Emergence of ghrelin as a treatment for cachexia syndromes

Cachexia is a constellation of symptoms that amount to body wasting in the setting of a variety of chronic illnesses, including cancer, heart failure, chronic kidney disease, and acquired immunodeficiency syndrome. Cachexia is particularly worrisome clinically because it is associated with a worsened prognosis of the underlying disease. Despite a large amount of study in this area, no single agent has been shown to have consistent efficacy in human trials. One promising class in this setting is ghrelin receptor agonists. Ghrelin binds to the growth hormone secretagogue-1a receptor in appetite-regulating centers in the brain, increasing expression of neuropeptide Y and agouti-related peptide during short-term treatment. Ghrelin has also been shown to have anti-inflammatory properties, which is significant, given that cachexia is thought to be produced at least partly by inflammation induced by the underlying disease. Animal studies have demonstrated efficacy using growth hormone secretagogue receptor agonists to treat cachexia caused by cancer, chemotherapy, and chronic kidney disease. Limited human trials using ghrelin or ghrelin receptor agonists in cancer and heart disease have shown improved appetite and body mass during treatment, although longer-term trials are needed to confirm sustained effects. Also uncertain-but an intriguing possibility-is whether the improved weight gain with ghrelin treatment might also lessen the severity of the underlying disease and improve outcomes.     

Hypo-activity induced skeletal muscle atrophy and potential nutritional interventions: A review

Periods of hypo-activity result in profound changes in skeletal muscle morphology and strength. This review primarily addresses the differential impact of de-training, bed-rest, limb immobilisation and unilateral lower limb suspension on muscle morphology, strength and fatigability. The degree of muscle atrophy differs depending on the hypo-activity model and the muscles in question, with the leg and postural muscles being the most susceptible to atrophy. Hypo-activity also results in the dramatic loss of strength that often surpasses the loss of muscle mass, and consequently, the nervous system and contractile properties adapt to adjust for this excessive loss of strength. In addition, the degree of muscle strength loss is different depending on the hypo-activity model, with immobilisation appearing to have a greater impact on strength than unloaded models. There is a step-wise difference in the magnitude of muscle loss so that, even after accounting for differential durations of interventions immobilisation ≥ unilateral lower limb suspension ≥ bed-rest ≥ de-training. Muscle fatigability varies between hypo-activity models but the results are equivocal and this may be due to task-specific adaptations. This review also addresses potential nutritional interventions for attenuating hypo-activity induced muscle atrophy and strength declines, in the absence of exercise. Essential amino acid supplementation stands as a strong candidate but other supplements are good contenders for attenuating hypo-activity induced atrophy and strength losses. Several potential nutritional supplements are highlighted that could be used to combat muscle atrophy but extensive research is needed to determine the most effective.     

中国成年人慢性病与肌肉重量、力量及质量的相关性分析

目的 探索我国成年人主要慢性病与肌肉重量、力量和质量的关系。方法 主要利用中国慢性病前瞻性研究项目的第二次重复调查,采用logistic回归分析主要慢性病种类、个数及患病年限与肌肉重量、力量和质量的相关性。结果 在24 242名研究对象中,糖尿病、冠心病、脑卒中和慢性阻塞性肺疾病（慢阻肺）的患病率分别为9.6%、5.8%、3.2%和26.8%,患以上任一慢性病者占38.8%。患上述任一慢性病与低手握力和低上肢肌肉质量（AMQ）呈正相关,且其患病年限越长,风险越高（线性趋势P值均<0.001）,患任一慢性病≥ 10年者低手握力和低AMQ的OR值（95%CI）分别为1.64（1.42~1.90）和1.83（1.60~2.10）;患1、2、≥ 3种慢性病者低手握力的OR值（95%CI）分别为1.26（1.17~1.37）、1.42（1.23~1.64）和2.27（1.55~3.32）,低AMQ的OR值（95%CI）分别为1.28（1.18~1.38）、1.67（1.46~1.92）和2.41（1.69~3.45）,且关联均存在线性趋势（线性趋势P值均<0.001）。糖尿病、冠心病和脑卒中均与低手握力和低AMQ呈正相关;慢阻肺患者低四肢肌肉重量指数（ASMI）、低全身肌肉重量指数（TSMI）和低手握力的风险高于非慢阻肺患者,且风险与患病年限呈正相关（线性趋势P值均<0.05）,患慢阻肺≥ 10年者低ASMI和低TSMI的OR值（95%CI）分别为2.39（1.36~4.20）和2.41（1.37~4.26）。结论 慢性病患者肌肉力量和质量更低,且随患慢性病个数及年限延长,低手握力、低AMQ的比例更高。     

A Strength-Endurance Index for Power Grip

Introduction The purpose of this study was to quantify muscle strength and endurance in power grip. Method Workers (74 M and 74 F, 18–72 years) squeezed a dynamometer for a 60 s, 18-cycle test. Initial strength (IS) and final strength (FS) were calculated as the mean peak force for cycles 1–3 and 16–18, respectively. Endurance was defined by the strength decrement index (SDI) where SDI = (IS − FS)/IS × 100. A grip strength-endurance analyzer was constructed from IS and SDI data which were depicted on two parallel, linearly scaled axes. Discrete IS and SDI scores were connected on each axis with a vector. The vector (Vmag) was measured directly from the analyzer and its direction identified from its slope. Integer scales transformed discrete IS and SDI scores into individual strength-endurance performance scores (SEPS). Results Better than 95% of the sample (n ≥ 141) scored within acceptable test ranges defined as the combined sample mean ± 2SD, for SDI, Vmag and SEPS. Vmag was the best predictor for SEPS. Linear regression for SEPS was SEPS (combined) = 0.09 (Vmag) − 0.29: (SEE = 0.829). The analyzer revealed individual scores outside acceptable ranges for injured and uninjured efforts. Conclusion The development of a power grip strength-endurance analyzer provided a simple method to graph individual power grip performances. Converting strength and endurance scores to integers and summing them (SEPS) provided a simple means to represent individual estimates of power grip strength-endurance performance.     

中国成年人睡眠时长及失眠症状与肌肉重量、力量及质量的相关性分析

目的探索我国成年人睡眠时长及失眠症状与低肌肉重量、力量和质量的关系。方法主要利用中国慢性病前瞻性研究(CKB)项目的第二次重复调查, 采用logistic回归分析睡眠时长、有无失眠症状及其年限与低肌肉重量、力量和质量的相关性。结果研究人群每天睡眠时长为(7.4±1.5)h, 9.3%睡眠时间过短(<6 h), 17.4%睡眠时间过长(≥9 h), 29.9%自报有失眠症状。以睡眠时间7～h为参照组, 睡眠时间过长与低肌肉重量、力量和质量呈正相关, 低四肢肌肉重量指数(ASMI)、低全身肌肉重量指数(TSMI)、低手握力和低上肢肌肉质量(AMQ)的OR值(95%CI)分别为1.32(1.18～1.48)、1.26(1.13～1.41)、1.33(1.18～1.49)和1.16(1.03～1.30)。与无失眠症状者相比, 自报有失眠症状者低ASMI和低TSMI的危险性均增加, 且其失眠症状年限越长, 低ASMI和低TSMI的风险越高(线性趋势均P<0.001)。与睡眠时间7～h且无失眠症状者相比, 睡眠时间过短且有失眠症状者低ASMI和低TSMI的风险明显增加, OR值(95%...     

中老年女性盆腔器官脱垂盆底肌力特征分析

目的分析中老年女性盆腔器官脱垂(POP)患者盆底肌力、肌电值及疲劳度变化特征。方法选择2019年1-10月沈阳市妇婴医院收治的中老年POP患者70例作为观察组,另选同时期于我院就诊的其他无盆底功能障碍的妇科良性疾病患者70例作为对照组。比较两组患者的盆底肌力(收缩力和阴道横截面肌力)和电生理指标(Ⅰ类和Ⅱ类肌纤维的肌力、肌电值和疲劳度)。结果观察组盆底肌力和阴道横截面肌力均低于对照组,组间差异有统计学意义(P<0.05)。观察组Ⅰ类和Ⅱ类肌纤维肌力和肌电值均低于对照组,组间差异有统计学意义(P<0.05);观察组Ⅰ类和Ⅱ类肌纤维疲劳度均高于对照组,组间差异有统计学意义(P<0.05).结论中老年POP患者盆底支持力明显低于其他妇科良性疾病患者,这不仅表现在盆底肌力方面,即便在Ⅰ类和Ⅱ类肌纤维的电生理指标方面也有所体现。     

中国成年人体力活动与肌肉重量、力量及质量的相关性分析

目的探索我国成年人体力活动、休闲静坐时间与低肌肉重量、力量和质量的关系。方法利用中国慢性病前瞻性研究(CKB)项目的第二次重复调查, 采用logistic回归分析体力活动水平、休闲静坐时间与低四肢肌肉重量指数(ASMI)、低全身肌肉重量指数(TSMI)、低肌肉力量和低肌肉质量(AMQ)的相关性。结果研究纳入24 245名研究对象, 体力活动水平为(18.3±13.8)MET-h/d, 休闲静坐时间为(4.4±1.9)h。以体力活动最低组为参照组, 高水平的体力活动与较低的低ASMI、低TSMI、低手握力和低AMQ有关, 对应的OR值(95%CI)分别为0.68(0.60～0.77)、0.66(0.58～0.75)、0.82(0.72～0.94)和0.84(0.74～0.95)。工作、交通、家务和休闲相关体力活动亚型亦与上述指标呈现不同程度的负相关。与休闲静坐时间最短组相比, 静坐时间最长组低TSMI的危险性增加(OR=1.13, 95%CI:0.99～1.30)。结论体力活动与低肌肉重量、力量和质量呈负相关, 而休闲静坐时间与低肌肉重量呈正相关。