生物电阻抗分析法评估血液透析患者干体重

目的利用生物电阻抗频谱分析法（bioimpedence analysis,BIA）了解维持性血液透析（hemodialysis,HD）患者的体液分布,同时了解其对血压的影响。方法选择苏州大学附属第一医院血透中心维持性血液透析患者85例,透析时间均大于3个月,应用BIA分别测定透析前后细胞内液（intra—cellular water,ICW）、细胞外液（extra—cellular water,ECW）,并分别计算占体重的百分比（ECW％、ICW％）。另外选取83名性别、年龄、体重匹配的正常个体作为对照组。结果HD患者透前ECW％明显高于同性别正常对照（P〈0．01）,透后较透前明显降低（P〈0．05）,透后接近正常人群水平（P〉0．05）。HD患者ICW％透析后降低,但与透前相比无明显差异,且与同性别正常对照组亦无明显差异（P〉0．05）;HD患者高血压组透前、透后均高于正常对照（P〈0．05）;HD患者正常血压组透前高于正常对照（P〈0．05）。透后与正常对照组无显著差异;HD患者低血压组透前与正常对照无差异（P〉0．05）,透后低于正常对照组（P〈0．05）。结论透析患者的体液分布存在明显异常,主要表现为透析前ECW％增加。透析脱水主要来自ECW,对ICW无明显影响。利用多频生物电阻抗测定透析后ECW％可用于评价HD患者干体重,但仍需进一步研究。     

生物电阻抗评估调整干体重对血液透析患者血压和心功能的影响

目的观察通过多频生物电阻抗评估调节不同干体重对血液透析（HD）高血压患者血压和心脏功能的影响。 方法选择泰安市中心医院肾内科2017年1月至2018年3月间维持性HD患者96例为HD组,选择106名健康体检者为健康对照组,测定各组细胞内液（ICW）、细胞外液（ECW）、细胞外液/总体液量（ECW/TBW）等生物电阻抗值进行比较。选取透析后生物电阻抗高于健康对照组的HD患者79例作为干体重调整组（DWAG）,根据生物电阻抗调整干体重3个月,分别于调整前后检测DWAG组患者透析后的体质量、血压、多频生物电阻抗及心脏彩超等指标。采用t检验比较HD组与健康对照组一般资料差异,采用单因素方差分析比较健康对照组与HD组患者透析前后ICW、ECW、ECW/TBW差异,DWAG患者干预前后的相关指标比较采用配对t检验。 结果HD组患者透析前后ICW、ECW、ECW/TBW均高于健康对照组［（27.49±3.96）L vs （26.36±3.93）L vs （23.91±4.92）L;（18.42±2.66）L vs （17.07±3.03）L vs （15.99±4.23）L;（41.03±2.03）% vs （39.73±3.64）% vs （37.59±4.63）%］,差异均具有统计学意义（t=5.660、4.829、6.717,P均<0.001;t=3.884、2.067、3.626,P<0.001、=0.040、<0.001）;与透析前相比较,透析后HD组患者的电阻抗值较透析前显著下降,差异具有统计学意义（t=1.984,P=0.049;t=3.281,P=0.001;t=3.056,P=0.003）。干体重调整后DWAG患者的ICW、ECW、ECW/TBW低于调整前［（26.11±2.97）L vs （28.09±4.17）L;（17.01±1.98）L vs （19.06±2.77）L;（38.97±3.19）% vs （40.49±2.57）%］,差异具有统计学意义（t=7.502,9.406,5.655,P均<0.001）;DWAG患者调整后收缩压和舒张压也分别较调整前下降［（148.52±7.31）mmHg vs （157.14±9.97）mmHg;（87.67±12.84）mmHg vs （92.30±11.71）mmHg］,差异具有统计学意义（t=8.641,4.193,P均<0.001）。心功能检测显示DWAG组患者LAD、LVDd、IVSd、LVPWd分别较调整前下降［（43.23±5.90）mm vs （43.47±5.82）mm;（48.76±6.42）mm vs （49.58±5.39）mm;（10.29±1.03）mm vs （10.45±0.79）mm;（10.53±1.04）mm vs （10.60±0.92）mm］,差异具有统计学意义（t=3.128,P=0.0002;t=2.251,P=0.027;t=2.560,P=0.012;t=2.221,P=0.029）,而LVEF较调整前提高［（64.63±4.47）% vs （63.51±3.40）%］,差异具有统计学意义（t=-3.569,P=0.001）。 结论参照多频生物电阻抗调整患者干体重可显著降低HD患者的血压,改善患者的心功能。     

应用生物电阻抗分析维持性血液透析患者体液分布特点

目的 应用多频生物电阻抗分析法研究维持性血液透析(MHD)患者透析前后体液分布特点。方法 选取临床干体质量达标的MHD患者86例,并选取同质的健康人群258例作为对照组,运用多频人体成分分析仪测量透析前后体质量(W)、身体总水(TBW)、细胞内液(ICW)、细胞外液(ECW),计算透析前后ICW/W、ICW/TBW、ICW/H2、ECW/W、ECW/TBW、ECW/H2以及ICW/ECW。结果 MHD患者透析前ECW/H2明显高于对照组[男(4.77±0.58 vs.4.52±0.36),P0.01;女(4.16±0.47 vs.3.97±0.32),P0.01],透后接近对照组透析前后ICW/TBW,ICW/ECW及ECW/TBW之间,以及与对照组比较均无明显差别。ICW/H2表现不完全一致,男性患者透析前ICW/H2高于对照组[男(9.42±1.26 vs.9.03±0.75,(P0.05)],透后接近对照组[男(8.83±1.15 vs.9.03±0.75,(P0.05)],女性患者透析前明显高于透后[女(8.07±0.79 vs.7.52±1.49,P0.05]。结论 1维持性血液透析患者体内潴留的水分并非主要分布于细胞外液,而是同时分布于细胞内液和细胞外液;透析超滤脱水不仅影细胞外液,同时影响细胞内液。2 ECW/H2和ICW/H2透析后明显下降,接近正常人,有可能成为评价维持性血液透析患者水负荷状态的一个指标,需要进一步研究。     

右小腿多频生物电阻抗评估老年血液透析患者干体重的临床研究

目的：探讨右小腿多频生物电阻抗评估老年血液透析患者干体重的临床价值。方法研究2013年1月至2014年9月行规律血液透析的46例老年患者,应用多频生物电阻抗分析仪测定其透析前后细胞外液量（ ECW）作为容量负荷指标,并观察调整干体重前后患者居家收缩压（Home - SBP）、服用降压药物限定日剂量（DDD）等情况。结果未控制高血压组男性和女性患者透析前、透析后的体重标准化的 ECW（ECW％）均显著高于对照组（ P <0.05）;正常血压组男性和女性患者透析前 ECW％均高于对照组（ P <0.05）,但透析后的 ECW％和对照组之间的差异均无显著性（ P >0.05）;未控制高血压组男性和女性患者透析前、透析后的 ECW％与正常血压组比较,差异均有显著性（ P <0.05）。ECW％增高患者降低干体重后透析后 ECW％、Home - SBP 和降压药用量均显著低于降体重前（ P <0.05）。结论右小腿多频生物电阻抗能够有效评估老年血液透析患者干体重。     

应用生物电阻抗法评估血液透析患者NT-proBNP差值与体液成分的关系

目的应用多频生物电阻抗的方法测量维持性血液透析(maintenance hemodialysis,MHD)患者透析前、后体液分布情况,再与透析前、后NT-proBNP的差值作比较,来探讨NT-proBNP差值与体液分布的关系。方法应用多频生物电阻抗测定84例透析患者透析前后MHD患者的体内水含量及分布,同时抽血测定其NT-proBNP值。计算透析前、后N末端脑钠肽前体(N-termind pro-brain natriuretic peptide,NT-proBNP)差值。应用相关分析各个指标之间的关系。结果透析前血清NT-proBNP与透析前身体水分总量(total water,TBW)、细胞外液(extracellular water,ECW)、细胞内液(intracellular water,ICW)、ECW/TBW无明显的相关性。透析后血清N末端脑钠肽前体(N-terminal pro-brain natriuretic peptide,NT-proBNP)与透析后ECW/TBW(r=0.251,P=0.025)呈正相关,与ICW呈显著的负相关(r=-2.333,P=0.037)。相关分析显示MHD患者透析前、后血清NT-proBNP的差与ECW(r=-0.235,P=0.036)、ECW/TBW(r=-0.252,P=0.024)、ECW/ICW(r=-0.228,P=0.042)呈显著负相关,与TBW(r=-0.121,P=0.284)和ICW(r=0.018,P=0.871)无明显的相关性。结论 NT-proBNP差值与MHD患者透析前后患者体液分布有较好的一致性,可以用于评价MHD患者的容量负荷。     

生物电阻抗技术监测血液透析时细胞外液量及其临床价值

目的：采用生物电阻抗技术监测血液透析过程中患者细胞外液量（ECV）的变化,以指导调整透析患者于体质量,透预防析中低血压或难治性高血压。方法：100例维持性血透患者,透析时间4～112（58．67±31．54）个月,根据临床表现分为正常血压组、症状性低血压组和难治性高血压组。采用生物电阻抗仪测定患者血透时的细胞外液量（ECV）％、细胞内液量（ICV）％、ECV／ICV的变化。观察透析过程中患者心率、呼吸、血压、超滤量和超滤率的变化,比较3组各项指标的变化,并分析各参数同的相互关系。结果：透析过程中随超滤量增加,超滤脱水率逐渐下降,3组中症状性低血压组超滤量最大,超滤率最高;难治性高血压组超滤量最小,超滤率最低。透析前3组ECV％、ECV／ICV均高于正常对照组,其中难治性高血压组最高。透析后3组ECV％、ECV/ICV均。显著下降,但难治性高血压组仍显著高于正常对照组。透析后3组ICV％显著升高,但仍低于正常对照组。透析时症状性低血压组随ECV下降,平均动脉压（MAP）明显下降,两者呈显著正相关（r=0．914,P〈0．001）。难治性高血压组随ECV下降,MAP逐渐升高,两者呈现负相关（r=-0．782,P=0．035）。对5例低血压和7例高血压患者在生物电阻抗监测ECV的指导下分别上调或下调干体质量后血压得到有效控制。结论：生物电阻抗监测ECV有助于指导调整干体质量,确定合适的超滤量,预防透析中低血压和控制高血压。     

应用生物电阻抗法评估维持性血液透析患者透析不同时间点血压与体液分布的关系

目的应用多频生物电阻抗方法测量维持性血液透析(maintenance hemodialysis,MHD)患者透析前后体液的情况并与透析不同时间点血压进行比较,来探讨透析各时间点血压的意义。方法应用人体成分分析仪测定74例透析患者透析前后体内液体分布,同时记录透析前后不同时点血压的数值。应用Spearman相关分析,分析血压和体液分布的关系。结果 (1)透析前诊室收缩压最高,之后逐渐降低,透析3h血压最低。透析结束30min后收缩压升高,具体数值介于透析0h和透析1h之间;(2)总体水含量(total body water,TBW)(r=0.248,P=0.033)、细胞外液(extracellular water,ECW)(r=0.251,P=0.031)、细胞内液(Intracellular water,ICW)(r=0.233,P=0.046)和水负荷(overhydration,OH)(r=0.233,P=0.046)与透析2h的收缩压存在明显的相关性;透析前TBW(r=0.305,P=0.008)、ECW(r=0.244,P=0.036)、ICW(r=0.265,P=0.023)和OH值(r=0.218,P=0.023)与透析后30min的舒张压存在明显的相关性;透析前TBW、ECW、ICW和OH值与诊室血压、平卧5min血压、透析0、1h血压没有明显的相关性,与透析第2h舒张压没有明显的相关性。(3)透析后TBW(r=0.286,P=0.014)、ECW(r=0.283,P=0.015)、ICW(r=0.239,P=0.040)和OH值(r=0.284,P=0.014)与透析后30min舒张压存在明显的相关性;透析后TBW(r=0.230,P=0.049)、ECW(r=0.240,P=0.039)和OH值(r=0.380,P=0.001)与透析后30min的收缩压存在明显的相关性;透析后TBW(r=0.321,P=0.005)、ECW(r=0.287,P=0.013)和ICW(r=0.264,P=0.023)与透析2h收缩压存在明显的相关性。结论 (1)使用透析前诊室血压、平卧5min以及透析0h的血压来判断透析患者的容量负荷误差较大。(2)应该更加关注透析2h的血压情况,以便更加及时、准确地调节超滤。(3)透析后30min的血压可以更好的反应患者的容量负荷。     

运用直接节段多频生物电阻抗技术评估血液透析患者肌肉质量

目的探讨运用直接节段多频生物电阻抗分析方法(direct segmental multi-frequency bioimpedance analysis,DSM-BIA)在维持性血液透析患者干体质量评估中的应用价值。方法选择40例维持性血液透析患者,采用DSM-BIA测定其透析前后细胞外液量(ECW)和身体水分总量(total body water,TBW)作为观察患者容量负荷的指标,观察患者在干体质量前后居家收缩压(home-SBP),测定患者透析前后的N末端脑钠肽前体(NT-proBNP)含量以及肌少症检出率。结果与维持性血液透析前比较,男、女患者在维持性血液透析后的血NT-proBNP水平、home-SBP水平、TBW、ECW/TBW以及肌少症检出率明显降低(P0.05);男、女患者以上指标比较,差异无统计学意义(P0.05)。结论直接节段多频生物电阻抗分析在维持性血液透析患者干体质量评估中有较好的应用价值。     

应用生物电阻抗法对临床评估达干体质量的血液透析患者的水负荷的研究

目的 应用生物电阻抗分析法评估正常人群和临床评估达干体质量的透析患者体内水的含量及其分布特点,并比较在两组人群之间的差异.方法 选石家庄市区健康志愿者240例作为对照组(A组),男120例,年龄(43.4±10.2)岁,记为A1组,女120例,年龄(44.7±13.5)岁,记为A2组;病例组(B组)选自2008年1～12月在我院血液净化中心临床法评估均达到干体质量的维持性血液透析的患者40例,男20例,年龄(45.6±10.8)岁,记为B1组,女20例,年龄(43.7±13.9)岁,记为B2组;所有患者均处于肾疾病的终末期,平均透析时间(20.0±7.2)个月.生物电阻抗测定并记录A组、B组透析前、B组透析后的总水含量占体质量的百分比(TBW%)、细胞外液占总水含量的百分比(ECW/TBW%)、细胞内液占总水含量的百分比(ICW/TBW%),与A组数据进行比较.同时密切观察并记录患者透析中的主诉、症状、血压、心率等.结果 B1组TBW%透析前与A1组比较(71.83±7.83)% vs(60.53±4.98)%和透析后与A1组比较(70.63±7.43)% vs(60.53±4.98)%,差异均有统计学意义(P<0.05),ECW/TBW%、ICW/TBW%则与A1组比较差异无统计学意义.②B2组TBW%透析前与A2组比较(71.28±10.38)% vs(59.07±6.73)%(P<0.05)和透析后与A2组比较(69.41±8.17)% vs(59.07±6.73)%(P<0.05),差异均有统计学意义,ECW/TBW%、ICW/TBW%则与A2组比较差异无统计学意义.结论 ①透析前患者TBW%高于正常人,增加的水在细胞内液和细胞外液是同步增加的.②透析后临床法评估达到干体质量的患者,用生物电阻抗测定TBW%仍高于正常人,说明临床评估干体质量的方法粗略,不精确.③生物电阻抗分析法通过对人体内水含量及其分布的测定,对干体质量的评估比临床法更准确.     

人体成分监测仪在血液透析患者干体重评估中的意义

目的：研究人体成分监测仪（BCM）在血液透析患者干体重评估中的意义。方法选择126例在我院血液透析中心透析的患者作为病例组,选择40例在我院体检中心体检健康的志愿者作为对照组,两组分别行BCM监测。记录测得的总体液量（TBW）、细胞外液（ECW）、细胞内液（ICW）、水负荷（OH）,记录患者透析脱水量、上机前血压以及对照组血压。利用ROC曲线分析OH值评估干体重的准确性,Logistic回归分析影响OH值的因素。结果（1）OH值与脱水量呈正相关（r＝0.462,P＜0.001）。（2）OH值评估干体重ROC曲线下面积（AUC）为0.877,当取3.30 L临界值时,灵敏度为0.909,特异性为0.833。（3）ECW、SBP是影响OH值的关键因素（P＜0.05）,且影响程度ECW＞SBP。结论 BCM可客观地监测透析患者体内多余水分,对干体重的评估有一定的意义。     

非乙醇性脂肪肝病患者身体成分及其危险因素分析

目的探讨非乙醇性脂肪肝病(NAFLD)患者与正常人群身体成分的差异及NAFLD的危险因素。方法选择40~69岁NAFLD患者172例,179名体检健康者(对照组);分别测量两组的身体成分和血生化指标。结果 NAFLD组细胞内液百分比、细胞外液百分比(ECW%)、蛋白质百分比、无机盐百分比、细胞外液与细胞内液比及高密度脂蛋白胆固醇均低于对照组(P0.05),而体脂肪百分比、体质量指数、腰围、臀围、腰臀比(WHR)及内脏脂肪面积、空腹血糖、总胆固醇、三酰甘油(TG)、极低密度脂蛋白胆固醇、低密度脂蛋白胆固醇均高于对照组,差异有统计学意义(P0.05)。Logistic回归分析显示,WHR、ECW%、TG与NAFLD具有相关性。结论 NAFLD患者的人体成分与健康人相比存在差异,代谢紊乱明显;NAFLD的发生可能与腹型肥胖、细胞外液百分比减少及高三酰甘油血症存在一定的关系。     

国产电极片可代替原装电极片用于体表生物电阻抗法细胞外液测量

目的探讨是否可以使用国产电极片代替原装电极片用于生物电阻抗法测量细胞外液(extracellular water,ECW)和细胞内液(intracellular water,ICW)。方法选择12例健康志愿者和23例维持性血液透析(maintenance hemodialysis,MHD)患者。受试者平卧5min后,使用Xitron体表生物电阻抗频谱分析仪测量不同频率下的电阻和电抗。先使用原装电极片测量一次,然后再用国产电极片测量1次。健康志愿者接受1次测量;MHD患者于血液透析前后分别进行一次测量。使用Xitron公司提供的软件计算ECW和ICW,用配对t检验及Bland-Altman作图分别比较两种测量方法获得的ECW和ICW的差异,以P0.05为差异有统计学意义,如果两种方法的差值的绝对值小于0.5L,则认为可用国产电极片代替原装电极片。结果原装电极片测量ECW(ECW-C)为(15.41±4.53)L,国产电极片ECW(ECW-Y)为(15.18±4.46)L;原装电极片测量ICW(ICW-C)为(17.87±6.03)L,国产电极片ICW(ICW-Y)为(19.93±6.09)L。配对t检验和Bland-Altman图上ECW-Y与ECW-C的差值为(-0.23±0.43)L;ICW-Y与ICW-C差值为(2.06±3.05)L。结论国产电极片可以代替原装电极片用于ECW测量,但不能用于ICW测量。     

The relationship between bioimpedance analysis, haemodynamic parameters of haemodialysis, biochemical parameters and dry weight

Adequate fluid management plays an important role in the treatment of haemodialysis patients and the assessment of dry weight is important for efficient therapy. Fluid volume parameters were assessed in adults undergoing haemodialysis for end-stage renal disease, using whole-body multifrequency bioimpedance analysis (BIA), and their relationship to haemodynamic and biochemical parameters of haemodialysis was evaluated. Ultrafiltration volume was correlated with age, sodium, haemoglobin, extracellular water (ECW)/total body water (TBW) ratio and ECW/intracellular water (ICW) ratio. The ECW/TBW ratio was correlated with age, body mass index, dry weight, predialysis systolic and diastolic blood pressure, and ECW/total body weight ratio. The ECW/ICW ratio correlated with age, dry weight, TBW, albumin, adequacy of dialysis and urea removal ratio. The study demonstrated a close relationship between bioimpedance-derived fluid volume parameters and the haemodynamic and biochemical parameters of haemodialysis. It is concluded that multifrequency whole-body BIA may have clinical value in the estimation of dry weight and other haemodynamic parameters of haemodialysis and so may protect patients from the risks associated with under- or over-hydration.     

Blood pressure, volume, and sodium control in an automated peritoneal dialysis population.

OBJECTIVES: To examine the control of blood pressure and volume, and the role of sodium removal in a single, large, contemporary, automated peritoneal dialysis (APD) population where icodextrin is used liberally and there is a policy to avoid long duration glucose-based daytime dwells. DESIGN: Observational cross-sectional study. SETTING: A university hospital. PATIENTS: 56 APD patients, with a mean duration on peritoneal dialysis of 1.9 years; 50% were prescribed icodextrin. MAIN OUTCOME MEASURES: Blood pressure, extracellular water volume (ECW)-to-intracellular water volume (ICW) ratio, and total (peritoneal and urinary) sodium removal. RESULTS: Sodium Removal: Mean total sodium removal, while low at 102.9 +/- 64.6 mmol/day, showed a wide range, with 41% having a sodium removal of >120 mmol/day. Total sodium removal correlated with total body water, ECW, and ICW (p < 0.001, p < 0.001, p < 0.025, respectively), as well as with height and weight (p < 0.06, p < 0.01 respectively). On multivariate analysis, only ultrafiltration volume and urine volume were significantly associated with total sodium removal (r(2) = 0.67, p < 0.0001 for both). There was also a correlation between sodium removal and urea nitrogen appearance (r(2) = 0.31, p < 0.001), with urea nitrogen appearance in turn being closely correlated with ICW (p < 0.001). Volume Status: The ECW/ICW ratio was 0.88 +/- 0.17, which was not significantly different to that found in hemodialysis patients without clinical evidence of fluid overload, either predialysis (0.96 +/- 0.16) or postdialysis (0.92 +/- 0.16); p = 0.07 and 0.36 respectively. Blood Pressure: Mean +/- standard deviation systolic blood pressure (BP) was 111.9 +/- 18.2 mmHg and diastolic BP was 63.3 +/- 11.9 mmHg, with only 4 (7%) patients having a systolic BP > 140 mmHg and 1 (2%) having a diastolic BP > 80 mmHg. Median number of antihypertensives was 1 per day. Blood pressure control and ECW/ICW ratio were similar in those with sodium removal >120 mmol/day compared to those with sodium removal < or =120 mmol/day (p = 0.39 for SBP, p = 0.70 for diastolic BP, p = 0.24 for ECW/ICW). CONCLUSIONS: We have shown that good blood pressure and volume control is achievable in a large contemporary APD population with liberal use of icodextrin and avoidance of long daytime glucose-based dwells. Neither low nor high sodium removal was associated with more frequent hypertension or volume expansion.     

Body composition and water compartment measurements in boys with Duchenne muscular dystrophy

OBJECTIVE: Duchenne muscular dystrophy (DMD) patients have a lower percentage of total body water and higher extracellular water to intracellular water (ECW/ICW) ratio compared with normal subjects. However, it is not known whether this is due to increased fat mass or a decreased amount of ICW in muscle cells in DMD patients. The purpose of this study was to (1) determine the effect of increased fat mass and decreased lean mass on the ECW to ICW ratio in DMD patients and to (2) determine the validity of multifrequency bioelectrical impedance analysis (MFBIA) in assessing body composition in DMD patients. DESIGN: This study has a quasi-experimental, comparative design using nonequivalent groups. A total of 46 boys ranging from 6 to 13 yrs of age participated in this study. There were 12 nonobese able-bodied controls, 19 obese able-bodied children (obese), and 15 boys with DMD. Body composition was measured by dual-energy x-ray absorptiometry (DEXA). Body composition and body water compartment analysis were assessed by MFBIA. All measurements obtained using MFBIA were compared with those obtained using DEXA for validation. RESULTS: Both MFBIA and DEXA measures were strongly correlated in control (r = 0.99), obese (r = 0.92), and DMD subjects (r = 0.95). However, lean tissue mass measured by DEXA in the DMD subjects was only slightly higher (19.2 +/- 1.1 vs. 18.2 +/- 1.2, P < 0.02) than as measured by MFBIA. Mean percentage of body fat measured by DEXA in the DMD subjects (30.4 +/- 3.1%) was significantly lower than as measured by MFBIA (38.7 +/- 2.2%). The mean percentage of body fat measured by DEXA in the control group (23.2 +/- 1.8%) was significantly (P < 0.001) lower than as measured by MFBIA (28.6 +/- 1.6%). The mean percentage of body fat measured by DEXA in obese able-bodied controls (40.8 +/- 0.9%) was not significantly different from that measured by MFBIA (40.4 +/- 1.5%). Compared with the obese and control subjects, DMD subjects showed reduced ICW and ECW, with an increased ECW/ICW ratio, as expected. However, the percentage of fat for the DMD group was not different from the obese group. CONCLUSIONS: DMD patients have elevated ECW/ICW ratios compared with obese subjects and nonobese controls. However, obese subjects and nonobese controls had similar ECW/ICW ratios, despite the increased fat tissue mass in obese subjects. This suggests that the elevated ECW/ICW ratios in DMD subjects are not due to increased fat mass but rather some other mechanism, likely impaired cellular homeostasis due to muscle membrane instability. Although MFBIA slightly underestimates lean tissue mass in boys with DMD, it has a potential role as an inexpensive and easy to use measurement tool to measure changes in muscle mass in the clinical setting.     

Abnormalities of body composition in peritoneal dialysis patients.

OBJECTIVES: Body composition changes occur in peritoneal dialysis (PD) due to abnormalities in nutrition and hydration. We investigated abnormalities of nutrition and hydration in PD patients compared with healthy controls by measurement of total body potassium (TBK) and body water compartments. DESIGN: Cross-sectional comparison study. METHODS: We measured TBK--an indicator of body cell mass--by whole body counting, total body water (TBW) by deuterium oxide dilution, and extracellular water (ECW) by bromide dilution in 29 PD patients and 32 controls. RESULTS: The absolute mean value of TBK for PD patients was not significantly lower than in controls. The ratios of observed TBK to predicted TBK from prediction formulas were compared. Equations used were those of Boddy, Bruce, Burkinshaw, and Ellis and our own equation derived from a local control database (Leeds). Observed/predicted ratios of TBK were significantly less in PD than in control subjects for all equations. Water volumes did not differ between PD and control groups. Observed/predicted ratios for TBK in PD patients correlated with serum potassium (Boddy r = 0.355, p = 0.06; Bruce r = 0.411, p < 0.05; Burkinshaw r = 0.457, p < 0.01; Leeds r = 0.412, p < or = 0.05; Ellis r = 0.356, p = 0.06) and tended to correlate with serum albumin (Bruce r = 0.343, p = 0.07; Burkinshaw r = 0.421, p < 0.05; Leeds r = 0.357, p = 0.06; Ellis r = 0.310, p = NS). There was no relationship with serum potassium in controls. Serum albumin in PD correlated with TBK (r = 0.445, p < 0.02), TBK/height (r = 0.419, p < 0.05), TBK/weight (r = 0.554, p = 0.002), and TBK/TBW (r = 0.586, p = 0.0001). Extracellular water/intracellular water (ECW/ICW) was inversely related to TBK (r = -0.455, p < 0.02 in PD; r = -0.387, p < 0.05 in controls) and to TBK/height (r = -0.446, p < 0.02 in PD; r = -0.411, p = 0.02 in controls). TBK/weight reduced with age in PD (r = -0.445, p < 0.02), as did TBK/TBW in PD (r = -0.463, p < 0.02). ECW/ICW tended to increase with age in PD (r = 0.351, p = 0.06). CONCLUSIONS: Observed/predicted ratio of TBK is reduced in PD patients relative to healthy controls, indicating reduced body cell mass. Serum albumin and potassium reflect TBK indices in PD. Body water volumes did not differ between PD and controls, implying no overall abnormality in hydration in the PD group. However, ECW is relatively increased compared to ICW with decreasing TBK indices, suggesting relative ECW expansion with reduction in body cell mass.