Improvement of nutritional status as assessed by multifrequency BIA during 15 weeks of refeeding in adolescent girls with anorexia nervosa

Body composition and energy expenditure in anorexia nervosa: preliminary data of outpatients with recovering and active disease

BACKGROUND

In Anorexia Nervosa (AN) recovery, body mass index (BMI) may not reflect body composition. To investigate recovery, bioelectrical impedance (BIA) parameters and energy expenditure were investigated in patients with active and recovering AN, with emphasis on phase angle (PA), a BIA parameter.

METHODS

BMI, PA, indirect BIA parameters (fat free mass, fat mass, total body water, fat free mass index, fat mass index) and resting metabolic rate (RMR) were obtained. Data from subjects distributed to active AN (ANact, n = 9), recovered AN (ANrec, n = 9) and healthy individuals (HI) (n = 16) were compared employing univariate methods and ordinal logistic regression.

RESULTS

In univariate comparison, the BMI would not distinguish recovered individuals; this distinction was observed for the PA (p =  < 0,001). PA showed a good capacity to discriminate, between ANrec and HI (AUC = 0.792; CI = 0.564- 1.000; p = 0.017). In 2 models of ordinal logistic regression PA (OR = 0.123; 95% CI 0.030; 0.503 and OR = 0.091; 95% CI 0.016; 0.528) remained as a significant independent variable, indicating that increases in PA are related to higher probabilities of moving from ANact, to ANrec and to HI group. Bivariate regression indicated the presence of a relationship between PA and (R2 = 0.266, p = 0.002).

CONCLUSIONS

Changes in body composition and energy expenditure were observed in recovered anorexics with normal BMI. PA can play an important role in the assessment of recovering anorexic patients.

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.

The Predictive Role of Raw Bioelectrical Impedance Variables in Disordered Eating Attitudes in Female Ballet Dance Students

The present study used receiver operating characteristic (ROC) curve analysis to investigate the accuracy of body composition and raw bioelectrical impedance analysis (BIA) in correctly classifying disordered eating attitudes (DEA) in dance students. Participants were 81 female dancers assigned in two groups: beginner training (BT; age (mean ± SD) = 10.09 ± 1.2 years, n = 32) and advanced training (AT; age = 15.37 ± 2.1 years, n = 49). Fat mass (FM) was estimated by Slaughter's equation and skeletal muscle with Poortman's equation. Impedance (Z), resistance (R), reactance (Xc) and phase angle (PhA) were obtained through multifrequency BIA at a frequency of 50 kHz. Fat-free mass (FFM) was assessed using Sun's equation. For evaluation of DEA, the Eating Attitudes Test-26 (EAT-26) questionnaire was performed. We defined an EAT-26 score ≥ 20 as positive for DEA. Comparisons between groups were performed by a one-way ANOVA test or Kruskall-Wallis test. Spearman's rank correlation coefficients were performed to assess associations between variables. ROC curve analysis was utilized to test the accuracy of body composition and BIA variables in predicting DEA. In the BT group, Xc and PhA demonstrated high accuracy in predicting DEA with an area under the curve (AUC) of 0.976 (95% confidence interval (CI): 0.85-1.00) and 0.957 (95% CI: 0.82-0.99), respectively, (both p < 0.0001). FFM Sun had an AUC of 0.836 (95% CI: 0.66-0.94) (p < 0.0001) in the BT group and FFM Slaughter was 0.797 (95% CI: 0.66-0.90) (p < 0.001) in the AT group. Reactance and Phase angle were excellent and useful predictors of DEA in the BT group.

Clinical, Psychopathological, Physical, and Sleep Evolution in Adolescents with Restrictive Anorexia Nervosa Participating in a Day Hospital Program

OBJECTIVE

To analyze the clinical, psychopathological, physical, and sleep-related evolution of adolescents with restricting-type of anorexia nervosa (AN-R) after 10 weeks of a daytime hospital program.

METHODS

Body composition, physical activity and sleep were measured objectively before and after 10 weeks of treatment. In addition, psychopathology and body image disturbances were measured with a self-report questionnaire.

RESULTS

Fourteen female adolescents with AN-R (14.3±1.6 years old) participated in the study. A significant increase was found in eight of the ten variables for body composition (p<0.05). There were no significant changes in psychopathology, body image disturbances or physical activity. Concerning sleep, a significant, moderately standardized and substantial increase in night latency was found (p=0.002), and there was a significant, small standardized and substantial decrease in night efficiency (p=0.035).

CONCLUSION

After 10 weeks of follow-up with adolescent patients with AN-R who attended a day hospital program, there was a positive evolution of body composition. However, with regard to sleep patterns, there was a worsening of latency and night efficiency. Therefore, sleep care should be addressed in acute treatment programs for adolescents with AN-R.

Body composition in anorexia nervosa: Meta-analysis and meta-regression of cross-sectional and longitudinal studies

OBJECTIVE

Clinically, anorexia nervosa (AN) presents with altered body composition. We quantified these alterations and evaluated their relationships with metabolites and hormones in patients with AN longitudinally.

METHOD

In accordance with PRISMA guidelines, we conducted 94 meta-analyses on 62 samples published during 1996-2019, comparing up to 2,319 pretreatment, posttreatment, and weight-recovered female patients with AN with up to 1,879 controls. Primary outcomes were fat mass, fat-free mass, body fat percentage, and their regional distribution. Secondary outcomes were bone mineral density, metabolites, and hormones. Meta-regressions examined relationships among those measures and moderators.

RESULTS

Pretreatment female patients with AN evidenced 50% lower fat mass (mean difference [MD]: -8.80 kg, 95% CI: -9.81, -7.79, Q = 1.01 × 10-63 ) and 4.98 kg (95% CI: -5.85, -4.12, Q = 1.99 × 10-28 ) lower fat-free mass, with fat mass preferentially stored in the trunk region during early weight restoration (4.2%, 95% CI: -2.1, -6.2, Q = 2.30 × 10-4 ). While the majority of traits returned to levels seen in healthy controls after weight restoration, fat-free mass (MD: -1.27 kg, 95% CI: -1.79, -0.75, Q = 5.49 × 10-6 ) and bone mineral density (MD: -0.10 kg, 95% CI: -0.18, -0.03, Q = 0.01) remained significantly altered.

DISCUSSION

Body composition is markedly altered in AN, warranting research into these phenotypes as clinical risk or relapse predictors. Notably, the long-term altered levels of fat-free mass and bone mineral density suggest that these parameters should be investigated as potential AN trait markers.

RESUMENOBJETIVO

Clínicamente, la anorexia nervosa (AN) se presenta con alteraciones en la composición corporal. Cuantificamos estas alteraciones y evaluamos longitudinalmente su relación con metabolitos y hormonas en pacientes con AN. MÉTODO: De acuerdo con las pautas PRISMA, realizamos 94 meta-análisis en 62 muestras publicadas entre 1996-2019, comparando hasta 2,319 pacientes mujeres en pre-tratamiento, post-tratamiento, y recuperadas en base al peso con hasta 1,879 controles. Las principales medidas fueron masa grasa, masa libre de grasa, porcentaje de grasa corporal y su distribución regional. Las medidas secundarias fueron densidad mineral ósea, metabolitos y hormonas. Las meta-regresiones examinaron las relaciones entre esas medidas y moderadores.

RESULTADOS

Las pacientes femeninas con AN pre-tratamiento mostraron un 50% menos de masa grasa (MD: -8.80 kg, CI 95%: -9.81, -7.79, Q = 1.01 × 10-63 ) y 4.98 kg (CI 95%: -5.85, -4.12, Q = 1.99 × 10-28 ) menos de masa libre de grasa, con masa grasa preferentemente almacenada en la región del tronco durante la recuperación temprana del peso (4.2%, CI 95%: -2.1, -6.2, Q = 2.30 × 10-4 ). Aunque la mayoría de los rasgos regresaron a los niveles vistos en los controles sanos después de la restauración del peso, la masa libre de grasa (MD: -1.27 kg, CI 95%: -1.79, -0.75, Q = 5.49 × 10-6 ) y la densidad mineral ósea (MD: -0.10 kg, CI 95%: -0.18, -0.03, Q = 0.01) permanecieron significativamente alteradas. DISCUSIÓN: La composición corporal es marcadamente alterada en la AN, lo que garantiza la investigación en estos fenotipos como predictores de riesgo clínico o de recaída. Notablemente, la alteración a largo plazo de los niveles de masa libre de grasa y densidad mineral ósea sugieren que estos parámetros debe ser investigados como potenciales rasgos indicadores de AN.

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.

Feasibility and acceptability of the Bod Pod procedure and changes in body composition from admission to discharge in adolescents hospitalized with eating disorders

The feasibility and acceptability of using the Bod Pod procedure to measure changes in body composition in 30 adolescent females admitted to an inpatient eating disorder unit was evaluated using written surveys, Bod Pod measurements obtained at admission and discharge, and medical records review. Participants rated the Bod Pod test as acceptable (100%; 30/30), comfortable (93%, 28/30), and they were willing to repeat the procedure (97%, 29/30). Ten participants did not complete the final Bod Pod: eight were discharged before a second measure could be obtained, one refused the test, and one left against medical advice. Three participants had undetectable readings at admission. Paired t-tests (n = 17) revealed a significant (p < 0.001) mean increase in fat mass (3.7 ± 2 kg), body fat percentage (6.6 ± 3.8%), and lean mass (1.4 ± 1.2 kg) from admission to discharge. The Bod Pod is a feasible and acceptable procedure to measure changes in body composition in adolescent females hospitalized with an eating disorder.

Changes in Body Composition in Anorexia Nervosa: Predictors of Recovery and Treatment Outcome

The restoration of body composition (BC) parameters is considered to be one of the most important goals in the treatment of patients with anorexia nervosa (AN). However, little is known about differences between AN diagnostic subtypes [restricting (AN-R) and binge/purging (AN-BP)] and weekly changes in BC during refeeding treatment. Therefore, the main objectives of our study were twofold: 1) to assess the changes in BC throughout nutritional treatment in an AN sample and 2) to analyze predictors of BC changes during treatment, as well as predictors of treatment outcome. The whole sample comprised 261 participants [118 adult females with AN (70 AN-R vs. 48 AN-BP), and 143 healthy controls]. BC was measured weekly during 15 weeks of day-hospital treatment using bioelectrical impedance analysis (BIA). Assessment measures also included the Eating Disorders Inventory-2, as well as a number of other clinical indices. Overall, the results showed that AN-R and AN-BP patients statistically differed in all BC measures at admission. However, no significant time×group interaction was found for almost all BC parameters. Significant time×group interactions were only found for basal metabolic rate (p = .041) and body mass index (BMI) (p = .035). Multiple regression models showed that the best predictors of pre-post changes in BC parameters (namely fat-free mass, muscular mass, total body water and BMI) were the baseline values of BC parameters. Stepwise predictive logistic regressions showed that only BMI and age were significantly associated with outcome, but not with the percentage of body fat. In conclusion, these data suggest that although AN patients tended to restore all BC parameters during nutritional treatment, only AN-BP patients obtained the same fat mass values as healthy controls. Put succinctly, the best predictors of changes in BC were baseline BC values, which did not, however, seem to influence treatment outcome.

The efficacy of Bioelectrical Impedance Analysis (BIA) in monitoring body composition changes during treatment of restrictive eating disorder patients

REVIEWS

Treating restrictive eating disorder patients is metabolically and psychologically complex. Determining body composition is an important diagnostic and treatment option for these patients, because it ascertains whether the acquisition of body mass during refeeding is metabolically appropriate - ideally an approximate 20/80% - 25/75% fat/lean body mass ratio. The purpose of this paper is to evaluate the efficacy of Bioelectrical Impedance Analysis (BIA) during the treatment period of patients with restrictive eating disorders. The search engines PubMed, Medline, and MSN were utilized using combinations of key words, "Bioimpedance Analysis", "body composition determination", "eating disorders", and "anorexia".

CONCLUSIONS

The literature indicates that the use of Bioelectrical Impedance Analysis (BIA) in eating disorder patients to be efficacious in determining body composition during the treatment period, and that only assessing weight changes does not necessarily reflect specific changes in various body compartments. Also, utilizing BIA has the advantage of using each patient as his/her own "control", potentially allowing for a more individualized nutrition regimen according to the body composition changes observed during treatment.

Evaluation of nutritional indicators and body composition in patients with advanced liver disease enrolled for liver transplantation

PURPOSE

Malnutrition is prevalent in patients with advanced liver disease (LD) related to multifactorial causes. Fluid retention can underestimate the nutritional status based on anthropometric measures. We evaluated nutritional indicators and body composition (BC) in patients with liver cirrhosis and correlated them with LD severity.

METHODS

Forty three patients with LD enrolled for liver transplantation were evaluated by Anthropometric measures, subjective evaluation (Global Assessment of Nutritional Status - SGA) and biochemical indicators. Single-frequency electrical bioimpedance (SFE-BIA) was used to evaluate body composition (BC). It measured resistance (R), reactance (Xc) and the phase angle (PA). LD severity was estimated by Child-Pugh and Meld criteria (Model for End-Stage Liver Disease).

RESULTS

Child-Pugh index between patients was 7.11 ± 1.70 and Meld was 12.23 ± 4.22. Arm Circumference, Arm Muscle Circumference and Arm Muscle Area, SGA, hemoglobin, hematocrit and albumin showed better correlation with disease severity. Xc and PA showed correlation both with Meld and Child-Pugh score when BC were evaluated. PA was depleted in 55.8% of the patients.

CONCLUSIONS

Diagnosis of malnutrition varied according to the method. Global assessment of nutritional status showed better correlation with disease severity than with objective methods. Single-frequency electrical bioimpedance for body composition analysis in cirrhotic patients must be cautiously used; however, primary vectors seems to be valid and promising in clinical practice.

Higher calorie diets increase rate of weight gain and shorten hospital stay in hospitalized adolescents with anorexia nervosa

PURPOSE

Current recommendations for refeeding in anorexia nervosa (AN) are conservative, beginning around 1,200 calories to avoid refeeding syndrome. We previously showed poor weight gain and long hospital stay using this approach and hypothesized that a higher calorie approach would improve outcomes.

METHODS

Adolescents hospitalized for malnutrition due to AN were included in this quasi-experimental study comparing lower and higher calories during refeeding. Participants enrolled between 2002 and 2012; higher calories were prescribed starting around 2008. Daily prospective measures included weight, heart rate, temperature, hydration markers and serum phosphorus. Participants received formula only to replace refused food. Percent Median Body Mass Index (%MBMI) was calculated using 50th percentile body mass index for age and sex. Unpaired t-tests compared two groups split at 1,200 calories.

RESULTS

Fifty-six adolescents with mean (±SEM) age 16.2 (±.3) years and admit %MBMI 79.2% (±1.5%) were hospitalized for 14.9 (±.9) days. The only significant difference between groups (N = 28 each) at baseline was starting calories (1,764 [±60] vs. 1,093 [±28], p < .001). Participants on higher calories had faster weight gain (.46 [±.04] vs. .26 [±.03] %MBMI/day, p < .001), greater daily calorie advances (122 [±8] vs. 98 [±6], p = .024), shorter hospital stay (11.9 [±1.0] vs. 17.6 [±1.2] days, p < .001), and a greater tendency to receive phosphate supplementation (12 vs. 8 participants, p = .273).

CONCLUSIONS

Higher calorie diets produced faster weight gain in hospitalized adolescents with AN as compared with the currently recommended lower calorie diets. No cases of the refeeding syndrome were seen using phosphate supplementation. These findings lend further support to the move toward more aggressive refeeding in AN.

The diagnostic accuracy of multi-frequency bioelectrical impedance analysis in diagnosing dehydration after stroke

Background

Non-invasive methods for detecting water-loss dehydration following acute stroke would be clinically useful. We evaluated the diagnostic accuracy of multi-frequency bioelectrical impedance analysis (MF-BIA) against reference standards serum osmolality and osmolarity.

Material/Methods

Patients admitted to an acute stroke unit were recruited. Blood samples for electrolytes and osmolality were taken within 20 minutes of MF-BIA. Total body water (TBW%), intracellular (ICW%) and extracellular water (ECW%), as percentages of total body weight, were calculated by MF-BIA equipment and from impedance measures using published equations for older people. These were compared to hydration status (based on serum osmolality and calculated osmolarity). The most promising Receiver Operating Characteristics curves were plotted.

Results

27 stroke patients were recruited (mean age 71.3, SD10.7). Only a TBW% cut-off at 46% was consistent with current dehydration (serum osmolality >300 mOsm/kg) and TBW% at 47% impending dehydration (calculated osmolarity ≥295–300 mOsm/L) with sensitivity and specificity both >60%. Even here diagnostic accuracy of MF-BIA was poor, a third of those with dehydration were wrongly classified as hydrated and a third classified as dehydrated were well hydrated. Secondary analyses assessing diagnostic accuracy of TBW% for men and women separately, and using TBW as a percentage of lean body mass showed some promise, but did not provide diagnostically accurate measures across the population.

Conclusions

MF-BIA appears ineffective at diagnosing water-loss dehydration after stroke and cannot be recommended as a test for dehydration, but separating assessment by sex, and using TBW as a percentage of lean body weight may warrant further investigation.

Impact of sarcopenia on survival in patients undergoing living donor liver transplantation

Skeletal muscle depletion, referred to as sarcopenia, predicts morbidity and mortality in patients undergoing digestive surgery. However, the impact on liver transplantation is unclear. The present study investigated the impact of sarcopenia on patients undergoing living donor liver transplantation (LDLT). Sarcopenia was assessed by a body composition analyzer in 124 adult patients undergoing LDLT between February 2008 and April 2012. The correlation of sarcopenia with other patient factors and the impact of sarcopenia on survival after LDLT were analyzed. The median ratio of preoperative skeletal muscle mass was 92% (range, 67-130%) of the standard mass. Preoperative skeletal muscle mass was significantly correlated with the branched-chain amino acids to tyrosine ratio (r = -0.254, p = 0.005) and body cell mass (r = 0.636, p < 0.001). The overall survival rate in patients with low skeletal muscle mass was significantly lower than in patients with normal/high skeletal muscle mass (p < 0.001). Perioperative nutritional therapy significantly increased overall survival in patients with low skeletal muscle mass (p = 0.009). Multivariate analysis showed that low skeletal muscle mass was an independent risk factor for death after transplantation. In conclusion, sarcopenia was closely involved with posttransplant mortality in patients undergoing LDLT. Perioperative nutritional therapy significantly improved overall survival in patients with sarcopenia.

A prospective examination of weight gain in hospitalized adolescents with anorexia nervosa on a recommended refeeding protocol

PURPOSE

Current refeeding recommendations for adolescents hospitalized with anorexia nervosa (AN) are conservative, starting with low calories and advancing slowly to avoid refeeding syndrome. The purpose of this study was to examine weight change and clinical outcomes in hospitalized adolescents with AN on a recommended refeeding protocol.

METHODS

Adolescents aged 13.1-20.5 years were followed during hospitalization for AN. Weight, vital signs, electrolytes, and 24-hour fluid balance were measured daily. Percent median body mass index (%MBMI) was calculated as 50th percentile BMI for age and gender. Calories were prescribed on admission and were increased every other day.

RESULTS

Thirty-five subjects with a mean (SD) age of 16.2 (1.9) years participated over 16.7 (6.4) days. Calories increased from 1,205 (289) to 2,668 (387). No subjects had refeeding syndrome; 20% had low serum phosphorus. Percent MBMI increased from 80.1 (11.5) to 84.5 (9.6); overall gain was 2.10 (1.98) kg. However, 83% of subjects initially lost weight. Mean %MBMI did not increase significantly until day 8. Higher calories prescribed at baseline were significantly associated with faster weight gain (p = .003) and shorter hospital stay (p = .030) in multivariate regression models adjusted for %MBMI and lowest heart rate on admission.

CONCLUSIONS

Hospitalized adolescents with AN demonstrated initial weight loss and slow weight gain on a recommended refeeding protocol. Higher calorie diets instituted at admission predicted faster weight gain and shorter hospital stay. These findings support the development of more aggressive feeding strategies in adolescents hospitalized with AN. Further research is needed to identify caloric and supplementation regimens to maximize weight gain safely while avoiding refeeding syndrome.

Steroid metabolism and excretion in severe anorexia nervosa: effects of refeeding

BACKGROUND

To our knowledge, changes in steroid metabolism in subjects with anorexia nervosa (AN) after weight gain have not been elucidated.

OBJECTIVE

We characterized urinary steroid excretion and metabolism in AN patients and investigated the effects of refeeding.

DESIGN

In an intervention study, we recruited 7 women with life-threatening weight loss upon admission and after a median [interquartile range (IQR)] of 95 d (88-125 d) of intensive refeeding; 15 age-matched women were recruited as control subjects. The major urinary metabolites were quantified in 24-h collections by capillary gas chromatography. A single examiner measured weights, heights, and skinfold thicknesses.

RESULTS

The median (IQR) age of patients was 24 y (21-26 y), and the duration of AN was 4.0 y (3.3-8.0 y). Body mass index (BMI; in kg/m(2)) increased from 12.8 (12.7-13.1) to 18.6 (18.0-19.6) after refeeding (P < 0.0001). Steroid values [median pre-, post-refeeding (P value)] were as follows: androgen metabolites [472, 1017 μg/24 h (0.93)], cortisol metabolites [1960, 3912 μg/24 h (0.60)], and ratios of androsterone (5α)/etiocholanolone (5β) [0.28, 0.63 (<0.001)], 5α-/5β-tetrahydrocortisol [0.20, 0.48 (0.02)], tetrahydrocortisols/tetrahydrocortisone [0.87, 0.61 (0.09)], 20-hydroxy-/20-oxocortisol metabolites [0.29, 0.47 (0.01)], and 20α-/20β-reduced cortisol metabolites [1.18, 1.89 (≥1.00)]. BMI change was positively correlated with 5α-/5β-tetrahydrocortisol (r = 0.95, P < 0.001). Before refeeding, the following metabolites were lower in patients than in control subjects: androsterone, 5α-tetrahydrocortisol, α-cortolone and α-cortol, 5α-/5β-tetrahydrocortisol, androsterone/etiocholanolone, and 20-hydroxy/20-oxocortisol (all P < 0.05). After refeeding, all steroid metabolites in patients were at concentrations that were comparable with those in control subjects.

CONCLUSIONS

Significant changes in urine steroid-metabolite excretion occurred upon starvation, which were reversed upon refeeding. For cortisol, there were decreases in 5α-/5β-tetrahydrocortisol and 20-hydroxy-/20-oxometabolites; for androgen, there was a decrease in androsterone/etiocholanolone.

Anorexia nervosa and nutritional assessment: contribution of body composition measurements

The psychiatric condition of patients suffering from anorexia nervosa (AN) is affected by their nutritional status. An optimal assessment of the nutritional status of patients is fundamental in understanding the relationship between malnutrition and the psychological symptoms. The present review evaluates some of the available methods for measuring body composition in patients with AN. We searched literature in Medline using several key terms relevant to the present review in order to identify papers. Only articles in English or French were reviewed. A brief description is provided for each body composition technique, with its applicability in AN as well as its limitation. All methods of measuring body composition are not yet validated and/or feasible in patients with AN. The present review article proposes a practical approach for selecting the most appropriate methods depending on the setting, (i.e. clinical v. research) and the goal of the assessment (initial v. follow-up) in order to have a more personalised treatment for patients suffering from AN.

Dietary modulation of body composition and insulin sensitivity during catch-up growth in rats: effects of oils rich in n-6 or n-3 PUFA

The present study investigates whether excessive fat accumulation and hyperinsulinaemia during catch-up growth on high-fat diets are altered by n-6 and n-3 PUFA derived from oils rich in either linoleic acid (LA), α-linolenic acid (ALA), arachidonic acid (AA) or DHA. It has been shown that, compared with food-restricted rats refed a high-fat (lard) diet low in PUFA, those refed isoenergetically on diets enriched in LA or ALA, independently of the n-6:n-3 ratio, show improved insulin sensitivity, lower fat mass and higher lean mass, the magnitude of which is related to the proportion of total PUFA precursors (LA+ALA) consumed. These relationships are best fitted by quadratic regression models (r2>0·8, P < 0·001), with threshold values for an impact on body composition corresponding to PUFA precursors contributing 25-30 % of energy intake. Isoenergetic refeeding on high-fat diets enriched in AA or DHA also led to improved body composition, with increases in lean mass as predicted by the quadratic model for PUFA precursors, but decreases in fat mass, which are disproportionately greater than predicted values; insulin sensitivity, however, was not improved. These findings pertaining to the impact of dietary intake of PUFA precursors (LA and ALA) and their elongated-desaturated products (AA and DHA), on body composition and insulin sensitivity, provide important insights into the search for diets aimed at counteracting the pathophysiological consequences of catch-up growth. In particular, diets enriched in essential fatty acids (LA and/or ALA) markedly improve insulin sensitivity and composition of weight regained, independently of the n-6:n-3 fatty acid ratio.

BMI, body composition, and the energy requirement for body weight gain in patients with anorexia nervosa

OBJECTIVE

Theories abound about the energy requirements for body weight gain in anorexia nervosa (AN). We hypothesized that malnutrition status affects the energy requirements.

METHOD

On admission, 97 AN patients were measured for body composition by dual-energy X-ray absorptiometry. The relationship between body mass index (BMI) and body composition was investigated. In addition, 21 patients who completed our treatment program were tested for energy intake and body weight.

RESULTS

The relationship between BMI and both fat-free mass and fat mass (FM) on admission was curvilinear. The weight gain per excess energy was greater in the group of patients with FM < 4 kg or BMI < 14 kg/m(2) than in the group with FM > or = 4 kg or BMI > or = 14 kg/m(2) (p = .037, p = .055, respectively).

DISCUSSION

The energy requirements for weight gain in AN patients are related to the initial FM and BMI.

Body composition determination by bioimpedance: an update

PURPOSE OF REVIEW

To review various methods for measuring body composition by bioimpedance and their limitations, as well as available impedance meters, including body fat analyzers for home use.

RECENT FINDINGS

Bioimpedance spectroscopy, which requires multifrequency impedance meters, is preferable for fluid volume measurements, especially extracellular fluid, whereas bioimpedance analysis at 50 kHz is more widely used for measuring fat-free mass. A method for using bioimpedance spectroscopy equations with 50 kHz impedance meters has been recently proposed and successfully tested. Low cost foot-to-foot impedance meters (body fat analyzers) with plantar electrodes on a body scale, that are easy and fast to use, have been compared with medical impedance meters and with dual X-ray absorptiometry measurements and found reasonably accurate, except for individuals with very low or high BMI.

SUMMARY

Body composition by bioimpedance is gaining acceptance in nutrition, hemodialysis, gerontology and sports medicine. Body fat analyzers that have been validated by comparison with dual x-ray absorptiometry could be useful to general practitioners, nutritionists and cardiologists.

How accurate are predictive formulas calculating energy expenditure in adolescent patients with anorexia nervosa?

BACKGROUND & AIMS

To compare resting energy expenditure, measured by indirect calorimetry, to values estimated by different predictive formulas in adolescent patients with anorexia nervosa.

METHODS

We studied 22 female in-patients with a mean age of 14.7 years (SD 1.2). Resting energy expenditure was measured by indirect calorimetry (Deltatrac II MBM-200). We compared measured resting energy expenditure to values estimated by several predictive formulas [Fleisch, Harris-Benedict, FAO, Schofield-HW, Schebendach] using the intraclass correlation coefficient and the Bland-Altman method.

RESULTS

Body mass index increased significantly (P<0.001). Measured resting energy expenditure increased during hospitalization (P<0.05). All formulas overestimated resting energy expenditure with respect to indirect calorimetry except the Schebendach formula. The intraclass correlation between indirect calorimetry and the formulas were poor (0.09-0.20). We observed a poor clinical agreement (Bland-Altman).

CONCLUSIONS

Body mass index and resting energy expenditure increased during hospitalization. The majority of the predictive formulas overestimate resting energy expenditure in adolescent patients with anorexia nervosa. Therefore, indirect calorimetry may be a very useful tool for calculating caloric requirements in these patients.

The altered fluid distribution in obesity may reflect plasma hypertonicity

OBJECTIVE

This study explored whether the increased extracellular relative to intracellular fluid (ECF/ICF) ratio in obesity might reflect osmotic effects of elevated plasma solute concentrations.

DESIGN

Cross-sectional, epidemiological survey.

SETTING AND SUBJECTS

The present analysis used nationally representative data from the Third National Health and Nutrition Examination Survey on community-dwelling adults (aged 40-59 years) in the US without evidence of glucose dysregulation or chronic disease (n=1285).

INTERVENTION

Body mass index (BMI) was estimated from measured height and weight. Total body reactance, an index of body fluid distribution, was determined by bioelectrical impedance analysis. Plasma tonicity (the cumulative index of osmotically effective plasma solute) was estimated from plasma glucose, sodium and potassium. Sex-specific relative odds of lower reactance (<or=50 Omega/m for women, <or=40 Omega/m for men) and plasma hypertonicity (tonicity >or=295 mmol/l) associated with overweight (25<or=BMI <30) and obesity (BMI>or=30) were estimated using logistic regression models that controlled for sociodemographic variables, smoking, leisure-time physical activity, total energy intake, serum creatinine, plasma insulin and glucose. Multinomial logistic regression models tested for associations between weight status and specific serum solute.

RESULTS

Independent of covariates, in men and women, overweight and obesity were associated with increased odds of lower reactance and hypertonicity. Overweight and obese individuals with lower reactance had significantly higher serum sodium than normal weight individuals.

CONCLUSIONS

Elevated plasma solute concentrations are associated with obesity in free-living adults. Physicians and researchers should be alert to a possible link between hypertonicity and obesity.

SPONSORSHIP

Grants from the NIH, Nestle Waters.

Eating disorders in children and adolescents: an update

PURPOSE OF REVIEW

Children and adolescents with eating disorders frequently present to child mental health and paediatric services and have significant morbidity, psychosocial impairment and mortality. Efforts to treat these individuals have been hampered by a poor evidence base for effective interventions. This article reviews research published during 2004 with a primary focus on this challenging clinical area.

RECENT FINDINGS

Research published during 2004 has replicated past epidemiological findings and expanded our understanding of the relationship of family meal structure and disordered eating. Research has provided assistance in the well known clinical conundrums of excessive exercising in anorexia nervosa and predicting when return of menses will occur. There has also been clarification of adolescent bingeing. Potential advances include a new, noninvasive method of measuring body composition and investigations in adolescents on leptin, neuro and gastrointestinal peptides. Importantly, further evidence of the effectiveness of family therapy for anorexia nervosa and short-term benefits from intervention programs have been published.

SUMMARY

The research base that will influence clinical practice in child and adolescent eating disorders is increasing. More research is required in all areas of intervention.

Bioelectrical impedance analysis in clinical practice: a new perspective on its use beyond body composition equations

PURPOSE OF REVIEW

The bioelectrical impedance analysis is not a direct method for estimating body composition. Its accuracy depends on regression equations, and recent papers have suggested that this approach should not be used in several clinical situations. Another option is to obtain information about the electrical properties of tissues by using raw bioelectrical impedance measurements, resistance and reactance. They can be expressed as a ratio (phase angle) or as a plot (bioelectrical impedance vector analysis). This review describes their use in clinical practice.

RECENT FINDINGS

The phase angle changes with sex and age. It is described as a prognostic tool in many clinical situations. There are some controversies about considering it as a nutritional marker. Studies in burn victims and sickle-cell disease corroborate its ability to evaluate cell membrane function. Bioelectrical impedance vector analysis allows a semi-quantitative estimation of body composition from information from tissue hydration and soft-tissue mass in a plot. It can be used in healthy individuals or patients, for a population or individual evaluation of fluid imbalance or an assessment of soft-tissue mass. It has also been used as a prognostic tool in dialysis and cancer patients.

SUMMARY

The phase angle can be considered a global marker of health, and future studies are needed to prove its utility in intervention studies. Bioelectrical impedance vector analysis has increased its utility in clinical practice, even when the equations may be inaccurate for body composition analysis.