Estimation of body water compartments in cirrhosis by multiple-frequency bioelectrical-impedance analysis

Current Concepts in Fluid Resuscitation and Vasopressor Use in Cirrhosis

Critically ill patients with cirrhosis and liver failure do not uncommonly have hypotension due to multifactorial reasons, which include a hyperdynamic state with increased cardiac index (CI), low systemic vascular resistance (SVR) due to portal hypertension, following the use of beta-blocker or diuretic therapy, and severe sepsis. These changes are mediated by microvascular alterations in the liver, systemic inflammation, activation of renin-angiotensin-aldosterone system, and vasodilatation due to endothelial dysfunction. Haemodynamic assessment includes measuring inferior vena cava indices, cardiac output (CO), and SVR using point-of-care ultrasound (POCUS), arterial waveform analysis, pulmonary artery pressures, and lactate clearance to guide fluid resuscitation. Fluid responsiveness reflects the ability of fluid bolus to increase the CO and is assessed effectively by POCUS, passive leg raises manoeuvre, and dynamic tests such as pulse pressure and stroke volume variation in spontaneously breathing and mechanically ventilated patients. Albumin has pleiotropic benefits through anti-inflammatory properties besides its standard action on oncotic pressure and volume expansion in patients with cirrhosis but has the potential for precipitating pulmonary oedema. In conclusion, fluid therapy in critically ill patients with liver disease is a complex and dynamic process that requires individualized management protocols to optimize patient outcomes.

A multi-channel bioimpedance-based device for Vietnamese hand gesture recognition

This study addresses the growing importance of hand gesture recognition across diverse fields, such as industry, education, and healthcare, targeting the often-neglected needs of the deaf and dumb community. The primary objective is to improve communication between individuals, thereby enhancing the overall quality of life, particularly in the context of advanced healthcare. This paper presents a novel approach for real-time hand gesture recognition using bio-impedance techniques. The developed device, powered by a Raspberry Pi and connected to electrodes for impedance data acquisition, employs an impedance chip for data collection. To categorize hand gestures, Convolutional Neuron Network (CNN), XGBoost, and Random Forest were used. The model successfully recognized up to nine distinct gestures, achieving an average accuracy of 97.24% across ten subjects using a subject-dependent strategy, showcasing the efficacy of the bioimpedance-based system in hand gesture recognition. The promising results lay a foundation for future developments in nonverbal communication between humans and machines as it contributes to the advancement of technology for the benefit of individuals with hearing impairments, addressing a critical social need.

A scoping review of the methods used in patients with liver cirrhosis to assess body composition and their nutritional findings

BACKGROUND AND OBJECTIVES

Body composition (BC) assessment in cirrhosis has a wide variety of methods with no consensus on the best tools for each body component in patients with Liver Cirrhosis (LC). We aimed to conduct a systematic scoping review of the most frequent body composition analysis methods and nutritional findings published in liver cirrhosis patients.

METHODS

We searched for articles in PubMed, Scopus, and ISI Web of Science databases. Keywords selected the BC methods and parameters in LC.

RESULTS

Eleven methods were found. The most frequently used were computed tomography (CT) 47.5%, Bioimpedance Analysis 35%, DXA 32.5%, and anthropometry 32.5%. Up to 15 BC parameters were reported from each method.

CONCLUSIONS

The vast heterogeneity in the results found during the qualitative analysis and imaging methods must reach a consensus to achieve a better clinical practice and improve nutritional treatment, as the physiopathology in LC compromises the nutritional status directly.

Perioperative exercise capacity in chronic liver injury patients with hepatocellular carcinoma undergoing hepatectomy

Dynamic assessment of preoperative exercise capacity may be a useful predictor of postoperative prognosis. We aimed to clarify whether perioperative exercise capacity was related to long-term survival in hepatocellular carcinoma patients with chronic liver injury undergoing hepatectomy. One hundred-six patients with hepatocellular carcinoma underwent pre- and postoperative cardiopulmonary exercise testing to determine their anaerobic threshold, defined as the point between carbon dioxide production and oxygen consumption per unit of time. Testing involved 35 items including blood biochemistry analysis, in-vivo component analysis, dual-energy X-ray absorptiometry, and cardiopulmonary exercise testing preoperatively and 6 months postoperatively. We classified patients with anaerobic threshold ≥ 90% 6 months postoperatively compared with the preoperative level as the maintenance group (n = 78) and patients with anaerobic threshold < 90% as the decrease group (n = 28). Five-year recurrence-free survival rates were 39.9% vs. 9.9% (maintenance vs. decrease group) (hazard ratio: 1.87 [95% confidence interval: 1.12–3.13]; P = 0.018). Five-year overall survival rates were maintenance: 81.9%, and decrease: 61.7% (hazard ratio: 2.95 [95% confidence interval: 1.37–6.33]; P = 0.006). Multivariable Cox proportional hazards models showed that perioperative maintenance of anaerobic threshold was an independent prognostic indicator for both recurrence-free- and overall survival. Although the mean anaerobic threshold from preoperative to postoperative month 6 decreased in the exercise-not-implemented group, the exercise-implemented group experienced increased anaerobic threshold, on average, at postoperative month 6. The significant prognostic factor affecting postoperative survival for chronic liver injury patients with HCC undergoing hepatectomy was maintenance of anaerobic threshold up to 6 months postoperatively.

Liver transplantation and alcoholic liver disease: History, controversies, and considerations

Alcohol consumption accounts for 3.8% of annual global mortality worldwide, and the majority of these deaths are due to alcoholic liver disease (ALD), mainly alcoholic cirrhosis. ALD is one of the most common indications for liver transplantation (LT). However, it remains a complicated topic on both medical and ethical grounds, as it is seen by many as a "self-inflicted disease". One of the strongest ethical arguments against LT for ALD is the probability of relapse. However, ALD remains a common indication for LT worldwide. For a patient to be placed on an LT waiting list, 6 mo of abstinence must have been achieved for most LT centers. However, this "6-mo rule" is an arbitrary threshold and has never been shown to affect survival, sobriety, or other outcomes. Recent studies have shown similar survival rates among individuals who undergo LT for ALD and those who undergo LT for other chronic causes of end-stage liver disease. There are specific factors that should be addressed when evaluating LT patients with ALD because these patients commonly have a high prevalence of multisystem alcohol-related changes. Risk factors for relapse include the presence of anxiety or depressive disorders, short pre-LT duration of sobriety, and lack of social support. Identification of risk factors and strengthening of the social support system may decrease relapse among these patients. Family counseling for LT candidates is highly encouraged to prevent alcohol consumption relapse. Relapse has been associated with unique histopathological changes, graft damage, graft loss, and even decreased survival in some studies. Research has demonstrated the importance of a multidisciplinary evaluation of LT candidates. Complete abstinence should be attempted to overcome addiction issues and to allow spontaneous liver recovery. Abstinence is the cornerstone of ALD therapy. Psychotherapies, including 12-step facilitation therapy, cognitive-behavioral therapy, and motivational enhancement therapy, help support abstinence. Nutritional therapy helps to reverse muscle wasting, weight loss, vitamin deficiencies, and trace element deficiencies associated with ALD. For muscular recovery, supervised physical activity has been shown to lead to a gain in muscle mass and improvement of functional activity. Early LT for acute alcoholic hepatitis has been the subject of recent clinical studies, with encouraging results in highly selected patients. The survival rates after LT for ALD are comparable to those of patients who underwent LT for other indications. Patients that undergo LT for ALD and survive over 5 years have a higher risk of cardiorespiratory disease, cerebrovascular events, and de novo malignancy.

Nutrition and Muscle in Cirrhosis

As the cirrhosis progresses, development of complication like ascites, hepatic encephalopathy, variceal bleeding, kidney dysfunction, and hepatocellular carcinoma signify increasing risk of short term mortality. Malnutrition and muscle wasting (sarcopenia) is yet other complications that negatively impact survival, quality of life, and response to stressors, such as infection and surgery in patients with cirrhosis. Conventionally, these are not routinely looked for, because nutritional assessment can be a difficult especially if there is associated fluid retention and/or obesity. Patients with cirrhosis may have a combination of loss of skeletal muscle and gain of adipose tissue, culminating in the condition of "sarcopenic obesity." Sarcopenia in cirrhotic patients has been associated with increased mortality, sepsis complications, hyperammonemia, overt hepatic encephalopathy, and increased length of stay after liver transplantation. Assessment of muscles with cross-sectional imaging studies has become an attractive index of nutritional status evaluation in cirrhosis, as sarcopenia, the major component of malnutrition, is primarily responsible for the adverse clinical consequences seen in patients with liver disease. Cirrhosis is a state of accelerated starvation, with increased gluconeogenesis that requires amino acid diversion from other metabolic functions. Protein homeostasis is disturbed in cirrhosis due to several factors such as hyperammonemia, hormonal, and cytokine abnormalities, physical inactivity and direct effects of ethanol and its metabolites. New approaches to manage sarcopenia are being evolved. Branched chain amino acid supplementation, Myostatin inhibitors, and mitochondrial protective agents are currently in various stages of evaluation in preclinical studies to prevent and reverse sarcopenia, in cirrhosis.

Body Composition Tools for Assessment of Adult Malnutrition at the Bedside: A Tutorial on Research Considerations and Clinical Applications

Because of the key role played by the body's lean tissue reserves (of which skeletal muscle is a major component) in the response to injury and illness, its maintenance is of central importance to nutrition status. With the recent development of the Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition diagnostic framework for malnutrition, the loss of muscle mass has been recognized as one of the defining criteria. Objective methods to evaluate muscle loss in individuals with acute and chronic illness are needed. Bioimpedance and ultrasound techniques are currently the best options for the clinical setting; however, additional research is needed to investigate how best to optimize measurements and minimize error and to establish if these techniques (and which specific approaches) can uniquely contribute to the assessment of malnutrition, beyond more subjective evaluation methods. In this tutorial, key concepts and statistical methods used in the validation of bedside methods to assess lean tissue compartments are discussed. Body composition assessment methods that are most widely available for practice and research in the clinical setting are presented, and clinical cases are used to illustrate how the clinician might use bioimpedance and/or ultrasound as a tool to assess nutrition status at the bedside. Future research needs regarding malnutrition assessment are identified.

Nutritional assessment in cirrhotic patients with hepatic encephalopathy

Hepatic encephalopathy (HE) is one of the worst complications of liver disease and can be greatly influenced by nutritional status. Ammonia metabolism, inflammation and muscle wasting are relevant processes in HE pathophysiology. Malnutrition worsens the prognosis in HE, requiring early assessment of nutritional status of these patients. Body composition changes induced by liver disease and limitations superimposed by HE hamper the proper accomplishment of exams in this population, but evidence is growing that assessment of muscle mass and muscle function is mandatory due to the role of skeletal muscles in ammonia metabolism. In this review, we present the pathophysiological aspects involved in HE to support further discussion about advantages and drawbacks of some methods for evaluating the nutritional status of cirrhotic patients with HE, focusing on body composition.

Evaluation of functional status, pulmonary capacity, body composition, and quality of life of end-stage liver disease patients who are candidates for liver surgery

INTRODUCTION

Muscular weakness in combination with malnutrition can induce a global motor impairment and physical inactivity, adversely impairing the daily living activities and quality of life of end-stage liver disease patients who are candidates for liver transplantation.

OBJECTIVES

To evaluate functional status, pulmonary capacity, body composition and quality of life in end-stage liver disease patients who are candidates for liver transplantation; to verify if there is a correlation between the functional variables of the individuals tested through the 6-minute walk test (6MWT) and covariables: pulmonary function test (PFP), quality of life and body composition.

METHODS

This study was carried out at the Liver Transplantation Unit of the State University of Campinas (UNICAMP). We included 46 patients with end-stage liver disease who underwent the following evaluations: medical history, quality of life questionnaire "Short Form 36" (SF-36), surface electromyography (sEMG) of the diaphragm and rectus abdominis muscles, body composition assessment by electrical vioimpedance (BIA), 6MWT and PFP.

RESULTS

Univariate analysis and Pearson's correlation found correlations between distance walked on 6MWT and QOL (P = .006 and P = .02) and TBW (P = .5 and P = .02). Pearson's correlation were found between respiratory variables of 6MWT, QOL, and PFP.

CONCLUSION

The functional status may be correlated to body composition, quality of life and pulmonary capacity of patients with liver disease, candidates for transplantation.

Comparison of body composition assessment methods in pediatric intestinal failure

OBJECTIVES

The aim of the study was to examine the agreement of multifrequency bioelectric impedance analysis (BIA) and anthropometry with reference methods for body composition assessment in children with intestinal failure (IF).

METHODS

We conducted a prospective pilot study in children 14 years or younger with IF resulting from either short bowel syndrome or motility disorders. Bland-Altman analysis was used to examine the agreement between BIA and deuterium dilution in measuring total body water (TBW) and lean body mass (LBM), and between BIA and dual-energy x-ray absorptiometry (DXA) techniques in measuring LBM and fat mass (FM). FM and percent body fat (%BF) measurements by BIA and anthropometry were also compared in relation to those measured by deuterium dilution.

RESULTS

Fifteen children with IF, median (interquartile range) age 7.2 (5.0, 10.0) years, and 10 (67%) boys, were studied. BIA and deuterium dilution were in good agreement with a mean bias (limits of agreement) of 0.9 (-3.2 to 5.0) for TBW (L) and 0.1 (-5.4 to 5.6) for LBM (kg) measurements. The mean bias (limits) for FM (kg) and %BF measurements were 0.4 (-3.8 to 4.6) kg and 1.7 (-16.9 to 20.3)%, respectively. The limits of agreement were within 1 standard deviation of the mean bias in 12 of 14 (86%) subjects for TBW and LBM, and in 11 of 14 (79%) for FM and %BF measurements. Mean bias (limits) for LBM (kg) and FM (kg) between BIA and DXA were 1.6 (-3.0 to 6.3) kg and -0.1 (-3.2 to 3.1) kg, respectively. Mean bias (limits) for FM (kg) and %BF between anthropometry and deuterium dilution were 0.2 (-4.2 to 4.6) and -0.2 (-19.5 to 19.1), respectively. The limits of agreement were within 1 standard deviation of the mean bias in 10 of 14 (71%) subjects.

CONCLUSIONS

In children with IF, TBW and LBM measurements by multifrequency BIA method were in agreement with isotope dilution and DXA methods, with small mean bias and clinically acceptable limits of agreement. In comparison with deuterium dilution, BIA was comparable to anthropometry for FM and %BF assessments with small mean bias, but the limits of agreement were large. BIA is a reliable method for TBW and LBM assessments in population studies; however, its reliability in individual patients, especially for FM assessments, cannot be guaranteed.

Assessment of preoperative exercise capacity in hepatocellular carcinoma patients with chronic liver injury undergoing hepatectomy

Background

Cardiopulmonary exercise testing measures oxygen uptake at increasing levels of work and predicts cardiopulmonary performance under conditions of stress, such as after abdominal surgery. Dynamic assessment of preoperative exercise capacity may be a useful predictor of postoperative prognosis. This study examined the relationship between preoperative exercise capacity and event-free survival in hepatocellular carcinoma (HCC) patients with chronic liver injury who underwent hepatectomy.

Methods

Sixty-one HCC patients underwent preoperative cardiopulmonary exercise testing to determine their anaerobic threshold (AT). The AT was defined as the break point between carbon dioxide production and oxygen consumption per unit of time (VO₂). Postoperative events including recurrence of HCC, death, liver failure, and complications of cirrhosis were recorded. Univariate and multivariate analyses were performed to evaluate associations between 35 clinical factors and outcomes, and identify independent prognostic indicators of event-free survival and maintenance of Child-Pugh class.

Results

Multivariate analyses identified preoperative branched-chain amino acid/tyrosine ratio (BTR) <5, alanine aminotransferase level ≥42 IU/l, and AT VO₂ <11.5 ml/min/kg as independent prognostic indicators of event-free survival. AT VO₂ <11.5 ml/min/kg and BTR <5 were identified as independent prognostic indicators of maintenance of Child-Pugh class.

Conclusions

This study identified preoperative exercise capacity as an independent prognostic indicator of event-free survival and maintenance of Child-Pugh class in HCC patients with chronic liver injury undergoing hepatectomy.

Body composition by whole-body bioelectrical impedance and prediction of clinically relevant outcomes: overvalued or underused?

BACKGROUND/OBJECTIVES

Body composition calculated using whole-body bioelectrical impedance analysis (BIA), almost invariably with height (H) and often with weight (W), can help patient management and predict clinical outcomes. This study aimed to examine the merits of this approach compared with simple anthropometry (W+H).

SUBJECTS/METHODS

Use was made of original data and validation studies based on reference body composition methods: water dilution, densitometry, dual-energy X-ray absorptiometry, and more robust methods. Prediction of clinical outcomes, including mortality and length of hospital stay, was examined in six studies of chronic obstructive pulmonary disease and a study with multiple patient groups. Vector analysis, phase angle, multi-frequency BIA and segmental impedance were not considered.

RESULTS

In a broad range of study populations, from neonates to older people, in health and disease, body composition calculated using BIA with simple anthropometry frequently offered no advantage over W+H alone, but in some situations it was superior and in others inferior. In predicting clinically relevant outcomes, the fat-free mass index (FFMI), established using BIA, had comparable and sometimes greater power than body mass index (BMI), but none of the reviewed papers used FFMI calculated from W+H or BMI to predict clinical outcomes.

CONCLUSIONS

A variable and generally weak evidence base was found to suggest that BIA with anthropometry is better at predicting body composition than simple anthropometry alone. No evidence was found from the reviewed studies that FFMI calculated from BIA and anthropometry was better at predicting clinical outcomes than FFMI calculated by simple anthropometry alone.

Malnutrition in cirrhosis: contribution and consequences of sarcopenia on metabolic and clinical responses

Malnutrition is the most common, reversible complication of cirrhosis that adversely affects survival, response to other complications, and quality of life. Sarcopenia, or loss of skeletal muscle mass, and loss of adipose tissue and altered substrate use as a source of energy are the 2 major components of malnutrition in cirrhosis. Current therapies include high protein supplementation especially as a late evening snack. Exercise protocols have the potential of aggravating hyperammonemia and portal hypertension. Recent advances in understanding the molecular regulation of muscle mass has helped identify potential novel therapeutic targets including myostatin antagonists, and mTOR resistance.

Nutritional assessment in patients with cirrhosis

CONTEXT

Malnutrition in cirrhotic patients with end-stage disease is common, and the degree of nutritional debilitation can play an important role in the pathogenesis of complications and cause a negative impact on prognosis. However, it involves difficulties and controversies regarding the identification of the best nutritional assessment method.

OBJECTIVE

To identify a method that provides a safe and effective nutritional diagnosis.

METHODS

Cross-sectional study with 129 cirrhotic patients. Anthropometric measurements, subjective global assessment, hand grip strength and bioelectrical impedance.

RESULTS

Through phase angle of bioelectrical impedance analysis (BIA) method, significant associations with Child-Pugh (P = 0.008), age group and gender were observed. The ROC (receiver operator characteristic) curve was generated to determine the best cutoff point of the phase angle of cirrhotic patients, serving as one of the reference parameters for the nutritional assessment with bioimpedance in this study, considering the classification through Child-Pugh score as the reference standard for the clinical conditions of patients with cirrhosis.

CONCLUSIONS

The assessment through bioelectrical impedance presented a statistically significant correlation with Child-Pugh score. The identification of phase angle of 5.44º is the new parameter suggested for the classification of the nutritional conditions of cirrhotic patients.

Value of the extracellular water ratio for assessment of cirrhotic patients with and without ascites

AIMS

Ascites, which often complicates liver cirrhosis, is reported to be a factor that worsens the outcome. The aims of this study were to quantify body water compartment changes in cirrhotic patients, with and without ascites, and to elucidate the value of body water analysis for predicting the development of ascites.

METHODS

A total of 109 cirrhotic patients, with and without ascites, and 65 controls were studied. Intra- and extracellular water (ECW) in the whole body and in the arm, leg and trunk were measured using the recently developed 8-electrodes multiple-frequency bioelectrical impedance analyzer. Furthermore, patients without ascites were followed to an episode of ascites or death.

RESULTS

Patients with liver cirrhosis had significantly higher ECW ratios than controls. ECW ratios were increased in cirrhotic patients with moderate and severe disease. The ECW ratio of the trunk showed highly significant changes in cirrhotic patients with ascites. The ECW ratio correlated with age, serum albumin, and prothrombin time. A relative expansion of ECW and low albumin were predictive of further episodes of ascites (log-rank 6.94, P < 0.01). In multivariate analysis, the ECW ratio was independently associated with the development of ascites.

CONCLUSION

Liver cirrhosis was characterized by a redistribution of body water. The ECW ratio is a reliable tool for quantification of redistribution of body water and can predict the development of ascites.

[Nutrition alterations in internal medicine. Body composition analysis with bioelectrical impedance]

OBJECTIVES

To determine the prevalence of malnutrition in patients in Internal Medicine. To describe the changes of corporal composition depending on body mass index (BMI). To evaluate validity of the different screening tools for the estimation of body composition.

MATERIAL AND METHODS

Prospective observational cross-sectional study of the prevalence of malnutrition in 300 patients (sample 1); these were chosen 136 patients (sample 2), classifying in four groups: BMI < 20: 30 patients; BMI = 20-25: 46 patients; BMI = 25-30: 30 patients, and BMI > 30: 30 patients. In the patients of sample 2, we carried out a protocol of nutritional evaluation with anthropometry, laboratory and bioelectrical impedance analysis.

RESULTS

The prevalence of desnutrition was 9.3% and the obesity was 22.3%. In undernourished patients, the measure of body compartments with bioelectrical impedance, expressed in percentage of body weight, were: fat mass 20.5%, fat-free mass 79.4% and total body mater 58.3%. The body composition in obeses was: fat mass 40.1%, fat-free mass 60.6% and total body water 44.3%. The patients with normal BMI, the meta index (impedance at 50 kHz/BMI) was 25.9 +/- 5.21; in undernourished the index was higher (36.7) and obeses lower (15.5). The meta index (30-20) estimates desnutrition-obesity with high sensibility and specificity. The prevalence of desnutrition varies from 6% to 69% and obesity from 23% to 74%, using different methods and criterions for the estimation of body composition.

CONCLUSIONS

In Internal Medicine, the overweight (BMI > 25) is the most prevalent nutritional alteration. The bioelectrical impedance analysis helps for estimation of body composition and meta index is a very useful indicator of malnutrition (desnutrition-obesity).

[Nutritional evaluation of the cirrhotic patient: an objective, subjective or multicompartmental approach?]

BACKGROUND

Malnutrition due to liver disease is common and its assessment is difficult. The parameters of nutritional evaluation often used in clinical practice have limited use in cirrhotic patients. Many of the clinical signs of malnutrition are the result of the underlying hepatic disease which tends to confound and alter the nutritional diagnosis.

AIM

To present a brief review of the different methods of nutritional evaluation together with their limitations and uses in cirrhotic patients.

CONCLUSION

The multicompartmental approach for four compartments was shown to be considerably sensitive in the detection of malnutrition. However the ample use of this method is impaired due to technical difficulties and high costs. The handgrip strength appears to be a simple, cheap and effective alternative to detected malnutrition and risk of malnutrition in these patients. Is the most sensitive method and is able to predict a significant incidence of major complications in undernourished cirrhotic patients.

The validity of bioelectrical impedance models in clinical populations

Bioelectrical impedance analysis (BIA) is the most commonly used body composition technique in published studies. Herein we review the theory and assumptions underlying the various BIA and bioelectrical impedance spectroscopy (BIS) models, because these assumptions may be invalidated in clinical populations. Single-frequency serial BIA and discrete multifrequency BIA may be of limited validity in populations other than healthy, young, euvolemic adults. Both models inaccurately predict total body water (TBW) and extracellular water (ECW) in populations with changes in trunk geometry or fluid compartmentalization, especially at the level of the individual. Single-frequency parallel BIA may predict body composition with greater accuracy than the serial model. Hand-to-hand and leg-to-leg BIA models do not accurately predict percent fat mass. BIS may predict ECW, but not TBW, more accurately than single-frequency BIA. Segmental BIS appears to be sensitive to fluid accumulation in the trunk. In general, bioelectrical impedance technology may be acceptable for determining body composition of groups and for monitoring changes in body composition within individuals over time. Use of the technology to make single measurements in individual patients, however, is not recommended. This has implications in clinical settings, in which measurement of individual patients is important.

Bioelectrical impedance analysis-part II: utilization in clinical practice

BIA is easy, non-invasive, relatively inexpensive and can be performed in almost any subject because it is portable. Part II of these ESPEN guidelines reports results for fat-free mass (FFM), body fat (BF), body cell mass (BCM), total body water (TBW), extracellular water (ECW) and intracellular water (ICW) from various studies in healthy and ill subjects. The data suggests that BIA works well in healthy subjects and in patients with stable water and electrolytes balance with a validated BIA equation that is appropriate with regard to age, sex and race. Clinical use of BIA in subjects at extremes of BMI ranges or with abnormal hydration cannot be recommended for routine assessment of patients until further validation has proven for BIA algorithm to be accurate in such conditions. Multi-frequency- and segmental-BIA may have advantages over single-frequency BIA in these conditions, but further validation is necessary. Longitudinal follow-up of body composition by BIA is possible in subjects with BMI 16-34 kg/m(2) without abnormal hydration, but must be interpreted with caution. Further validation of BIA is necessary to understand the mechanisms for the changes observed in acute illness, altered fat/lean mass ratios, extreme heights and body shape abnormalities.

Body composition in patients with short bowel syndrome: An assessment by bioelectric impedance spectroscopy (BIS) and dual–energy absorptiometry (DXA)

OBJECTIVE

To describe body composition in patients with short bowel syndrome (SBS) by using bioelectric impedance spectroscopy (BIS), dual-energy X-ray absorptiometry (DXA) measurements and anthropometrical-derived estimates.

SUBJECTS

In all, 19 patients were included, mean age 54 y, range 36-77 (F/M=11/8). Mean BMI was 21.5 kg/m(2). Eight patients were on home parenteral nutrition (HPN).

METHODS

Total body water (TBW), intracellular water and extracellular water were assessed by BIS. TBW were derived from DXA. Fat-free mass (FFM) was assessed by BIS and DXA. TBW and FFM were predicted according to an empirical formula. Differences were analysed using the Bland-Altman method.

RESULTS

The mean difference between TBW (DXA) and TBW (BIS) was -1.1 l in women and -1.8 l in men. For FFM, the mean difference between FFM (DXA) and FFM (BIS) was -1.7 kg in women and -2.5 kg in men. The mean difference between TBW (DXA) and TBW (BIS) for all patients was -1.2 l and limits of agreement were (-7.80-5.40). Hydration of FFM assessed by BIS gave a mean of 0.75 (0.08).

CONCLUSION

The limits of agreement (Bland-Altman) between DXA and BIS were wide, indicating that methods are not interchangeable, which limits its clinical utility. Most of our patients with SBS were maintained in a stable clinical condition within normal limits of body weight and BMI. FFM and TBW did not appear to be altered in ileostomates or those on HPN.

Evaluation of bioimpedance spectroscopy for measurements of body water distribution in healthy women before, during, and after pregnancy

Bioimpedance spectroscopy (BIS) is a technique of interest in the study of human pregnancy because it can assess extracellular (ECW), intracellular (ICW), and total body water (TBW) as ECW plus ICW. The technique requires appropriate resistivity coefficients and has not been sufficiently evaluated during the reproductive cycle. Therefore, in a methodological study, we estimated ECW, ICW, and TBW, by means of BIS, and compared the results with the corresponding estimates obtained by using reference methods. Furthermore, results obtained by means of population-specific resistivity coefficients were compared with results obtained by means of general resistivity coefficients. These comparisons were made before pregnancy, in gestational weeks 14 and 32, as well as 2 wk postpartum in 21 healthy women. The reference methods were isotope and bromide dilution. Average ICW, ECW, and TBW, estimated by means of BIS, were in agreement with reference data before pregnancy, in gestational week 14, and postpartum. The corresponding comparison in gestational week 32 showed good agreement for ICW, whereas estimates by means of BIS were significantly ( P < 0.001) lower than the corresponding reference values for ECW and TBW. Thus the BIS technique, which was based on a model developed for the nonpregnant body, estimated increases in ICW accurately, whereas increases in ECW and TBW tended to be underestimated. Estimates obtained by using population-specific and general resistivity coefficients were very similar. In conclusion, the results indicated that BIS is potentially useful for studies during pregnancy but that further work is needed before it can be generally applied in such studies.

Sequential changes of body composition in patients with enterocutaneous fistula during the 10 days after admission

AIM: To investigate the sequential changes of body composition in the metabolic response that occurred in a group of patients with enterocutaneous fistula after admission to the hospital.

METHODS: Sixty-one patients with enterocutaneous fistula admitted to our hospital had measurements of body composition by multiple-frequency bioelectrical impedance analysis after admission and 5, 10 days later. Sequential measurements of plasma constitutive proteins were also made.

RESULTS: The body weight, fat-free mass, body mass index, and body cell mass were initially well below the normal range, especially the body mass index and body cell mass. And all the data gradually moved up over the 10-day study period, only a highly significant difference was found in body cell mass. Once the patients received nutrition supplement, ECW began to return to normal range slowly as well as ICW and TBW began to rise up, and ECW/TBW significantly declined to near normal level by day 10 in either male or female patients. There was a reprioritization of plasma constitutive protein synthesis that was obligatory and independent of changes in FFM.

CONCLUSION: Serial measurements can quantify the disturbance of body composition in enterocutaneous fistula patients. The early nutritional intervention rapidly ameliorates the abnormal distribution of body water while the state-of-the-art surgical management prevents the further deterioration in cellular composition.