The metabolic responses to starvation and refeeding in adolescents with anorexia nervosa

Adaptive Effects of Endocrine Hormones on Metabolism of Macronutrients during Fasting and Starvation: A Scoping Review

Food deprivation can occur for different reasons. Fasting (<24 h duration) occurs to meet religious or well-being goals. Starvation (>1-day duration) occurs when there is intentional (hunger strike or treatment of a medical condition) or unintentional (anorexia nervosa, drought, epidemic famine, war, or natural disaster) food deprivation. A scoping review was undertaken using the PubMed database to explore 1805 abstracts and review 88 eligible full-text articles to explore the adaptive relationships that emerge between cortisol, insulin, glucagon, and thyroid hormones on the metabolic pathways of macronutrients in humans during fasting and starvation. The collected data indicate that fasting and starvation prime the human body to increase cortisol levels and decrease the insulin/glucagon ratio and triiodothyronine (T3) levels. During fasting, increased levels of cortisol and a decreased insulin/glucagon ratio enhance glycogenolysis and reduce the peripheral uptake of glucose and glycogenesis, whereas decreased T3 levels potentially reduce glycogenolysis. During starvation, increased levels of cortisol and a decreased insulin/glucagon ratio enhance lipolysis, proteolysis, fatty acid and amino acid oxidation, ketogenesis, and ureagenesis, and decreased T3 levels reduce thermogenesis. We present a potential crosstalk between T3 and the above hormones, including between T3 and leptin, to extend their adaptive roles in the metabolism of endogenous macronutrients during food deprivation.

Energy expenditure during nutritional rehabilitation: a scoping review to investigate hypermetabolism in individuals with anorexia nervosa

BACKGROUND

Weight gain and nutritional rehabilitation are essential first steps to achieve medical stabilization in anorexia nervosa, and frequent resistance to weight gain requires patients to consume high kilocalorie loads. Adaptive hypometabolism is common when patients begin treatment, and rebound hypermetabolism is suspected to be a significant barrier to weight gain. The aim of this review was to summarize existing data describing metabolic changes in anorexia nervosa during weight restoration. The reported findings challenge current hypotheses of weight gain resistance and highlight key areas for future research.

METHODS

Using scoping review guidelines, three databases were searched for studies investigating metabolic changes in anorexia nervosa before and after renourishment. Two reviewers systematically screened the titles and abstracts of 447 articles, and full-text versions of 106 studies were assessed for eligibility. A total of 36 studies were included for review. Data regarding the study description, sample population (including age, weight, BMI, duration of treatment, and caloric intake), and metabolic variable descriptions were extracted.

RESULTS

Female patients with anorexia nervosa from studies across 13 countries were included. Across the studies, average BMI increased from 13.7 kg/m2 at admission to 17.57 kg/m2. Patients presented to treatment with clinically reduced energy expenditure levels. After varying levels of nutritional rehabilitation and weight restoration, measured energy expenditure increased significantly in 76% of the studies. Energy expenditure values at the second timepoint increased to the standard range for normal weight female teenagers and adults. Despite these increases, the studies do not indicate the presence of a hypermetabolic state during renourishment. Additionally, all studies including both measured and predicted energy expenditure reported that predicted energy expenditure overestimated measured values.

CONCLUSION

This study provides a detailed evaluation of the literature investigating energy expenditure and metabolic rate in patients with anorexia nervosa before and following a period of renourishment. The findings from this review identify important gaps in the current beliefs of energy expenditure in anorexia nervosa and highlight a need for further exploration of metabolic alterations during weight restoration.

Course and outcome in individuals with atypical anorexia nervosa: Findings from the Study of Refeeding to Optimize iNpatient Gains (StRONG)

OBJECTIVE

We previously reported that participants with atypical anorexia nervosa (atypical AN) had higher historical and admission weights, greater eating disorder psychopathology, but similar rates of amenorrhea and weight suppression at baseline as compared to anorexia nervosa (AN); here, we compare 1-year outcomes.

METHOD

Weight, % median body mass index (%mBMI), Eating Disorder Examination Questionnaire (EDE-Q) scores, resumption of menses, and rehospitalizations were examined at 3, 6, and 12 months post-discharge. Analyses (N = 111) compared changes in %mBMI, weight suppression, and EDE-Q scores over time between atypical AN and AN.

RESULTS

Among the participants (48 atypical AN, 63 AN), both groups gained weight but those with atypical AN had lower gains than those with AN in %mBMI (p = .02) and greater weight suppression (p = .002) over time. EDE-Q scores improved over time, independent of weight suppression, with no significant difference between atypical AN and AN. Groups did not differ by rates of resumption of menses (80% atypical AN, 76.9% AN) or rehospitalization (29.2% atypical AN, 37.9% AN). Greater weight suppression predicted longer time to restore menses and more days of rehospitalization.

DISCUSSION

Individuals with atypical AN regained a smaller proportion of body mass and were more weight suppressed over time. Change in eating disorder cognitions, resumption of menses, and rehospitalization rates at 1-year follow-up did not differ between groups. There was no significant difference in weight suppression between groups for those who were psychologically improved at 12 months. Findings highlight limitations in our understanding of weight recovery in atypical AN. New metrics for recovery are urgently needed.

PUBLIC SIGNIFICANCE

Little is known about outcome in atypical anorexia nervosa (atypical AN). We examined recovery metrics in young people with atypical AN and anorexia nervosa (AN) 1 year after medical hospitalization. Individuals with atypical AN showed slower weight gain and remained further from their pre-illness weight. There were no differences in the rates of psychological recovery, resumption of menses, or rehospitalization. New metrics are needed to assess recovery in atypical AN.

Deiodinases and the Metabolic Code for Thyroid Hormone Action

Deiodinases modify the biological activity of thyroid hormone (TH) molecules, ie, they may activate thyroxine (T4) to 3,5,3'-triiodothyronine (T3), or they may inactivate T3 to 3,3'-diiodo-L-thyronine (T2) or T4 to reverse triiodothyronine (rT3). Although evidence of deiodination of T4 to T3 has been available since the 1950s, objective evidence of TH metabolism was not established until the 1970s. The modern paradigm considers that the deiodinases not only play a role in the homeostasis of circulating T3, but they also provide dynamic control of TH signaling: cells that express the activating type 2 deiodinase (D2) have enhanced TH signaling due to intracellular build-up of T3; the opposite is seen in cells that express type 3 deiodinase (D3), the inactivating deiodinase. D2 and D3 are expressed in metabolically relevant tissues such as brown adipose tissue, skeletal muscle and liver, and their roles have been investigated using cell, animal, and human models. During development, D2 and D3 expression customize for each tissue/organ the timing and intensity of TH signaling. In adult cells, D2 is induced by cyclic adenosine monophosphate (cAMP), and its expression is invariably associated with enhanced T3 signaling, expression of PGC1 and accelerated energy expenditure. In contrast, D3 expression is induced by hypoxia-inducible factor 1α (HIF-1a), dampening T3 signaling and the metabolic rate. The coordinated expression of these enzymes adjusts TH signaling in a time- and tissue-specific fashion, affecting metabolic pathways in health and disease states.

Arrested Puberty in an Adolescent Male with Anorexia Nervosa Successfully Resumed with Multidisciplinary Care

The normal development of puberty depends on the specific pulsatility of gonadorelin, which is finely regulated by genetic and environmental factors. In the published literature, eating disorders figure as a cause of pubertal delay/arrest in females but are rarely considered in males with disordered puberty. A 16.7-year-old male was referred to the Department of Pediatrics with arrested puberty due to severe malnutrition in the context of food restriction. Past medical history was relevant for asthma. Generalized cachexia, facial lanugo hair, cutaneous xerosis, and Russell's sign were noted; he had a height of 155.5 cm (−2.5 SD; target height: 168 cm, −1.1 SD) and a BMI of 12.4 kg/m² (−6.8 SD); left and right testicular volumes were 8 mL and 10 mL, respectively. He had a twin brother who had normal auxological/pubertal development (height: 167 cm, −1.05 SD; testicular volumes: 20 mL). Anorexia nervosa was diagnosed, and he was enrolled in a personalized treatment and surveillance program. “Nonthyroid illness” resembling secondary hypothyroidism was noted, as was low bone mineral density. Clinical and biochemical follow-up showed significant improvements in BMI (16.2 kg/m², −2.55 SD), completion of puberty (testicular volumes: 25 mL), and reversion of main neuroendocrine abnormalities. Herein, we present an adolescent male with arrested puberty in the context of anorexia nervosa. The recognition of this rare condition in males allows a personalized approach to disordered puberty, with resumption of normal function of the hypothalamic-pituitary-gonadal axis and achievement of pubertal milestones.

Short-term Outcomes of the Study of Refeeding to Optimize Inpatient Gains for Patients With Anorexia Nervosa: A Multicenter Randomized Clinical Trial

IMPORTANCE

The standard of care for refeeding inpatients with anorexia nervosa, starting with low calories and advancing cautiously, is associated with slow weight gain and protracted hospital stay. Limited data suggest that higher-calorie refeeding improves these outcomes with no increased risk of refeeding syndrome.

OBJECTIVE

To compare the short-term efficacy, safety, and cost of lower-calorie vs higher-calorie refeeding for malnourished adolescents and young adults with anorexia nervosa.

DESIGN, SETTING, AND PARTICIPANTS

In this multicenter randomized clinical trial with prospective follow-up conducted at 2 inpatient eating disorder programs at large tertiary care hospitals, 120 adolescents and young adults aged 12 to 24 years hospitalized with anorexia nervosa or atypical anorexia nervosa and 60% or more of median body mass index were enrolled from February 8, 2016, to March 7, 2019. The primary analysis was a modified intent-to-treat approach.

INTERVENTIONS

Higher-calorie refeeding, beginning at 2000 kcal/d and increasing by 200 kcal/d vs lower-calorie refeeding, beginning at 1400 k/cal and increasing by 200 kcal every other day.

MAIN OUTCOMES AND MEASURES

Main outcomes were end-of-treatment outcomes; the primary end point of this trial will be clinical remission over 12 months. Short-term efficacy was defined a priori as time to restore medical stability in the hospital, measured by the following 6 indices: 24-hour heart rate of 45 beats/min or more, systolic blood pressure of 90 mm Hg or more, temperature of 35.6 °C or more, orthostatic increase in heart rate of 35 beats/min or less, orthostatic decrease in systolic blood pressure of 20 mm Hg or less, and 75% or more of median body mass index for age and sex. The prespecified safety outcome was incidence of electrolyte abnormalities; cost efficacy was defined as savings associated with length of stay.

RESULTS

Because 9 participants withdrew prior to treatment, the modified intention-to-treat analyses included 111 participants (93%; 101 females [91%]; mean [SD] age, 16.4 [2.5] years). Higher-calorie refeeding restored medical stability significantly earlier than lower-calorie refeeding (hazard ratio, 1.67 [95% CI, 1.10-2.53]; P = .01). Electrolyte abnormalities and other adverse events did not differ by group. Hospital stay was 4.0 days shorter (95% CI, -6.1 to -1.9 days) among the group receiving higher-calorie refeeding, which was associated with a savings of $19 056 (95% CI, -$28 819 to -$9293) in hospital charges per participant.

CONCLUSIONS AND RELEVANCE

In the first randomized clinical trial in the US to compare refeeding approaches in patients with anorexia nervosa and atypical anorexia nervosa, higher-calorie refeeding demonstrated short-term efficacy with no increase in safety events during hospitalization.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02488109.

Higher Caloric Exposure in Critically Ill Patients Transiently Accelerates Thyroid Hormone Activation

INTRODUCTION

The inflammatory response of critical illness is accompanied by nonthyroidal illness syndrome (NTIS). Feeding has been shown to attenuate this process, but this has not been explored prospectively over time in critically ill patients.

OBJECTIVE

To explore the impact of calorie exposure on NTIS over time in critically ill patients.

METHODS

Mechanically ventilated patients with systemic inflammatory response syndrome (SIRS) were randomized to receive either 100% or 40% of their estimated caloric needs (ECN). Thyroid hormones were measured daily for 7 days or until intensive care unit discharge or death. Mixed level regression modeling was used to explore the effect of randomization group on plasma triiodothyronine (T3), reverse triiodothyronine (rT3), thyroxine (T4), and thyroid stimulating hormone (TSH), as well as the T3/rT3 ratio.

RESULTS

Thirty-five participants (n=19 in 100% ECN; n=16 in 40% ECN) were recruited. Adjusting for group differences in baseline T3/rT3 ratio, the parameters defining the fitted curves (intercept, linear effect of study day, and quadratic effect of study day) differed by randomization group (P = 0.001, P = 0.01, and P = 0.02 respectively). Plots of the fitted curves revealed that participants in the 100% ECN group had a 54% higher T3/rT3 ratio on postintervention day 1 compared with the 40% ECN group, a difference which attenuated over time. This was driven by a 23% higher plasma T3 and 10% lower plasma rT3 levels on postintervention 1.

CONCLUSIONS

Higher caloric exposure in NTIS patients transiently attenuates the drop of the plasma T3/rT3 ratio, an effect that is minimized and finally lost over the following 3 days of continued higher caloric exposure.

Paradigms of Dynamic Control of Thyroid Hormone Signaling

Thyroid hormone (TH) molecules enter cells via membrane transporters and, depending on the cell type, can be activated (i.e., T4 to T3 conversion) or inactivated (i.e., T3 to 3,3'-diiodo-l-thyronine or T4 to reverse T3 conversion). These reactions are catalyzed by the deiodinases. The biologically active hormone, T3, eventually binds to intracellular TH receptors (TRs), TRα and TRβ, and initiate TH signaling, that is, regulation of target genes and other metabolic pathways. At least three families of transmembrane transporters, MCT, OATP, and LAT, facilitate the entry of TH into cells, which follow the gradient of free hormone between the extracellular fluid and the cytoplasm. Inactivation or marked downregulation of TH transporters can dampen TH signaling. At the same time, dynamic modifications in the expression or activity of TRs and transcriptional coregulators can affect positively or negatively the intensity of TH signaling. However, the deiodinases are the element that provides greatest amplitude in dynamic control of TH signaling. Cells that express the activating deiodinase DIO2 can rapidly enhance TH signaling due to intracellular buildup of T3. In contrast, TH signaling is dampened in cells that express the inactivating deiodinase DIO3. This explains how THs can regulate pathways in development, metabolism, and growth, despite rather stable levels in the circulation. As a consequence, TH signaling is unique for each cell (tissue or organ), depending on circulating TH levels and on the exclusive blend of transporters, deiodinases, and TRs present in each cell. In this review we explore the key mechanisms underlying customization of TH signaling during development, in health and in disease states.

Intermittent Dieting: Theoretical Considerations for the Athlete

Athletes utilise numerous strategies to reduce body weight or body fat prior to competition. The traditional approach requires continuous energy restriction (CER) for the entire weight loss phase (typically days to weeks). However, there is some suggestion that intermittent energy restriction (IER), which involves alternating periods of energy restriction with periods of greater energy intake (referred to as ‘refeeds’ or ‘diet breaks’) may result in superior weight loss outcomes than CER. This may be due to refeed periods causing transitory restoration of energy balance. Some studies indicate that intermittent periods of energy balance during energy restriction attenuate some of the adaptive responses that resist the continuation of weight and fat loss. While IER—like CER—is known to effectively reduce body fat in non-athletes, evidence for effectiveness of IER in athletic populations is lacking. This review provides theoretical considerations for successful body composition adjustment using IER, with discussion of how the limited existing evidence can be cautiously applied in athlete practice.

MECHANISMS IN ENDOCRINOLOGY: Anorexia nervosa and endocrinology: a clinical update

Anorexia nervosa is a syndrome, that is collections of symptoms, which is not defined by its etiology. The severe cases are intractable. The syndrome is associated with multiple, profound endocrine alterations which may be adaptive, reactive or etiologic. Adaptive changes potentially may be inappropriate in clinical settings such as inpatient intensive re-nutrition or in a setting with somatic comorbidity. Electrolyte levels must be closely monitored during the refeeding process, and the need for weight gain must be balanced against potentially fatal refeeding complications. An important focus of clinical research should be to identify biomarkers associated with different stages of weight loss and re-nutrition combined with psychometric data. Besides well-established peripheral endocrine actions, several hormones also are released directly to different brain areas, where they may exert behavioral and psychogenic actions that could offer therapeutic targets. We need reliable biomarkers for predicting outcome and to ensure safe re-nutrition, however, first of all we need them to explore the metabolism in anorexia nervosa to open new avenues with therapeutic targets. A breakthrough in our understanding and treatment of this whimsical disease remains. Considering this, the aim of the present review is to provide an updated overview of the many endocrine changes in a clinical perspective.

The Role of Leptin in Maintaining Plasma Glucose During Starvation

For 20 years it has been known that concentrations of leptin, a hormone produced by the white adipose tissue (WAT) largely in proportion to body fat, drops precipitously with starvation, particularly in lean humans and animals. The role of leptin to suppress the thyroid and reproductive axes during a prolonged fast has been well defined; however, the impact of leptin on metabolic regulation has been incompletely understood. However emerging evidence suggests that, in starvation, hypoleptinemia increases activity of the hypothalamic-pituitary-adrenal axis, promoting WAT lipolysis, increasing hepatic acetyl-CoA concentrations, and maintaining euglycemia. In addition, leptin may be largely responsible for mediating a shift from a reliance upon glucose metabolism (absorption and glycogenolysis) to fat metabolism (lipolysis increasing gluconeogenesis) which preserves substrates for the brain, heart, and other critical organs. In this way a leptin-mediated glucose-fatty acid cycle appears to maintain glycemia and permit survival in starvation.

The use of metabolic balance studies in the objective discrimination between intestinal insufficiency and intestinal failure

Background: In research settings that use metabolic balance studies (MBSs) of stable adult patients with short bowel syndrome, intestinal failure (IF) and dependence on parenteral support (PS) have been defined objectively as energy absorption <84% of calculated basal metabolic rate (BMR), wet weight (WW) absorption <23 g · kg body weight^-1 · d^-1, or both. Objective: This study aimed to explore and validate these borderlines in the clinical setting.Design: Intestinal absorption was measured from April 2003 to March 2015 in 175 consecutive patients with intestinal insufficiency (INS) in 96-h MBSs. They had not received PS 3 mo before referral.Results: To avoid the need for PS, the minimum absorptive requirements were energy absorption of ≥81% of BMR and WW absorption of ≥21 g · kg body weight^-1 · d^-1, which were equivalent to findings in research settings (differences of 3.6% and 8.7%; P = 0.65 and 0.60, respectively). Oral failure defined as energy intake <130% of calculated BMR or WW intake <40 g · kg body weight^-1 · d^-1 was seen in 71% and 82% of the 10% of patients with the lowest energy absorption and WW absorption, respectively.Conclusions: In clinical settings, the borderlines between INS and IF were not significantly different from those in research settings, even in an unselected patient population in which oral failure was also a predominant cause of nutritional dyshomeostasis. MBSs may be recommended to identify the individual patient in the spectrum from INS to IF, to objectivize the cause of nutritional dyshomeostasis (oral failure, malabsorption, or both), and to quantify the effects of treatment.

Daily Changes in Composition and Diversity of the Intestinal Microbiota in Patients with Anorexia Nervosa: A Series of Three Cases

Anorexia nervosa, a severe psychiatric illness, is associated with an intestinal microbial dysbiosis. Individual microbial signatures dominate in healthy samples, even over time and under controlled conditions, but whether microbial markers of the disorder overcome inter-individual variation during the acute stage of illness or renourishment is unknown. We characterized daily changes in the intestinal microbiota in three acutely ill patients with anorexia nervosa over the entire course of hospital-based renourishment and found significant, patient-specific changes in microbial composition and diversity. This preliminary case series suggests that even in a state of pathology, individual microbial signatures persist in accounting for the majority of intestinal microbial variation. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Coupling between Nutrient Availability and Thyroid Hormone Activation

The activity of the thyroid gland is stimulated by food availability via leptin-induced thyrotropin-releasing hormone/thyroid-stimulating hormone expression. Here we show that food availability also stimulates thyroid hormone activation by accelerating the conversion of thyroxine to triiodothyronine via type 2 deiodinase in mouse skeletal muscle and in a cell model transitioning from 0.1 to 10% FBS. The underlying mechanism is transcriptional derepression of DIO2 through the mTORC2 pathway as defined in rictor knockdown cells. In cells kept in 0.1% FBS, there is DIO2 inhibition via FOXO1 binding to the DIO2 promoter. Repression of DIO2 by FOXO1 was confirmed using its specific inhibitor AS1842856 or adenoviral infection of constitutively active FOXO1. ChIP studies indicate that 4 h after 10% FBS-containing medium, FOXO1 binding markedly decreases, and the DIO2 promoter is activated. Studies in the insulin receptor FOXO1 KO mouse indicate that insulin is a key signaling molecule in this process. We conclude that FOXO1 represses DIO2 during fasting and that derepression occurs via nutritional activation of the PI3K-mTORC2-Akt pathway.

Association between resting energy expenditure, psychopathology and HPA-axis in eating disorders

AIM: To investigate the complex relationships between resting energy expenditure (REE), eating psychopathology, and Hypothalamus Pituitary Adrenal axis functioning in patients with eating disorders.

METHODS: The study was designed as a cross-sectional survey, and it was planned by the Clinic for Eating Disorders of the University of Florence (Italy). The protocol was approved by the Ethics Committee of the Institution. Twenty two anorexia nervosa and twenty one Bulimia Nervosa patients were assessed by means of a clinical interview and the structured clinical interview for diagnostic and statistical manual of mental disorders, fourth edition. Eating attitudes and behaviour were specifically investigated by means of the eating disorder examination questionnaire (EDE-Q). Patients were also evaluated by means of the symptom checklist (SCL 90-R), REE was measured by means of indirect calorimetry, and blood cortisol morning levels were evaluated.

RESULTS: Both anorexia nervosa and bulimia nervosa patients showed a reduced REE as compared with predicted REE. Body mass index (BMI) was positively associated with resting energy expenditure in Bulimics, whereas a strong, negative association between BMI and REE was observed in Anorectics. The pattern of associations between variables supported a mediation model, where shape concern accounted for variations in REE and cortisol levels (mediator), and variations in the mediator significantly accounted for variations in REE. When these associations where taken into account together, the relationship between shape concern and REE was no longer significant, whereas the association between cortisol levels and REE retained its significance, showing strong evidence for a single, dominant mediator. Anorectics and Bulimics showed an opposite pattern of association between BMI and REE. In Anorectics only, a higher REE was associated with a more severe eating disorder specific psychopathology, and cortisol levels represent a possible mediating factor for this relationship.

CONCLUSION: The data supported a mediation model where cortisol levels mediated the relationship between eating psychopathology (concern about body shape) and REE.

Triiodothyronine (T3) and metabolic rate in adolescents with eating disorders: Is there a correlation?

AIM

To examine the correlation between T3 and resting energy expenditure (REE) in adolescent patients with eating disorders (ED) to assess whether T3 can be used to predict metabolic rate suppression and recovery.

METHODS

A retrospective chart review was performed on patients with ED (Anorexia Nervosa [AN], Bulimia Nervosa [BN], and Eating Disorder NOS [EDNOS]), aged 11-22 years, who had T3 and REE measured within 1 month (N=38 AN, 32 BN/EDNOS). REE was measured by indirect calorimetry (IC) and represented as the percentage of expected REE (%EREE) predicted by the Harris-Benedict equation. Pearson correlation coefficients were calculated to examine the relationship between T3 and %EREE and how each correlates with anthropometric data, laboratory values, and diagnosis.

RESULTS

T3 was significantly correlated with %EREE in the AN group but not in the total population or BN/EDNOS group. In the total study population, T3 alone correlated significantly with weight, Body Mass Index (BMI), BMI percentile, %Ideal Body Weight (%IBW), %Maximum Weight Lost (%MWL), LH, and estradiol. In the AN group, T3 and %EREE both correlated with BMI, BMI percentile, LH, and estradiol; however, only T3 correlated with %IBW and %MWL. In the BN/EDNOS group, T3 correlated with BMI, BMI percentile, %IBW, and estradiol while %EREE correlated with none.

CONCLUSION

In patients with AN, T3 correlated significantly with markers of malnutrition and %EREE and may serve as a surrogate measure when IC is unavailable. Following T3 during treatment of AN may assist clinicians in assessing metabolic suppression and recovery and help guide caloric prescriptions and goal weights.

Nutritional rehabilitation increases the resting energy expenditure of malnourished children with severe cerebral palsy

AIM

The aim of this study was to measure resting energy expenditure (REE) and energy intake in children with quadriplegic cerebral palsy (CP), to relate these to anthropometric measurements, and to determine the influence of nutritional rehabilitation on REE.

METHODS

Fifty-six children (20 females, 36 males; age range 3y 11mo-18y; mean age 10y; SD 3y 11mo) with CP (Gross Motor Function Classification System level V) participated in this cross-sectional study. Children were excluded if they had a known metabolic disorder, genetic syndrome, or chromosomal abnormality. Thirty-three of the children were tube fed and 23 were fed orally. A comparison group comprised 111 (42 females, 69 males) healthy children who had undergone anthropometric and REE measurements and were of similar age to the children with CP (4-19y). REE was measured by indirect calorimetry and energy intake was determined from weighed food records.

RESULTS

The REE in the children with CP was low (79.5%) compared with that predicted and highly variable (SD 38.4%). Fat-free mass was the strongest predictor of REE, accounting for 27% of the variation. Energy intake as a percentage of REE in was greatly overestimated in oral-fed children with CP (293%). In a subset of children with CP (n=14), an increased energy intake by gastrostomy tube feeding resulted in an increase in REE from 70.0% to 101.9% of that predicted.

INTERPRETATION

The REE of children with CP is low and variable and is not strongly related to any one anthropometric measurement. Food records in oral-fed children with CP are of little value owing to their inaccuracy. This study provided support for the hypothesis that the low REE found in malnourished children with CP is partly due to a low energy intake.

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.

A placebo-controlled pilot study of adjunctive olanzapine for adolescents with anorexia nervosa

OBJECTIVE

The objective of this study was to explore whether the addition of olanzapine versus placebo increases weight gain and improves psychological symptoms in adolescents with anorexia nervosa-restricting type who are participating in a comprehensive eating disorders treatment program.

METHODS

Twenty underweight females participated in this 10-week, double-blind, placebo-controlled pilot study of olanzapine. The primary efficacy measure was change in percentage of median body weight measured at baseline and weeks 5 and 10. Secondary efficacy measures included clinician-rated and self-reported measures of psychological functioning measured at 2-week intervals and eating disorder symptoms measured at baseline and weeks 5 and 10 as well as laboratory assessments (including indirect calorimetry), which were also performed at baseline and weeks 5 and 10. A mixed models approach to repeated measures analysis of variance was utilized to detect any treatment-by-time interaction.

RESULTS

Fifteen of 20 enrolled females (median age, 17.1 years; range, 12.3-21.8 years; mean body mass index, 16.3) completed this 10-week pilot study. Change in % median body weight did not differ between the treatment groups at midpoint or end of study. Both groups gained weight at a similar rate and had similar improvements in eating attitudes and behaviors, psychological functioning, and resting energy expenditure. A trend of increasing fasting glucose and insulin levels was found only in the olanzapine group at week 10.

CONCLUSIONS

These preliminary findings do not support a role for adjunctive olanzapine for underweight adolescent females with anorexia nervosa-restricting type who are receiving standard care in an eating disorder treatment program (clinical trials.gov; no. NCT00592930).

Metabolic assessment of menstruating and nonmenstruating normal weight adolescents

OBJECTIVE

Resumption of menses (ROM) is a key indicator of recovery in AN, but patients may remain amenorrheic despite weight restoration. The objective of this study is to better understand the mechanism of amenorrhea in patients with eating disorders.

METHOD

A retrospective chart review was conducted of 382 normal weight adolescents with a history of anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified, who had been referred for indirect calorimetry tests. Resting energy expenditure (REE) was compared between amenorrheic (n = 60) and regularly menstruating females (n = 121).

RESULTS

Participants with amenorrhea had a mean REE of 1,103 kcal/24 h (79% predicted), whereas participants who were menstruating regularly had a mean REE of 1,217 kcal/24 h (85% predicted; p = 0.001). The amenorrheic group was found to be at a lower mean body weight (53.7 +/- 5.6 kg vs. 57.5 +/- 7.4 kg; p < or = 0.001), at a lower percent ideal body weight (98.5 +/- 8.3% vs. 102.8 +/- 10.2%; p = 0.005), and at a lower BMI (20.5 +/- 1.7 vs. 21.5 +/- 2.2; p = 0.002).

DISCUSSION

This study highlights that amenorrheic participants with a history of eating disorders who are at normal body weight are hypometabolic, suggesting an adaptive response to dietary restriction.

Energy metabolism and body composition in long-term recovery from anorexia nervosa

OBJECTIVE

The aim of this study was to determine if energy metabolism and body composition differ between women recovered from anorexia nervosa for 2 or more years (RAN) and control (C) women.

METHOD

Using a cross-sectional design, 16 RAN and 18 C women were studied. Respiratory quotient (RQ) and resting energy expenditure (REE) were measured using indirect calorimetry and body composition using dual energy X-ray absorptiometry.

RESULTS

The REE between RAN and C women was not significantly different, even when adjusted for body composition. However, RAN women had a higher rate of fat oxidation (p = .015), controlling for diet and body composition. There were no significant differences between the groups for body composition, percent body fat, or percent truncal fat mass.

DISCUSSION

Although RAN women have a higher rate of fat oxidation, there were no significant differences in REE or body composition when compared with C women.

Metabolic and psychological changes during refeeding in anorexia nervosa

OBJECTIVE

This study aimed to examine resting metabolic rate (RMR) and psychological changes during refeeding in 10 women with anorexia nervosa participating in a partial hospitalization eating disorder program.

RESULTS

Participants' admission RMRs, as assessed by the MedGem Analyzer, were below their RMRs predicted by the Harris- Benedict equation, t(1,9)=5.77, p<0.01. Correlational analyses revealed a trend toward smaller increases in RMR being associated with higher admission BMI (r=-0.49, p=0.08), but not with highest lifetime BMI. Over the course of treatment, RMR per pound of Fat-Free Mass (FFM) increased from the beginning to the middle, t(1,9)=-3.02, p<0.05, and to the end stage of treatment, t(1,9)=-2.53, p<0.05. Scores on the Eating Attitudes Test-26, Eating Disorder Inventory-2, Brief Symptom Inventory (BSI), BSI Depression subscale, and Mizes Anorectic Cognitions scale significantly improved throughout treatment (all p<0.05); however, body dissatisfaction did not improve.

DISCUSSION

Results suggest that weight restoration programs for anorexia nervosa cannot rely on FFM or standard formulas to predict caloric needs throughout refeeding, and that admission BMI is one factor to be considered in predicting caloric needs during refeeding. Furthermore, ways to improve body dissatisfaction during refeeding needs to be more of a treatment focus.

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.

Changes in heart rate with refeeding in anorexia nervosa: a pilot study

OBJECTIVE

To find differences in heart rate before and after refeeding and to identify which parameters of autonomic activity and endocrine function are associated with these differences.

METHODS

Before and after the start of refeeding, body weight, RR interval (RRI), heart rate variability, endocrine function, and energy expenditure were measured in nine female anorexia nervosa patients.

RESULTS

After short-term refeeding, mean daytime heart rate rose from 54.9 to 69.4 bpm (P<.05). The changes in sympathetic activity were correlated negatively with the changes in RRI (r=-.933, P<.001). Urine C-peptide, IGF-1, and fT3 increased significantly, and norepinephrine tended to increase.

CONCLUSION

We demonstrated that autonomic nervous activity was relevant to changes in heart rate during refeeding, and it is speculated that the increases in insulin secretion, thyroid function, and IGF-1 were responsible for the mechanisms.

Changes of pain perception, autonomic function, and endocrine parameters during treatment of anorectic adolescents

OBJECTIVES

The underlying mechanisms of reduced pain perception in anorexia nervosa (AN) are unknown. To gain more insight into the pathology, the authors investigated pain perception, autonomic function, and endocrine parameters before and during successful treatment of adolescent AN patients.

METHOD

Heat pain perception was assessed in 15 female adolescent AN patients and matched controls. Results were correlated with autonomic and endocrine parameters (free triiodothyronine, free cortisol). Autonomic function was studied using heart rate variability and pupillary light reflex assessment. To investigate the influence of therapy on these parameters, data were obtained at three different time points.

RESULTS

Heat pain thresholds were significantly increased in the acute state and decreased after weight had been regained for 6 months. Similarly, an increased parasympathetic tone was present in the acute state only. The relative amplitude of the pupillary light reflex showed a positive correlation to pain thresholds over time and predicted disease progression. In addition, the authors found a negative correlation between increased pain thresholds and low free cortisol.

CONCLUSION

Increased pain thresholds are associated with increased parasympathetic tone and a hypothyroid state in AN. This may either indicate common central mechanisms or suggest a causative interaction.

Criminally prosecuted cases of child starvation

OBJECTIVE

Here we describe the clinical findings and legal outcomes in 12 prosecuted cases of infant and child starvation.

METHODS

Medical records, investigation records, and transcripts of court testimony were reviewed in the cases of 12 infants and children from locations throughout Texas who had been starved deliberately. The children's ages ranged from 2 months to 13 years. The caretakers of all children received both civil and criminal charges; cases were tried over an 11-year time span. Clinical presentations, examination findings, laboratory findings, symptoms of refeeding syndrome, and legal outcomes were examined. Two illustrative cases are presented in detail here.

RESULTS

Of the 12 cases reviewed, the median age was 2.7 years, with a range of 2.25 months to 13 years 7 months. Half of the children died shortly before or soon after presentation for medical care or to law enforcement. Survival was more common in older children than in infants. Most of the children were secluded from others, and all had access to food denied or severely restricted. Caretakers claimed few, benign, or no past medical illnesses in the children. Based on weight and height measurements, 10 of the children had severe wasting and stunting, and 2 had mild or moderate wasting. There was a tendency toward more severe wasting in the fatal cases. All children manifested multiorgan effects of starvation. All survivors manifested complications with refeeding. Approximately half of the children had past or present injuries or history suggestive of physical or sexual abuse. Parental rights were terminated in all cases. A total of 25 individuals were charged criminally; 23 were found guilty or pled guilty, and trials for 2 individuals were pending at the time of this writing. The types of criminal charges and punishment varied from deferred adjudication to a life sentence.

CONCLUSIONS

Life-threatening criminal starvation of infants and children is a rare and severe form of child maltreatment. In our series, infants were more wasted at the time of presentation and less likely to survive prolonged starvation than were older children. As with other forms of child abuse, caretakers' histories regarding the children's illnesses were inconsistent with the severity and chronicity of the children's degree of wasting. All victims in our series showed multiorgan effects of chronic malnutrition and deprivation, and all survivors developed refeeding complications and required prolonged periods of recovery.

The distribution of white blood cell fat oxidation in health and disease

Fat oxidation is important for maintaining health and for supplying energy for exercise. We have proposed that the predisposition for individual rates of fat oxidation is determined genetically but may be modulated by acute exercise or exercise training. The purpose of this study was to examine cellular fat oxidation in white blood cells (WBC) using [9,10-3H]palmitic acid. Sedentary controls free of symptoms (SED-C, n=32), were compared with known carnitine palmitoyltransferase (CPT) II-deficient patients (n =2), patients with fatiguing diseases (chronic fatigue syndrome, CFS, n=6; multiple sclerosis, MS, n=31), obesity (OB, n=5), eating disorders (ED, n=16), sedentary individuals prior to and after exercise (SED-Ex, n=12), exercise-trained sedentary individuals (SED-Tr, n=12), and elite runners (ER, n=5). Fat oxidation in WBC for all subjects was normally distributed (mean=0.270 +/- 0.090 nmol/h per 10(9) WBC) and ranged from 0.09 nmol/h per 10(9) WBC in CPT II-deficient patients to 0.59 nmol/h per 10(9) WBC in ER. There were no significant sex or acute exercise effects on WBC fat oxidation. Patients with MS, OB or ED were not different from SED-C; however, in CPT II-deficient patients, fat oxidation was low, while that of CFS patients was high. Exercise training in SED-C resulted in a 16% increase in fat oxidation but in ER it was still 97% higher than in SED-C. We propose that while WBC fat oxidation is not significantly affected by sex or acute exercise, and only by 15-20% with training, genetic factors play a role in determining both high and low fat oxidation in certain groups of individuals. The genetic predisposition for individual rates of fat oxidation may be easily measured using WBC fat oxidation, as has been shown for CPT II-deficient patients and for elite runners. Ranges of WBC fat oxidation that are abnormally low (<20 nmol/h per 10(9) WBC, normal 20-35) or high (>35 nmol/h per 10(9) WBC) are proposed based on genetic factors evaluated in this study.

Body composition measured by dual-energy X-ray absorptiometry in patients who have undergone small-intestinal resection

BACKGROUND

Patients who have undergone resection of the small intestine have lower body weight than do healthy persons. It remains unclear whether it is the body fat mass or the lean tissue mass that is reduced.

OBJECTIVE

We compared body-composition values in patients who had undergone small-intestinal resection with reference values obtained in healthy volunteers, and we studied the relation between body-composition estimates and the net intestinal absorption of energy.

DESIGN

In a cross-sectional study, we included 20 men and 24 women who had undergone small-intestinal resection and had malabsorption of energy > 2000 kJ/d. Diagnoses were Crohn disease (n = 37) and other conditions (n = 7). Body composition was estimated by dual-energy X-ray absorptiometry, and data were compared with those from a reference group of 173 healthy volunteers. Energy absorption was measured during 48-h balance studies by using bomb calorimetry, and individual values were expressed relative to the basal metabolic rate.

RESULTS

Body weight and body mass index in patients were significantly (P < 0.05) lower than the reference values. Fat mass was 6.4 kg (30%) lower (95% CI: -8.8, -3.9 kg), but lean tissue mass was only slightly and insignificantly lower (1.5 kg, or 3.3%; 95% CI: -3.7, 0.60 kg). Weight, body mass index, and body-composition estimates by dual-energy X-ray absorptiometry did not correlate significantly with the net energy absorption relative to the basal metabolic rate, expressed as a percentage.

CONCLUSIONS

Patients who had undergone small-intestinal resection had significantly lower body weights and body mass indexes than did healthy persons, and they had significant changes in body composition, mainly decreased body fat mass.

Children and adolescents with eating disorders: the state of the art

BACKGROUND

Eating disorders in children and adolescents remain a serious cause of morbidity and mortality in children, adolescents, and young adults. The working knowledge of pathophysiology, recognition, and management of eating disorders continues to evolve as research in this field continues.

OBJECTIVES

This article builds on previous background and position papers outlining issues relevant to the care of the adolescent patient with an eating disorder.

METHODS

The eating disorder special interest group from the Society for Adolescent Medicine recognized the need to update the state of the art published guidelines for the care of the adolescent patient with an eating disorder. This article was a multidisciplinary, group effort to summarize the current knowledge of best practice in the field.

RESULTS

This article summarizes newer findings on pathogenesis and etiology, prevention and screening, risk factors, nutritional issues, care from the primary care clinician's perspective, appropriate use of a multidisciplinary team, and issues of managed care and reimbursement.

CONCLUSIONS

Primary prevention combined with early recognition and treatment helps decrease morbidity and mortality in adolescents with eating disorders.

Research on energy expenditure in individuals with eating disorders: a review

OBJECTIVE

This study reviews the published research on energy expenditure in individuals with anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED).

METHOD

Individual studies are reviewed and their results summarized.

RESULTS

The most consistent finding is a reduction in resting energy expenditure (REE) in patients with AN, which increases with increased energy intake and body weight. Data regarding BN are inconsistent. Three available studies in subjects with BED have not found evidence of changes in energy expenditure corrected for lean body mass compared with obese non-binge eaters.

DISCUSSION

The ability to measure REE reliably and cost-effectively may aid in the refeeding of patients with AN in whom REE is reduced. Changes in individuals with BN and BED have yet to be consistently identified.

Research on energy expenditure in individuals with eating disorders: a review

OBJECTIVE

This study reviews the published research on energy expenditure in individuals with anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED).

METHOD

Individual studies are reviewed and their results summarized.

RESULTS

The most consistent finding is evidence of reduction in resting energy expenditure (REE) in patients with AN, which increases with increased energy intake and body weight. Data regarding BN are inconsistent. Three available studies in subjects with BED have not found evidence of changes in energy expenditure corrected for lean body mass compared with obese non-binge eaters.

DISCUSSION

The ability to reliably and cost-effectively measure REE may aid in the refeeding of patients with AN where REE is reduced. Changes in BN and BED subjects have yet to be identified consistently.

Body composition in adolescents with anorexia nervosa

BACKGROUND

Malnourished patients with anorexia nervosa have altered body composition characterized by depletion of fat and fat-free mass.

OBJECTIVES

The objectives of this study were to assess the body composition of adolescents with anorexia nervosa compared with that of control subjects and to investigate the relation between simple anthropometric measures and reference techniques for measuring body composition.

DESIGN

Twenty-three adolescent females with anorexia nervosa aged 15.46 +/- 1.34 y (x +/- SD) were studied. Body composition was measured by anthropometry, dual-energy X-ray absorptiometry (DXA) (for body fat), and prompt gamma in vivo neutron activation analysis [for total body nitrogen (TBN)]. Twenty-five female subjects provided the control DXA data. TBN measurements were compared with prediction equations based on sex, height, age, and weight.

RESULTS

Anorexia nervosa patients had significantly lower weight (40.2 +/- 4.6 kg), body mass index (in kg/m(2): 15.3 +/- 1.2), percentage of body fat (DXA) (13.8 +/- 5.8%), percentage of TBN predicted for age (73 +/- 10%), trunk fat (2.1 +/- 1.0 kg), leg fat (2.6 +/- 1.1 kg), and trunk-to-leg fat ratio than did control subjects (P < 0.05). In anorexia nervosa patients, significant correlations were found between triceps skinfold thickness and percentage of body fat (r = 0.83), body mass index and percentage of body fat (r = 0.46), and body weight and TBN (r = 0.84, P < 0.05).

CONCLUSIONS

Hospitalized adolescent females with anorexia nervosa are depleted of total body fat and protein. We identified 3 simple anthropometric measures (triceps skinfold thickness, BMI, and body weight) that can be used to assess body composition and nutritional status in malnourished adolescents with anorexia nervosa.

The prediction of basal metabolic rate in female patients with anorexia nervosa

OBJECTIVE

To evaluate in female patients with anorexia nervosa the accuracy of a specific predictive formula for basal metabolic rate (BMR) already proposed in the literature and to derive a new disease-specific equation with the same purpose.

DESIGN

Cross-sectional study.

SUBJECTS

One-hundred and twenty adolescent girls (<18 y) and young-adult women (18-30 y) with anorexia nervosa.

MEASUREMENTS

BMR was determined by indirect calorimetry or predicted according to the Schebendach formula, which was specifically derived for anorexia nervosa.

RESULTS

On average the Schebendach formula performed well in the adolescent group but not in the young-adult group. The range including 95% of the predicted-measured differences was in both cases wider than 2000 kJ/day. In the young-adult patients the accuracy of the prediction was also related to age and body mass index. Weight and age (but not height or body mass index) emerged as predictors of BMR in the sample as a whole, and only weight when the two age groups were considered separately, thus leading to three different equations. The intercepts of these regression lines were very close and not significantly different from zero while their standard error of estimate was 500-550 kJ/day.

CONCLUSION

The Schebendach formula is not very accurate in estimating the BMR of female anorectic patients. Moreover, in this group the relationship between BMR and weight was altered. The predictive formulas proposed by the present study have a reasonable prediction power.

Resting energy expenditure and plasma leptin levels in anorexia nervosa during acute refeeding

OBJECTIVE

To examine changes in plasma leptin levels and resting energy expenditure (REE) during short-term refeeding of patients with anorexia nervosa (AN).

METHOD

This was a longitudinal study of 21 women meeting the DSM-IV criteria for AN who were admitted to the hospital for renutrition. Height, weight, percent body fat (assessed by skin fold thickness), REE (measured by indirect calorimetry), and circulating plasma leptin concentration were assessed at the time of admission and 7 days later.

RESULTS

Over the course of 1 week of refeeding, body mass index (BMI) increased 0.75 +/- 0.15 kg/m(2) (p <.0001), body fat increased 0.9 +/- 0.2% (p <.0001), and REE increased 107 +/- 33 kcal/24 hr (p =.0037). The change in mean leptin levels was not statistically significant (0.45 +/- 0.44 ng/ml; p =.32).

DISCUSSION

Leptin is unlikely responsible for the increase in REE observed with short-term refeeding.