50岁及以上人群手握力与空气污染的关联研究

目的 分析室内、外空气污染与≥50岁人群手握力的关联。方法 采用WHO全球老龄化与成人健康研究中国项目第一轮基线调查,室外空气污染以PM_2.5平均浓度（基于卫星遥感数据进行估计）进行描述,室内空气污染通过燃料和烟囱使用情况进行描述,采用两水平（个体层面和社区层面）线性模型分析室内、外空气污染与中国≥50岁人群手握力的关系。结果 共纳入13 175名≥50岁中老年人。手握力为（26.67±0.54）kg。调整性别、年龄、居住地区、文化程度、家庭经济水平、水果蔬菜摄入状况、吸烟、饮酒和体力活动后,室外PM_2.5浓度与手握力呈负相关（β=-0.23,95% CI：-0.31～-0.14）。在农村,相比使用固体燃料（非清洁）,使用清洁燃料可以提高手握力值（β=1.41,95% CI：0.36～2.46）。但在城市地区,未发现使用清洁燃料对手握力值有显著影响（β=0.19,95% CI：-0.95～1.32）。结论 室外PM_2.5与室内污染合并暴露与≥50岁人群低手握力显著相关,提示了慢性长期空气污染暴露有可能是我国中老年人较低机体功能的重要危险因素之一。     

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。     

中国10个地区成年人膳食模式与低肌肉重量、力量和质量的相关性分析

目的 探索我国成年人主要膳食模式与低肌肉重量、力量和质量的关系。方法 基于中国慢性病前瞻性研究（CKB）项目第二次重复调查,对20个食物组进行因子分析提取膳食模式。将四肢肌肉重量指数（ASMI）、全身肌肉重量指数（TSMI）、手握力和上肢肌肉质量（AMQ）分性别的最低五分位数作为判断低肌肉重量、力量和质量的截断值。采用logistic回归分析膳食模式与低肌肉重量、力量和质量的相关性。结果 提取出2种主要膳食模式,平衡膳食模式以摄入多种食物为特征,米肉膳食模式以摄入大米、肉类、家禽和鱼类较多为特点。平衡膳食模式得分高者,低TSMI、低手握力和低AMQ的危险性降低,对应OR值（95%CI）分别为0.83（0.74~0.95）、0.64（0.56~0.74）和0.82（0.72~0.93）,且关联具有线性趋势（P<0.05）;米肉膳食模式得分高者,低ASMI、低TSMI和低手握力的危险性更低,OR值（95%CI）分别为0.67（0.55~0.82）、0.69（0.56~0.85）和0.74（0.60~0.91）,且关联具有线性趋势（P<0.05）。结论 平衡膳食模式和米肉膳食模式得分较高者的肌肉重量、力量和质量更高。     

2013年中国人群血压升高对死亡和期望寿命的影响

目的 评估2013年中国不同地区、性别人群血压升高造成的死亡和期望寿命损失情况。方法 用2013年中国慢性病及其危险因素监测数据和2013年人口死亡信息登记管理系统中死因监测数据,根据比较风险评估理论,计算分性别、城乡、东中西部地区人群血压升高的人群归因分值（PAF）,进而估计血压升高造成的死亡和期望寿命损失。结果 2013年中国≥ 25岁人群SBP平均为（129.48±20.27）mmHg,血压升高[SBP高于（115±6）mmHg）]导致208.79万人死亡,占总死亡人数的22.78%;男性SBP[（131.15±18.73）mmHg]、归因于血压升高的死亡数（115.17万例）、死亡率（165.56/10万）、标化死亡率（106.97/10万）均高于女性[分别为（127.79±21.60）mmHg、93.62万例、141.99/10万和68.93/10万]。农村人群SBP[（130.25±20.66）mmHg]、归因死亡数（112.34万例）、归因死亡率（178.58/10万）和PAF（23.59%）均高于城市人群[分别为（128.58±19.77）mmHg、96.45万例、132.87/10万和21.54%];东、中、西部地区人群之间的SBP水平接近,归因死亡数、归因死亡率和PAF在中部地区最高,分别为76.58万例、179.93/10万和26.72%。2013年中国≥ 25岁人群血压升高导致的心血管病和慢性肾病死亡数为199.12万和9.66万,分别占心血管病总死亡数的52.31%和慢性肾病总死亡数的62.11%。血压升高导致疾病死亡数最多的前3种疾病是缺血性心脏病（66.56万例）、出血性脑卒中（53.31万例）和缺血性脑卒中（35.93万例）。若消除血压升高因素影响,人均期望寿命可平均增加2.86岁,其中女性增加数量高于男性（分别为3.07和2.64岁）,中部地区人群高于东西部地区人群（分别为3.48、2.56和2.58岁）,农村人群高于城市（分别为2.97和2.59岁）。结论 2013年中国人群血压升高对死亡和期望寿命造成严重影响。     

50岁及以上人群握力水平对认知功能影响的前瞻性队列研究

目的 探讨≥50岁人群握力水平对认知功能及其变化的影响。方法 数据来源于WHO“全球老龄化与成人健康研究”（SAGE）上海现场基线及两次随访调查,对其中参加全部3轮调查、排除自报脑卒中或抑郁症患者后共计3 600人进行分析,评估基线时不同水平的握力状况对认知功能及其变化的影响。认知功能通过评估词语回忆、语言流畅度及数字跨度测试结果,并采用因子分析方法进行综合,得到认知功能总分。使用线性混合效应模型分析基线握力水平对认知功能变化的影响。结果 研究对象中男性1 668人（46.3%）,女性1 932人（53.7%）,基线年龄为（61.2±8.1）岁、握力为（28.19±12.18）kg、认知功能得分为58.93±14.56。研究对象认知功能得分在随访中呈下降趋势,且不同年龄组、文化程度和家庭经济水平者,其认知功能得分随时间下降幅度不同。在调整年龄、文化程度、婚姻状况、家庭经济水平、慢性病共患情况、吸烟、饮酒、体力活动、蔬菜水果摄入和BMI等后,未发现基线握力水平与基线及第一次随访认知功能相关,但与基线握力较低者相比,握力水平较高的调查对象,其第二次随访认知功能较好,且其认知功能的下降速度较慢（男性：β=1.938,95%CI：0.644~3.231,P=0.003;女性：β=2.192,95%CI：0.975~3.409,P < 0.001;50~64岁：β=1.652,95%CI：0.646~2.659,P=0.001）。结论 较高的握力水平,能减缓认知功能的衰退,可作为中老年人认知状况的预测因素。     

上海市50岁及以上人群维生素D水平与握力的关联研究

目的 探讨上海市≥50岁人群维生素D水平与握力的关系。方法 数据来源于WHO全球老龄化与成人健康研究我国上海市2018-2019年数据,采用logistic回归模型分析维生素D水平与握力的关系,进一步按照性别、年龄及乳制品摄入情况进行分层;采用限制性立方样条曲线绘制维生素D水平与低握力的剂量-反应曲线。结果 共4 391人纳入研究,其中男性2 054人（46.8%）;年龄（67.02±8.81）岁;低握力1 421人（32.4%）;维生素D不足及缺乏分别为1 533人（34.9%）和401人（9.1%）。在调整相关混杂因素后,logistic回归分析结果显示,维生素D缺乏的人群发生低握力的风险更高（OR=1.41,95%CI：1.09~1.83）;在男性中,调整相关混杂因素后,维生素D缺乏与低握力发生风险呈显著正相关（OR=1.67,95%CI：1.12~2.50）,而女性中两者之间无关联（OR=1.30,95%CI：0.97~1.74）;在60~69岁及≥80岁年龄组中,调整相关混杂因素后,维生素D缺乏与低握力发生风险呈显著正相关（OR=1.57,95%CI：1.05~2.35;OR=2.40,95%CI：1.08~5.31）,在乳制品摄入<250 ml/d的人群中,调整相关混杂因素后,二者之间呈显著正相关（OR=1.57,95%CI：1.17~2.09）,而在乳制品摄入≥250 ml/d的人群中无明显关联。限制性立方条样图显示,低握力的发生风险可能随维生素D含量的上升而降低,但差异无统计学意义（P>0.05）。结论 维生素D水平与握力存在一定的关系,维生素D缺乏人群出现低握力的风险更高。     

中国成年人生存质量及影响因素分析

目的 了解中国成年人群生存质量及其影响因素。方法 纳入2010年中国慢性病及其危险因素监测所有调查对象共83 666名。应用问卷收集调查对象的年龄、性别、相关疾病患病情况等信息。并使用WHO生存质量测定简表(WHOQOL-BREF)测定其生存质量。采用t检验和方差分析比较不同组间各维度得分的差异。运用基于多阶段复杂抽样设计的多元线性回归模型,分析生存质量的影响因素。结果 中国成年人生理、心理、社会关系和环境4个维度的得分为73.97±13.84、66.65±14.21、65.76±14.08和56.59±15.15。年龄越大文化程度越低,4个维度的得分越低,差异有统计学意义(P<0.05);农村人群得分高于城市,已婚或同居人群得分高于其他人群,差异有统计学意义(P<0.05)。女性生理和心理两个维度的得分低于男性,差异有统计学意义(P<0.05)。除环境维度外,慢性病患病状况对其他3个维度的得分影响较大,差异有统计学意义(P<0.05)。结论 年龄、性别、城乡、文化程度、婚姻状况和慢性病患病状况是中国成年人群生存质量得分的重要影响因素。     

中国10个地区成年人跟骨骨密度的描述性分析

目的 描述中国慢性病前瞻性研究（CKB）10个地区人群跟骨骨密度的地区和人群分布差异。方法 在参与第二次重复调查的研究对象中,剔除重要指标缺失者后,分析10个地区38~87岁24 677人经定量超声骨密度仪测定的跟骨骨密度的地区和人群差异。结果 研究人群中,跟骨骨密度指标平均水平：宽带超声衰减（109.7±12.6）dB/MHz,超声声速（1 554.7±45.6）m/s,强度指数（88.3±18.8）,T值（-0.74±1.28）。城市人群跟骨骨密度高于农村;男性高于女性。跟骨骨密度随着年龄增加而降低,女性随年龄降低的幅度比男性更为明显。吸烟者、绝经后妇女的跟骨骨密度更低;常饮牛奶和/或酸奶者、高体力活动水平者的跟骨骨密度更高。结论 CKB的10个项目地区人群的跟骨骨密度存在明显的地区和人群差异。     

山西省农村地区居民血清总胆固醇水平追踪分析

目的 分析山西省733名农村居民血清TC水平的纵向变化状况。方法 以曾经参加过2002年中国居民营养与健康调查的山西省5个农村地区居民为基础,于2015年进行追踪调查,采集调查对象空腹静脉血,采用胆固醇氧化酶法测定血清TC浓度。结果 733名研究对象中,男性332名,女性401名。2002年基线调查时年龄为（42.6±9.5）岁,76.2%的男性和83.8%的女性文化程度在初中及以下。男性与女性吸烟的比例分别为65.7%和1.2%,饮酒比例分别为26.8%和4.0%,肥胖比例分别为6.3%和12.0%,中心性肥胖比例分别为27.1%和31.9%。2015年追踪调查时年龄为（55.8±9.5）岁,男性与女性吸烟比例分别为48.2%和1.5%,饮酒比例分别为49.7%和3.0%,肥胖比例分别上升至11.8%和18.2%,中心性肥胖比例分别上升至41.6%和53.6%。2002－2015年,追踪人群血清TC水平由（3.82±0.89）mmol/L上升至（4.72±0.97）mmol/L,平均上升幅度为27.2%。男性血清TC水平由（3.84±0.94）mmol/L上升至（4.54±0.93）mmol/L,女性血清TC水平由（3.81±0.84）mmol/L上升至（4.86±0.98）mmol/L,增幅分别为22.7%和30.9%。18～、30～、40～、50～59岁组的血清TC水平由（3.42±0.83）、（3.72±0.77）、（3.90±0.83）、（4.00±1.03）mmol/L上升至（4.38±1.01）、（4.79±0.92）、（4.73±0.99）、（4.76±0.96）mmol/L。各年龄组增加幅度分别为31.4%、32.1%、25.2%和22.6%。经配对t检验和方差分析,不同性别、年龄、文化程度、婚姻状况、心血管疾病家族史、吸烟、饮酒、BMI和腰围组的血清TC水平在不同年度的差异均有统计学意义（P<0.01）。结论 山西省农村居民血清TC水平纵向上升速度较快。     

中国2014年7~14岁学生血红蛋白水平及贫血状况分析

目的 了解我国7~14岁学生血红蛋白水平及贫血流行状况。方法 基于2014年全国学生体质与健康调研数据库,抽取检测了血红蛋白的7、9、12和14岁共71 130名学生作为研究对象,采用2011年WHO贫血诊断标准,了解研究对象血红蛋白水平和贫血患病率,分析我国7~14岁学生贫血流行现状。结果 2014年我国7、9、12和14岁学生血红蛋白水平分别为（129.25±11.37）g/L、（131.04±11.08）g/L、（135.02±12.12）g/L和（138.47±13.97）g/L,贫血检出率分别为9.0%、6.5%、8.6%和7.7%,其中男生为（135.49±13.33）g/L,女生为（131.38±11.67）g/L。总体贫血患病率为7.9%,其中女生（9.7%）显著高于男生（6.2%）（P<0.01）;乡村学生（8.8%）显著高于城市（7.1%）（P<0.001）。消瘦、正常、超重和肥胖学生的血红蛋白水平分别为（133.19±12.56）g/L、（133.28±12.76）g/L、（134.24±12.73）g/L和（133.79±12.16）g/L;贫血率分别为8.8%、8.3%、6.7%和5.9%,四组间差异有统计学意义（P<0.001）。结论 我国7~14岁学生贫血检出率仍较高,且在不同性别、城乡、年龄以及营养状况人群中存在差异。     

Patients With Type 2 Diabetes Show a Greater Decline in Muscle Mass,Muscle Strength,and Functional Capacity With Aging

BackgroundThe loss of muscle mass with aging reduces muscle strength, impairs functional capacity, and increases the risk of developing chronic metabolic disease. It has been suggested that the development of type 2 diabetes results in a more rapid decline in muscle mass, strength, and functional capacity.ObjectiveTo investigate the impact of type 2 diabetes on muscle mass, strength, and functional capacity in an older population.MethodsMuscle mass (DXA and muscle biopsies), strength (1-repetition maximum), functional capacity (sit-to-stand test and handgrip strength), and reaction time performance (computer task) were compared between 60 older men with type 2 diabetes (71 ± 1 years) and 32 age-matched normoglycemic controls (70 ± 1 years). Data were analyzed using ANCOVA to adjust for several potential confounders.ResultsLeg lean mass and appendicular skeletal muscle mass were significantly lower in older men with type 2 diabetes (19.1 ± 0.3 and 25.9 ± 0.4 kg, respectively) compared with normoglycemic controls (19.7 ± 0.3 and 26.7 ± 0.5 kg, respectively). Additionally, leg extension strength was significantly lower in the group with type 2 diabetes (84 ± 2 vs 91 ± 2 kg, respectively). In agreement, functional performance was impaired in the men with type 2 diabetes, with longer sit-to-stand time (9.1 ± 0.4 vs 7.8 ± 0.3 seconds) and lower handgrip strength (39.5 ± 5.8 vs 44.6 ± 6.1 kg) when compared with normoglycemic controls. However, muscle fiber size and reaction time performance did not differ between groups.ConclusionOlder patients with type 2 diabetes show an accelerated decline in leg lean mass, muscle strength, and functional capacity when compared with normoglycemic controls. Exercise intervention programs should be individualized to specifically target muscle mass, strength, and functional capacity in the older population with type 2 diabetes.     

Asian Working Group for Sarcopenia: 2019 Consensus Update on Sarcopenia Diagnosis and Treatment

Clinical and research interest in sarcopenia has burgeoned internationally, Asia included. The Asian Working Group for Sarcopenia (AWGS) 2014 consensus defined sarcopenia as “age-related loss of muscle mass, plus low muscle strength, and/or low physical performance” and specified cutoffs for each diagnostic component; research in Asia consequently flourished, prompting this update. AWGS 2019 retains the previous definition of sarcopenia but revises the diagnostic algorithm, protocols, and some criteria: low muscle strength is defined as handgrip strength <28 kg for men and <18 kg for women; criteria for low physical performance are 6-m walk <1.0 m/s, Short Physical Performance Battery score ≤9, or 5-time chair stand test ≥12 seconds. AWGS 2019 retains the original cutoffs for height-adjusted muscle mass: dual-energy X-ray absorptiometry, <7.0 kg/m² in men and <5.4 kg/m² in women; and bioimpedance, <7.0 kg/m² in men and <5.7 kg/m² in women. In addition, the AWGS 2019 update proposes separate algorithms for community vs hospital settings, which both begin by screening either calf circumference (<34 cm in men, <33 cm in women), SARC-F (≥4), or SARC-CalF (≥11), to facilitate earlier identification of people at risk for sarcopenia. Although skeletal muscle strength and mass are both still considered fundamental to a definitive clinical diagnosis, AWGS 2019 also introduces “possible sarcopenia,” defined by either low muscle strength or low physical performance only, specifically for use in primary health care or community-based health promotion, to enable earlier lifestyle interventions. Although defining sarcopenia by body mass index–adjusted muscle mass instead of height-adjusted muscle mass may predict adverse outcomes better, more evidence is needed before changing current recommendations. Lifestyle interventions, especially exercise and nutritional supplementation, prevail as mainstays of treatment. Further research is needed to investigate potential long-term benefits of lifestyle interventions, nutritional supplements, or pharmacotherapy for sarcopenia in Asians.     

Associations of Sarcopenia and Sarcopenic Obesity With Metabolic Syndrome Considering Both Muscle Mass and Muscle Strength

Objectives:

We investigated the associations of sarcopenia-defined both in terms of muscle mass and muscle strength-and sarcopenic obesity with metabolic syndrome.

Methods:

Secondary data pertaining to 309 subjects (85 men and 224 women) were collected from participants in exercise programs at a health center in a suburban area. Muscle mass was measured using bioelectrical impedance analysis, and muscle strength was measured via handgrip strength. Sarcopenia based on muscle mass alone was defined as a weight-adjusted skeletal muscle mass index more than two standard deviations below the mean of a sex-specific young reference group (class II sarcopenia). Two cut-off values for low handgrip strength were used: the first criteria were <26 kg for men and <18 kg for women, and the second criteria were the lowest quintile of handgrip strength among the study subjects. Sarcopenic obesity was defined as the combination of class II sarcopenia and being in the two highest quintiles of total body fat percentage among the subjects. The associations of sarcopenia and sarcopenic obesity with metabolic syndrome were evaluated using logistic regression models.

Results:

The age-adjusted risk ratios (RRs) of metabolic syndrome being compared in people with or without sarcopenia defined in terms of muscle mass were 1.25 (95% confidence interval [CI], 1.06 to 1.47, p=0.008) in men and 1.12 (95% CI, 1.06 to 1.19, p<0.001) in women, which were found to be statistically significant relationships. The RRs of metabolic syndrome being compared in people with or without sarcopenic obesity were 1.31 in men (95% CI, 1.10 to 1.56, p=0.003) and 1.17 in women (95% CI, 1.10 to 1.25, p<0.001), which were likewise found to be statistically significant relationships.

Conclusions:

The associations of sarcopenia defined in terms of muscle mass and sarcopenic obesity with metabolic syndrome were statistically significant in both men and women. Therefore, sarcopenia and sarcopenic obesity must be considered as part of the community-based management of non-communicable diseases.     

Daily Supplementation With Whey,Soy, or Whey-Soy Blended Protein for 6 Months Maintained Lean Muscle Mass and Physical Performance in Older Adults With Low Lean Mass

BackgroundFew studies have investigated the effect of long-term protein supplementation alone on muscle health in older adults with low lean mass.ObjectiveTo determine the effect of whey, soy or whey-soy blended protein supplementation on lean muscle mass and physical performance in older adults with low lean mass.DesignA 4-arm randomized controlled trial.Participants/settingChinese older adults (n = 123, 65-79 years) with low lean mass (appendicular skeletal muscle index < 7.0 kg/m² in men and < 5.4 kg/m² in women) living in the urban area of Guangzhou participated between October 2015 and June 2016.InterventionParticipants were randomly assigned to receive approximately 16 g/d of whey, soy, or whey-soy blend protein or maintained habitual diets in control group for 6 months.Main outcome measuresLean mass, handgrip strength, and physical performance (gait speed, chair stand test, and Short Physical Performance Battery) were assessed at baseline and 6 months.Statistical analysesTwo-way analysis of variance with the main effects of treatment and time and treatment × time interaction and analysis of covariance was used to determine differences in outcomes.ResultsAppendicular skeletal muscle index, lean mass, percent lean mass in legs and appendicular areas, gait speed, and Short Physical Performance Battery score were maintained in the treatment groups and decreased in the control group, resulting in significant reduction in these variables from baseline in the control compared with treatment groups (all P < .01; percent differences between treatment and control groups ranged from 80% to 156%). The chair stand test time at month 6 decreased from baseline in the treatment groups and increased in the control group, resulting in a significant increase in the control compared with treatment groups (all P < .01; percent differences between treatment and control groups ranged from 132% to 155%). Handgrip strength remained unchanged. There were no significant differences in outcomes among treatment groups.ConclusionsSupplementation with whey, soy, or whey-soy blended protein for 6 months equally maintained lean muscle mass and physical performance in older adults with low lean mass.     

Comparisons of Sarcopenia Defined by IWGS and EWGSOP Criteria Among Older People: Results From the I-Lan Longitudinal Aging Study

ObjectiveTo compare clinical characteristics of sarcopenia defined by the International Working Group on Sarcopenia (IWGS) and European Working Group on Sarcopenia in Older People (EWGSOP) criteria among older people in Taiwan.DesignA prospective population-based community study.SettingI-Lan County of Taiwan.ParticipantsA total of 100 young healthy volunteers and 408 elderly people.InterventionNone.MeasurementsAnthropometry, skeletal muscle mass measured by dual x-ray absorptiometry, relative appendicular skeletal muscle index (RASM), percentage skeletal muscle index (SMI), 6-meter walking speed, and handgrip strength.ResultsThe prevalence of sarcopenia was 5.8% to 14.9% in men and 4.1% to 16.6% in women according to IWGS and EWGSOP criteria by using RASM or SMI as the muscle mass indices. The agreement of sarcopenia diagnosed by IWGS and EWGSOP criteria was only fair by using either RASM or SMI (kappa = 0.448 by RASM, kappa = 0.471 by SMI). The prevalence of sarcopenia was lower by the IWGS definition than the EWGSOP definition, but it was remarkably lower by using RASM than SMI in both criteria. Overall, sarcopenic individuals defined by SMI were older, had a higher BMI but similar total skeletal muscle mass, and had poorer muscle strength and physical performance than nonsarcopenic individuals. However, by using RASM, sarcopenic individuals had less total skeletal muscle mass but similar BMI than nonsarcopenic individuals. Multivariable logistic regression showed that age was the strongest associative factor for sarcopenia in both IWGS and EWGSOP criteria. Obesity played a neutral role in sarcopenia when it is defined by using RASM, but significantly increased the risk of sarcopenia in both criteria by using SMI.ConclusionThe agreement of sarcopenia defined by IWGS and EWGSOP was only fair, and the prevalence varied largely by using different skeletal muscle mass indices. Proper selections for cutoff values of handgrip strength, walking speed, and skeletal muscle indices with full considerations of gender and ethnic differences were of critical importance to reach the universal diagnostic criteria for sarcopenia internationally.     

Physical activity, protein intake, and appendicular skeletal muscle mass in older men.

BACKGROUND: Aging is associated with physical inactivity, low energy intake, and loss of skeletal muscle mass. It is not clear whether regular physical activity and adequate dietary protein intake can attenuate the loss of skeletal muscle mass. OBJECTIVE: We hypothesized that the maintenance of physical activity and dietary protein intake would attenuate the age-related decline in total appendicular skeletal muscle mass. DESIGN: Total appendicular skeletal muscle mass was determined by dual-energy X-ray absorptiometry in 44 healthy, older white men aged 49-85 y. Physical activity level was determined by using a uniaxial accelerometer over a 9-d period. Dietary protein intake was estimated from a 3-d food record. RESULTS: Aging was inversely associated with total appendicular skeletal muscle mass in older men (r = -0.43; slope: -0. 119 +/- 0.039 kg/y; P < 0.01). An effect of age on appendicular skeletal muscle mass persisted after standing height and physical activity were controlled for (r = -0.34; slope: -0.120 +/- 0.052 kg/y; P = 0.03). Furthermore, an effect of age on appendicular skeletal muscle mass persisted after standing height and dietary protein intake per kilogram body mass was controlled for (r = -0.41; slope: -0.127 +/- 0.045 kg/y; P < 0.01). CONCLUSIONS: Maintaining regular physical activity and adequate protein intake may not offset the age-related loss of appendicular skeletal muscle mass in older men. Prospective studies are needed to confirm these results and to determine whether anabolic physical activity (eg, strength training) can attenuate the age-related loss of muscle mass in the elderly.     

Walking Speed and Muscle Mass Estimated by the D3-Creatine Dilution Method Are Important Components of Sarcopenia Associated With Incident Mobility Disability in Older Men: A Classification and Regression Tree Analysis

ObjectivesIt is unknown whether muscle mass measured by the D₃-creatine dilution method is a superior predictor of incident mobility disability than traditional components of sarcopenia definitions (including grip strength, walking speed, appendicular lean mass). The objective of this study was to determine the relative importance of strength; physical performance; and lean, fat, and muscle mass in predicting incident mobility disability in older men.DesignLongitudinal cohort study of participants in the Osteoporotic Fractures in Men (MrOS) study.Setting and ParticipantsMuscle mass was assessed by D₃-creatine dilution in 1098 men (aged 83.7 ± 3.7 years). Participants also completed anthropomorphic measures, 6-m walking speed (m/s), grip strength (kg), chair stands (seconds), and dual x-ray absorptiometry appendicular lean mass (ALM), and total body fat percentage. Men self-reported incident mobility disability defined by the development of an inability to complete at least one of walking 2-3 blocks, climbing 10 steps, or carrying 10 lb over 2.2 ± 0.3 years.MethodsClassification and regression tree analysis was conducted to determine relative variable importance and algorithm cutpoints for predicting incident mobility disability. Given the proximity of walking speed with the primary outcome (mobility disability), analyses were conducted with and without walking speed.ResultsWalking speed followed by D₃Cr muscle mass/weight were the most important variables (variable importance: 53% and 12%, respectively) in the prediction of self-reported incident mobility disability. D₃Cr muscle mass was the most important variable in predicting incident mobility disability when walking speed was excluded, followed by chair stands (variable importance: 35% and 33%, respectively). Body fat percentage, ALM, and grip strength were not selected as nodes in either analysis and had low or negligible variable importance.Conclusions and ImplicationsThis study has provided valuable insights into the importance of different variables in predicting incident mobility disability in older men. Muscle mass by D₃Cr may be a key tool for predicting the risk of negative outcomes in older adults in the future, particularly in post-acute and long-term care settings.     

Cumulative and Incremental Value of Sarcopenia Components on Predicting Adverse Outcomes

ObjectivesTo examine the incremental value of sarcopenia components, following the diagnosis algorithm of the Asian consensus, on predicting adverse outcomes.DesignA prospective cohort study.Setting and ParticipantsFour thousand community-dwelling Chinese adults (2000 men) aged 65 years or older in Hong Kong (mean age = 72.5 ± 5.2).MethodsSARC-F was used as the initial predictor of 9 adverse outcomes. In step 2, muscle strength (ie, grip strength) and/or functions (ie, chair-stand, walking speed) were added on top of SARC-F. In step 3, height-, weight-, and body mass index–adjusted appendicular skeletal mass (ASM) measured by dual-energy x-ray absorptiometry (DXA) were added separately to all models formulated in step 2. The areas under the receiver operating characteristic curve (AUCs) were calculated for the models formulated in all steps. Each cumulative AUC would be compared with the AUC yielded in the previous step to evaluate the incremental prediction value.ResultsOn top of SARC-F, assessing grip strength, walking speed, or 5-time chair-stand significantly increased the AUC for most adverse outcomes. In particular, assessing both grip strength and gait speed yielded the highest AUC in most prediction models (AUC = 0.539-0.770) and significantly increased the AUC for all outcomes except for recurrent falls. With both muscle strength and function assessed, adding ASM failed to significantly increase the AUC except for 2 conditions. In the 2 conditions, however, a higher height-adjusted ASM was associated with a higher risk of having worsened physical limitations [OR 1.25, 95% confidence interval (CI) 1.12-1.40] and decline in the physical quality of life (OR 1.18, 95% CI 1.06-1.33) in women.Conclusions and ImplicationsAssessing muscle strength and function provides additional power to predict adverse outcomes on top of SARC-F. Further assessment of muscle mass with DXA provides no extra constructive value ito bettering the prediction regardless of the adjustment parameters. Alternative technologies to measure muscle mass might be required.     

Sarcopenia and Appendicular Muscle Mass as Predictors of Impaired Fasting Glucose/Type 2 Diabetes in Elderly Women

Elderly women exhibit a high risk of type 2 diabetes (T2D), but no definitive data exist about the possible role of postmenopausal increases in visceral adiposity, the loss of lean body mass, or decreases in the sum of the lean mass of arms and legs (appendicular skeletal muscle mass (ASMM)). This retrospective, longitudinal study investigated whether body composition (bioelectrical impedance analysis) predicted the development of impaired fasting glucose (IFG) or T2D in a cohort of 159 elderly women (age: 71 ± 5 years, follow-up: 94 months) from southern Italy (Clinical Nutrition and Geriatric Units of the “Mater Domini” University Hospital in Catanzaro, Calabria region, and the “P. Giaccone ”University Hospital in Palermo, Sicily region). Sarcopenia was defined in a subgroup of 128 women according to the EWGSOP criteria as the presence of low muscle strength (handgrip strength <16 kg) plus low muscle mass (reported as appendicular skeletal muscle mass <15 kg). Participants with a low ASMM had a higher IFG/T2D incidence than those with a normal ASMM (17% vs. 6%, p-adjusted = 0.044); this finding was independent of BMI, fat mass, waist circumference, and habitual fat intake (OR = 3.81, p = 0.034). A higher incidence of IFG/T2D was observed in the subgroup with sarcopenia than those without sarcopenia (33% vs. 7%, p-adjusted = 0.005) independent of BMI and fat mass (OR = 6.75, p = 0.007). In conclusion, this study demonstrates that elderly women with low ASMM had a higher probability of developing IFG/T2D. Further studies are needed to confirm these results in men and in other age groups.