Eating Disorders Review
July/August 2011
Volume 22, Issue 4

At the 10^th London International Eating Disorders Conference, held at the University of London late in March, clinicians in concurrent sessions addressed three particularly challenging topics: managing compulsive exercise, treating patients with severe and enduring anorexia nervosa (AN), and treating eating disorders patients who have a history of childhood trauma.

Managing Compulsive Exercise

Drs. Caroline Meyer and Lorin Taranis, of Loughborough University, Leicester, UK, and Dr. Stephen Touyz, of the University of Sydney, Australia, noted that many treatment programs currently prohibit exercise for patients with eating disorders. This practice has largely developed because staff members and clinicians have found it hard to enforce partial exercise programs. In addition, policing such policies creates a battle of wills that only adds more strain to the therapeutic relationship. The panel noted that battles over exercise distract both the patients and the staff from the major goal of therapy, helping patients assume responsibility for themselves.

Dr. Meyer and colleagues believe that a supervised program of exercise is an essential component of treatment of patients with AN and bulimia nervosa. Dr. Meyer noted there is "a basis of misinformation to these patients' behavior, which is just as true for beliefs concerning exercise as it is for distorted views about food." Using cognitive behavioral therapy (CBT), such false beliefs can be challenged by providing accurate information on the type and level of activity necessary for optimal health, along with emphasis on the deleterious effects of excessive exercise in the presence of malnutrition, she said. An important footnote to this is that such sessions must be conducted by professionals with specific expertise in eating disorders and excessive exercise.

Dr. Meyer, who directs Loughborough University's Centre for Research into Eating Disorders, (LUCRED), also described the LEAP program (Loughborough Eating Disorders Activity Therapy Program). The LEAP program applies CBT to counteract excessive exercise among eating disorders patients. As she explained, LEAP is a semi-structured manualized CBT treatment program that is problem-oriented, concerned with the present instead of the past, and that focuses on maintenance. The core principles are to go with and not against the patient, to educate patients about healthy and unhealthy exercise, and, perhaps most importantly, to help patients gain control over exercise, she said. "Control" includes helping patients relearn healthy/non-compulsive attitudes, beliefs, and behaviors about physical activity and excessive exercise. Patients learn the underlying factors that led them to excessively exercise in the first place and also to better understand the connections between compulsive exercise and eating disorders.

The LEAP structure allows for group or individual sessions, and the program includes 8 one-hour sessions that are organized around four core themes: education, guided discovery, skills training, and relapse prevention.(Drs. Meyer, Taranis, and Touyz recently developed The Compulsive Exercise Test (CET) to assess the primary factors that maintain excessive exercise [See Eur Eat Disord Rev 2011 May 19:256].

Treating Severe and Enduring AN

Dr. Bryony Bamford, of St. George's Hospital, University of London, told the audience there is currently no exact definition of severe and enduring AN (SE-AN), but patients do have a distinguishable profile. This profile includes: (1) being consistently ill for 10 years or more, (2) undergoing at least one unsuccessful evidence-based treatment, (3) having severe impairment across a number of life domains, and (4) having a strong motivation to hold onto AN, and thus a reluctance to continue active treatment. In addition, treatment seems risky because when patients do regain their weight, they may drop out of therapy. Often therapists are frustrated because these patients seem disengaged from help and seem hopeless.

Dr. Bamford presented a different model of treatment, one that she said "moves beyond the focus on 'cure' or 'absence of symptoms' to helping individuals build meaningful and valued lives." The focus on quality of life can also be seen in psychological interventions in other fields than the eating disorders field, said Dr. Bamford. And, these patients may be "more motivated to improve the quality of their lives rather than to change their eating patterns or weight status," she said.

Intervention for this group of patients focuses on acceptance, management, reducing risk, and improving quality of life. It is also important to address threats that are of immediate concern to the patient and to treat these separately rather than focusing on the overall illness, she noted. In addition, the emphasis should be on finding ways to cope that address the beliefs about illness rather than focusing on the symptoms of the illness.

According to Dr. Bamford, rehabilitation programs should include skills training, goal-setting, enhancing "hope," and managing secondary consequences rather than the primary illness. Constantly working on enhancing motivation is another key, she noted. This is coupled with an agreement on minimum steps, and setting firm behavioral goals. Patients will also need training in useful social skills, rather than emphasizing the symptoms of the illness. In addition to all this, the therapeutic alliance requires an emphasis on consistency, reassurance, encouragement, and patience, with a good degree of hope. The alliance must also be collaborative and it also helps to view the patient as an expert in her own care—find out what works and what doesn't work, Dr. Bamford advised. Finally, practical considerations also help, such as setting shorter sessions or taking a slower pace when warranted. Flexibility is also important—for example, finding out when a good time will be to meet, and telephoning the patient before the session, reinforcing the idea that "I would like to see you," said Dr. Bamford.

A Complex Challenge: Childhood Trauma and Disordered Eating

Eating disorder patients who have a history of traumatic experiences or violence during childhood, such as physical or sexual abuse or neglect, are far more likely to respond poorly to treatment than are other patients, according to Stephen Wonderlich, PhD, and Heather Simonich, MA, from the Neuropsychiatric Research Institute, Fargo, ND, and Óyvind Ró, PhD, MD, of Oslo University Hospital, Oslo, Norway. In such cases, the path to an eating disorder may start with trauma, which can lead to shame, dissociation, impulse control, anxiety, substance use, cognitions, or mood instability, and then to an eating disorder.

Eating disorders patients who have undergone trauma in childhood can also develop post-traumatic stress disorder (PTSD). This may take the form of simple PTSD after a single event in adulthood, or complex PTSD, typically after multiple repeated, prolonged traumas during childhood, which may also lead to dissociative syndromes. Patients with eating disorders and PTSD have a number of telltale symptoms, including recurring intrusive images, sleeping difficulties, difficulty concentrating, lack of interest, and social withdrawal. Childhood trauma may be hidden, and reactivated during treatment. Or the trauma may be known but the patient may have detached from it, describing the symptoms as occurring in someone else. Finally, patients may directly seek help for both PTSD and an eating disorder.

The clinical picture is different for patients with eating disorders without PTSD and those with both disorders, said Dr. Rø. For example, in the absence of PTSD, a patient may have a drive to be thin and fear of weight gain. With PTSD due to sexual abuse, a patient may feel disgust, dirtiness, a need for purification, and may develop a fear of thinness/fatness to avoid attracting unwanted attention. "Their symptoms could be understood as a reaction to 'being in extreme danger," he said.

Better understanding will lead to better treatment for these complex patients, according to Dr. Wonderlich. Treatment difficulties are commonly encountered. Staff members are challenged by the risk for overinvolvement or burnout, and with problems of setting boundaries with these patients. Negative transference reactions are also common, where some therapists may appear to be abusive and other therapists may seem to be withholding or failing to protect the patient. Because some patients have experienced a repetitive pattern of being traumatized in close relationships, there is the risk of "re-traumatization" during treatment.

And, to add even more challenge to treating such patients, there may be a close connection between memories of sexual trauma and eating disorders symptoms. That is, food (smell, consistency, color, taste, time of the meal and even the mealtime atmosphere) may trigger memories of trauma. Some strategies to counteract and disrupt the connection between food and trauma include helping the patient become aware of the connection, differentiating between now and then, helping the patient experiment in safe settings, and helping him or her "avoid the avoidance," said Dr. Wonderlich.

Two approaches that are proving helpful for these challenging patients are trauma-focused cognitive behavioral therapy (TF-CBT), first described by Cohen et al. in 2006, and drug therapies. According to Dr. Wonderlich and his colleagues, studies have consistently shown that TF-CBT assignment, improvement in parental support, and improvement in parental distress about the child's victimization predict a better outcome for the child. The best candidates for TF-CBT are children 4 to 18 years of age with a history of single or multiple trauma, prominent trauma symptoms, depression, or anxiety.Children with severe behavioral problems may need alternative interventions. Dr. Wonderlich also pointed out that of all the classes of drugs that have been studied in this group of patients, the SSRIs are considered the drugs of choice; these include sertraline, paroxetine, and fluoxetine.

UPDATE: Chewing and Spitting Behavior

The phenomenon of chewing and spitting (CS) is still little understood despite being relatively common among eating disorders patients. As reported in a poster session at the International Conference on Eating Disorders in Miami in April, chewing and then spitting out food is associated with greater eating pathology and is reported in all types of eating disorders. To better understand the implications of this behavior, Nora A. Durkin and colleagues at the University of Minnesota and University of North Dakota School of Medicine analyzed data from 985 participants who presented for outpatient treatment from 1985 to 1996. Lifetime rates of CS varied across eating disorders diagnoses: in anorexia nervosa patients, 38.2%; in patients with bulimia nervosa, 33.7%; and among those with eating disorders not otherwise specified, 24.7%. CS was also significantly related to binge eating and use of compensatory behaviors, including higher rates of binge eating, laxative use, diuretic use, exercise, fasting, skipping meals, and eating small or low-calorie meals. Patients who used CS also had lower current, highest, lowest, and goal body mass indexes (BMIs) compared to those who did not report CS. Patients who reported CS were younger compared to those who did not report it. Collectively, these findings indicate that CS is associated with greater eating pathology and is not equally prevalent across eating disorder diagnoses. Future research should clarify the correlates, mechanisms, and functions of CS in eating disorders. According to the authors, clinicians should be alert for this unusual behavior, as it may carry implications for progression of illness and treatment.

A Pilot Study of Olanzapine in Teens with Restrictive AN

Patients with restricting-type anorexia nervosa (AN-R) have intense fears of becoming overweight and distorted perceptions of their bodies, and as a result severely limit their caloric intake. This leads to serious nutritional deficiencies, electrolyte and acid-base imbalance, dehydration, cardiac irregularities, and a hypometabolic state due to malnutrition. Among adolescents, this can lead to reductions in peak bone mass, delayed puberty, and significant growth retardation. Most importantly, the mortality rate for patients with AN-R has been reported as between 6% and 18%.

Olanzapine, a second-generation antipsychotic agent developed for the treatment of schizophrenia, acts on the 5-HT neuronal system, which regulates appetite, motor activity, and mood, and has effects on obsessions and impulsive behavior as well. Thus, it seemed like a natural agent to try among patients with AN-R. Dr. Vivian Kafantaris and colleagues designed a double-blind, placebo-controlled pilot study of olanzapine and enrolled 20 underweight females diagnosed with AN-R (J Child Adolesc Psychopharmacol 2011; 21: 207).

All females between 12 and 21 years who were receiving treatment for AN over a 4-year period were screened for eligibility for the study. This included inpatients, those attending day hospital treatment, and outpatients. Recruitment was challenging, for of the 94 women eligible for the study, 74 (79%) chose not to participate. The most common reasons given for declining the study were fear of gaining weight or wanting to gain weight without the need for medication.

The primary measure of efficacy was percentage of mean body weight (%MBW), which was measured at baseline and at weeks 5 and 10. Secondary measures were physician-rated and reported measures of psychological functioning, measured at 2-week intervals, and eating disorder symptoms recorded at baseline and then at weeks 5 and 10. Laboratory assessments, including indirect calorimetry, were also part of the study. The patients received a daily dose of 2.5 mg olanzapine, or placebo, in a single oral dose in the evening or at bedtime for one week. The daily dosage was then increased by 2.5 mg each week to a target dose of 10 mg per day by week 4. The research psychiatrists evaluated tolerability of medication weekly by physical examination, including blood pressure and pulse.

Week 10: No weight gain, and increased serum glucose and insulin levels

Mean %MBW improved in both treatment arms, and at the 10-week point, this differed significantly from baseline. Contrary to the researchers' hypothesis, adding olanzapine to a comprehensive eating disorder treatment program did not improve %MBW at any time point during the study. However, by week 10 the researchers did record significant increases in serum insulin and fasting glucose levels in the group receiving olanzapine. According to the authors, these increases suggest a direct metabolic effect of olanzapine and the need for closely monitoring patients during long-term use.

Three women in the olanzapine group withdrew before week 5, citing dissatisfaction with the medication, whereas the two non-completers from the placebo arm were removed by investigators because of worsening symptoms. The mean dose achieved at week 10 was 8.5 mg. Both treatment groups remained at low body weights at the end of the study, and did not have improved attitudes or behaviors. In other words, they remained at high risk.

On the clinician-administered scale of functional abilities, the Toronto Extremity Salvage score, or TESS, there were no significant group-by-time interactions for any of the categories, including increased appetite, drowsiness, increased motor activity, rigidity, tremors, dystonia, akathisia or dyskinesia.

On the basis of their results, the authors do not feel there is a role for olanzapine in the treatment of underweight teens with AN-R receiving standard care in an eating disorders treatment center.

Suicide Risk among Eating Disorders Patients

Suicide is the second leading cause of death (after cardiac disease) among persons with anorexia nervosa (AN), and a major cause of death among people with eating disorders (Int J Eat Disord 2007; 40: 293). Results of studies in Spain and Italy provide new information on the risk of suicide among these patients.

Suicide and personality

A collaborative team led by Dr. Laura Forcano and colleagues in Barcelona, and Dr. Cynthia Bulik at the University of North Carolina at Chapel Hill, recently evaluated the relationship between suicide and personality among 172 patients with AN (Compr Psychiatry 2011; 52:352). The team examined the prevalence of lifetime suicide attempts in women with AN, and then factored in eating disorder symptoms, general psychopathology, and personality in a healthy control group and then across groups with restricting and purging subtypes of AN.

The study group was diagnosed according to DSM-IV criteria by experienced psychologists and psychiatrists. The mean age was 24.7 years; the mean age at onset of illness was 19.7 years; and the mean duration of illness was 5 years. Mean weekly number of binge-eating episodes was 0.8 and the number of mean weekly vomiting episodes was 2.3. The mean body mass index (kg/m²) was 15.6. Most patients were single and unemployed, and had completed primary or secondary schooling. The control group included 146 female undergraduate students (mean age 21.1 years and mean BMI 21.1). In contrast to those in the patient group, most controls were engaged to be married and employed, and had completed their secondary education.

To assess the lifetime incidence of suicide attempts, all participants were asked, "Have you ever attempted suicide?" during structured clinical face-to-face interviews. To be qualified as a suicide attempt, the suicidal gesture had to be self-destructive with intent to die. Study participants also completed a series of questionnaires, including the Symptom Checklist- Revised and the Eating Disorders Inventory-2.

Different patterns among the groups

The prevalence of suicide attempts differed significantly across the three groups studied. The prevalence was 0% among controls, 8.65% in the restricting AN group, but 25% in the purging AN group. Depression measures were elevated in those with suicide attempts. Among the women in the restricting AN group, those who attempted suicide scored significantly higher on Phobic Activity, measured by the Symptom Checklist-Revised, than those who did not.

The authors noted that the higher prevalence of suicide attempts among the purging AN patients supported the theory that suicide attempts in AN patients are largely concentrated among those who have purging as part of their symptom profile. Purging behaviors may signal greater psychopathology and impulsivity, as well as more dysfunctional expression of anger, which may increase the risk for suicide.

Patients with at least one suicide attempt during their lifetime also had greater depressive symptoms, as measured by the Symptom Checklist-90; this finding echoes results of previous studies. The authors noted that phobic anxiety was the one measure that distinguished between restricting AN patients with and without suicide attempts. The Phobic Anxiety scale measures symptoms associated with phobic anxiety states, such as feeling fear in open spaces, being afraid to leave one's home, and feeling nervous when left alone. The authors also suggest that clinicians be particularly vigilant for possible suicidal ideation in persons with restricting AN who show symptoms of agoraphobia. Among restricting AN patients, greater anxiety may signal greater suicide risk.

A meta-analysis of suicide risk

A meta-analysis of 40 suicide risk studies among eating disorders patients showed that patients with AN and BN share a number of risk factors for suicide and that although the suicide risk among patients with AN has fallen over the past decades, these patients are still at higher risk for suicide than are persons in the general population (Acta Psychiatr Scand 2011; 124:6). The reduction was attributed to improved detection of patients in need of treatment, improved diagnostic criteria and reduced stigma against receiving treatment for mental disorders—along with an expansion of services for people with eating disorders.

Antonio Preti, MD, and colleagues at Centro Medico Gennuruxi, Cagliari, Italy, did a PubMed/Medline search for studies including more than 40 persons, where follow-up lasted at least 5 years. The researchers identified 40 studies of patients with AN, 16 studies of BN, and 3 of binge eating disorder. Of 16,342 patients with AN, 245 suicides were reported over a mean follow-up of 11.1 years (the suicide rate was 0.124 per 100 person-years).

Higher-than-expected suicide rates were found among patients with BN, but the rates were still lower than those among AN patients. The crude suicide rate for BN patients was 0.20%, and the average suicide rate was per study was 0.20%. The suicide rate was 0.030 per 100 person-years. Among the general population, the crude suicide rate was 0.21%, with a suicide rate of 0.004 per 100 person-years.

The lower suicide mortality rates for persons with BN were puzzling, since the patients in both AN and BN groups share numerous risk factors. In some samples, higher suicide attempt rates were reported among BN patients than among restrictive AN patients. One explanation might be that patients with AN could be more exposed to the lethal outcome of suicide attempts because of the complications of starvation. Another is the stigma against suicide present in some countries.

The authors recommend that follow-up data on patients include data on suicide, and that patients lost at follow-up also be reported. In addition, the authors called for a worldwide effort to study suicide among patients with BN through establishment of a consortium to study the risk of suicide in patients with eating disorders.

Body Mass Index Reporting at School: Helpful or Harmful?

Childhood obesity is currently recognized as one of America's most serious health problems, with serious repercussions for disease and disability later in life. As a result, some authorities have recommended identifying children at risk through school-based measurement and reporting of body mass index (BMI, kg/m²). In 2003, Arkansas became the first state to require annual BMI screening in their public schools. Similar legislation is now in place in 20 states.

Maria G. Portilla, MD, writing in the Journal of the American Dietetic Association (2011; 3:442) notes that although organizations such as the American Academy of Pediatrics (AAP) have recommended annual BMI measurements, these measurements were never meant to be done in schools, but by primary care physicians as part of regular annual exams. In 2009, the AAP raised the possibility that BMI screening programs might worsen stigma about weight and body image problems already experienced by obese children and teens, leading to inappropriate weight loss practices that could result in an eating disorder (Pediatrics 2009; 124[suppl]:S89).

Two cases

Dr. Portilla reported two cases of students treated at a tertiary children's hospital who reported disordered eating and excessive exercise after getting the results of their BMI screening at school. One student was a 14-year-old male whose BMI screening was done in spring 2006. After he was teased by other students and became concerned about his elevated BMI (31.4), the boy began dieting, purging, and exercising excessively to lose weight over the summer. He lost 41.8 lb over the summer, and presented at an eating disorders clinic that fall. He had dizziness upon standing, chest pain on exertion, cold intolerance, and lethargy. He was admitted to the hospital for medical stabilization and refeeding, and after 20 days was discharged and followed up with therapy and medical/nutritional management in the eating disorder clinic for 6 months. There was no follow-up by the school system regarding the BMI report because state law does not mandate this. The boy's disordered eating resolved and he was referred to his family doctor for follow-up.

A second student, a 13-year old female, began dieting and exercising excessively after learning about her "elevated" BMI (20.8) on a report card in spring 2004. She avoided "junk foods" and greatly increased her exercise; her mother attributed these new behaviors to her daughter's concerns about her BMI. After treatment by a counselor and nutritionist for 6 to 8 months, the girl had some improvement, but then began to restrict her diet when school began in the fall. The girl had body image distortion but denied any bulimic behavior. She was depressed and had thoughts of harming herself. She presented at the eating disorder clinic the next year, with weakness, dizziness, fatigue and syncope. The "only" physical finding was malnutrition; a mental health professional diagnosed her as having an eating disorder not otherwise specified and depression with suicidal ideation and recommended that the girl be admitted for treatment. The parents refused. The girl was followed-up in the eating disorders clinic, where she had regular therapy and medical/nutritional monitoring. She gradually improved, gaining weight to a normal range; she had her first menstrual period 14 months after starting therapy. She was discharged from the program nearly 2 years after her initial presentation and was referred back to her primary care physician.

Short-term effects of the Arkansas program

Dr. Portilla points out that among students who received BMI assessments in Arkansas during 2007, 72% reported an increase in physical activity, 11% indicated they were embarrassed by their BMI measurements, 27% started dieting after learning their BMIs, and 5% began taking diet pills (MMWR Morbid Mortal 2008;122e682). And, as a result of the school health report cards, 19% of parents reported they had considered putting their children on diets, even though the reports suggested that a pediatrician should evaluate the child first. The Youth Risk Behavior Survey data noted that in 2007, Arkansas students, when compared with students at a national level, were more likely to practice unhealthy eating behaviors, such as taking diet pills, vomiting, or taking laxatives to control their weight. Some states are now re-thinking the value and impact of BMI screening at school, and some legislators have introduced legislation to overturn BMI screening by schools.

The author agrees that childhood overweight and obesity are paramount health problems in the U.S. School and state governments are attempting to inform parents about this problem, but she suggests that if schools are to include such programs, a better tactic should be to include specific steps to encourage healthy lifestyles and efforts to avoid potential harm. Other suggestions are to include a registered dietitian in the school's process of obtaining BMI assessments and notifying parents, as well as providing a healthy eating environment at school, says Dr. Portilla.

Family-Based Treatment: Finding Satisfaction for All Family Members

According to Sherry Van Blyderveen, PhD, of McMaster Children's Hospital in Hamilton, Ontario, Canada, treatment of young patients struggling with eating disorders is different from that of older patients. First, treatment is largely imposed on these patients, who value their eating disorders, and many young patients subsequently drop out of treatment prematurely.

As Dr. Van Blyderveen and colleagues reported at the at the International Conference on Eating Disorders in Miami in April, few studies have evaluated patient satisfaction with treatment for an eating disorder, and even fewer have considered measuring the family's satisfaction with family-based treatment. The authors assessed patient and parent satisfaction with a pediatric eating disorders outpatient program at an academic teaching hospital, and determined correlates of satisfaction.

Forty-seven patients, their parents, and therapists all completed the Client Satisfaction Questionnaire (CSQ-18). Factors considered as possible correlates for both patient and parent satisfaction included those related to the patient (e.g., age, diagnosis, symptom severity, comorbidity, substance abuse), or to the family (one or two-parent family; parents' mental health), and to treatment (physical distance and travel time from home to the hospital; family-based therapy and the phase of treatment; degree of patient autonomy regarding food selection, consumption, and exercise; proportion of FBT, relative to individual, treatment provided; provision of adjuncts to treatment; key issues addressed in therapy; and therapeutic challenges).

Another factor: Less travel time to treatment

The researchers found that two-parent families and those who had less travel time to the treatment center were more satisfied with treatment programs. The greater the severity of the youth's binge eating, purging, restriction, and physical activity, the less satisfied youth and parents were. When young patients had greater autonomy over their own diet and nutrition and were closer to their target weight, their satisfaction and parents' satisfaction was greater. Young patients who were allowed more physical activity also reported greater satisfaction with their treatment.

Food Choices among Weight-Restored AN Patients

The English poet William Cowper wrote, "Variety's the very spice of life." For weight-restored anorexia nervosa (AN) patients, dietary variety may be one key to successful recovery.

As Janet Schebendach, PhD, RD, and Laurel E. Mayer MD and colleagues at Columbia University discovered, differences in variety of foods chosen by 41 weight-restored patients may have helped or hurt their recovery efforts (J Am Diet Assoc 2011; 111:732). The women were hospitalized between June 2000 and July 2005, and completed a 4-day food record before discharge; they were then followed for up to 1 year. Patient outcomes were categorized as a success (n=29) or failure (n=12) using Morgan-Russell criteria.

Although the total number of foods selected did not differ between the success and failure groups (73 vs. 74 foods), a significant difference in the total number of different foods was observed. The researchers noted that those in the failure group selected fewer and the success group selected more.

Less energy from fat forecast failure

And what other patterns did the researchers see? Before hospital discharge, energy intake was similar between the success and failure groups but not statistically significant (2415 kcal vs. 2175 kcal, respectively). The failure group consumed significantly less total fat than did the success group. Accordingly, the percentage of energy from fat was also significantly lower in the failure group compared to the success group. The treatment success group selected a different food 71% of the time, while the failure group selected a different food only 58% of the time.

The treatment groups also differed significantly in the variety of foods chosen from five major food groups: added fats, added sugars, caloric beverages, starchy carbohydrates, and miscellaneous foods. The success group selected considerably more, and the failure groups considerably fewer, foods from the added fats group, and the caloric beverage group. The successful group was more likely to included added sugars and miscellaneous foods (such as pasta sauce) than was the failure group.

First, changes in eating behaviors, then in body weight

The authors surmise that eating behavior changes precede changes in body weight. Despite the substantial difference in variety of foods, no substantial difference in body mass index (BMI) or total energy intake was seen before patients were discharged from the hospital. The authors speculate that continued restriction of overall dietary variety, purposeful restriction of highly palatable food groups, and food monotony resulting from repeated exposure to the same foods, culminated in decreased energy intake and weight loss during the year after hospital discharge.

Refeeding Patients with Anorexia Nervosa

Refeeding anorexia nervosa (AN) patients can be safer and more efficient once the pathophysiology of protein-calorie malnutrition is better understood, according to Dr. M.R. Kohn and co-workers at the University of Sydney, Australia (Current Opinion in Pediatrics 2011 Jun 8. [Epub ahead of print].

According to the authors, the time-honored notion of "starting low and going slow" with the prescription of daily calories seems unlikely to be essential for preventing refeeding syndrome. When the authors reviewed recent publications, they found that this approach does not necessarily make the refeeding process safer. On the contrary, it typically results in weight loss, extends hospitalization time, and delays nutritional recovery.

The dietary composition of macronutrients, in particular avoiding a high proportion of calories from carbohydrates, appears to be more important than is the absolute number of calories. And, the means of initial refeeding appears increasingly important in this process, particularly following reports of postprandial hypoglycemia.

The authors propose that the current guidelines for refeeding AN patients be revised, considering the evidence of the use of continuous feeding strategies with fewer than 40% of calories from carbohydrates. This approach has important implications for the prevention of the refeeding syndrome as well as for the safety and efficiency of refeeding of children and adolescents with AN in the hospital.

Tracking Brain Activity in Adolescent Eating Disorder Subtypes

Advances in brain-imaging techniques are providing new inroads into the neurophysiology of eating disorders. Functional magnetic resonance imaging, or fMRI, has been very helpful in this realm. fMRI, which is based on measurement of an increase in blood flow to local blood vessels that accompanies neural activity in the brain, does not require injection of contrast media and involves a short scanning time, of from 1.5 to 2 minutes, compared to the 20 to 30 minutes required for a typical positron-emission tomographic study (PET scan).

Identifying eating disorder subtypes by brain activation

Earlier this year, James Lock, MD, PhD and a team at Stanford University School of Medicine found preliminary evidence that during adolescence, eating disorder subtypes may be identifiable in terms of neural correlates of inhibitory control (Am J Psychiatry 2011; 168:55). As Dr. Lock and colleagues noted, behavior and personality characteristics differ among persons with eating disorders, depending on subtype. For example, patients with binge eating or purging behaviors, such as in the anorexia nervosa(AN) binge-purge subtype and/or with bulimia nervosa, often show impulsive and disinhibited personality characteristics. In contrast, those with the restrictive subtype of AN often show overly controlled behaviors.

In this, the first study to examine brain activation associated with response inhibition in adolescents with eating disorders, Dr. Lock and colleagues compared 13 patients with the binge-purge subtype of AN to 14 patients with AN, restrictive subtype, and 13 healthy controls. They hypothesized that brain activation associated with inhibitory control during a Go-NoGo task would be different in teens with eating disorders compared to healthy controls.

To perform the scans, the group used a magnet housed in the Lucas Imaging Center at Stanford University. Subjects performed a rapid jittered event related Go-NoGo task including a series of letters. The subjects pushed a button in response to all letters except for the occasional appearance of the letter X. fMRI images were collected with a scanner and spiral pulse sequence.

The results of the preliminary study supported the hypothesis that differences in neural function could be identified between AN, restricting type,  AN binge-purge subtype, and healthy controls during a task that required inhibitory control. Patients with AN binge-purge subtypes showed increased activation in the right dorsolateral prefrontal cortex, an executive control region of the brain, suggesting inefficient or possibly compensatory activation.

Subtypes could be differentiated

Dr. Lock and colleagues note that their preliminary findings suggest that adolescent subjects with binge-purge behaviors and restricting-type AN likely differ from each other on a neural level and therefore risks and effective interventions may not be the same between these two groups. Because the scans were done in a group of adolescents who were not severely malnourished and who had relatively short durations of eating disorder symptoms, the findings suggest that these neural processes occur prior to or early in the evolution of the eating disorder and may not be the result of chronic disease or state-dependent starvation.

Noting the ongoing debate about potential crossover between AN, restricting subtype AN, binge-purge subtype AN, and bulimia nervosa, the authors feel that their current study provides preliminary evidence that, at least during adolescence, eating disorder subtypes may be distinguishable in terms of neural correlates of inhibitory control.

Q & A: Hypokalemic Nephropathy

Q: A patient I follow who suffers from long-standing anorexia nervosa (AN) with binge-eating and purging has developed serious renal disease. Her internist and nephrologist have told her that her renal disease may be related to her long history of purging. I've never heard of this relationship. Is this a well-known complication of AN? (D.F., Baltimore)

A: Associations of renal disease and AN have been recorded for many years. A German case series published in 1978 of 23 patients with AN who had been hypokalemic for an average of 6.5 years reported that histological findings in nine patients showed chronic abacterial interstitial nephritis, and that two patients developed terminal renal failure. Because of the association with low serum potassium, they used the term "chronic kaliopenic nephropathy" to describe these cases (Klin Wochenschr; 1978; 56 Suppl 1:91-6.) Subsequently, cases of "hypokalemic nephropathy" have been regularly reported, in relation to AN binge eating/purging subtype (CMAJ, published on line, June 13, 2011) sometimes in association with laxative abuse, bulimia nervosa (Int J Eat Disord; 2005 Dec; 38(4):383-5), and sometimes in association with excessive licorice ingestion (Int J Eat Disord; 1999 Jul;26(1):111-4.).

Chronic diuretic abuse with untreated hypokalemia may also result in this syndrome. If caught early enough, treatment with potassium replacement may help reverse the disorder, but if hypokalemia persists untreated for a long time the condition may become irreversible. Although eating disorders are present in around 30% to 40% of patients with hypokalemic nephropathy, the prevalence of hypokalemic nephropathy in people with eating disorders is unknown. The take-home message is that patients who are frequent purgers, laxative abusers, and diuretic abusers require frequent monitoring of their serum potassium levels. When hypokalemia is found, replacement treatment should be instituted and maintained as long as the eating disorder symptoms persist.

— JY