Validation of bioelectrical impedance analysis in patients with amyotrophic lateral sclerosis

Nutritional and Microbiota-Based Approaches in Amyotrophic Lateral Sclerosis: From Prevention to Treatment

Metabolic alterations, including hypermetabolism, lipid imbalances, and glucose dysregulation, are pivotal contributors to the onset and progression of Amyotrophic Lateral Sclerosis (ALS). These changes exacerbate systemic energy deficits, heighten oxidative stress, and fuel neuroinflammation. Simultaneously, gastrointestinal dysfunction and gut microbiota (GM) dysbiosis intensify disease pathology by driving immune dysregulation, compromising the intestinal barrier, and altering gut-brain axis (GBA) signaling, and lastly advancing neurodegeneration. Therapeutic and preventive strategies focused on nutrition offer promising opportunities to address these interconnected pathophysiological mechanisms. Diets enriched with antioxidants, omega-3 fatty acids, and anti-inflammatory compounds-such as the Mediterranean diet-have shown potential in reducing oxidative stress and systemic inflammation. Additionally, microbiota-targeted approaches, including probiotics, prebiotics, postbiotics, and fecal microbiota transplantation, are emerging as innovative tools to restore microbial balance, strengthen gut integrity, and optimize GBA function. This review highlights the critical need for personalized strategies integrating immunonutrition and microbiota modulation to slow ALS progression, improve quality of life, and develop preventive measures for neurodegenerative and neuroinflammatory diseases. Future research should prioritize comprehensive dietary and microbiota-based interventions to uncover their therapeutic potential and establish evidence-based guidelines for managing ALS and related disorders.

Malnutrition in Amyotrophic Lateral Sclerosis: Insights from Morphofunctional Assessment and Global Leadership Initiative on Malnutrition Criteria

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease frequently accompanied by malnutrition due to weight loss, increased energy expenditure, and muscle mass loss. This study aimed to evaluate morphofunctional assessment tools as predictors of malnutrition and to investigate their relationship with muscle status and disease severity in ALS patients. A cross-sectional study was conducted with 45 ALS patients at the San Cecilio University Hospital in Granada. Malnutrition was assessed using the Global Leadership Initiative on Malnutrition (GLIM) criteria. Morphofunctional assessment was performed using Bioimpedance Vectorial Analysis (BIVA), handgrip strength (HGS), and Short Physical Performance Battery (SPPB). Malnutrition prevalence was 38% according to GLIM criteria. Significant differences were observed between malnourished and non-malnourished groups in age (70 ± 9 vs. 62 ± 10 years, p = 0.01), sex (female prevalence: 58.8% vs. 25.0%, p = 0.02), dysphagia prevalence (83% vs. 29%, p < 0.001), PEG/PRG use (35.3% vs. 3.6%, p = 0.01), and ALSFRS-R scores (30 ± 12 vs. 34 ± 12, p = 0.02). Malnourished patients had lower values in anthropometric measurements, muscle mass obtained by BIVA, and phase angle (PA) (4.05 ± 0.8° vs. 5.09 ± 0.8°, p < 0.001). No significant differences were found in muscle strength or functional status. PA showed significant correlations with muscle strength (r = 0.52, p < 0.001) and muscle mass measures (r = 0.48, p < 0.001). Moreover, PA was associated with poorer disease progression and physical performance. In our sample, BIVA metrics such as PA (<4.3°), SPA (<-0.8), body cell mass (<9.2 kg/m), and extracellular water (>49.75%) were identified as malnutrition risk factors. The study underscores the critical importance of comprehensive morphofunctional assessment and the use of advanced diagnostic criteria, for early identification and intervention in malnutrition among people with ALS. Further research is warranted to validate these findings and develop targeted nutritional strategies into routine clinical practice.

A comparison between bioelectrical impedance analysis and air-displacement plethysmography in assessing fat-free mass in patients with motor neurone diseases: a cross-sectional study

AIM

To determine the validity of bioelectrical impedance analysis (BIA) in quantifying fat-free mass (FFM) compared to air-displacement plethysmography (ADP) in patients with a motor neurone disease (MND).

METHODS

FFM of 140 patients diagnosed with MND was determined by ADP using the BodPod (i.e. the gold standard), and by BIA using the whole-body Bodystat. FFM values were translated to predicted resting energy expenditure (REE); the actual REE was measured using indirect calorimetry, resulting in a metabolic index. Validity of the BIA compared to the ADP was assessed using Bland-Altman analysis and Pearson's r. To assess the clinical relevance of differences, we evaluated changes in metabolic index and in individualized protein demand.

RESULTS

Despite the high correlation between ADP and BIA (r = 0.93), averaged across patients, the assessed mean fat-free mass was 51.7 kg (± 0.9) using ADP and 54.2 kg (± 1.0) using BIA. Hence, BIA overestimated fat-free mass by 2.5 kg (95% CI 1.8-3.2, p < 0.001). Clinically, an increased metabolic index would be more often underdiagnosed in patients with MND using BIA (31.4% according to BIA versus 44.2% according to ADP, p = 0.048). A clinically relevant overestimation of ≥ 15 g in protein demand was observed for 4 (2.9%) patients using BIA.

CONCLUSIONS

BIA systematically overestimates FFM in patients with MND. Although the differences are limited with ADP, underscoring the utility of BIA for research, overestimation of fat-free mass may have consequences for clinical decision-making, especially when interest lies in determining the metabolic index.

Phase Angle and Bioelectrical Impedance Vector Analysis (BIVA) in Amyotrophic Lateral Sclerosis (ALS) Patients

Phase angle (PhA) and bioelectrical impedance vector analysis (BIVA) have emerged as valuable tools for assessing nutritional status and prognosis in various patient populations, but there is a lack of studies in rare neurodegenerative diseases. The purpose of this cross-sectional study was to investigate these bioelectrical parameters in patients with amyotrophic lateral sclerosis (ALS), compared with healthy peers. The tetrapolar impedance method was applied and bioimpedance analysis (BIA) was performed. Bioelectrical parameters were obtained (Resistance—R; Reactance—Xc) or calculated (PhA; BIVA). For BIVA, bivariate vectors and confidence ellipses were graphically represented. In addition, R and Xc were used to determine body composition (BC) (Fat Mass—FM; Fat-Free Mass—FFM; and Total Body Water—TBW). In this study, 40 participants were divided into two groups: case group (n = 20, ALS patients) and control group (n = 20, healthy subjects. Our main results showed that ALS patients presented low levels of BMI, FFM, R, and Xc adjusted by height (R/H, Xc/H), hydration, and cellularity, compared to the healthy subjects. Our findings highlight BC and bioelectrical parameters, including PhA and BIVA, as valuable indicators of nutrition status, which should be implemented in the nutrition care process of ALS patients during the disease course.

Association Between Fat Depletion and Prognosis of Amyotrophic Lateral Sclerosis: CT-Based Body Composition Analysis

OBJECTIVE

The purpose of this study was to present the results of our investigation of the prognostic value of adipopenia and sarcopenia in patients with amyotrophic lateral sclerosis (ALS).

METHODS

Consecutive patients with ALS with abdominal computed tomography (CT) were retrospectively identified at a single tertiary hospital between January 2010 and July 2021. Deep learning-based volumetric CT body composition analysis software was used to obtain abdominal waist fat volume, fat attenuation, and skeletal muscle area at the L3 level, then normalized to the fat volume index (FVI) and skeletal muscle index (SMI). Adipopenia and sarcopenia were defined as the sex-specific lowest quartile and SMI reference values, respectively. The associations of CT-derived body composition parameters with clinical variables, such as body mass index (BMI) and creatinine, were evaluated by Pearson correlation analyses, and associations with survival were assessed using the multivariable Cox regression analysis.

RESULTS

Eighty subjects (40 men, 65.5 ± 9.4 years of age) were investigated (median interval between disease onset and CT examination = 25 months). The mean BMI at the CT examination was 20.3 ± 4.3 kg/m2 . The BMI showed a positive correlation with both FVI (R = 0.70, p < 0.001) and SMI (R = 0.63, p < 0.001), and the serum creatinine level was associated with SMI (R = 0.68, p < 0.001). After adjusting for sex, age, King's stage, BMI, creatinine, progression rate, and sarcopenia, adipopenia was associated with shorter survival (hazard ratio [HR] = 5.94, 95% confidence interval [CI] = 1.01, 35.0, p = 0.049). In a subgroup analysis for subjects with nutritional failure (stage 4a), the HR of adipopenia was 15.1 (95% CI = 2.45, 93.4, p = 0.003).

INTERPRETATION

Deep learning-based CT-derived adipopenia in patients with ALS is an independent poor prognostic factor for survival. ANN NEUROL 2023;94:1116-1125.

Malnutrition assessment by Global Leadership Initiative on Malnutrition criteria in patients with amyotrophic lateral sclerosis

Malnutrition can play an important prognostic role in terms of survival in patients with amyotrophic lateral sclerosis (ALS). In this clinical context, applying criteria defining malnutrition requires particular attention, especially in the initial stage of the disease. This article discusses the application of the most recent criteria used for the definition of malnutrition when applied to patients with ALS. Currently, the Global Leadership Initiative on Malnutrition (GLIM) criteria, which have received a worldwide consensus, are based on parameters such as unintentional weight loss, low body mass index (BMI), and reduced muscle mass (phenotypic criteria) in combination with reduced food intake and assimilation or inflammation and disease (etiologic criteria). However, as discussed in this review, the initial unintentional weight loss and the consequent BMI reduction could be attributed, at least in part, to muscle atrophy, which also alters the reliability of muscle mass assessment. Moreover, the condition of hypermetabolism, which is observed in up to 50% of these patients, may complicate the calculation of total energy requirements. Finally, it remains to be established if the presence of neuroinflammation can be considered a type of inflammatory process able to induce malnutrition in these patients. In conclusion, the monitoring of BMI, associated with body composition evaluation by bioimpedance measurement or specific formulas, could be a practicable approach to the diagnosis of malnutrition in patients with ALS. In addition, attention should be given to dietary intake (e.g., in patients with dysphagia) and excessive involuntary weight loss. On the other hand, as suggested by GLIM criteria, a single assessment of BMI resulting in <20 kg/m² or <22 kg/m² in patients aged <70 y and ≥70 y, respectively, should always be considered a sign of malnutrition.

Urine specific gravity to identify and predict hydration need in ALS

Introduction: Multiple factors contribute to increased risk of dehydration in amyotrophic lateral sclerosis (ALS), which contributes to shortened survival independent of nutritional status. The assessment of hydration by doubly labeled water is restricted due to the limited availability of this gold standard technique for clinical use. This prompted us to examine the utility of urine-specific gravity (USG) as a predictor of hydration need in ALS subjects. Material and Methods: Using data from a multicenter study of 80 ALS subjects with 250 visits, we conducted a secondary analysis of the original data set from doubly labeled water experiments. We used a cross-section of the data (one visit per 75 subjects) in the model selection step ("test set"), and a repeated measures analysis in the validation step with data from 63 subjects and 142 follow-up visits. The sensitivity to detect inadequate water turnover rate (a surrogate for water intake) was the goal of the predictive model presented for clinical use. Results and discussion: The final predictive model to estimate water requirement included USG, gender, body mass index, and the ALSFRS gross motor subscale score. We developed a best-fit equation to estimate water intake from USG, determine hydration status, and improve clinical care of real-world ALS subjects.

Body composition in amyotrophic lateral sclerosis subjects and its effect on disease progression and survival

BACKGROUND

Motor neuron degeneration and malnutrition alter body composition in amyotrophic lateral sclerosis (ALS). Resulting losses of weight, fat mass (FM), and fat-free mass (FFM) shorten survival. Nutritional management relies on body weight or BMI; neither reliably indicates malnutrition nor differentiates body compartments.

OBJECTIVES

We aimed to 1) develop an equation to compute FM and FFM using clinical data, validated against DXA; and 2) examine the effect of computed FM and FFM on disease course and survival.

METHODS

We studied 364 ALS patients from 3 cohorts. In Cohort #1 we used logistic regression on clinical and demographic data to create an equation (test cohort). In Cohort #2 we validated FM and FFM computed using this equation against DXA (validation cohort). In Cohort #3, we examined the effect of computed body composition on disease course and survival.

RESULTS

In Cohort #1 (n = 29) the model incorporated sex, age, BMI, and bulbar-onset to create an equation to estimate body fat: % body fat = 1.73 - [19.80*gender (1 if male or 0 if female)] + [0.25*weight (kg)] + [0.95*BMI (kg/m2)] - (5.20*1 if bulbar-onset or *0 if limb-onset). In Cohort #2 (n = 104), body composition using this equation, compared to other published equations, showed the least variance from DXA values. In Cohort #3 (n = 314), loss of body composition over 6 mo was greater in males. Adjusted survival was predicted by low baseline FM (HR: 1.39; 95% CI: 1.07, 1.80), and loss of FM (HR: 1.87; 95% CI: 1.30, 2.69) and FFM (HR: 1.73; 95% CI: 1.20, 2.49) over 6 mo.

CONCLUSIONS

Our equation broadens the traditional nutritional evaluation in clinics and reliably estimates body composition. Measuring body composition could target FM as a focus for nutritional management to ensure adequate energy intake and complement measures, such as the ALS functional rating scale-revised score and forced vital capacity, currently used.

Body Fat Percentage and Availability of Oral Food Intake: Prognostic Factors and Implications for Nutrition in Amyotrophic Lateral Sclerosis

Adequate nutritional support and high body mass index (BMI) are good prognostic factors for disease progression and survival in amyotrophic lateral sclerosis (ALS). However, whether the composition of body weight, such as body fat percentage, has an independent effect on ALS prognosis remains unclear. The clinical data of 53 ALS patients were collected by medical record review. The data included: disease onset, sex, age, time of diagnosis, survival duration, presence of percutaneous endoscopic gastrostomy (PEG), nasogastric tube, tracheostomy, and availability of oral intake throughout the course of the disease, and interval measurement values of body mass by bioelectrical impedance analysis (BIA). The interval change (∆) of the BIA parameters was calculated by subtracting the follow-up values from the baseline values. Change in body fat percentage/interval between BIA measurements (months) (hazard ratio [HR] = 0.374, p = 0.0247), and availability of oral food intake (HR = 0.167, p = 0.02), were statistically significant for survival duration in multivariate hazard proportional regression analysis. Survival analysis and Kaplan–Meier curves showed similar results. Higher average monthly change in body fat percentage and availability of oral food intake are prognostic factors in ALS survival.

Association between Body Composition and Dysphagia in Patients with Amyotrophic Lateral Sclerosis

Background: The influence of changes in body composition on swallowing in patients with Amyotrophic Lateral Sclerosis (ALS) is unknown. Understanding the interrelation between body compartments and dysphagia may establish specific treatments related to both nutritional aspects as to myofunctional ones designed to delay swallowing loss. Aim: The aim of the study was to evaluate the relationship between body composition and dysphagia during the course of the disease. Methods: The protocol of this study included assessments carried out quarterly for one year and included: analysis of body composition by multi-frequency segmental bioimpedance, nutritional diagnosis, maximum strength test of the tongue and lips, analysis of swallowing using the Functional Oral Intake Score (FOIS) and Swallowing Rating Scale of the American Speech-Language-Hearing Association (ASHA), speech intelligibility and analysis of disease severity. To measure the degree of relationship between quantitative variables, Spearman’s correlation was used. Results: Thirty-four patients were evaluated, 28 Spinal Group and 6 Bulbar Group. The results did not show any significant differences in the analysis of body composition between the groups. Positive associations were found between body compartments and swallowing analysis. The phase angle showed a strong correlation between the FOIS scales (r = 0.74, p < 0.01), ASHA (r = 0.77, p < 0.01) and tongue (r = 0.66, p < 0.01). Conclusions: Changes in body compartments were related to swallowing functionality and speech intelligibility in ALS patients, emphasizing the importance of analyzing body compartments for decision making by the interdisciplinary team. Although these preliminary data were collected in a small sample size, they serve to motivate future studies in this area.

Metabolic Abnormalities, Dietary Risk Factors and Nutritional Management in Amyotrophic Lateral Sclerosis

Amyotrophic Lateral Sclerosis (ALS) is a devastating progressive neurodegenerative disease that affects motor neurons, leading to a relentless paralysis of skeletal muscles and eventual respiratory failure. Although a small percentage of patients may have a longer survival time (up to 10 years), in most cases, the median survival time is from 20 to 48 months. The pathogenesis and risk factors for ALS are still unclear: among the various aspects taken into consideration, metabolic abnormalities and nutritional factors have been the focus of recent interests. Although there are no consistent findings regarding prior type-2 diabetes, hypercholesterolemia and ALS incidence, abnormalities in lipid and glucose metabolism may be linked to disease progression, leading to a relatively longer survival (probably as a result of counteract malnutrition and cachexia in the advanced stages of the disease). Among potential dietary risk factors, a higher risk of ALS has been associated with an increased intake of glutamate, while the consumption of antioxidant and anti-inflammatory compounds, such as vitamin E, n-3 polyunsaturated fatty acids, and carotenoids, has been related to lower incidence. Poor nutritional status and weight loss in ALS resulting from poor oral intake, progressive muscle atrophy, and the potential hypermetabolic state have been associated with rapid disease progression. It seems important to routinely perform a nutritional assessment of ALS patients at the earliest referral: weight maintenance (if adequate) or gain (if underweight) is suggested from the scientific literature; evidence of improved diet quality (in terms of nutrients and limits for pro-inflammatory dietary factors) and glucose and lipid control is yet to be confirmed, but it is advised. Further research is warranted to better understand the role of nutrition and the underlying metabolic abnormalities in ALS, and their contribution to the pathogenic mechanisms leading to ALS initiation and progression.

Potential bioelectrical impedance analysis (BIA) parameters in prediction muscle strength in women with anorexia nervosa

OBJECTIVES

The role of physical activity in anorexia nervosa (AN) treatment has been investigated. Muscle strength (MS) reflects physical condition and can predict AN patients' response to this novel treatment approach. This study was intended to find bioelectrical impedance analysis (BIA) parameters that predict AN patients' MS.

METHODS

The study included 42 AN patients and 42 healthy ones in the control group. BIA parameters that predict MS were assessed by dividing AN patients into groups by their hand grip strength test score (higher/lower than 22.5 kg).

RESULTS

The highest accuracy for distinguishing AN subjects from the control group was achieved by cell membrane capacitance (AUC = 0.916), impedance at 200 kHz and 5 kHz ratio (AUC = 0.924), phase angle (PA) 5 kHz (AUC = 0.906) and PA 50 kHz (AUC = 0.919). The low MS group had significantly lower values of PA 50 kHz (mean: 4.03 ± 0.80° vs. 4.58 ± 0.65°; p = 0.032) and fat-free mass index (mean: 12.22 ± 1.41 kg/m² vs. 13.14 ± 0.94 kg/m²; p = 0.026). In the univariate model, PA 50 kHz ≥4.037° was associated with the lowest chance of muscle weakness (OR = 0.230; p = 0.005). In the multivariate analysis, PA 50 kHz was the only significant factor of MS (OR = 0.01; p = 0.027).

CONCLUSIONS

PA 50 kHz is the best BIA parameter to predict MS in AN patients. It could be useful for assessment before physical activity treatment application.

Hypermetabolism is a reality in amyotrophic lateral sclerosis compared to healthy subjects

RATIONALE

Hypermetabolism (HM) in Amyotrophic lateral sclerosis (ALS) is the reflection of a high energy metabolic level, but this alteration seems controversial. The main objective of the study was to confirm the existence of HM during ALS compared to healthy subjects.

METHODS

A cohort of ALS patients was compared to a control group without metabolic disorder. The assessment included anthropometric criteria measurements, body composition by bioelectric impedance analysis and resting energy expenditure (REE) by indirect calorimetry. HM was defined as a variation > +10% between measured and calculated REE. Statistical analysis used Mann-Withney and Chi2 tests. Multivariate analysis included logistic regression.

RESULTS

287 patients and 75 controls were included. The metabolic level was higher in ALS patients (1500 kcal/24 h [1290-1693] vs. 1230 kcal/24 h [1000-1455], p < 0.0001) as well as the REE/fat free mass ratio (33.5 kcal/kg/24 h [30.4-37.8] vs. 28.3 kcal/kg/24 h [26.1-33.6], p < 0.0001). 55.0% of ALS patients had HM vs. 13.3% of controls (p < 0.0001). HM was strongly and positively associated with ALS (OR = 9.50 [4.49-20.10], p < 0.0001).

CONCLUSIONS

HM in ALS is a reality, which affects more than half of the patients and is associated with ALS. This work confirms a very frequent metabolic deterioration during ALS. The identification of HM can allow a better adaptation of the patients' nutritional intake.

Predictive factors for gastrostomy at time of diagnosis and impact on survival in patients with amyotrophic lateral sclerosis

BACKGROUND

Gastrostomy is recommended in patients with Amyotrophic Lateral Sclerosis (ALS) in the presence of weight loss over 10% as compared to usual weight, repeated aspirations or meal time duration longer than 45 min. Currently, the impact of gastrostomy on survival of ALS patients is not clear.

AIMS

i) to describe diagnosis factors associated with the indication for gastrostomy ii) to evaluate survival of ALS patients with gastrostomy indication according to their acceptance of feeding tube placement.

METHODS

Patients with ALS were included and followed in the ALS referral centre of Limoges's teaching hospital between 2006 and 2017. Neurological, nutritional and respiratory status was assessed prospectively from diagnosis to death. Statistical analysis was performed using Mann-Whitney test, Chi² tests, Cox model and multivariate logistic regression.

RESULTS

Two hundred and eighty-five patients were included. Among the 182 for whom gastrostomy was indicated, 63.7% accepted the placement. The median time was 7.3 months [IQR: 3.2-15.0] and 2.7 months [IQR: 0.9-5.8] respectively from diagnosis to indication and from indication to placement. Weight loss >5% significantly increased the risk of death by 17% (p < 0.0001). At time of diagnosis, bulbar onset, a loss of one point in the body mass index or on the bulbar functional scale were all positively associated with indication for gastrostomy (aOR = 10.0 [95%CI: 1.96-25.0]; p = 0.002, aOR = 1.17 [95%CI: 1.02-1.36]; p = 0.025 and aOR = 1.19 [95%CI: 1.06-1.32]; p = 0.002, respectively). However, gastrostomy placement did not have any impact on survival (aHR = 1.25 [95%CI: 0.88-1.79]; p = 0.22).

CONCLUSION

Both neurological and nutritional criteria were associated with an indication for gastrostomy at diagnosis. Gastrostomy placement had no impact on survival. The study of earlier gastrostomy placement might be of interest in further prospective studies.

Nutritional prognostic factors for survival in amyotrophic lateral sclerosis patients undergone percutaneous endoscopic gastrostomy placement

Objective: There are conflicting data on nutritional factors influencing survival in amyotrophic lateral sclerosis (ALS) patients after percutaneous endoscopic gastrostomy (PEG) placement. We performed an observational cross-sectional study evaluating body mass index (BMI) categories and cholesterol levels as prognostic factors for survival after PEG. Moreover, we assessed body composition in a subgroup of patients to better explain the influence of BMI on survival. Methods: Neurological and nutritional parameters were evaluated at the time of PEG implantation in 47 consecutive patients. Moreover, body composition was evaluated in a subgroup of 22 patients by bioelectrical impedance analysis. Survival was calculated as the time from the PEG placement to death. Results: Underweight patients had a significantly increased risk of death as compared to normal-weight patients using Cox regression analysis [HR = 3.37 (1.29-8.81); p = 0.04]. Similarly, older age at the onset of symptoms significantly increased the risk of death [HR = 1.07 (1.02-1.12); p = 0.001]. Neither overweight/obesity nor hypercholesterolemia affected survival. All ALS patients showed an altered body composition compared to the general population. In addition, a BMI <18.5 kg/m² identified patients with a significant reduction of body cell mass (BCM) and phase angle (PhA) compared to patients with normal BMI taken as the reference value. Conclusions: In the later stages of the disease, only a BMI < 18.5 kg/m² and older age at symptom onset had a prognostic value on survival. Dyslipidemia did not affect survival. The low BCM and PhA characterizing underweight patients support the role of BMI as a predictor of survival.

Anthropometrical and Bioelectrical Impedance Analysis Parameters in Anorexia Nervosa Patients' Nutritional Status Assessment

Background and Objectives: Body mass index (BMI) is still the only recommended measurable nutritional status assessment parameter in anorexia nervosa (AN). The aim of this study was to measure other anthropometrical and bioelectrical impedance analysis (BIA) parameters in AN patients and to evaluate their nutritional status assessment value. Materials and Methods: The 46 AN female patients were examined at the beginning of hospitalization and followed-up in three measurements (in 6 ± 2 weeks’ intervals). Anthropometrical assessment was based on BMI, circumferences of arm, calf, thigh, hips, waist, their ratio (waist-to-hip ratio (WHR)), and a skinfold test over biceps and triceps muscle, under the scapula, over the hip, and 2 cm from the umbilicus. The BIA parameters included phase angle (PA), membrane capacitance (Cm), and impedance at 200 kHz, and a 5 kHz ratio (Z_200/5). Results: In the 1st measurement, BMI correlated with all anthropometric and BIA parameters (p < 0.05). For BIA parameters, the correlation included arm circumference and WHR (p < 0.05). In the follow-up, significant changes were observed in BMI and all BIA parameters. The correlation between BMI and all BIA parameters was present in the 2nd and 3rd measurements (p < 0.05). In the 4th measurement, BMI correlated only with Cm (p = 0.0114). Comparison of BIA parameters according to the state of starvation (BMI < 16.0 kg/m²) revealed that all studied BIA parameters were characterized by statistically significant sensitivity and specificity in the detection of this condition (p < 0.05), except PA in the 4th measurement (p = 0.2099). Conclusions: Selected BIA and anthropometrical parameters could be used for AN patients’ assessment. The study confirmed dynamic changes of BIA parameters during the follow-up. They could be useful in the detection of the state of starvation.

Electrical Changes in Polish Patients with Chronic Heart Failure: Preliminary Observations

Introduction: Direct parameters resistance (R), reactance (Xc), phase angle (PA), capacitance of membrane (Cm), and impedance ratio (Z200/Z5)) determined by bioelectrical impedance analysis (BIA) detect changes in tissue electrical properties and have been found to be a marker of cell membrane function in various diseases. Materials and Method: The cross-sectional study was conducted to investigate whether direct bioimpedance parameters differ in a group of heart failure (HF) patients divided on the basis of the New York Heart Association (NYHA) functional classes I–II and III–IV. BIA was evaluated in 100 patients with HF treated in Clinic of Cardiology and Internal Medicine, Department of Cardiology, Military Hospital, Lublin. Results: In men, lower PA values (p = 0.01), Xc (p < 0.01), Cm (p = 0.02), and higher values of the Z200/Z5 ratio (p < 0.01) were observed in patients classified into NYHA groups III and IV in comparison to those with lower stages of disease. Similar correlations were noted in women (only Cm differences were insignificant). In addition, in men, C-Reactive Protein (CRP) correlated negatively with PA (p < 0.01), Xc (p < 0.01), and Cm (p < 0.01) and positively with the Z200/Z5 index (p < 0.01). There were no similar correlations observed in women. Conclusion: Patients with advanced CHF have altered electrical values. Changes in electrical values may directly reflect tissues as well as the whole-body condition.

Causal effects of blood lipids on amyotrophic lateral sclerosis: a Mendelian randomization study

Amyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disorder that is predicted to increase across the globe by ~70% in the following decades. Understanding the disease causal mechanism underlying ALS and identifying modifiable risks factors for ALS hold the key for the development of effective preventative and treatment strategies. Here, we investigate the causal effects of four blood lipid traits that include high-density lipoprotein, low-density lipoprotein (LDL), total cholesterol and triglycerides on the risk of ALS. By leveraging instrument variables from multiple large-scale genome-wide association studies in both European and East Asian populations, we carry out one of the largest and most comprehensive Mendelian randomization analyses performed to date on the causal relationship between lipids and ALS. Among the four lipids, we found that only LDL is causally associated with ALS and that higher LDL level increases the risk of ALS in both the European and East Asian populations. Specifically, the odds ratio of ALS per 1 standard deviation (i.e. 39.0 mg/dL) increase of LDL is estimated to be 1.14 [95% confidence interval (CI), 1.05–1.24; P = 1.38E-3] in the European population and 1.06 (95% CI, 1.00–1.12; P = 0.044) in the East Asian population. The identified causal relationship between LDL and ALS is robust with respect to the choice of statistical methods and is validated through extensive sensitivity analyses that guard against various model assumption violations. Our study provides important evidence supporting the causal role of higher LDL on increasing the risk of ALS, paving ways for the development of preventative strategies for reducing the disease burden of ALS across multiple nations.

Hypermetabolism is a deleterious prognostic factor in patients with amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

The aim of this study was to investigate patients with amyotrophic lateral sclerosis in order to determine their nutritional, neurological and respiratory parameters, and survival according to metabolic level.

METHODS

Nutritional assessment included resting energy expenditure (REE) measured by indirect calorimetry [hypermetabolism if REE variation (ΔREE) > 10%] and fat mass (FM) using impedancemetry. Neurological assessment included the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised score. Survival analysis used the Kaplan-Meier method and multivariate Cox model.

RESULTS

A total of 315 patients were analysed. Median age at diagnosis was 65.9 years and 55.2% of patients were hypermetabolic. With regard to the metabolic level (ΔREE: < 10%, 10-20% and >20%), patients with ΔREE > 20% initially had a lower FM(29.7% vs. 32.1% in those with ΔREE ≤10%; P = 0.0054). During follow-up, the median slope of Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised tended to worsen more in patients with ΔREE > 20% (-1.4 vs. -1.0 points/month in those with ΔREE ≤10%; P = 0.07). Overall median survival since diagnosis was 18.4 months. ΔREE > 20% tended to increase the risk of dying compared with ΔREE ≤10% (hazard ratio, 1.33; P = 0.055). In multivariate analysis, an increased REE:FM ratio was independently associated with death (hazard ratio, 1.005; P = 0.001).

CONCLUSIONS

Hypermetabolism is present in more than half of patients with amyotrophic lateral sclerosis. It modifies the body composition at diagnosis, and patients with hypermetabolism >20% have a worse prognosis than those without hypermetabolism.

Bioimpedance Measurements in Adolescents with Polycystic Ovary Syndrome: A Pilot Study

Limited data are available on the body composition of adolescent women with polycystic ovary syndrome (PCOS). The aim of this study was to examine differences in body composition indices of metabolism, homeostasis and inflammation, between Greek adolescent females suffering from PCOS and age- and body mass index (BMI)-matched non-PCOS controls. Thirteen PCOS patients and nine non-PCOS controls, aged 13-24 years participated in this cross-sectional study. Study participants underwent assessment by a novel dual frequency bioimpedance device (BIA-ACC). The following body composition indices were measured in each adolescent: extra cellular water (ECW) as inflammation marker, total body water (TBW) as homeostasis marker, extracellular mass to body cell mass ratio (ECM/BCM), fat mass (FM), fat-free mass (FFM) and intracellular water (ICW) as markers of body mass composition and metabolism. Non-linear analysis showed no statistically significant differences in the body composition characteristics between PCOS patients and controls. Further studies with larger sample sizes are needed to confirm whether adolescents with PCOS actually have similar body composition profile with their non-PCOS peers.

Capacitance of Membrane As a Prognostic Indicator of Survival in Head and Neck Cancer

BACKGROUND

Evaluation of prognostic value of capacitance of membrane (Cm), parameter measured by bioelectrical impedance (BIA) as an alternative to known clinical factors in patients with Head and Neck Cancer (HNC).

METHODS

A cohort of 75 stage IIIB and IV HNC patients treated in Department of Otolaryngology, Head and Neck Surgery, Medical University of Lublin, Poland were prospectively evaluated. Cm measurements were performed in all patients using a bioelectrical impedance analyzer that was set on a frequency of 50 kHz. Results of Cm measurements were presented in nF. Survival differences were estimated using Kaplan-Meier method.

RESULTS

Significantly higher Cm median was noted in well-nourished(n = 45) compared to malnourished (n = 30) patients (1.41 vs 1.01 respectively; p = 0.0009). Established in ROC curves analysis cut-off value (0.743) was characterized by 98% specificity and 37% sensitivity in the detection of malnutrition. Median overall survival (mOS) in the cohort was 32months. At the time of analysis deaths were recorded in 47 cases (62.7%). In patients who had Cm below the level of 0.743 risk of OS shortening was significantly higher than in other patients (12.1 and 43.4 months respectively; HR = 8.47, 95%CI: 2.91-24.66; χ2 = 15.38, p = 0.0001).

CONCLUSION

Cm is a strong, independent prognostic factor in head and neck cancer.

Bioelectrical impedance phase angle as a prognostic indicator of survival in head-and-neck cancer

BACKGROUND

Phase angle could be an alternative to subjective global assessment for the assessment of nutrition status in patients with head-and-neck cancer.

METHODS

We prospectively evaluated a cohort of 75 stage iiib and iv head-and-neck patients treated at the Otolaryngology Department, Head and Neck Surgery, Medical University of Lublin, Poland. Bioelectrical impedance analysis was performed in all patients using an analyzer that operated at 50 kHz. The phase angle was calculated as reactance divided by resistance (Xc/R) and expressed in degrees. The Kaplan-Meier method was used to calculate survival.

RESULTS

Median overall survival in the cohort was 32.0 months. At the time of analysis, 47 deaths had been recorded in the cohort (62.7%). The risk of shortened overall survival was significantly higher in patients whose phase angle was less than 4.733 degrees than in the remaining patients (19.6 months vs. 45 months, p = 0.0489; chi-square: 3.88; hazard ratio: 1.8856; 95% confidence interval: 1.0031 to 3.5446).

CONCLUSIONS

Phase angle might be prognostic of survival in patients with advanced head-and-neck cancer. Further investigation in a larger population is required to confirm our results.

Extracellular-to-body cell mass ratio and subjective global assessment in head-and-neck cancers

BACKGROUND

The ratio of extracellular mass to body cell mass (ecm/bcm), determined by bioelectrical impedance analysis, has been found to be a potentially useful indicator of nutrition status. Subjective global assessment (sga) is a subjective method of evaluating nutrition status in head-and-neck cancer. The present study was conducted to investigate the association between ecm/bcm and sga in head-and-neck cancer.

METHODS

Patients were classified as either well-nourished or malnourished by sga. Bioelectrical impedance analysis was conducted on a population of 75 patients with histologically confirmed head-and-neck cancer, and the ecm/bcm was calculated. Receiver operating characteristic curves were estimated using the nonparametric method to determine an optimal cut-off value of the ecm/bcm.

RESULTS

Compared with malnourished patients, those who were well-nourished had a statistically significantly lower ecm/bcm (1.11 vs. 1.28, p = 0.005). An ecm/bcm cut-off of 1.194 was 76% sensitive and 63% specific in detecting malnutrition.

CONCLUSIONS

The ecm/bcm can be an indicator that detects malnutrition in patients with head-and-neck cancer. Further observations are needed to validate the significance of the ecm/bcm and to monitor nutrition interventions.

Body composition analysis in head and neck squamous cell carcinoma

Direct bioimpedance measures [resistance, reactance, phase angle] determined by bioelectrical impedance analysis (BIA) detect changes in tissue electrical properties. Bioelectrical impedance analysis vector (BIVA) technique is a promising tool, using the pure data obtained by BIA evaluation for the screening and monitoring of nutrition and hydration status. BIVA has the potential to be used as a routine method in the clinical setting for the assessment and management of body fluids. The study was conducted to evaluate soft tissue hydration and mass through pattern analysis of vector plots as height, normalized resistance, and reactance measurements by bioelectric impedance vector analysis in patients with head and neck cancer. Whole body measurements were made with ImpediMed bioimpedance analysis in 134 adult, white, male subjects 22–87 years old: 67 patients with head and neck cancer (H&NC) and 67 healthy volunteers matched by sex, age and BMI as a control group. All patients were previously untreated and without active nutritional interventions. Mean vectors of H&NC group versus the control group were characterized by an increased normalized resistance component with a reduced reactance component (separate 95 % confidence limits, P < 0.05). BIVA may offer objective measures to improve clinical decision-making and predict outcomes. In patients with H&NC to reduce post-operational complications monitoring bioimpedance vector trajectory may support therapy planning of individual patients before surgery.

Adipose Tissue Distribution Predicts Survival in Amyotrophic Lateral Sclerosis

Background

amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that leads to death within a few years after diagnosis. Malnutrition and weight loss are frequent and are indexes of poor prognosis. Total body fat and fat distribution have not been studied in ALS patients.

Objectives

Our aim was to describe adipose tissue content and distribution in ALS patients.

Design

We performed a cross-sectional study in a group of ALS patients (n = 62, mean disease duration 22 months) along with age and gender matched healthy controls (n = 62) using a MRI-based method to study quantitatively the fat distribution.

Results

Total body fat of ALS patients was not changed as compared with controls. However, ALS patients displayed increased visceral fat and an increased ratio of visceral to subcutaneous fat. Visceral fat was not correlated with clinical severity as judged using the ALS functional rating scale (ALS-FRS-R), while subcutaneous fat in ALS patients correlated positively with ALS-FRS-R and disease progression. Multiple regression analysis showed that gender and ALS-FRS-R, but not site of onset, were significant predictors of total and subcutaneous fat. Increased subcutaneous fat predicted survival in male patients but not in female patients (p<0.05).

Conclusions

Fat distribution is altered in ALS patients, with increased visceral fat as compared with healthy controls. Subcutaneous fat content is a predictor of survival of ALS patients.

Nutrition assessment and management in amyotrophic lateral sclerosis

In recent years nutrition assessment and management in amyotrophic lateral sclerosis (ALS) have drawn increased attention. Frequent evaluation of nutrition status is warranted in ALS, given the common occurrence of dysphagia and hypermetabolism and varying disease progression rates. Nutrition management includes dietary and swallow strategies, possible gastrostomy tube placement, and recommendations for vitamin and mineral supplementation. Strategies to assess and optimize nutrition status and prolong survival in ALS patients are reviewed with recommendations based on current research.

Energy requirement assessed by doubly-labeled water method in patients with advanced amyotrophic lateral sclerosis managed by tracheotomy positive pressure ventilation

This study aimed to clarify the energy requirement in patients with amyotrophic lateral sclerosis (ALS) undergoing tracheostomy positive pressure ventilation with tracheostomy. Total energy expenditure (TEE) was measured in 10 hospitalized bedridden ALS patients using the doubly-labeled water (DLW) method. The mean TEE/day and TEE/fat- free mass estimated by DLW method were 934 ± 201 kcal/day and 34.8 ± 5.5 kcal/kg/day, respectively. The mean TEE/resting metabolic rate (RMR) was 0.85 when RMR was estimated by the Harris-Benedict equation, 0.91 by Dietary Reference Intake (DRI), and 0.97 by Ganpule's equation using fat-free mass (FFM). The ratios of TEE to measured RMR were 1.05, 1.15 and 1.23 in three patients. In conclusion, multiplying measured RMR by 1.1 to 1.2 is considered to be appropriate to estimate energy need. However, because it is difficult to measure RMR directly in a clinical setting, an appropriate equation for estimating RMR for ALS patient should be developed.

Altered tissue electrical properties in squamous cell carcinoma in head and neck tumors: Preliminary observations

BACKGROUND

The purpose of this study was to investigate tissue electrical properties in patients with head and neck cancer.

METHODS

In the cross-sectional study direct bioimpedance measures (resistance, reactance, and phase angle) determined by bioelectrical impedance analysis (BIA) were performed on 31 patients with head and neck cancer and 31 healthy volunteers matched by age and sex as a control group.

RESULTS

Phase angle at 50 kHz was found to be significantly lower (p = .000006) in patients with head and neck cancer than in the control group (4.69° ± 0.71 vs 5.59° ± 0.70, respectively). Resistance was significantly (p = .0002) greater in patients with head and neck cancer than in the control group (596.24 ± 96.31 ohm vs 513.73 ± 65.79 ohm, respectively).

CONCLUSION

Presurgical patients diagnosed with head and neck cancer have altered tissue electrical properties. Further observations would be valuable to calculate survival, validate the prognostic significance of phase angle, and monitor nutritional and therapeutic interventions in this patient population.

First assessment at home of amyotrophic lateral sclerosis (ALS) patients by a nutrition network in the French region of Limousin

Malnutrition is associated with poor survival among patients with amyotrophic lateral sclerosis (ALS). This study aimed to evaluate nutritional assessment by a network during first consultations in patients' homes. Patients identified by the regional ALS centre gave their informed consent. Assessment included functional, nutritional issues, evaluation of the need for help, whether personal or the use of aids, and noted any dietary supplementation and modification of the texture of food. Forty patients were seen a mean of 7.4 months after diagnosis; 52.5% had bulbar disease, 7.5% were malnourished; 29.4 ± 10.1 kcal/kg/day were consumed and protein intake was 1.3 ± 0.5 g/kg/day. Thirty-five percent of patients were anorexic, 43.8% reported taste disorders, and 70% had dysphagia, significantly associated with salivary stasis. Only 30% of dysphagic patients ate texture-modified food, and 90% of patients with problems drinking liquids did not use a thickener. In conclusion, assessment at home by a nutritional network can be conducted promptly. Malnutrition is rare in early disease, despite the fact that patients' diets are often low in energy and dysphagia is common. Unexpected taste disorders are detected. Dysphagia is very common but inadequately addressed. Consequently, home assessment by the network led several beneficial interventions.

Which equation best predicts energy expenditure in amyotrophic lateral sclerosis?

OBJECTIVE

The purpose of this study was to compare measured resting energy expenditure (REE) with estimates from three common prediction equations with the goal of determining which equation best estimates REE in amyotrophic lateral sclerosis (ALS).

DESIGN

Cross-sectional measurements of REE from indirect calorimetry were compared to calculations from the Harris Benedict, Mifflin-St Jeor, and Ireton-Jones equations. Additional measurements to identify predictors of REE included pulmonary function tests, fat-free mass by bioelectrical impedance, and anthropometrics.

SUBJECTS/SETTING

Participants were 56 men and women with ALS. For comparison, subjects were categorized by disease progression into three groups.

STATISTICAL ANALYSES

Pearson correlations and paired t tests were used to compare measured REE with predicted REE from each equation, and the accuracy of each equation was quantified by the root mean squared prediction error and the percentage of REE estimates within 10% of measured values. Bias for each equation was calculated as the mean percentage difference between calculated and measured REE. Multiple linear regression was used to determine the best predictor variables for REE.

RESULTS

Across the disease spectrum, the Harris Benedict and Mifflin-St Jeor equations provided clinically acceptable estimates of REE, whereas the Ireton-Jones equations consistently overestimated REE. The best predictors of REE among this cohort were fat-free mass, sex, and age.

CONCLUSIONS

When estimating energy requirements for patients with ALS, clinicians should choose prediction equations that incorporate sex and age as predictor variables, such as the Harris Benedict and Mifflin-St Jeor equations.

Bioelectrical impedance analysis can be a useful screen for excess adiposity in spinal muscular atrophy

Accurate, noninvasive measures of body composition are needed for management of patients with spinal muscular atrophy. Fat mass index (fat mass/height(2) in kg/m(2)) was measured in 16 subjects with spinal muscular atrophy using 5 bioelectrical impedance analysis equations and compared with a reference method, dual-energy x-ray absorptiometry. The machine default equation, validated by Cordain, was the primary analysis. Fat mass index calculated by impedance measures differed by between -2.5 kg/m(2) and 1.7 kg/m(2) from the reference mean (8.3 ± 5.0 kg/m(2)). The Cordain equation provided the smallest difference (-0.4 ± 2.0 kg/m(2)), with correlation coefficient of 0.92. The Cordain equation showed high sensitivity (85.7%) and specificity (100%) for prediction of ''at risk for overweight'' (fat mass index > 85th percentile for age and gender). Although insufficiently accurate for use as a research tool, bioelectrical impedance can have application as a well-tolerated, noninvasive, easily used screening tool for excess adiposity in patients with spinal muscular atrophy.

Bioelectrical impedance analysis in clinical practice: implications for hepatitis C therapy BIA and hepatitis C

Background

Body composition analysis using phase angle (PA), determined by bioelectrical impedance analysis (BIA), reflects tissue electrical properties and has prognostic value in liver cirrhosis. Objective of this prospective study was to investigate clinical use and prognostic value of BIA-derived phase angle and alterations in body composition for hepatitis C infection (HCV) following antiviral therapy.

Methods

37 consecutive patients with HCV infection were enrolled, BIA was performed, and PA was calculated from each pair of measurements. 22 HCV genotype 3 patients treated for 24 weeks and 15 genotype 1 patients treated for 48 weeks, were examined before and after antiviral treatment and compared to 10 untreated HCV patients at 0, 24, and 48 weeks. Basic laboratory data were correlated to body composition alterations.

Results

Significant reduction in body fat (BF: 24.2 ± 6.7 kg vs. 19.9 ± 6.6 kg, genotype1; 15.4 ± 10.9 kg vs. 13.2 ± 12.1 kg, genotype 3) and body cell mass (BCM: 27.3 ± 6.8 kg vs. 24.3 ± 7.2 kg, genotype1; 27.7 ± 8.8 kg vs. 24.6 ± 7.6 kg, genotype 3) was found following treatment. PA in genotype 3 patients was significantly lowered after antiviral treatment compared to initial measurements (5.9 ± 0.7° vs. 5.4 ± 0.8°). Total body water (TBW) was significantly decreased in treated patients with genotype 1 (41.4 ± 7.9 l vs. 40.8 ± 9.5 l). PA reduction was accompanied by flu-like syndromes, whereas TBW decline was more frequently associated with fatigue and cephalgia.

Discussion

BIA offers a sophisticated analysis of body composition including BF, BCM, and TBW for HCV patients following antiviral regimens. PA reduction was associated with increased adverse effects of the antiviral therapy allowing a more dynamic therapy application.

High metabolic level in patients with familial amyotrophic lateral sclerosis

An abnormally elevated level of resting energy expenditure (REE, measured by indirect calorimetry) has been reported in a subset of patients with sporadic amyotrophic lateral sclerosis (SALS). Hypermetabolism (measured REE/calculated REE (cREE)> or =1.1, or 110%) has also been observed in transgenic mice harbouring ALS-causing mutations in the SOD1 gene. By contrast, the REE of patients with familial amyotrophic lateral sclerosis (FALS) has never been assessed. Our objective was to evaluate the metabolic and nutritional parameters of FALS patients and to compare them with those of SALS patients, and search for correlations with clinical parameters. Eleven patients with FALS (from 10 different families, none carrying a SOD1 mutation) were evaluated by indirect calorimetry in our centre. As a control group, we used a sample of 33 patients with SALS, matched for age and sex with the FALS patients. 11/11 (100%) patients with FALS were hypermetabolic, compared to 17/33 (52%) patients with SALS (p=0.009). Measured REE (mREE) and mREE/cREE (metabolic level) were significantly higher in FALS patients than in SALS patients (p=0.03 and p=0.0008, respectively). No correlation was found between metabolic measures and neurological or respiratory parameters. In conclusion, hypermetabolism appears to be a common feature of subjects with FALS, suggesting that this impairment of energy homeostasis may be genetically driven. The high metabolic level of FALS patients should be taken into account for their nutritional management (need for a high-energy diet to prevent malnutrition).