Factors associated with the increase in resting energy expenditure during refeeding in malnourished anorexia nervosa patients

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.

Clinical Correlates of Measured and Predicted Resting Energy Expenditure in Patients with Anorexia Nervosa: A Retrospective Cohort Study

Resting energy expenditure (REE; i.e., the calorie amount required for 24 h during a non-active period) is an important parameter in nutritional rehabilitation of patients with anorexia nervosa (AN). This study determined whether age, body mass index, AN duration/subtype/specific symptoms/clinical severity, cognitive function alterations, and psychiatric comorbidities influenced REE or the difference between the calculated and estimated REE. Patients with AN who were followed at a daycare treatment facility between May 2017 and January 2020 (n = 138) underwent a complete assessment that included the MINI, Eating Disorder Examination Questionnaire, d2 test of attention, body fat composition by bioelectrical impedance analysis (BIA) and REE measurement by indirect calorimetry (REEIC). AN subtype (N = 66 for restrictive subtype and N = 69 for non-restrictive subtype; p = 0.005), free-fat mass (<0.001), and fat mass (<0.001) were associated with REEIC. Age (p < 0.001), height (p = 0.003), and AN duration (N = 46 for <3 years and N = 82 for ≥3 years; p = 0.012) were associated with the difference between estimated REE (using the Schebendach equation) and measured REEIC. Therefore, the Schebendach equation was adjusted differently in the two patients’ subgroups (AN duration ≤ or >3 years). Overall, REE was higher in patients with restrictive than non-restrictive AN. In the absence of BIA measures, REE-estimating equations should take into account AN duration.

Gastrointestinal symptoms following treatment for anorexia nervosa: A systematic literature review

OBJECTIVE

Gastrointestinal (GI) disturbances are a frequent and burdensome experience for patients with anorexia nervosa (AN). How GI symptoms respond to current interventions is not well characterized, yet is critical to facilitate treatment success, and to inform the development of new treatments for AN. Therefore, the aim of this systematic review was to identify which treatments are effective in improving GI symptoms in patients with AN.

METHOD

A systematic search for studies of AN treatments measuring GI symptoms pre- and post-treatment was conducted in May 2020 (PROSPERO ID: CRD42020181328). After removal of duplicates, title and abstracts of 3,370 studies were screened. Methodological quality was assessed using National Institute of Health Quality Assessment Tool.

RESULTS

Following full-text screening, 13 studies (12 observational studies and 1 randomized double-blind placebo-controlled trial) with 401 participants met eligibility criteria and were included. All observational studies included a component of nutritional rehabilitation, with half (n = 6) involving concurrent psychological treatment. The randomized controlled trial reported a drug therapy. Eleven studies reported an improvement in all (n = 6) or at least one (n = 5) patient-reported GI symptom following treatment. Two studies reported no change. Methodological quality was fair or poor across all studies.

DISCUSSION

This is the first systematic review to synthesize available evidence on the trajectory of patient-reported GI symptoms from commencement to end of treatment for AN. The results suggest that most studies showed improvement in one or more GI symptom in response to current treatments. Future therapeutic approaches should consider GI symptoms within their design for optimal treatment adherence and outcomes.

The Gut Microbiome Derived From Anorexia Nervosa Patients Impairs Weight Gain and Behavioral Performance in Female Mice

Anorexia nervosa (AN) results in gut dysbiosis, but whether the dysbiosis contributes to AN-specific pathologies such as poor weight gain and neuropsychiatric abnormalities remains unclear. To address this, germ-free mice were reconstituted with the microbiota of four patients with restricting-type AN (gAN mice) and four healthy control individuals (gHC mice). The effects of gut microbes on weight gain and behavioral characteristics were examined. Fecal microbial profiles in recipient gnotobiotic mice were clustered with those of the human donors. Compared with gHC mice, gAN mice showed a decrease in body weight gain, concomitant with reduced food intake. Food efficiency ratio (body weight gain/food intake) was also significantly lower in gAN mice than in gHC mice, suggesting that decreased appetite as well as the capacity to convert ingested food to unit of body substance may contribute to poor weight gain. Both anxiety-related behavior measured by open-field tests and compulsive behavior measured by a marble-burying test were increased only in gAN mice but not in gHC mice. Serotonin levels in the brain stem of gAN mice were lower than those in the brain stem of gHC mice. Moreover, the genus Bacteroides showed the highest correlation with the number of buried marbles among all genera identified. Administration of Bacteroides vulgatus reversed compulsive behavior but failed to exert any substantial effect on body weight. Collectively, these results indicate that AN-specific dysbiosis may contribute to both poor weight gain and mental disorders in patients with AN.

Gut-Brain Interactions: Implications for a Role of the Gut Microbiota in the Treatment and Prognosis of Anorexia Nervosa and Comparison to Type I Diabetes

Anorexia nervosa has poor prognosis and treatment outcomes and is influenced by genetic, metabolic, and psychological factors. Gut microbes interact with gut physiology to influence metabolism and neurobiology, although potential therapeutic benefits remain unknown. Type 1 diabetes is linked to anorexia nervosa through energy dysregulation, which in both disease states is related to the gut microbiota, disordered eating, and genetics.

Vagal Interoceptive Modulation of Motivated Behavior

In addition to regulating the ingestion and digestion of food, sensory feedback from gut to brain modifies emotional state and motivated behavior by subconsciously shaping cognitive and affective responses to events that bias behavioral choice. This focused review highlights evidence that gut-derived signals impact motivated behavior by engaging vagal afferents and central neural circuits that generally serve to limit or terminate goal-directed approach behaviors, and to initiate or maintain behavioral avoidance.

A systematic review of studies on the faecal microbiota in anorexia nervosa: future research may need to include microbiota from the small intestine

PURPOSE

Anorexia nervosa (AN) is a poorly understood and often chronic condition. Deviations in the gut microbiota have been reported to influence the gut-brain axis in other disorders. Therefore, if present in AN, it may impact on symptoms and illness progression. A review of the gut microbiota studies in AN is presented.

METHOD

A literature search on PubMed yielded 27 articles; 14 were selected and based on relevance, 9 articles were included. The findings were interpreted in the larger context of preclinical research and clinical observations.

RESULTS

8 out of 9 included studies analysed microbiota from faeces samples, while the last analysed a protein in plasma produced by the gut. Two studies were longitudinal and included an intervention (i.e., weight restoration), five were cross-sectional, one was a case report, and the last was a case series consisting of three cases. Deviations in abundance, diversity, and microbial composition of the faecal microbiota in AN were found.

CONCLUSION

There are currently only a few studies on the gut microbiota in AN, all done on faeces samples, and not all describe the microbiota at the species level extensively. The Archaeon Methanobrevibacter smithii was increased in participants with a BMI < 25 in one study and specifically in AN patients in three studies. Methanobrevibacter smithii may, if detected, be a benchmark biomarker for future studies. We propose that microbiota samples could also be collected from the small intestine, where a major exchange of nutrients takes place and where the microbiota may have a biological impact on AN.

Outcomes of an inpatient refeeding protocol in youth with Anorexia Nervosa and atypical Anorexia Nervosa at Children's Hospitals and Clinics of Minnesota

BACKGROUND

Historically, inpatient protocols have adopted relatively conservative approaches to refeeding in Anorexia Nervosa (AN) in order to reduce the risk of refeeding syndrome, a potentially fatal constellation of symptoms. However, increasing evidence suggests that patients with AN can tolerate higher caloric prescriptions during treatment, which may result in prevention of initial weight loss, shorter hospital stays, and less exposure to the effects of severe malnutrition. Therefore the present study sought to examine the effectiveness of a more accelerated refeeding protocol in an inpatient AN and atypical AN sample.

METHODS

Participants were youth (ages 10-22) with AN (n = 113) and atypical AN (n = 16) who were hospitalized for medical stabilization. A retrospective chart review was conducted to assess changes in calories, weight status (percentage of median BMI, %mBMI), and indicators of refeeding syndrome, specifically hypophosphatemia, during hospitalization. Weight was assessed again approximately 4 weeks after discharge.

RESULTS

No cases of refeeding syndrome were observed, though 47.3 % of participants evidenced hypophosphatemia during treatment. Phosphorous levels were monitored in all participants, and 77.5 % were prescribed supplemental phosphorous at the time of discharge. Higher rates of caloric changes were predictive of greater changes in %mBMI during hospitalization. Rates of caloric and weight change were not related to an increased likelihood of re-admission.

CONCLUSIONS

Results suggest that a more accelerated approach to inpatient refeeding in youth with AN and atypical AN can be safely implemented and is not associated with refeeding syndrome, provided there is close monitoring and correction of electrolytes. These findings suggest that this approach has the potential to decrease length of stay and burden associated with inpatient hospitalization, while supporting continued progress after hospitalization.

A systematic review of approaches to refeeding in patients with anorexia nervosa

OBJECTIVE

Given the importance of weight restoration for recovery in patients with anorexia nervosa (AN), we examined approaches to refeeding in adolescents and adults across treatment settings.

METHODS

Systematic review of PubMed, PsycINFO, Scopus, and Clinical Trials databases (1960-2015) using terms refeeding, weight restoration, hypophosphatemia, anorexia nervosa, anorexia, and anorexic.

RESULTS

Of 948 screened abstracts, 27 met these inclusion criteria: participants had AN; reproducible refeeding approach; weight gain, hypophosphatemia or cognitive/behavioral outcomes. Twenty-six studies (96%) were observational/prospective or retrospective and performed in hospital. Twelve studies published since 2010 examined approaches starting with higher calories than currently recommended (≥1400 kcal/d). The evidence supports 8 conclusions: 1) In mildly and moderately malnourished patients, lower calorie refeeding is too conservative; 2) Both meal-based approaches or combined nasogastric+meals can administer higher calories; 3) Higher calorie refeeding has not been associated with increased risk for the refeeding syndrome under close medical monitoring with electrolyte correction; 4) In severely malnourished inpatients, there is insufficient evidence to change the current standard of care; 5) Parenteral nutrition is not recommended; 6) Nutrient compositions within recommended ranges are appropriate; 7) More research is needed in non-hospital settings; 8) The long-term impact of different approaches is unknown;

DISCUSSION

Findings support higher calorie approaches to refeeding in mildly and moderately malnourished patients under close medical monitoring, however the safety, long-term outcomes, and feasibility outside of hospital have not been established. Further research is also needed on refeeding approaches in severely malnourished patients, methods of delivery, nutrient compositions and treatment settings.

Gut Dysbiosis in Patients with Anorexia Nervosa

Anorexia nervosa (AN) is a psychological illness with devastating physical consequences; however, its pathophysiological mechanism remains unclear. Because numerous reports have indicated the importance of gut microbiota in the regulation of weight gain, it is reasonable to speculate that AN patients might have a microbial imbalance, i.e. dysbiosis, in their gut. In this study, we compared the fecal microbiota of female patients with AN (n = 25), including restrictive (ANR, n = 14) and binge-eating (ANBP, n = 11) subtypes, with those of age-matched healthy female controls (n = 21) using the Yakult Intestinal Flora-SCAN based on 16S or 23S rRNA–targeted RT–quantitative PCR technology. AN patients had significantly lower amounts of total bacteria and obligate anaerobes including those from the Clostridium coccoides group, Clostridium leptum subgroup, and Bacteroides fragilis group than the age-matched healthy women. Lower numbers of Streptococcus were also found in the AN group than in the control group. In the analysis based on AN subtypes, the counts of the Bacteroides fragilis group in the ANR and ANBP groups and the counts of the Clostridium coccoides group in the ANR group were significantly lower than those in the control group. The detection rate of the Lactobacillus plantarum subgroup was significantly lower in the AN group than in the control group. The AN group had significantly lower acetic and propionic acid concentrations in the feces than the control group. Moreover, the subtype analysis showed that the fecal concentrations of acetic acid were lower in the ANR group than in the control group. Principal component analysis confirmed a clear difference in the bacterial components between the AN patients and healthy women. Collectively, these results clearly indicate the existence of dysbiosis in the gut of AN patients.

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.

Chronic starvation secondary to anorexia nervosa is associated with an adaptive suppression of resting energy expenditure

BACKGROUND

Chronic starvation is accompanied by a reduction in resting energy expenditure (REE). It is not clear whether this is due mainly to a reduction in body mass or also involves a significant reduction in the cellular metabolic rate of the fat-free mass (FFM).

OBJECTIVES

The main goal was to compare measured REE (REEm) with REE predicted by dual-energy X-ray absorptiometry modeling of organ-tissue mass (REEp) in malnourished patients with severe anorexia nervosa (AN) and in healthy lean control subjects. REE adjusted for FFM and fat mass was also compared between the groups.

DESIGN

This was a cross-sectional study of 30 patients with AN and 25 lean control subjects. REE was measured by indirect calorimetry. Body composition was modeled using dual-energy X-ray absorptiometry, and REE was predicted for each group based on organ-tissue mass.

RESULTS

REEm was significantly lower than REEp in subjects with AN (854 ± 41 vs 1080 ± 25 kcal/d, P < .001), but not in control subjects. In addition, REE adjusted for both FFM and fat mass was significantly lower in the subjects with AN (1031 ± 37 vs 1178 ± 32 kcal/d, P < .01). Finally, compared with the lean control subjects, both organ and skeletal muscle mass were approximately 20% smaller in subjects with AN.

CONCLUSIONS

Chronic starvation is accompanied by a significant reduction in the metabolic rate of the FFM. The organs and/or tissues accounting for this are unknown. In addition, this study suggests that protein is mobilized proportionately from organs and skeletal muscle during starvation. This too may be an adaptive response to chronic starvation.

Refeeding hypophosphatemia in adolescents with anorexia nervosa: a systematic review

The rate of adolescents presenting with anorexia nervosa (AN) is increasing. Medically unstable adolescents are admitted to the hospital for nutrition restoration. A lack of global consensus on appropriate refeeding practices of malnourished patients has resulted in inconsistent refeeding practices. Refeeding hypophosphatemia (RH) is the most common complication associated with refeeding the malnourished patient. This review sought to identify the range of refeeding rates adopted globally and the implication that total energy intake and malnutrition may have on RH while refeeding adolescents with anorexia nervosa. Studies were identified by a systematic electronic search of medical databases from 1980 to September 2012. Seventeen publications were identified, including 6 chart reviews, 1 observational study, and 10 case reports, with a total of 1039 subjects. The average refeeding energy intake was 1186 kcal/d, ranging from 125-1900 kcal/d, with a mean percentage median body mass index (% mBMI) of 78%. The average incidence rate of RH was 14%. A significant correlation between malnutrition (% mBMI) and post-refeeding phosphate was identified (R (2) = 0.6, P = .01). This review highlights the disparity in refeeding rates adopted internationally in treating malnourished adolescents with anorexia nervosa. Based on this review, the severity of malnutrition seems to be a marker for the development of RH more so than total energy intake.

The effect of atypical antipsychotic medications in individuals with anorexia nervosa: a systematic review and meta-analysis

OBJECTIVE

Given that atypical antipsychotic medications have been increasingly prescribed for improving weight gain in anorexia nervosa (AN), we conducted a systematic review and meta-analyses to estimate the influence of atypical antipsychotics on BMI, eating disorder, and psychiatric symptoms in individuals with AN.

METHOD

Independent reviewers selected studies and extracted study characteristics, methodologic quality, and outcomes for the intention-to-treat group from randomized clinical trials comparing the effect of atypical antipsychotic use to placebo or an active control treatment on BMI.

RESULTS

Compared with placebo, atypical antipsychotics were associated with a nonsignificant increase in BMI (weighted mean difference, WMD = 0.18, 95% CI: -0.36, 0.72; I(2) = 26%) and a nonsignificant effect on the drive for thinness and body dissatisfaction. Compared with placebo or active control, these medications led to an increase in anxiety and overall eating disorder symptoms. However, there was a significant reduction over placebo or active control on level of depression.

Metabolic and nutritional needs to normalize body mass index by doubling the admission body weight in severe anorexia nervosa

Anorexia nervosa exhibits one of the highest death rates among psychiatric patients and a relevant fraction of it is derived from undernutrition. Nutritional and medical treatment of extreme undernutrition present two very complex and conflicting tasks: (1) to avoid "refeeding syndrome" caused by a too fast correction of malnutrition; and (2) to avoid "underfeeding" caused by a too cautious refeeding. To obtain optimal treatment results, the caloric intake should be planned starting with indirect calorimetry measurements and electrolyte abnormalities accurately controlled and treated. This article reports the case of an anorexia nervosa young female affected by extreme undernutrition (BMI 9.6 kg/m(2)) who doubled her admission body weight (from 22.5 kg to 44 kg) in a reasonable time with the use of enteral tube feeding for gradual correction of undernutrition. Refeeding syndrome was avoided through a specialized and flexible program according to clinical, laboratory, and physiological findings.

Using body mass index to predict optimal thyroid dosing after thyroidectomy

BACKGROUND

Current postoperative thyroid replacement dosing is weight based, with adjustments made after thyroid-stimulating hormone values. This method can lead to considerable delays in achieving euthyroidism and often fails to accurately dose over- and underweight patients. Our aim was to develop an accurate dosing method that uses patient body mass index (BMI) data.

STUDY DESIGN

A retrospective review of a prospectively collected thyroid database was performed. We selected adult patients undergoing thyroidectomy, with benign pathology, who achieved euthyroidism on thyroid hormone supplementation. Body mass index and euthyroid dose were plotted and regression was used to fit curves to the data. Statistical analysis was performed using STATA 10.1 software (Stata Corp).

RESULTS

One hundred twenty-two patients met inclusion criteria. At initial follow-up, only 39 patients were euthyroid (32%). Fifty-three percent of patients with BMI >30 kg/m(2) were overdosed, and 46% of patients with BMI <25 kg/m(2) were underdosed. The line of best fit demonstrated an overall quadratic relationship between BMI and euthyroid dose. A linear relationship best described the data up to a BMI of 50. Beyond that, the line approached 1.1 μg/kg. A regression equation was derived for calculating initial levothyroxine dose (μg/kg/d = -0.018 × BMI + 2.13 [F statistic = 52.7, root mean square error of 0.24]).

CONCLUSIONS

The current standard of weight-based thyroid replacement fails to appropriately dose underweight and overweight patients. Body mass index can be used to more accurately dose thyroid hormone using a simple formula.

Prognosis in 41 severely malnourished anorexia nervosa patients

BACKGROUND & AIMS

To report the prognosis in 41 anorexia nervosa (AN) patients suffering from very severe malnutrition (mean BMI: 10.1 ± 0.57 kg/m(2)).

PATIENTS AND METHODS

Compared with 443 less malnourished AN patients, the 41 patients were older (27.8 ± 5.4 vs 22.4 ± 2.1 yrs), their AN was longer (9.6 ± 3.4 vs 5.0 ± 1.5 yrs) and more often of the restrictive subtype (P < 0.05).

RESULTS

In 27% of the patients, all nutritional marker levels were in normal range. All patients received a prudent tube-refeeding: energy was increased from 12 to 40 kcal/kg/day, protein from 1.0 to 1.5 g/kg/day within 10 days. During stay, 1 patient died, 2 others suffered from myocardial infarction, 2 others from acute pancreatitis, and 5 from mental confusion. Compared with the other 443 AN patients, the 40 remaining patients had worse 6-yr prognosis: 2 died (7% vs 1.2%), 29% had severe outcome (vs 10%), and only 41% recovered (vs 62%).

CONCLUSION

In AN patients with BMI < 11 kg/m(2), a prudent tube-refeeding could avoid short-term mortality, but long-term prognosis was bad.

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.

Resting Energy Expenditure in Anorexia Nervosa: Measured versus Estimated

Introduction. Aim of this study was to compare the resting energy expenditure (REE) measured by the Douglas bag method with the REE estimated with the FitMate method, the Harris-Benedict equation, and the Müller et al. equation for individuals with BMI < 18.5 kg/m(2) in a severe group of underweight patients with anorexia nervosa (AN). Methods. 15 subjects with AN participated in the study. The Douglas bag method and the FitMate method were used to measure REE and the dual energy X-ray absorptiometry to assess body composition after one day of refeeding. Results. FitMate method and the Müller et al. equation gave an accurate REE estimation, while the Harris-Benedict equation overestimated the REE when compared with the Douglas bag method. Conclusion. The data support the use of the FitMate method and the Müller et al. equation, but not the Harris-Benedict equation, to estimate REE in AN patients after short-term refeeding.

Anorexia nervosa and generalized anxiety disorder: further explorations of the relation between anxiety and body mass index

We explore comorbidity of anorexia nervosa (AN) and generalized anxiety disorder (GAD) and their relation with body mass index (BMI) and evaluate the presence of fasting and excessive exercise which both have anxiolytic and weight loss effects. All participants were female: 32 with AN only, 607 with GAD only, 22 with AN and GAD (AN+GAD), and 5424 with no history of AN or GAD (referent) from the Swedish Twin study of Adults: Genes and Environment (STAGE). Lowest adult BMI differed significantly (p<.001) and was lower in those with AN+GAD than those with AN only (p<.029). Those with AN+GAD were most likely to endorse fasting and excessive exercise, followed by women with AN only, women with GAD only, and the referent. Comorbid AN and GAD may be a particularly pernicious presentation influencing both BMI and proclivity to engage in behaviors such as fasting and exercise that serve both weight loss and anxiolytic goals.

Obesity and thyroid function

A moderate elevation of thyrotropin (TSH) concentrations, which is associated with triiodothyronine (T3) values in or slightly above the upper normal range, is frequently found in obese humans. These alterations seem rather a consequence than a cause of obesity since weight loss leads to a normalization of elevated thyroid hormone levels. Elevated thyroid hormone concentrations increase the resting energy expenditure (REE). The underlying pathways are not fully understood. As a consequence of the increased REE, the availability of accumulated energy for conversion into fat is diminished. In conclusion, the alterations of thyroid hormones in obesity suggest an adaptation process. Since rapid weight loss is associated with a decrease of TSH and T3, the resulting decrease in REE may contribute towards the difficulties maintaining weight loss. Leptin seems to be a promising link between obesity and alterations of thyroid hormones since leptin concentrations influence TSH release.

Nutritional rehabilitation: practical guidelines for refeeding the anorectic patient

Weight restoration is crucial for successful treatment of anorexia nervosa. Without it, patients may face serious or even fatal medical complications of severe starvation. However, the process of nutritional rehabilitation can also be risky to the patient. The refeeding syndrome, a problem of electrolyte and fluid shifts, can cause permanent disability or even death. It is essential to identify at-risk patients, to monitor them carefully, and to initiate a nutritional rehabilitation program that aims to avoid the refeeding syndrome. A judicious, slow initiation of caloric intake, requires daily management to respond to entities such as liver inflammation and hypoglycemia that can complicate the body's conversion from a catabolic to an anabolic state. In addition, nutritional rehabilitation should take into account clinical characteristics unique to these patients, such as gastroparesis and slowed colonic transit, so that measures can be taken to ameliorate the physical discomforts of weight restoration. Adjunct methods of refeeding such as the use of enteral or parenteral nutrition may play a small but important role in a select patient group who cannot tolerate oral nutritional rehabilitation alone.

Childhood anxiety associated with low BMI in women with anorexia nervosa

OBJECTIVE

Extremely low body mass index (BMI) values are associated with increased risk for death and poor long-term prognosis in individuals with anorexia nervosa (AN). The present study explores childhood personality characteristics that could be associated with the ability to attain an extremely low BMI.

METHODS

Participants were 326 women from the Genetics of Anorexia Nervosa (GAN) Study who completed the Structured Interview for Anorexia Nervosa and Bulimic Syndromes and whose mother completed the Child Behavioral Checklist and/or Revised Dimensions of Temperament Survey.

RESULTS

Children who were described as having greater fear or anxiety by their mothers attained lower BMIs during AN (p < 0.02). Path analysis in the GAN and a validation sample, Price Foundation Anorexia Nervosa Trios Study, confirmed the relation between early childhood anxiety, caloric restriction, qualitative food item restriction, excessive exercise, and low BMI. Path analysis also confirmed a relation between childhood anxiety and caloric restriction, which mediated the relation between childhood anxiety and low BMI in the GAN sample only.

CONCLUSION

Fearful or anxious behavior as a child was associated with the attainment of low BMI in AN and childhood anxiety was associated with caloric restriction. Measures of anxiety and factors associated with anxiety-proneness in childhood may index children at risk for restrictive behaviors and extremely low BMIs in AN.

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.

Exploratory study to decrease postprandial anxiety: Just relax!

OBJECTIVE

Critical first steps in the treatment of anorexia nervosa (AN) include re-nutrition and weight restoration, both highly anxiety provoking for patients. We explored the impact of progressive muscle relaxation (PMR), guided imagery (GI), self-directed relaxation (SR), and control (C) on reducing postprandial anxiety in 64 females with AN.

METHOD

Participants began the study upon hospital admission. They received relaxation training after lunch for 15 days. Pre- and post-session anxiety and treatment acceptability ratings were made daily.

RESULTS

Although all conditions improved relaxation and decreased anxiety, feelings of fullness, and thoughts about weight, the three active conditions significantly reduced anxiety and increased relaxation more than C (p < .0001). Participants significantly enjoyed the three active treatments, were more likely to recommend them to a friend, and were more likely to use either PMR or GI again versus C (p < .0001).

CONCLUSION

Relaxation may be a valuable component for reducing postprandial anxiety in AN.

Strategies to reverse bone loss in women with functional hypothalamic amenorrhea: a systematic review of the literature

Functional hypothalamic amenorrhea (FHA) impairs the attainment of peak bone mass and as such can increase the risk of fractures later in life. To document available treatment strategies, we conducted a systematic review of the literature. We report that hormonal therapies have limited effectiveness in increasing bone mass, whereas increased caloric intake resulting in weight gain and/or resumption of menses is an essential strategy for restoring bone mass in women with FHA.

INTRODUCTION

Women with functional hypothalamic amenorrhea (FHA) may not achieve peak bone mass (PBM), which increases the risk of stress fractures, and may increase the risk of osteoporotic fractures in later life.

METHODS

To identify effective treatment strategies for women with FHA, we conducted a systematic review of the literature. We included randomized controlled trials (RCTs), cross-sectional studies, and case studies that reported on the effects of pharmacological and non-pharmacological interventions on bone mineral density (BMD) or bone turnover in women with FHA.

RESULTS

Most published studies (n=26) were designed to treat the hormonal abnormalities observed in women with FHA (such as low estrogen, leptin, insulin-like growth factor-1, and DHEA); however none of these treatments demonstrated consistent improvements in BMD. Therapies containing an estrogen given for 8-24 months resulted in variable improvements (1.0-19.0%) in BMD, but failed to restore bone mass to that of age-matched controls. Three studies reported on the use of bisphosphonates (3-12 months) in anorexic women, which appear to have limited effectiveness to improve BMD compared to nutritional treatments. Another three investigations showed no improvements in BMD after androgen therapy (DHEA and testosterone) in anorexic women. In contrast, reports (n=9) describing an increase in caloric intake that results in weight gain and/or the resumption of menses reported a 1.1-16.9% increase in BMD concomitant with an improvement in bone formation and reduction in bone resorption markers.

CONCLUSIONS

Our literature review indicates that the most successful, and indeed essential strategy for improving BMD in women with FHA is to increase caloric intake such that body mass is increased and there is a resumption of menses. Further long-term studies to determine the persistence of this effect and to determine the effects of this and other strategies on fracture risk are needed.

A randomized trial on the efficacy of a 2-month tube feeding regimen in anorexia nervosa: A 1-year follow-up study

BACKGROUND & AIMS

Despite the high mortality rate in malnourished anorexia nervosa (AN) patients, very few trials have prospectively studied the efficacy of tube feeding.

METHODS

This open prospective study was conducted in malnourished AN patients, who were randomized in tube feeding (n=41) or control (n=40) groups during a 2-month period. Thereafter, body weight, body mass gain, energy intake, eating behavior and relapse rates were compared during a 1-year follow-up, using paired Student t-test and ANOVA.

RESULTS

At the end of the 2-months period, weight gain was 39% higher in the tube feeding group than in the control group (194+/-14 vs 126+/-19g/day; P<0.01). The fat-free mass gain was greater in the tube-feeding group: 109+/-14 vs 61+/-17g/day (P<0.01). Energy intake was higher in the tube feeding group than in the control group (P<0.05), as well as the decrease in bingeing episodes (P<0.01). Most patients thought that CEN improved their eating disorder. After discharge, the relapse-free period was longer in the CEN group than in the control one: 34.3+/-8.2 weeks vs 26.8+/-7.5 weeks (P<0.05).

CONCLUSION

CEN is helpful in malnourished AN patients for weight restoration, without hindrance on the eating behavior therapy nor inducing a more rapid relapse.

Hormonal and psychological factors linked to the increased thermic effect of food in malnourished fasting anorexia nervosa

OBJECTIVES

In patients with anorexia nervosa (AN), weight gain is lower than that expected from the energy content of the meals. Thus we investigated the thermic effect of food (TEF) in relation to subjective feelings and plasma hormone levels in a group of AN patients.

METHODS

TEF, feelings (14 items), and plasma release of beta-endorphin, ACTH, cortisol, dopamine, and catecholamines were evaluated in 15 AN patients (body mass index, 13.6 +/- 1.2 kg.m(-2)) and in 15 healthy women after three gastric loads (0, 300, 700 kcal) infused by a nasogastric tube in a blind design.

RESULTS

In AN, the blind loads induced an energy-dependent increase in TEF (P < 0.001), which was higher than that observed in healthy women (P < 0.001). Only in AN, a load-dependent decline in the high basal plasma level of beta-endorphin (P < 0.01), an increase in plasma ACTH (P < 0.02) after the two caloric loads, and an increase in cortisol, norepinephrine, and dopamine levels after the 700-kcal load only (P < 0.05) were noted. A calorie-dependent (P < 0.001) increase in nausea, abdominal discomfort, and fear of being fat ratings and a decrease in liking to eat (P < 0.001) and body image were observed in AN patients (P < 0.05). TEF correlated with ratings on satiation, nausea, uncomfortable abdominal swelling, body image, and fear of being fat (for all, P < 0.01).

CONCLUSION

In AN women, blindly infused loads induced a dose-dependent increase in TEF, which correlated with the increase in plasma cortisol, ACTH, and catecholamines as in unpleasant sensations, fear of being fat, and anxiety as well as a decline in elevated basal beta-endorphin. These results could explain the difficulty for AN patients in gaining weight.

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.

Smoking in eating disorders

OBJECTIVE

Smoking has been reported as an appetite and weight control method in eating disorders; however, few studies have explored patterns of smoking across subtypes of eating disorders. The aim of this paper was to explore the patterns and prevalence of smoking behavior in 1,524 women from two of the multisite Price Foundation Genetic studies.

METHOD

Smoking behavior was assessed in 306 individuals with anorexia nervosa-restricting type (RAN), 186 with anorexia nervosa-purging type (PAN), 180 with anorexia nervosa and bulimia nervosa (ANBN), 107 with anorexia nervosa-binging type (BAN), 71 individuals with purging type-bulimia nervosa (PBN), and 674 female community controls. We compared smoking prevalence and smoking behaviors across eating disorder (ED) subtypes and in comparison to controls using the Fagerstrom Test of Nicotine Dependence (FTND).

RESULTS

Overall, women with eating disorders reported higher rates of smoking and greater nicotine dependence than controls. Women with binge/purge subtypes of eating disorders reported the highest rates of smoking of all of the subtypes. Smoking in eating disorders was related to impulsive personality traits.

CONCLUSIONS

Women with eating disorders appear to be at increased risk for smoking, particularly those who binge eat and/or purge and display impulsive personality characteristics. Given the high prevalence, the impact of ongoing smoking on maintenance of eating disorders symptoms is worthy of both clinical and research attention.

Medical complications of anorexia nervosa and bulimia nervosa

PURPOSE OF REVIEW

This review focuses on recent publications concerning medical complications in patients with eating disorders, including anorexia nervosa and bulimia nervosa.

RECENT FINDINGS

Recent literature continues to reflect that multiple organ systems are frequently affected by eating disorders. The literature underscores the frequently cited risk of premature death in those with anorexia nervosa. A plethora of dermatologic changes have been described, some signaling serious underlying pathophysiology, such as purpura, which indicates a bleeding diathesis. Much of the literature continues to delineate the fact that diabetic patients with eating disorders are at high risk of developing diabetic complications. Gastrointestinal complications can be serious, including gastric dilatation and severe liver dysfunction. Acrocyanosis is common, and patients with anorexia nervosa are at risk of various arrhythmias. Low-weight patients are at high risk for osteopenia/osteoporosis. Nutritional abnormalities are also common, including sodium depletion and hypovolemia, hypophosphatemia and hypomagnesemia. Resting energy expenditure, although very low in low-weight patients, increases dramatically early in refeeding.

SUMMARY

Medical complications are common and often serious in patients with eating disorders, particularly those with anorexia nervosa.