CT评价腹股沟疝患者肌肉质量方法的前瞻性研究

目的　应用CT技术评价老年腹股沟疝患者的肌肉质量。方法　拟接受腹股沟疝手术、年龄在70~90岁的男性住院患者30例为研究对象,40~50岁10名男性健康受试者为成人对照组,10名同年龄段接受健康查体老年人为老年对照组,记录一般资料,应用CT技术扫描腹部和大腿,通过专用软件计算相应肌肉面积。结果　研究组握力（36.44±14.15）kg明显少于成人对照组（77.30±22.69）kg （P=0.001）,研究组小腿围（25.18±2.31）cm 明显少于成人对照组（27.62±2.33）cm （P=0.006）。CT扫描显示研究组与成人对照组L3（第3腰椎）平面腹部面积、皮下脂肪面积、腹腔脂肪面积和竖脊肌总面积相近,研究组腹部肌肉面积（12 094.23±1 970.30）mm2和竖脊肌肌肉面积（1 642.60±266.90）mm2明显少于成人对照组的（17 462.00±1 600.58）mm2和（2 003.50±350.91）mm2（P=0.001, P=0.007）。L3骨骼肌指数为50.64±7.52,存在肌肉减少症（≤52.4）为66.7 %（20/30）。与同年龄正常查体老人腹部肌肉CT结果相似。研究组下肢骨骼肌面积明显少于成人对照组（P=0.001）,下肢脂肪和股骨面积两组比较差异无统计学意义（P＞0.05）。结论　老年腹股沟疝患者肌肉质量和力量明显低于成人对照组,CT技术可作为评价工具。     

肌少症和骨质疏松对类风湿关节炎患者脊柱骨质疏松性骨折的协同影响

目的探讨肌少症和骨质疏松(OP)对RA患者脊柱骨质疏松性骨折(OPF)发生的协同影响.方法选择389例住院的RA患者和同期156例年龄、性别相匹配的健康人,采用双能X线吸收测量(DEXA)法测定腰椎和髋部的骨密度(BMD),采用生物电阻抗法测定四肢骨骼肌质量,摄脊柱X线正侧位片并以半定量法进行脊柱骨折的判定.统计学方法:2组间计量资料比较采用t检验,组间率的比较采用x2检验,2项分类资料的多元回归分析采用Logistic回紧(backward LR法)分析.结果RA患者各测定部位BMD均低于对照组(P<0.01),RA组骨质疏松发生率(128/389,32.9%)高于对照组[(20/156,12.8%),χ^2=22.706,P<0.01];RA患者脊柱OPF发生率为21.6%(84/389),高于对照组中[(3.8%,6/156),χ^2=25.439,P<0.01].RA患者中肌少症的发生率为54.8%,高于对照组[(9.6%,15/156),χ^2=93.241,P<0.01];RA组肌少症合并骨质疏松的发生率(28.5%)高于对照组[(5.8%),χ^2=118.110,P<0.01 ].不同骨量(骨量正常、骨量减少、骨质疏松)分组间RA患者脊柱OPF发生率的差异有统计学意义(χ^2=43.373,P<0.01),且呈现出随着骨量逐渐降低,脊柱OPF发生率逐渐升高的趋势(χ^2=43.003,P<0.01).伴肌少症的RA患者脊柱OPF发生率(27.2%,58/213)高于无肌少症的RA患者[(14.8%,26/176),χ^2=8.833,P=0.003].根据骨质疏松和肌少症分组的3组间(1=无肌少症和骨质疏松;2=单纯肌少症或骨质疏松;3=肌少症合并骨质疏松)RA患者脊柱OPF发生率的差异有统计学意义(χ^2=33.832,P<0.01),且从第1组到第3组脊柱OPF的发生率有逐渐增高的趋势(χ^2=37.164,P<0.01).与未服用糖皮质激素(GC)组相比,服用GC组的RA患者具有更高的肌少症发生率(χ^2=7.136,P=0.008)、OP发生率(CI=10.900,P=0.004)和脊柱OPF发生率(χ^2=20.673,P<0.01).Logistic回归分析显示:高龄[OR(95%CI)=1.069(1.038,1.101),P<0.01]、服用GC[OR(95%CI)=3.169(1.679,5.984),P<0.01]、肌少症和骨质疏松[OR(95%CI)=2.113(1.430,3.124),P<0.01]的同时存在为RA患者发生脊柱OPF的危险因素.结论RA患者肌少症、骨质疏松和脊柱OPF的发生率均明显增高,且肌少症和骨质疏松对RA患者脊柱OPF的发生具有协同作用.     

Reliability of Skeletal Muscle Area Measurement on CT with Different Parameters: A Phantom Study

ObjectiveTo evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters.Materials and MethodsA phantom, simulating the L2–4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings.ResultsThe skeletal muscle area (threshold, −29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30–150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0–44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used.ConclusionMeasurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.     

Age-related changes in muscle architecture and metabolism in humans: The likely contribution of physical inactivity to age-related functional decline

In the United Kingdom (UK), it is projected that by 2035 people aged >65 years will make up 23 % of the population, with those aged >85 years accounting for 5% of the total population. Ageing is associated with progressive changes in muscle metabolism and a decline in functional capacity, leading to a loss of independence. Muscle metabolic changes associated with ageing have been linked to alterations in muscle architecture and declines in muscle mass and insulin sensitivity. However, the biological features often attributed to muscle ageing are also seen in controlled studies of physical inactivity (e.g. reduced step-count and bed-rest), and it is currently unclear how many of these ageing features are due to ageing per se or sedentarism. This is particularly relevant at a time of home confinements reducing physical activity levels during the Covid-19 pandemic. Current knowledge gaps include the relative contribution that physical inactivity plays in the development of many of the negative features associated with muscle decline in older age. Similarly, data demonstrating positive effects of government recommended physical activity guidelines on muscle health are largely non-existent. It is imperative therefore that research examining interactions between ageing, physical activity and muscle mass and metabolic health is prioritised so that it can inform on the “normal” muscle ageing process and on strategies for improving health span and well-being. This review will focus on important changes in muscle architecture and metabolism that accompany ageing and highlight the likely contribution of physical inactivity to these changes.     

Sarcopenia and Obesity: Gender-Different Relationship with Functional Limitation in Older Persons

Age-related body composition changes such as sarcopenia and obesity affect functional decline in the elderly. We investigated the relationship between body composition parameters and functional limitation in older Korean adults. We enrolled 242 men and 231 women aged ≥ 65 yr from the Korean elderly cohort. We used appendicular skeletal muscle mass (ASM) divided by height² (ASM/Ht²) and ASM divided by weight (ASM/Wt). The isokinetic strength of knee extensor muscles were measured using an isokinetic device. Functional limitations were assessed using the Short Physical Performance Battery (SPPB) score less than nine. Men within the bottom tertile of ASM/Ht² confer an increased risk for functional limitation compared with those within the top tertile (OR, 6.24; 95% CI, 1.78-22.0). However, in women, subjects within the lowest ASM/Wt tertile had a higher risk compared with those within the highest tertile instead of ASM/Ht² (OR, 7.60; 95% CI, 2.25-25.7). Leg muscle strength remained the strong measure even after controlling for muscle mass only in women. Only large waist circumference was positively associated with functional limitation only in women. We might consider a different muscle index to assess functional limitation according to the gender.     

AWGS2019 vs EWGSOP2 for diagnosing sarcopenia to predict long-term prognosis in Chinese patients with gastric cancer after radical gastrectomy

BACKGROUNDSarcopenia is a nutrition-related disease and has a profound effect on the long-term overall survival (OS) of patients with gastric cancer. Its diagnostic criterion is critical to clinical diagnosis and treatment. However, previous research reported widely differing sarcopenia prevalence due to different criteria. AWGS2019 and EWGSOP2 are the two latest and widely adopted criteria.AIMTo compare the effects of AWGS2019 and EWGSOP2 on the long-term OS of Chinese gastric cancer patient after radical gastrectomy.METHODSAn observational study was conducted from July 2014 to January 2017, which included 648 consecutive gastric cancer patients who underwent radical gastrectomy. The sarcopenia elements (skeletal muscle index, handgrip strength, and gait speed) were measured within 1 mo or 7 d before surgery. The patients were followed at fixed intervals to gain the outcomes. Multivariate Cox regression analysis was performed to determine the association between sarcopenia and the long-term OS of these patients according to the two criteria separately. The predictive performance of the models with AWGS2019 and EWGSOP2 were evaluated by the concordance index (C-index) and area under the time-dependent receiver operating characteristic curve (AUC). The Akaike information criterion (AIC) was applied to compare model fits.RESULTSThe prevalence of sarcopenia was 20.5% and 11.3% according to AWGS2019 and EWGSOP2, respectively. Sarcopenia was an independent risk factor for the long-term OS no matter based on AWGS2019 or EWGSOP2, but AWGS2019-sarcopenia in multivariate model had a higher hazard ratio (HR) [2.150 (1.547-2.988)] than EWGSOP2-sarcopenia [HR 1.599 (1.092-2.339)]. Meanwhile, the model with AWGS2019-sarcopenia [C-index 0.773 (0.742-0.804); AIC 2193.7; time-dependent AUC 0.812 (0.756-0.867) for 1-year OS, 0.815 (0.778-0.852) for 3-year OS, and 0.809 (0.759-0.859) for 5-year OS] had better predictive power and model fits than the model with EWGSOP2-sarcopenia [C-index 0.762 (0.729-0.795); AIC 2215.2; time-dependent AUC 0.797 (0.741-0.854) for 1-year OS, 0.804 (0.767-0.842) for 3-year OS, and 0.799 (0.748-0.850) for 5-year OS].CONCLUSIONSarcopenia is an independent risk factor for the long-term OS in Chinese gastric cancer patients undergoing radical gastrectomy. The prediction model with AWGS2019-sarcopenia has better predictive power and model fits than the prediction model with EWGSOP2-sarcopenia. AWGS2019 may be more appropriate for diagnosing sarcopenia in these Chinese patients than EWGSOP2.     

Vitamin D Receptor Signaling Enhances Locomotive Ability in Mice

Bone fractures markedly reduce quality of life and life expectancy in elderly people. Although osteoporosis increases bone fragility, fractures frequently occur in patients with normal bone mineral density. Because most fractures occur on falling, preventing falls is another focus for reducing bone fractures. In this study, we investigated the role of vitamin D receptor (VDR) signaling in locomotive ability. In the rotarod test, physical exercise enhanced locomotive ability of wild‐type (WT) mice by 1.6‐fold, whereas exercise did not enhance locomotive ability of VDR knockout (KO) mice. Compared with WT mice, VDR KO mice had smaller peripheral nerve axonal diameter and disordered AChR morphology on the extensor digitorum longus muscle. Eldecalcitol (ED‐71, ELD), an analog of 1,25(OH)₂D₃, administered to rotarod‐trained C57BL/6 mice enhanced locomotor performance compared with vehicle‐treated nontrained mice. The area of AChR cluster on the extensor digitorum longus was greater in ELD‐treated mice than in vehicle‐treated mice. ELD and 1,25(OH)₂D₃ enhanced expression of IGF‐1, myelin basic protein, and VDR in rat primary Schwann cells. VDR signaling regulates neuromuscular maintenance and enhances locomotive ability after physical exercise. Further investigation is required, but Schwann cells and the neuromuscular junction are targets of vitamin D₃ signaling in locomotive ability. © 2014 American Society for Bone and Mineral Research.     

住院老年慢性病患者肌少症的相关影响因素分析

背景　肌少症与增龄相关,表现为进行性的全身肌量减少和/或肌强度下降或肌肉生理功能减退。不仅会引起疾病,还会导致高额的社会医疗支出。目的　调查住院老年慢性病患者肌少症的发生率,探究住院老年慢性病患者肌少症的相关因素,以利于肌少症的早期筛查和预防。方法　入选2017年11月-2018年11月于北京大学人民医院老年科住院的慢性病患者（≥60岁）共236例。收集患者人口学资料及慢性病、过去3个月用药情况、实验室检查指标,采用老年抑郁量表（GDS-30）、简易营养评价精法（MNA-SF量表）评估患者抑郁、营养状况。根据亚洲肌少症工作组（AWGS）诊断标准诊断肌少症,将患者分为肌少症组63例和非肌少症组173例,比较两组患者临床资料,采用多因素Logistic回归分析住院老年慢性病患者肌少症的相关因素。结果　肌少症组和非肌少症组患者性别、年龄、体质指数（BMI）、骨质疏松症发生率、血红蛋白（Hb）、血清白蛋白（Alb）、尿素氮（BUN）、总胆固醇（TC）、三酰甘油（TG）/高密度脂蛋白胆固醇（HDL-C）比值、估算肾小球滤过率（eGFR）、营养不良及风险、四肢骨骼肌质量指数（ASMI）、握力、步速比较,差异均有统计学意义（P<0.05）。多因素Logistic回归分析结果显示,年龄〔OR=1.052,95%CI（1.007,1.099）〕、BMI〔OR=0.885,95%CI（0.793,0.988）〕、骨质疏松症〔OR=2.217,95%CI（1.100,4.467）〕、Hb〔OR=0.936,95%CI（0.909,0.964）〕、TG/HDL-C比值〔OR=1.501,95%CI（1.074,2.099）〕与住院老年慢性病患者发生肌少症有回归关系（P<0.05）。根据BMI四分位数分组,不同BMI分组患者肌少症发生率比较,差异有统计学意义（P<0.05）;其中BMI 24.7~27.0 kg/㎡组患者肌少症发生率低于BMI≤22.4 kg/㎡组（χ2=12.844,P<0.001）。根据TG/HDL-C比值四分位数分组,不同TG/HDL-C比值患者肌少症发生率比较,差异无统计学意义（P>0.05）。结论　年龄、骨质疏松症、Hb水平降低、TG/HDL-C比值升高与住院老年慢性病患者肌少症的发生相关;BMI与肌少症的发生呈U型相关。     

睡眠质量与老年肌肉减少症关系的研究

背景　肌肉减少症与睡眠障碍均在老年人群中高发。睡眠质量差可抑制干扰合成代谢激素,从而影响骨骼肌合成,但关于睡眠质量与老年肌肉减少症之间关系的研究较少。目的　探讨睡眠质量与老年肌肉减少症之间的关系,为老年肌肉减少症的防治提供科学依据。方法　采用随机抽样的方法,对2017年12月-2018年12月前来乌鲁木齐市某体检中心体检的1 391例≥60岁老年人进行问卷调查（一般人口学资料及睡眠质量）和体格检查（四肢骨骼肌质量、步速、握力）。睡眠质量的调查采用匹兹堡睡眠质量指数量表（PSQI）,肌肉减少症诊断参照肌肉减少症亚洲工作组诊断标准。睡眠质量对老年肌肉减少症的影响采用多因素Logistic回归进行分析。结果　1 391例被调查对象中,194例（13.9%）患有肌肉减少症;PSQI平均得分为（6.22±3.87）分,713例（51.3%）PSQI>5分,即睡眠质量较差。不同年龄、月收入、婚姻状况、饮酒情况老年人肌肉减少症发生情况比较,差异有统计学意义（P<0.05）。不同性别、年龄、文化程度、月收入、婚姻状况、吸烟情况、饮酒情况患者睡眠质量较差者占比比较,差异有统计学意义（P<0.05）。肌肉减少症患者PSQI总分、主观睡眠质量、入睡时间、睡眠时间、睡眠效率及日间功能障碍得分高于非肌肉减少症者,差异有统计学意义（P<0.05）。与PSQI≤5分相比,PSQI>5分患肌肉减少症的风险较大〔OR（95%CI）=1.74（1.27,2.38）〕。按性别分层后,与PSQI≤5分相比,女性PSQI>5分患肌肉减少症的风险较大〔OR（95%CI）=2.17（1.37,3.43）〕,男性PSQI>5分与PSQI≤5分者患肌肉减少症的风险差异无统计学意义〔OR（95%CI）=1.51（0.96,2.37）〕。结论　对于≥60老年女性而言,睡眠质量差是肌肉减少症的危险因素。