绝经后女性肌少症

肌少症为老龄化进展过程中以骨骼肌质量及力量下降为特征的临床综合征,并伴有残疾、生活质量降低甚至死亡,在老年人群中广泛存在,严重影响老年人的生活质量,是当今社会重要的公共健康问题。目前国际上关于肌少症的诊断及筛查方法尚未统一,多个组织先后制定了肌少症共识,提出肌少症的诊断切点,临床实践中使用握力、步速等方法来评估老年人肌肉情况。绝经是一种与年龄相关的生理状况,与自然衰退的雌激素水平相关,易导致肌肉质量和力量的降低,增加肌少症患病率。绝经后女性肌肉组织的质量、功能以及肌肉组织的成分发生变化与雌激素水平降低有关,还受营养、运动、环境、遗传等其他多种复杂因素影响,目前尚没有明确关于肌少症的治疗药物,但现有证据认为阻抗运动、膳食营养、性激素替代治疗等对于改善老年绝经后女性肌肉的质量及力量具有重要作用。目前绝经与肌少症的关系还处于探索阶段,仍有许多值得进一步研究的问题,本文就肌少症的诊断及绝经后激素变化和增龄与肌少症的关系等进行综述。     

“肌少-骨质疏松症”的研究现状与进展

人口的老龄化增加了许多老年慢性疾病的患病率,肌少症和骨质疏松症是与年龄相关的退行性疾病,具有相似的病理生理基础,包括遗传学、脂肪浸润、内分泌和机械因素等。"肌少-骨质疏松症"是一种新的老年综合征,在老年人群中广泛存在,并且可能带来严重的并发症,临床实践中应常规使用DXA、手握力、步行速度来评估老年人群的肌肉和骨骼情况,这对于有高危因素的老年患者可能会有帮助。针对"肌少-骨质疏松症"的研究可以更加全面的认识肌肉骨骼相关的退行性疾病,治疗上提示骨质疏松症和骨质疏松性骨折需要全面考虑肌肉和骨骼的情况并进行综合干预。尽管目前没有明确关于"肌少-骨质疏松症"的治疗药物,但有充分证据表明足够的蛋白质和钙摄入量,增加身体活动及维持维生素D的适当水平可以对骨骼和肌肉产生双重作用,这些都有助于改善身体的活动功能并减少老年人群跌倒和发生骨折的风险。笔者对"肌少-骨质疏松症"的流行病学、病理生理学、诊断、治疗和管理策略进行综述。     

维生素D在纤维肌痛综合征中的影响机制及研究进展

纤维肌痛综合征是一种病因不明,以广泛性慢性疼痛、各种躯体功能和心理障碍表现为特点的临床综合征,严重影响患者生活质量。维生素D作为一种人体必需营养素,其活性形式1,25-二羟维生素D不仅对肌肉骨骼系统有益,而且对人体其他生理功能具有重要作用。国内外研究发现,维生素D缺乏与纤维肌痛综合征等慢性疼痛之间存在关联。纤维肌痛综合征属中医学“筋痹”“肝痹”范畴,补肝、疏肝等中药或方剂对于改善纤维肌痛综合征疼痛及伴发症状具有较好疗效,其机制可能为补肝、疏肝之品中含有维生素D的活性成分。通过对维生素D与纤维肌痛综合征两者之间联系进行阐释,为纤维肌痛综合征的防治提供更多的理论依据。     

2021年“第14届肌少症、恶病质和消耗性疾病协会学术年会”热点内容介绍

肌少症、恶病质和消耗性疾病协会(SCWD)于2021年12月11—12日以网络虚拟会议的形式召开第14届学术年会。大会从基础科学和临床科学角度对肌少症、恶病质及消耗性疾病的话题展开广泛讨论,主要包括:(1)恶病质与肌少症的发生发展存在多组织器官系统参与的代谢串扰,如脂肪/肌肉串扰、神经/肌肉串扰、肿瘤/脂肪/肌肉串扰、骨髓/中枢神经系统串扰;(2)衰老相关性厌食与恶病质和肌少症关系密切,应加强认识衰老相关性厌食的病因与危害;(3)恶病质和肌少症与心力衰竭之间相互影响,心力衰竭对患者的危害程度不亚于癌症给机体带来的影响,应加强恶病质和肌少症与心力衰竭关系的认识和研究;(4)多种治疗恶病质和肌少症的新方法与新药物被提出,如Anamorelin、Enobosarm、TCMCB07等。药物治疗是未来治疗恶病质主要方式之一;(5)分子作用机制、医学转化研究、临床诊疗标准等是目前恶病质和肌少症基础与临床研究的热点也是难点。     

肌肉减少症研究进展

人口老龄化使得肌肉减少症(sarcopenia)（简称肌少症）的患病率逐年增加,流行病学调查显示该疾病会带来严重的致残率和致死率,受到国内外学者的诸多关注,对于肌少症的发病机制、危险因素、诊断评估以及治疗均有大量研究,但目前国内外对于该疾病的认识仍然存在差异。我国对于肌少症的研究尚处于探索阶段,肌少症作为脆性骨折的一个独立危险因素,及时诊治肌少症对降低骨折与跌倒风险具有重要意义,研究肌少症与骨质疏松症的相关性也是目前预防跌倒性骨折的重要研究方向。本文将从概述、流行病学、发病机制、诊断和治疗干预等方面对肌少症的新进展进行综述。     

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。     

肌肉质量测定方法的研究新进展

随着社会的快速发展,对人口老龄化引发的健康问题关注度越来越高。与衰老相伴随的肌少症亦慢慢走近了人们视野,以肌肉质量减少和/或肌肉力量下降或功能减退为其主要临床表现,严重影响老年人群的生活质量。因此,对肌少症的筛查与早期干预至关重要。肌肉质量评估是肌少症诊断与评估疗效必不可少的条件,双能X线骨密度仪（DXA）、计算机断层扫描（CT）、核磁共振成像（MRI）、生物电阻抗分析（BIA）等为临床肌肉质量常用的检测方法。除上述技术外,近来超声技术和D3-肌酸稀释法在肌肉质量评估中也展示不同视角。本文将对以上技术在肌肉质量检测中的研究进展进行系统综述。     

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。     

老年肌少症护理评估的研究进展

介绍肌少症的诊断依据,从肌量、肌力、肌肉功能和风险评估方面综述肌少症的护理评估方法,并对老年肌少症的护理评估提出建议,旨在为开展老年肌少症护理评估及筛查提供参考。     

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。     

Impact of nutrition on muscle mass, strength, and performance in older adults

Muscle strength plays an important role in determining risk for falls, which result in fractures and other injuries. While bone loss has long been recognized as an inevitable consequence of aging, sarcopenia—the gradual loss of skeletal muscle mass and strength that occurs with advancing age—has recently received increased attention. A review of the literature was undertaken to identify nutritional factors that contribute to loss of muscle mass. The role of protein, acid–base balance, vitamin D/calcium, and other minor nutrients like B vitamins was reviewed. Muscle wasting is a multifactorial process involving intrinsic and extrinsic alterations. A loss of fast twitch fibers, glycation of proteins, and insulin resistance may play an important role in the loss of muscle strength and development of sarcopenia. Protein intake plays an integral part in muscle health and an intake of 1.0–1.2 g/kg of body weight per day is probably optimal for older adults. There is a moderate inverse relationship between vitamin D status and muscle strength. Chronic ingestion of acid-producing diets appears to have a negative impact on muscle performance, and decreases in vitamin B₁₂ and folic acid intake may also impair muscle function through their action on homocysteine. An adequate nutritional intake and an optimal dietary acid–base balance are important elements of any strategy to preserve muscle mass and strength during aging.     

Branched-chain amino acids plus vitamin D supplementation promote increased muscle strength following lumbar surgery for lumbar spinal stenosis: a randomized trial

BACKGROUND CONTEXTAdequate nutrition is essential to address the surgical stress response and mitigate loss of muscle mass, strength, and functionality in older adults with lumbar spinal stenosis (LSS). However, it is unknown whether amino acids and/or vitamin D are beneficial in older adults following lumbar surgery for LSS.PURPOSETo evaluate whether branched-chain amino acids (BCAA) plus vitamin D supplementation could attenuate the loss of muscle mass and strength, accelerate the return of functional mobility, and improve clinical outcomes following lumbar surgery for LSS.STUDY DESIGN/SETTINGA single-center, single-blind randomized controlled trial.PATIENT SAMPLEEighty patients who received lumbar surgery for LSS.OUTCOME MEASURESThe primary outcome was the Zurich claudication questionnaire (ZCQ), and secondary outcomes included knee muscle strength, muscle mass measured by bioelectrical impedance analysis, gait speed and a timed up-and-go test (TUG) at 12 weeks postoperatively. Follow-up assessment was performed for the ZCQ at 52 weeks postoperatively.METHODSPatients ingested the supplementation (BCAA group: BCAA plus vitamin D, Nonamino acid group: nonamino acid) twice daily for 3 weeks from the day after surgery, and received two hours of postoperative inpatient rehabilitation 5 times a week.RESULTSNo significant differences were observed in the mean changes on the ZCQ between the two groups at 12 weeks and 52 weeks. At 2 weeks postoperatively, the nonamino acid group showed significant deterioration compared with the BCAA group for strengths of knee extensor and knee flexor (p < .01). At 12 weeks, the BCAA group showed significant improvements in knee extensor strength and knee flexor strength compared with the nonamino acid group (p <.01). There were no significant differences in mean changes of muscle mass, maximum gait speed, and TUG at 12 weeks between two groups.CONCLUSIONSBCAA plus vitamin D supplementation did not improve LSS-related clinical outcomes after lumbar surgery for LSS, even though muscle strength increased. Future studies should focus on long-term outcomes for muscle mass and physical function, including development of sarcopenia and frailty.     

中老年2型糖尿病患者肌少症相关因素研究

目的通过研究中老年2型糖尿病(type 2 diabetes mellitus,T2DM)患者肌少症(Sarcopenia)发生的危险因素,为预防和治疗肌少症提供思路。方法收集2018年5~11月于郑州大学第一附属医院内分泌科住院的289例中老年T2DM患者作为研究对象,以同期该院57名正常体检人群作为对照组,比较两组患者一般资料、血生化、HbA1c、肌力等指标的差异及两组肌少症的检出率。对两定量资料进行Pearson相关分析及Logistic回归分析,分析肌少症发生的危险因素。结果T2DM组中肌少症的检出率(22.83%)大于正常对照组(12.28%)(P<0.05)。T2DM组中,全身骨骼肌肌肉含量与体重、体质量指数(body mass index,BMI)、全髋部骨密度、腹部脂肪面积、25(OH)D3含量呈正相关,与空腹血糖、糖尿病病程呈负相关。低BMI、低全髋部骨密度、低25(OH)D3、长糖尿病病程是肌少症发生的危险因素。结论2型糖尿病患者是肌少症发生的危险人群,针对T2DM患者发生肌少症的相关危险因素采取干预措施,可减少跌倒、骨折、致残、致死事件的发生。     

Is vitamin D a determinant of muscle mass and strength?

There remains little consensus on the link between vitamin levels and muscle mass or strength. We therefore investigated the association of serum 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)(2) D), and parathyroid hormone (PTH) levels with skeletal muscle mass and strength. We studied 311 men (mean age, 56 years; range, 23-91 years) and 356 women (mean age, 57 years; range, 21-97 years) representing an age-stratified, random sample of community adults. Multivariate linear regression models were used to examine the association of skeletal muscle mass (by total body dual-energy X-ray absorptiometry) and strength (handgrip force and isometric knee extension moment) with each of 25(OH)D, 1,25(OH)(2) D, and PTH quartiles, adjusted for age, physical activity, fat mass, and season. We found no consistent association between 25(OH)D or PTH and any of our measurements of muscle mass or strength, in either men or women. However, in subjects younger than 65 years, there was a statistically significant association between low 1,25(OH)(2) D levels and low skeletal mass in both men and women and low isometric knee extension moment in women, after adjustment for potential confounders. Modestly low 25(OH)D or high PTH levels may not contribute significantly to sarcopenia or muscle weakness in community adults. The link between low 25(OH)D and increased fall risk reported by others may be due to factors that affect neuromuscular function rather than muscle strength. The association between low 1,25(OH)(2) D and low skeletal mass and low knee extension moment, particularly in younger people, needs further exploration.     

Vitamin D Deficiency and its Role in Muscle-Bone Interactions in the Elderly

In this commentary, we focus on common ‘downstream’ links of vitamin D between muscle and bone health. Both direct and indirect effects of 1,25 dihydroxyvitamin D (1,25(OH)D) link the mutual age-related decline in muscle function and bone density, independent of physical activity. Changes in calcium absorption associated with vitamin D deficiency affect both muscle and bone mass. The age-related decline in vitamin D receptor expression and 1,25(OH)D activity impact on proinflammatory cytokines such as tumor necrosis factor -α and interleukin-6 in skeletal muscle and vitamin D deficiency appears to enhance both bone marrow adipogenesis and intramuscular adipose tissue impacting as reduced functionality in both skeletal tissues. Controversial findings on the role of 1,25(OH)D on skeletal muscle may relate to differences in vitamin D receptor expression throughout different stages of muscle cell differentiation. Prolonged vitamin D insufficiency in the elderly is associated with reductions in both bone mineral density and type 2 muscle fibers with the outcomes of skeletal fragility in combination with reduced muscle power, leading to increased risk of falls and fracture.     

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.     

Impact of Sarcopenia on Survival in Patients Undergoing Living Donor Liver Transplantation

Skeletal muscle depletion, referred to as sarcopenia, predicts morbidity and mortality in patients undergoing digestive surgery. However, the impact on liver transplantation is unclear. The present study investigated the impact of sarcopenia on patients undergoing living donor liver transplantation (LDLT). Sarcopenia was assessed by a body composition analyzer in 124 adult patients undergoing LDLT between February 2008 and April 2012. The correlation of sarcopenia with other patient factors and the impact of sarcopenia on survival after LDLT were analyzed. The median ratio of preoperative skeletal muscle mass was 92% (range, 67–130%) of the standard mass. Preoperative skeletal muscle mass was significantly correlated with the branched‐chain amino acids to tyrosine ratio (r = ?0.254, p = 0.005) and body cell mass (r = 0.636, p < 0.001). The overall survival rate in patients with low skeletal muscle mass was significantly lower than in patients with normal/high skeletal muscle mass (p < 0.001). Perioperative nutritional therapy significantly increased overall survival in patients with low skeletal muscle mass (p = 0.009). Multivariate analysis showed that low skeletal muscle mass was an independent risk factor for death after transplantation. In conclusion, sarcopenia was closely involved with posttransplant mortality in patients undergoing LDLT. Perioperative nutritional therapy significantly improved overall survival in patients with sarcopenia.