静态和动态平衡不良的发生风险；肌少症和骨质疏松症对绝经后女性静态平衡不良和动态平衡不良的发生具有协同效应。     

有氧联合抗阻运动对老年维持性血液透析肥胖型肌少症患者的影响

目的 探讨有氧联合抗阻运动对老年维持性血液透析肥胖型肌少症患者的影响,为制订有效的运动干预措施提供参考。方法 采用便利抽样法,选取行维持性血液透析的肥胖型肌少症患者随机分配为干预组(n=30)和对照组(n=30)。对照组给予常规护理,干预组在对照组基础上,给予上肢弹力球、下肢弹力带加空中踩脚踏车的有氧联合抗阻运动。干预12周,对两组重要肌肉、肥胖、实验室指标及生活质量得分进行比较。结果 干预组29例、对照组30例完成研究。6周后干预组内脏脂肪面积显著低于对照组;12周后干预组握力、血清白蛋白及生活质量得分显著高于对照组,体脂率、内脏脂肪面积显著低于对照组(均P<0.05)。结论 有氧联合抗阻运动可有效改善老年维持性血液透析肥胖型肌少症患者的肌肉力量及营养状况,提高生活质量。     

肌肉减少症病因学研究现状与展望

肌肉减少症是一种与年龄有关的肌肉力量下降和躯体功能受限的老年综合征,老年人出现跌倒、身体残疾、住院和早逝等不良后果风险增加。人均寿命延长导致老龄化,肌肉减少症的发病率和患病率明显升高。2016年国际卫生组织将其纳入《国际疾病分类第十次修订版:临床修改》(ICD-10-CM),疾病编码为M62.84。目前肌肉减少症最常用的定义是欧洲老年人肌肉减少症工作组(EWGSOP)提出的,表示与增龄相关的进行性的全身肌肉量减少、肌肉强度下降或肌肉生理功能减退,2019年EWGSOP更新肌肉减少症定义。肌肉减少症被认为是晚年负面健康结果的相关决定因素,肌肉力量和活动能力的丧失导致躯体平衡障碍,老年人发生跌倒和骨折的比率升高,增加社会残疾率及医疗负担,明确病因十分重要。近年来国内外学者研究发现肌肉减少症与运动因素、内分泌因素、慢性炎症、营养状况、肠道菌群、遗传因素及社会心理素等相关,但具体病因尚不明确。本文通过查阅大量有关文献,对肌肉减少症病因学研究现状与进展作一综述。     

肌少症的CT、MR诊断及临床意义

肌少症(sarcopenia)于1997年被正式定义,是一种与年龄相关、全身广泛性复杂综合征,主要特征为骨骼肌量减少、肌力下降和功能减退。肌少症发病率随年龄增大而逐渐增高,明显降低老年人的生活质量,提高老年人群死亡率,给家庭及社会带来了极大的负面影响。近年来肌少症受到国内外学者越来越多的关注。肌量的评估是诊断肌少症的重要方面。双能X线及生物电阻抗可测量全身肌量,但是精确程度不高。CT与MR目前被认为是评估骨骼肌量的形态学金标准。CT、MR骨骼肌形态学相关研究,与骨质疏松及脆性骨折的发生有密切关系,可以对老年人及各种疾病患者的预后及生存率进行预测,并对身体成分及增肌训练的效果进行监测。临床在进行CT及MR检查,尤其是对老年人进行检查的同时应注意对肌少症的筛查与诊断。本文就肌少症的CT、MR诊断及其临床意义做一综述。     

Sarcopenia

Sarcopenia is defined as a combination of low muscle mass with low muscle function. The term was first used to designate the loss of muscle mass and performance associated with aging. Now, recognized causes of sarcopenia also include chronic disease, a physically inactive lifestyle, loss of mobility, and malnutrition. Sarcopenia should be differentiated from cachexia, which is characterized not only by low muscle mass but also by weight loss and anorexia. Sarcopenia results from complex and interdependent pathophysiological mechanisms that include aging, physical inactivity, neuromuscular compromise, resistance to postprandial anabolism, insulin resistance, lipotoxicity, endocrine factors, oxidative stress, mitochondrial dysfunction, and inflammation. The prevalence of sarcopenia ranges from 3% to 24% depending on the diagnostic criteria used and increases with age. Among patients with rheumatoid arthritis 20% to 30% have sarcopenia, which correlates with disease severity. Sarcopenia exacts a heavy toll of functional impairment, metabolic disorders, morbidity, mortality, and healthcare costs. Thus, the consequences of sarcopenia include disability, quality of life impairments, falls, osteoporosis, dyslipidemia, an increased cardiovascular risk, metabolic syndrome, and immunosuppression. The adverse effects of sarcopenia are particularly great in patients with a high fat mass, a condition known as sarcopenic obesity. The diagnosis of sarcopenia rests on muscle mass measurements and on functional tests that evaluate either muscle strength or physical performance (walking, balance). No specific biomarkers have been identified to date. The management of sarcopenia requires a multimodal approach combining a sufficient intake of high-quality protein and fatty acids, physical exercise, and antiinflammatory medications. Selective androgen receptor modulators and anti-myostatin antibodies are being evaluated as potential stimulators of muscle anabolism.     

Association Between Sarcopenia-Related Phenotypes and Aerobic Capacity Indexes of Older Women

The purpose of the present study was to examine the association between fat-free mass (FFM), quadriceps strength and sarcopenia with aerobic fitness indexes of elderly women. A total of 189 volunteers (66.7 ± 5.46 years) underwent aerobic capacity measurement through a symptom-limited cardiopulmonary exercise test to determine their individual ventilatory thresholds (VT) and peak oxygen uptake (VO₂ peak). Quadriceps muscle strength was assessed using an isokinetic dynamometer. Also, dual energy X-ray absorptiometry was used to assess FFM and cutoff values were used to classify subjects as sarcopenic or nonsarcopenic. Correlations, student t-test and analysis of variance were used to examine the data. Both FFM and quadriceps strength variables were positively and significantly correlated with the measured aerobic capacity indexes. These results were observed for peak exercise as well as for ventilatory thresholds. Individuals classified as sarcopenic presented significantly lower muscle strength and (VO₂ peak) when compared to nonsarcopenic. It can be concluded that FFM and quadriceps strength are significantly related to aerobic capacity indexes in older women, and that besides presenting lower quadriceps strength, women classified as sarcopenic have lower peak oxygen consumption. Taken together, the present results indicate that both FFM and strength play a role in the age-related decline of aerobic capacity.

Key points

• Maximal aerobic capacity, generally expressed as peak oxygen consumption (VO₂ peak), declines with advancing age and this process is associated with an increased risk for cardiovascular diseases.
• Also, the aging process is associated with a progressive loss of muscle mass and strength and this phenomenon has been referred to as Sarcopenia. Sarcopenia has been described in both elderly men and women and has been linked to multiple negative clinical outcomes.
• The present study provide evidence that muscle-related phenotypes are associated with aerobic capacity of older individuals, thus suggesting that sarcopenia explains in part the decline in aerobic fitness observed with advancing age.

Key words: Sarcopenia, VO₂ peak, muscle strength, elderly, cardiorespiratory fitness, peak torque     

Impact of sarcopenia in trauma and surgical patient population: A literature review

Sarcopenia refers to the progressive and generalised loss of skeletal muscle mass and strength with a risk of adverse outcomes such as physical disability, poor quality of life and mortality. The present review explored the impact, diagnosis, prevention and management of sarcopenia in surgical and trauma patients. Recent evidence suggests that there are many factors contributing to its development other than age. Pathophysiology of sarcopenia is complex which makes its diagnosis difficult and there is no universal approach. It is a predictor of poor outcomes including post-operative complications, length of hospital stay and mortality in trauma and surgery patients. Sedentary lifestyle, age-dependent hormone and cytokine imbalance, decreased protein synthesis and regeneration, and motor unit remodelling are some of the main risk factors for sarcopenia. Dual energy X-ray absorptiometry, bio-electrical impedance analysis and computed tomography are frequently utilized for its diagnosis. Management of sarcopenia involves appropriate management of comorbidities, interventions to facilitate physical activities, nutrition interventions and pharmacotherapy.     

Developing Consensus Criteria for Sarcopenia: An Update

Sarcopenia, the age‐related loss of muscle mass and strength, is a major cause of impaired physical function, which contributes to mobility disability, falls and hospitalizations in older adults. Lower muscle mass and strength are also associated with lower bone mineral density and greater risk for osteoporotic fractures. Thus, identification of sarcopenia could be important for fracture prevention as it may help improve fracture risk assessment, and muscle mass and strength can be improved with exercise, even among the frailest older adults. Unfortunately, there are no consensus diagnostic criteria for sarcopenia. Consequently there is no guidance to help clinicians identify older adults with clinically meaningful low muscle mass or weakness. Further, development of novel sarcopenia therapies is hindered not only due to the difficulty in identifying participants for clinical trials, and but also because there are no validated, clinically appropriate endpoints for assessment of treatment efficacy. There is currently a major push to establish a consensus definition of sarcopenia, and recent work holds promise that this goal may be within reach. This article discusses the evolution of the definition of sarcopenia, and focuses on the latest recommended diagnostic criteria proposed by the Foundation for the National Institutes of Health (FNIH) Sarcopenia Project. While these empirically‐based cut‐points for clinically important low muscle mass and weakness are a significant step forward for the sarcopenia field, important questions remain to be answered before consensus diagnostic criteria can be definitively established. Ongoing work to refine sarcopenia criteria will further advance the field and bring this important contributor to falls, fractures and disability into the mainstream of clinical care and ultimately lead to better quality of life with aging. © 2015 American Society for Bone and Mineral Research.     

Sarcopenia in premenopausal and postmenopausal women with osteopenia, osteoporosis and normal bone mineral density

Sarcopenia, the decline of muscle mass with age, causes impaired gait, disability and falls. It may therefore increase the risk of fracture for osteoporotic women. The aims of this study were to determine the prevalence of sarcopenia in osteopenic and osteoporotic women, and to determine if hormone replacement therapy (HRT), diet, or physical activity (PA) has a role in the prevention of sarcopenia. One hundred and thirty-one premenopausal and 82 postmenopausal (54 taking HRT) healthy women (17–77 years) volunteered for the study. Body composition was measured by dual X-ray absorptiometry (DXA). Sarcopenia was defined as a relative skeletal muscle index (RSMI) (appendicular skeletal muscle mass divided by height) below 5.45 kg/m². Osteopenia was defined by a densitometric t -score for bone mineral density (BMD) (g/cm²) below –1.0 and osteoporosis by a t -score below –2.5. Nutrient intake was assessed using 3-day food records and physical activity (PA) was measured using the Baecke Physical Activity Questionnaire. Pearson chi-squared, independent t -tests, simple correlation and multiple regression were used to analyze the data. In premenopausal osteopenic women the prevalence of sarcopenia was 12.5%. In postmenopausal women it was 25% for those with osteopenia, and 50% for those with osteoporosis. PA was independently related to RSMI (=0.222, p =0.0001), but diet and HRT were not. After adjusting for PA, RSMI was not significantly related to BMD. These data suggest that the relationship between RSMI, BMD and risk of osteoporosis may largely be mediated through participation in PA. Sarcopenia screening simultaneous to BMD examinations by DXA, may be of value in identifying osteoporotic women with sarcopenia, a group that may be most in need of exercise interventions to increase muscle and BMD.     

Sarcopenia and osteopenia among 70–80-year-old home-dwelling Finnish women: prevalence and association with functional performance

Summary

This study showed that the prevalence of sarcopenia (low muscle mass and performance) among 70–80-year-old home-dwelling Finnish women is very low, while every third woman has WHO-based osteopenia (low bone mass). Muscle mass and derived indices of sarcopenia were not significantly related to measures of functional ability.

Introduction

This study aims to determine the prevalence of sarcopenia and osteopenia among four hundred nine 70–80-year-old independently living Finnish women. The study compared consensus diagnostic criteria for age-related sarcopenia recently published by the European Working Group on Sarcopenia in Older People (EWGSOP) and the International Working Group on Sarcopenia (IWG) and assessed their associations with functional ability.

Methods

Femoral bone mineral density and body composition were measured with dual-energy X-ray absorptiometry. Skeletal muscle mass index (SMI), gait speed, and handgrip strength were used for sarcopenia diagnosis. Independent samples t tests determined group differences in body composition and functional ability according to recommended diagnostic cutpoints. Scatter plots were used to illustrate the correlations between the outcome measures used for diagnosis.

Results

Prevalence of sarcopenia was 0.9 and 2.7 % according to the EWGSOP and IWG, respectively. Thirty-six percent of the women had WHO-based osteopenia. Women with higher gait speed had significantly lower body weight and fat mass percentage, higher lean mass percentage, and better functional ability. Women with a low SMI weighed significantly less, with no significant differences in other outcome measures. SMI, gait speed, and grip strength were significantly correlated.

Conclusions

Our study suggests that when using consensus definitions, sarcopenia is infrequent among older home-dwelling women while every third woman has osteopenia. In clinical practice, attention should be paid to the decline in functional ability rather than focusing on low muscle mass alone.