Longitudinal changes in the physical activity of adolescents with anorexia nervosa and their influence on body composition and leptin serum levels after recovery

Momentary physiological indices related to eating disorders: A systematic and methodological review

Eating disorders (ED) are serious psychiatric illnesses, with no everyday support to intervene on the high rates of relapse. Understanding physiological indices that can be measured by wearable sensor technologies may provide new momentary interventions for individuals with ED. This systematic review, searching large databases, synthesises studies investigating peripheral physiological (PP) indices commonly included in wearable wristbands (heart rate [HR], heart rate variability [HRV], electrodermal activity [EDA], peripheral skin temperature [PST], and acceleration) in ED. Inclusion criteria included: (a) full peer-reviewed empirical articles in English; (b) human participants with active ED; and (c) containing one of five wearable physiological measures. Kmet risk of bias was assessed. Ninety-four studies were included (Anorexia nervosa [AN; N = 4418], bulimia nervosa [BN; N = 916], binge eating disorder [BED; N = 1604], other specified feeding and eating disorders [OSFED; N = 424], and transdiagnostic [N = 47]). Participants with AN displayed lower HR and EDA and higher HRV compared to healthy individuals. Those with BN showed higher HRV, and lower EDA and PST compared to healthy individuals. Other ED and Transdiagnostic samples showed mixed results. PP differences are indicated through various assessments in ED, which may suggest diagnostic associations, although more studies are needed to validate observed patterns. Results suggest important therapeutic potential for PP in ED, and larger studies including diverse participants and diagnostic groups are needed to fully uncover their role in ED.

Chronic food restriction in mice and increased systemic ghrelin induce preference for running wheel activity

OBJECTIVES

In eating disorders, particularly anorexia nervosa (AN), patients exhibit intense physical activity which is inappropriate regarding food restriction and chronic undernutrition, and exacerbates weight loss and energy deprivation. Rodent models of food restriction exhibit increased running wheel activity in the food anticipation period, also known as Food Anticipatory Activity (FAA). FAA probably has various physiological and/or neurobiological origins. Plasma concentrations of the orexigenic hormone ghrelin are, for example, increased during FAA. We hypothesize that the drive for physical activity in chronic food restriction is triggered by metabolic factors but also relies on motivational aspects that we aim to decipher in this study.

METHODS

Young female C57Bl6/J mice were exposed to a paradigm based on a progressive 50% quantitative food restriction alone (FR) or associated with running wheel activity (Food Restriction Wheel: FRW) in their home-cage during 15 days. We measured preference for running wheel in a three-chamber apparatus in which animals could choose to explore either a known running wheel or a novel object. Testing took place either during resting or during FAA. We calculated the time spent in each compartment and the activity in running wheels. After progressive refeeding over 10 days, mice were tested again when refed. Plasma levels of both ghrelin isoforms were measured with selective immunoassays.

RESULTS

When tested during FAA period, food restricted mice displayed increased preference for the running wheel compared to ad libitum fed controls. Both FR and FRW mice exhibited increased running time and distance in the wheel and running distance was correlated with ghrelin levels. Similar preference and behavior were found when testing took place during the resting period. Animals housed without an active wheel also exhibited active running. Progressive refeeding resulted in body weight restoration, a decrease in FAA and completely abolished preference for the running wheel. Refed animals displayed similar behavior as ad libitum fed controls.

CONCLUSIONS

These data provide evidence that food restriction-induced physical activity is closely correlated with metabolic adaptations to nutritional status implicating ghrelin in the quantity of physical activity.

Body composition assessment in adult females with anorexia nervosa and bulimia nervosa - a cross-sectional study comparing dual-energy X-ray absorptiometry scan and isotopic dilution of deuterium

BACKGROUND

Eating disorders (EDs) compromise individuals' nutritional status, affecting among other organs and systems, bone health.

OBJECTIVE

This study aimed to assess and compare bone mineral density (BMD) from dual-energy x-ray absorptiometry (DXA) scan and deuterium (D₂O) dilution of adult females with anorexia nervosa (AN) and bulimia nervosa (BN).

METHODS

This was a cross-sectional study with 53 female participants (18-49 years) with a diagnosis of AN (N = 25) or BN (N = 28). DXA scan was performed to assess BMD, fat mass, and fat-free mass, and D₂O dilution was used to assess total body water (TBW), fat mass, and fat-free mass. Interviews/questionnaires were used to assess symptoms, illness trajectory, and physical activity. T-test, Chi-squared test, Pearson's linear correlation, linear regressions, and Bland-Altman analyses were performed, with a significance level of 5%.

RESULTS

TBW below the recommended level for adult females (≥ 45%) was more frequent in BN (60%) compared with AN (21%; P = 0.013). FMI (soft tissue only) (t-test P = 0.06), and FFMI (t-test P = 0.08) agreed between DXA scan and D₂O dilution. Only FFMI did not show systematic bias of proportion (β:-0.2, P = 0.177). The diagnosis of BN, binge-eating episodes, and physical activity in AN were associated with the differences in the methods' results. FMI was positively associated with BMD in AN, and both FMI and FFMI were positively associated with BMD in BN.

CONCLUSION

In adult females with EDs, DXA scan and D₂O dilution achieved agreement for FMI and FFMI. Changes in fat mass and fat-free mass are important in understanding the mechanisms behind bone loss in EDs. Protocols for body composition assessment in EDs can help to minimize the effect of the ED diagnosis, ED behaviors (i.e., excessive exercise and purging behaviors) and weight on the accuracy of measurements.

Changes in unhealthy exercise in outpatient eating disorder treatment: examining emotion avoidance mechanisms

Unhealthy exercise (UE) is a common symptom of eating disorders (EDs) associated with elevated chronicity and relapse. Previous research suggests that UE serves an emotion regulation function, especially to reduce negative affect. UE may be especially prevalent among individuals with anorexia nervosa (AN), as UE and restrictive eating may be used to avoid unpleasant emotions. It is unclear whether changes in emotion avoidance (EA) can lead to changes in UE over time. The current study examined whether month 1 EA mediated the relation between baseline UE and month 2 UE in a clinical sample of 127 patients (M_age = 22.52 [SD = 11.75], 92.9% female) recruited from an ED outpatient treatment program. The current study also explored whether this mediation was stronger for individuals with AN than other ED diagnoses. Findings revealed that changes in EA significantly mediated the relation between changes in UE from baseline to month 2 of treatment. ED diagnosis did not moderate this relation. Findings suggest that improvements in EA may reduce UE over time. Treatment should target UE through cultivation of increased emotion acceptance.Level of evidence Level III: evidence obtained from well-designed cohort study.

High levels of physical activity in female adolescents with anorexia nervosa: medical and psychopathological correlates

PURPOSE

While overexercise is commonly described in patients who experience anorexia nervosa (AN), it represents a condition still underestimated, especially in the paediatric population.

METHOD

The present study aims at assessing the possible associations between levels of physical activity (PA) and clinical features, endocrinological data and psychopathological traits in a sample of 244 female adolescents hospitalised for AN subdivided into two groups according to PA levels (high PA vs. no/low PA). The two groups were compared through multivariate analyses, while multiple regression analysis was conducted to determine whether physical activity predict specific outcomes.

RESULTS

No significant differences were found between the two groups in terms of last Body Mass Index (BMI) before illness, BMI at admission and disease duration, while a difference emerged in delta BMI(rapidity of weight loss), significantly higher in high-PA group (p = 0.021). Significant differences were observed in Free triiodothyronine- (p < 0.001), Free thyroxine (p = 0.046), Follicle-stimulating hormone (p = 0.019), Luteinising hormone (p = 0.002) levels, with values remarkably lower in high-PA group. Concerning psychopathological scales, the high-PA group showed worst Children's Global Assessment Scale (CGAS) scores (p = 0.035). Regression analyses revealed that higher PA predicts higher delta BMI (p = 0.021), presence of amenorrhea (p = 0.003), lower heart rate (p = 0.012), lower thyroid (Free triiodothyronine p < 0.001, Free thyroxine p = 0.029) and gynaecological hormones' levels (Follicle-stimulating hormone p = 0.023, Luteinising hormone p = 0.003, 17-Beta estradiol p = 0.041). Concerning psychiatric measures, HPA predicts worst scores at CGAS (p = 0.019), and at scales for evaluation of alexithymia (p = 0.028) and depression (p = 0.004).

CONCLUSIONS

Results suggest that high levels of physical activity in acute AN associate with worst clinical conditions at admission, especially in terms of endocrinological and medical features.

LEVEL OF EVIDENCE

Level III.

Vulnerable and Resilient Phenotypes in a Mouse Model of Anorexia Nervosa

BACKGROUND

Increased physical activity is a common feature of anorexia nervosa (AN). Although high activity levels are associated with greater risk of developing AN, particularly when combined with dieting, most individuals who diet and exercise maintain a healthy body weight. It is unclear why some individuals develop AN while most do not. A rodent model of resilience and vulnerability to AN would be valuable to research. Dopamine, which is believed to play a crucial role in AN, regulates both reward and activity and may modulate vulnerability.

METHODS

Adolescent and young adult female C57BL/6N mice were tested in the activity-based anorexia (ABA) model, with an extended period of food restriction in adult mice. ABA was also tested in dopamine transporter knockdown mice and wild-type littermates. Mice that adapted to conditions and maintained a stable body weight were characterized as resilient.

RESULTS

In adults, vulnerable and resilient phenotypes emerged in both the ABA and food-restricted mice without wheels. Vulnerable mice exhibited a pronounced increase in running throughout the light cycle, which dramatically peaked prior to requiring removal from the experiment. Resilient mice exhibited an adaptive decrease in total running, appropriate food anticipatory activity, and increased consumption, thereby achieving stable body weight. Hyperdopaminergia accelerated progression of the vulnerable phenotype.

CONCLUSIONS

Our demonstration of distinct resilient and vulnerable phenotypes in mouse ABA significantly advances the utility of the model for identifying genes and neural substrates mediating AN risk and resilience. Modulation of dopamine may play a central role in the underlying circuit.

Physical activity and sleep during the first week of anorexia nervosa inpatient care

BACKGROUND

Individuals with Anorexia Nervosa are often described as restless, hyperactive and having disturbed sleep. The result reproducibility and generalisability of these results are low due to the use of unreliable methods, different measurement methods and outcome measures. A reliable method to measure both physical activity and sleep is through accelerometry. The main purpose of the study was to quantify the physical activity and sleeping behaviour of anorexia nervosa patients. Another purpose was to increase result reproducibility and generalisability of the study.

MATERIAL AND METHODS

Accelerometer data were collected from the first week of treatment of anorexia nervosa at an inpatient ward. Raw data from the Axivity AX3© accelerometer was used with the open-source package GGIR for analysis, in the free statistical software R. Accelerometer measurements were transformed into euclidean norm minus one with negative values rounded to zero (ENMO). Physical activity measurements of interest were 24h average ENMO, daytime average ENMO, inactivity, light activity, moderate activity, and vigorous activity. Sleep parameters of interest were sleep duration, sleep efficiency, awakenings, and wake after sleep onset. The sleep duration of different age groups was compared to recommendations by the National Sleep Foundation using a Fisher's exact test.

RESULTS

Of 67 patients, due to data quality 58 (93% female) were included in the analysis. Average age of participants was 17.8 (±6.9) years and body mass index was 15.5 (±1.9) kg/m2. Daytime average ENMO was 17.4 (±5.1) mg. Participants spent 862.6 (±66.2) min per day inactive, 88.4 (±22.6) min with light activities, 25.8 (±16.7) min with moderate activities and 0.5 (±1.8) min with vigorous activities. Participants slept for 461.0 (±68.4) min, waking up 1.45 (±1.25) times per night for 54.6 (±35.8) min, having an average sleep quality of 0.88 (±0.10). 31% of participants met sleep recommendations, with a significantly higher number of 6-13 year old patients failing to reach recommendations compared to 14-25 year old patients.

CONCLUSION

The patient group spent most of their time inactive at the beginning of treatment. Most patients failed to reach sleep recommendations. The use of raw data and opensource software should ensure result reproducibility, enable comparison across points in treatment and comparison with healthy individuals.

Lower leptin level at discharge in acute anorexia nervosa is associated with early weight-loss

OBJECTIVE

Predictive values of acute phase metabolic abnormalities of anorexia nervosa (AN) have seldom been studied. As early postrestoration weight loss is associated with poor outcome, discharge biologic parameters were assessed to detect an association with 2-month follow-up weight loss as a proxy to poor outcome.

METHOD

Fasting plasma levels of leptin, acyl-ghrelin, obestatin, PYY, oxytocin and BDNF were measured in 26 inpatients, at inclusion, at discharge and 2 months later. A body mass index less than 18 2-month postdischarge was considered a poor outcome.

RESULTS

Nineteen patients (73%) had a fair outcome and seven (27%) had a poor one with a mean loss of 0.69 versus 4.54 kg, respectively. Only discharge leptin levels were significantly higher in fair versus poor outcome patients (14.1 vs. 7.0 ng/ml, p = 0.006). The logistic regression model using discharge leptin, acyl-ghrelin, obestatin, oxytocin, PYY and BDNF levels as predictors of outcome disclosed a nearly significant effect of leptin (p < 0.10). Receiver operating characteristic analysis showed 11.9 ng/ml was the best value of threshold. Neither clinical variables differed according to outcome.

CONCLUSION

Leptin level may be a biomarker of early weight relapse after acute inpatient treatment of AN. Its clinical usefulness in monitoring care in AN should further be determined.

Dimensions of unhealthy exercise and their associations with restrictive eating and binge eating

Unhealthy exercise is a core symptom of eating disorders that predicts greater chronicity and risk of relapse. A detailed conceptualization of unhealthy exercise in the context of eating disorders is only beginning to emerge, and associations between specific dimensions of unhealthy exercise and eating disorder symptoms have received little attention. The aim of the current study was to examine associations between three key dimensions of unhealthy exercise - compulsive exercise (i.e., rule-driven exercise to avoid negative affect), exercise to control weight/shape, and exercise to compensate for recent food intake - with restrictive eating and binge eating. Participants were 239 women drawn from two separate studies of emotions and eating behavior; 126 (52.7%) endorsed restrictive eating and/or objective binge eating episodes in the past three months. Unhealthy exercise dimensions were measured using the Compulsive Exercise Test and investigator-designed items, and eating disorder symptoms were assessed using the Eating Pathology Symptoms Inventory. Restrictive eating was only associated with avoidance and rule-driven exercise, whereas binge eating was significantly correlated with all unhealthy exercise variables. Multiple regression results revealed that only compensatory exercise was uniquely associated with binge eating. Unhealthy exercise consists of partially distinct dimensions with differential relations to core eating disorder symptoms. Future research should examine unhealthy exercise dimensions in patients with eating disorder diagnoses and consider whether treatments for specific unhealthy exercise forms might be beneficial.

Psychological and nutritional correlates of objectively assessed physical activity in patients with anorexia nervosa

BACKGROUND

Physical activity (PA) plays a role in the course of anorexia nervosa (AN).

OBJECTIVE

To assess the association between PA, nutritional status and psychological parameters in patients with AN.

METHOD

Using a wearable activity monitor, PA was assessed in 60 female AN inpatients, by step count and time spent in 4 metabolic equivalent (MET)-intensity levels: sedentary behaviour, light, moderate and vigorous PA. In addition, BMI, psychological (patient-reported outcome questionnaires) and nutritional parameters (body fat, energy and macronutrient intake) were assessed.

RESULTS

The study population spent little time in vigorous PA. BMI on admission and discharge was higher when more time was spent in sedentary behaviour, and lower with more time spent in light PA. Relationships between PA and patient-reported outcomes were weak and limited to an association between vigorous PA and compulsiveness. Low fat mass was associated with more time spent in light PA, while subjects with higher step counts showed less intake of energy, carbohydrates and fat.

CONCLUSION

The relationship between inadequate food intake and increased PA in patients with AN requires further investigation.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Assessment of Physical Activity Patterns in Adolescent Patients with Anorexia Nervosa and Their Effect on Weight Gain

(1) Background: Altered physical activity (PA) affects weight recovery in anorexia nervosa (AN) patients. The study aimed to objectively characterize PA patterns and their effect on weight trajectory in adolescent AN patients. (2) Methods: PA was assessed in 47 patients on admission to inpatient treatment, in n = 25 of these patients again 4 weeks after discharge (follow-up, FU), as well as in 20 adolescent healthy controls using the Sense Wear™ armband. The following PA categories were defined by metabolic equivalent (MET) ranges: sedentary behavior (SB), light (LPA), moderate (MPA), vigorous (VPA), and high-level PA (HLPA= MPA + VPA). (3) Results: LPA on admission was significantly higher in AN patients than in controls (103 vs. 55 min/d, p < 0.001), and LPA in AN decreased over time to 90 min/d (p = 0.006). Patients with higher admission LPA (n = 12) still had elevated LPA at FU (p = 0.003). High admission LPA was associated with a higher inpatient BMI percentage gain (ΔBMI%; 18.2% ± 10.0% vs. 12.0% ± 9.7%, p = 0.037) but with a loss of ΔBMI% at FU (-2.3% ± 3.6% vs. 0.8% ± 3.6%, p = 0.045). HLPA at baseline was associated with a lower inpatient ΔBMI% (p = 0.045). (4) Conclusion: Elevated LPA in AN patients decreased after inpatient treatment, and PA patterns had an impact on weight trajectory.

Physical Activity in Eating Disorders: A Systematic Review

Abnormally high levels of physical activity have been documented throughout the literature in patients with eating disorders (ED), especially those diagnosed with anorexia nervosa (AN). Yet no clear definition, conceptualization, or treatment of the problematic use of physical activity (PPA) in ED patients exists. The aim of this review is to propose a new classification of PPA, report the prevalence, triggers, predictors, maintainers and other related factors of PPA in ED patients, in addition to proposing a comprehensive model of the development of PPA in AN. A total of 47 articles, retrieved from Medline and Web of Science, met the inclusion criteria and were included in the analysis. As a result, the new approach of PPA was divided into two groups (group 1 and group 2) according to the dimension (quantitative vs qualitative approach) of physical activity that was evaluated. The prevalence of PPA in ED was reported in 20 out of 47 studies, the comparison of PPA between ED versus controls in 21 articles, and the links between PPA and psychological factors in ED in 26 articles, including depression (16/26), anxiety (13/26), obsessive–compulsiveness (9/26), self-esteem (4/26), addictiveness (1/26), regulation and verbal expression of emotions (1/26) and anhedonia (1/26). The links between PPA and ED symptomatology, PPA and weight, body mass index (BMI) and body composition in ED, PPA and age, onset, illness duration and lifetime activity status in ED, PPA and ED treatment outcome were reported in 18, 15, 7, 5 articles, respectively. All of the factors have been systematically clustered into group 1 and group 2. Results focused more on AN rather than BN due to the limited studies on the latter. Additionally, a model for the development of PPA in AN patients was proposed, encompassing five periods evolving into three clinical stages. Thus, two very opposite components of PPA in AN were suggested: voluntarily PPA increased in AN was viewed as a conscious strategy to maximize weight loss, while involuntarily PPA increased proportionally with weight-loss, indicating that exercise might be under the control of a subconscious biological drive and involuntary cognition.

Moving beyond self-report data collection in the natural environment: A review of the past and future directions for ambulatory assessment in eating disorders

OBJECTIVE

In recent years, ecological momentary assessment (EMA) has been used to repeatedly assess eating disorder (ED) symptoms in naturalistic settings, which has allowed for increased understanding of temporal processes that potentiate ED behaviors. However, there remain notable limitations of self-report EMA, and with the rapid proliferation of technology there are ever-increasing possibilities to improve ambulatory assessment methods to further the understanding and treatment of EDs. Therefore, the purpose of this review was to (a) systematically review the studies in EDs that have utilized ambulatory assessment methods other than self-report, and (b) provide directions for future research and clinical applications.

METHOD

A systematic literature search of electronic databases was conducted, and data regarding study characteristics and methodological quality were extracted.

RESULTS

The search identified 17 studies that used ambulatory assessment methods to gather objective data, and focused primarily on autonomic functioning, physical activity, and cognitive processes in ED and control groups.

DISCUSSION

Together the literature demonstrates the promise of using a range of ecologically valid ambulatory assessment approaches in EDs, though there remains limited research that has utilized methods other than self-report (e.g., wearable sensors), particularly in recent years. Going forward, there are several technology-enhanced momentary assessment methods that have potential to improve the understanding and treatment of EDs.

Autonomic Nervous System Response during Light Physical Activity in Adolescents with Anorexia Nervosa Measured by Wearable Devices

Anorexia nervosa (AN) is associated with a wide range of disturbances of the autonomic nervous system. The aim of the present study was to monitor the heart rate (HR) and the heart rate variability (HRV) during light physical activity in a group of adolescent girls with AN and in age-matched controls using a wearable, minimally obtrusive device. For the study, we enrolled a sample of 23 adolescents with AN and 17 controls. After performing a 12-lead electrocardiogram and echocardiography, we used a wearable device to record a one-lead electrocardiogram for 5 min at baseline for 5 min during light physical exercise (Task) and for 5 min during recovery. From the recording, we extracted HR and HRV indices. Among subjects with AN, the HR increased at task and decreased at recovery, whereas among controls it did not change between the test phases. HRV features showed a different trend between the two groups, with an increased low-to-high frequency ratio (LF/HF) in the AN group due to increased LF and decreased HF, differently from controls that, otherwise, slightly increased their standard deviation of NN intervals (SDNN) and the root mean square of successive differences (RMSSD). The response in the AN group during the task as compared to that of healthy adolescents suggests a possible sympathetic activation or parasympathetic withdrawal, differently from controls. This result could be related to the low energy availability associated to the excessive loss of fat and lean mass in subjects with AN, that could drive to autonomic imbalance even during light physical activity.

Clinical Trials Required to Assess Potential Benefits and Side Effects of Treatment of Patients With Anorexia Nervosa With Recombinant Human Leptin

The core phenotype of anorexia nervosa (AN) comprises the age and stage dependent intertwining of both its primary and secondary (i.e., starvation induced) somatic and mental symptoms. Hypoleptinemia acts as a key trigger for the adaptation to starvation by affecting diverse brain regions including the reward system and by induction of alterations of the hypothalamus-pituitary-“target-organ” axes, e.g., resulting in amenorrhea as a characteristic symptom of AN. Particularly, the rat model activity-based anorexia (ABA) convincingly demonstrates the pivotal role of hypoleptinemia in the development of starvation-induced hyperactivity. STAT3 signaling in dopaminergic neurons in the ventral tegmental area (VTA) plays a crucial role in the transmission of the leptin signal in ABA. In patients with AN, an inverted U-shaped relationship has been observed between their serum leptin levels and physical activity. Albeit obese and therewith of a very different phenotype, humans diagnosed with rare congenital leptin deficiency have starvation like symptoms including hypothalamic amenorrhea in females. Over the past 20 years, such patients have been successfully treated with recombinant human (rh) leptin (metreleptin) within a compassionate use program. The extreme hunger of these patients subsides within hours upon initiation of treatment; substantial weight loss and menarche in females ensue after medium term treatment. In contrast, metreleptin had little effect in patients with multifactorial obesity. Small clinical trials have been conducted for hypothalamic amenorrhea and to increase bone mineral density, in which metreleptin proved beneficial. Up to now, metreleptin has not yet been used to treat patients with AN. Metreleptin has been approved by the FDA under strict regulations solely for the treatment of generalized lipodystrophy. The recent approval by the EMA may offer, for the first time, the possibility to treat extremely hyperactive patients with AN off-label. Furthermore, a potential dissection of hypoleptinemia-induced AN symptoms from the primary cognitions and behaviors of these patients could ensue. Accordingly, the aim of this article is to review the current state of the art of leptin in relation to AN to provide the theoretical basis for the initiation of clinical trials for treatment of this eating disorder.

High-intensity exercise is associated with a better nutritional status in anorexia nervosa

OBJECTIVE

Our aim is to investigate the links between duration and intensity of exercise and the nutritional status in terms of body composition in acute anorexia nervosa (AN) patients.

METHOD

One hundred ninety-one hospitalized women suffering from AN were included. Exercise duration and intensity were assessed using a semistructured questionnaire. Body composition was measured using bioelectrical impedance. Linear multiple regression analyses were carried out using body mass index, fat-free mass index, and fat mass index as dependent variables and including systematically exercise duration, exercise intensity, and other confounding variables described in the literature that were significantly associated with each dependent variable in univariate analysis.

RESULTS

A lower BMI was linked to lower exercise intensity, AN restrictive type, and presence of amenorrhea. A lower FFMI was linked to lower exercise intensity, older age, AN restrictive type, and premenarchal AN. Duration of exercise was not linked to the nutritional status.

CONCLUSIONS

Exercising at higher intensity in AN is associated with a better nutritional status, thus, a better resistance to starvation. The impact of therapeutic physical activity sessions, adapted in terms of exercise intensity and patient's clinical status, should be evaluated during nutrition rehabilitation.

The Role of Objectively Measured, Altered Physical Activity Patterns for Body Mass Index Change during Inpatient Treatment in Female Patients with Anorexia Nervosa

Increased physical activity (PA) affects outcomes in patients with anorexia nervosa (AN). To objectively assess PA patterns of hospitalized AN patients in comparison with healthy, outpatient controls (HC), and to analyze the effect of PA on Body Mass Index (BMI) change in patients with AN, we measured PA in 50 female patients with AN (median age = 25 years, range = 18–52 years; mean BMI = 14.4 ± 2.0 kg/m²) at the initiation of inpatient treatment and in 30 female healthy controls (median age = 26 years, range = 19–53 years; mean BMI = 21.3 ± 1.7 kg/m²) using the SenseWear™ armband. Duration of inpatient stay and weight at discharge were abstracted from medical records. Compared with controls, AN patients spent more time in very light-intensity physical activity (VLPA) (median VLPA = 647 vs. 566 min/day, p = 0.004) and light-intensity physical activity (LPA) (median LPA = 126 vs. 84 min/day, p < 0.001) and less time in moderate-intensity physical activity (MPA) (median MPA = 82 vs. 114 min/day, p = 0.022) and vigorous physical activity (VPA) (median VPA = 0 vs. 16 min/day, p < 0.001). PA and BMI increase were not associated in a linear model, and BMI increase was mostly explained by lower admission BMI and longer inpatient stay. In a non-linear model, an influence of PA on BMI increase seemed probable (jack knife validation, r² = 0.203; p < 0.001). No direct association was observed between physical inactivity and BMI increase in AN. An altered PA pattern exists in AN patients compared to controls, yet the origin and consequences thereof deserve further investigation.

Metabolic Barriers to Weight Gain in Patients With Anorexia Nervosa: A Young Adult Case Report

Background: Over-proportionally high energy requirements in some patients with anorexia nervosa (AN) have been reported, but their exact origin remains unclear. Objective: To objectively measure metabolic alterations in an AN patient with high energy requirements as judged by clinical observation. Materials and Methods: We present the case of a young woman with AN (index patient, IP; 19 years, admission BMI 13.9 kg/m²). After 3 months of treatment at BMI 17.4 kg/m², we assessed her resting energy expenditure (REE), respiratory exchange ratio (RER), diet-induced thermogenesis (DIT), seated non-exercise physical activity (NEPA in Volt by infrared sensors), and exercise activity thermogenesis (EAT) in a metabolic chamber; body composition (bioimpedance analysis), energy intake (15d-food protocol), physical activity (accelerometry) and endocrine parameters. The IP was compared for REE, RER, DIT and seated NEPA to six AN patients (AN-C) and four healthy women (HC-1), and for EAT to another six healthy women (HC-2). Results: Our IP showed high REE (110% of predicted REE according to Harris & Benedict) and high seated NEPA (47% increase over AN-C, 40% over HC-1), whereas DIT (IP: 78 vs. HC-1: 145 ± 51 kJ/180 min) and EAT (IP: 157 vs. HC-2: 235 ± 30 kJ/30 min) were low, when compared with HC. The other AN patients showed a lower REE (AN: 87 ± 2% vs. HC: 97 ± 2% predicted) at increased DIT (AN: 187 ± 91 vs. HC: 145 ± 51 kJ/180 min) when compared with HC. RER of the IP was low (IP: 0.72 vs. 0.77 in AN-C; 0.77 in HC-1 and 0.80 in HC-2). Conclusions: Complex and variable disturbances of energy metabolism might exist in a subgroup of patients with AN during refeeding, which could lead to unexpectedly high energy requirements. Future studies need to confirm the existence, and investigate the characteristics and prevalence of this subgroup. Clinical trial Registry number: NCT02087280, https://www.clinicaltrials.gov/.

Characterization and correlates of exercise among adolescents with anorexia nervosa and bulimia nervosa

OBJECTIVE

To characterize exercise behaviors among adolescents with anorexia nervosa (AN), atypical AN, or bulimia nervosa (BN), and determine associations between exercise and medical risk.

STUDY DESIGN

Cross-sectional electronic medical records of all patients evaluated by the Eating Disorder Program at Stanford between January 1997 and February 2011 were retrospectively reviewed.

RESULTS

1,083 subjects (961 females, 122 males; mean age 15.6) met eligibility criteria. Most patients (89.7%) reported exercise (mean 7.0 h per week over mean 5.4 days per week) prior to presentation. Running (49.9%), calisthenics (40.7%), walking (23.4%), soccer (20.9%), and swimming (18.2%) were the most common exercises; a majority (60.6%) reported team sport participation. Males were less likely to report team exercise (p = .005). Bradycardia (heart rate <50) at presentation was associated with team sport participation (adjusted odds ratio [AOR] 1.66, 95% confidence interval [CI] 1.02-2.72) and hours of exercise per week (AOR 1.05, 95% CI 1.02-1.09), controlling for diagnosis, sex, age, duration of illness, rate of weight loss, and percent median body mass index (%mBMI).

DISCUSSION

Adolescents with AN, atypical AN, and BN reported high levels of exercise. Females reported more team sport participation. Greater exercise frequency and team sport participation were associated with bradycardia. Further studies assessing the relationship between exercise and bradycardia may help inform the medical management of adolescents with these eating disorders who are more physically active.

Leptin and Physical Activity in Adult Patients with Anorexia Nervosa: Failure to Demonstrate a Simple Linear Association

High physical activity (PA) in patients with anorexia nervosa (AN) is hypothesized to be, at least in part, a consequence of hypoleptinemia. However, most studies on the association of leptin and PA in AN were performed in adolescents or young adults, and PA was generally measured with subjective tools. We aimed to explore the association of leptin and PA in adults with AN using an objective technique to quantify PA. Using a cross-sectional, observational design, we analyzed body fat (bioelectrical impedance), PA (accelerometry, SenseWear™ armband) and plasma leptin (ELISA) in 61 women with AN (median age: 25 years, range: 18–52 years; median BMI: 14.8 ± 2.0 kg/m²) at the start of hospitalization. Results indicated a mean step count per day of 12,841 ± 6408 (range: 3956–37,750). Leptin was closely associated with BMI and body fat (ρ = 0.508 and ρ = 0.669, p < 0.001), but not with steps (ρ = 0.015, p = 0.908). Moreover, no significant association was observed between BMI and steps (ρ = 0.189, p = 0.146). In conclusion, there was no simple, linear association of leptin and PA, highlighting the need for more complex and non-linear models to analyze the association of leptin and PA in adults with AN in future studies.

Cannabinoid CB1 /CB2 receptor agonists attenuate hyperactivity and body weight loss in a rat model of activity-based anorexia

BACKGROUND AND PURPOSE

Anorexia nervosa (AN) is a serious psychiatric condition characterized by excessive body weight loss and disturbed perceptions of body shape and size, often associated with excessive physical activity. There is currently no effective drug-related therapy of this disease and this leads to high relapse rate. Clinical data suggest that a promising therapy to treat and reduce reoccurrence of AN may be based on the use of drugs that target the endocannabinoid (EC) system, which appears dysregulated in AN patients.

EXPERIMENTAL APPROACH

The activity-based anorexia (ABA) rodent model mimics the severe body weight loss and increased physical activity, as well as the neuroendocrine disturbances (i.e. hypoleptinaemia and hypercortisolaemia) in AN. This study investigated whether cannabinoid agonists can effectively modify anorexic-like behaviours and neuroendocrine changes in rats subjected to a repeated ABA regime that mimics the human condition in which patients repeatedly undergo a recovery and illness cycle.

KEY RESULTS

Our data show that subchronic treatment with both the natural CB₁ /CB₂ receptor agonist Δ⁹ -tetrahydrocannabinol and the synthetic CB₁ /CB₂ receptor agonist CP-55,940 significantly reduced body weight loss and running wheel activity in ABA rats. These behavioural effects were accompanied by an increase in leptin signalling and a decrease in plasma levels of corticosterone.

CONCLUSION AND IMPLICATIONS

Taken together, our results further demonstrate the involvement of the EC system in AN pathophysiology and that strategies which modulate EC signalling are useful to treat this disorder, specifically in patients where physical hyperactivity plays a central role in its progression and maintenance.

Body composition and menstrual status in adults with a history of anorexia nervosa-at what fat percentage is the menstrual cycle restored?

OBJECTIVE

To study the association between body composition measures and menstrual status in a large sample of adult patients with a history of anorexia nervosa and to calculate the predicted probability of resumption of menstrual function. Furthermore, to establish whether fat percentage is superior to body mass index in predicting the resumption of menses.

METHOD

One hundred and thirteen adult women with a history of anorexia nervosa underwent a dual energy X-ray absorptiometry (DXA) scan and completed questionnaires regarding medication prescription and menstrual function.

RESULTS

Fifty percent of patients were expected to resume their menstrual function at a body mass index of 19 kg m^-2 or a fat percentage of 23%. Twenty-five percent of patients were expected to resume their menstrual function at body mass index 14 kg m^-2 or fat percentage 11%. Fat percentage and body mass index were equally capable of predicting the resumption of menses.

DISCUSSION

Fat percentage and body mass index were positive predictors of the resumption of menses, however, body composition measured by dual energy X-ray absorptiometry was not superior to body mass index in predicting menstrual recovery, which is of great clinical relevance as body mass index is easier and cheaper to obtain. Body composition measures only account for one of numerous factors involved in the resumption of menses. Regression models based on our data had a R² value of 0.14, indicating that only 14% of the variation in menstrual recovery could be explained by the variables included. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2017; 50:370-377).

Physical activity, body weight, and resumption of menses in anorexia nervosa

Few data are available on long-term outcomes and increased physical activity at the end of inpatient treatment in patients with anorexia nervosa. Hence we assessed the association between physical activity, measured objectively by Sense Wear Armband (SWA), and body mass index (BMI; kg/m²) and menses resumption at one-year follow-up in 32 females with anorexia nervosa who had restored normal body weight by the end of a specialist inpatient treatment. Combined logistic regression models used to evaluate the relationship between variables at discharge, BMI and resumption of menses at one-year follow-up revealed no significant association between BMI at one-year follow-up and physical activity patterns at inpatient discharge. However, total daily steps at inpatient discharge were significantly lower in patients who had resumed menstruation, as confirmed by logistic regression analysis. A small reduction in daily steps at inpatient discharge (~1000 steps) was found to increase the probability of menses resumption at one-year follow-up by ~3%. These data provide preliminary indications as to the potential usefulness of assessing daily steps to predict the resumption of menses at one-year follow-up in patients with anorexia nervosa who restore body weight by the end of inpatient treatment, although confirmation on larger samples is urgently required.

Dimensions of Compulsive Exercise across Eating Disorder Diagnostic Subtypes and the Validation of the Spanish Version of the Compulsive Exercise Test

Objectives: Compulsive exercise in eating disorders has been traditionally considered as a behavior that serves the purpose of weight/shape control. More recently, it has been postulated that there may be other factors that drive the compulsive need to exercise. This has led to the development of the Compulsive Exercise Test (CET); a self-reported questionnaire that aims to explore the cognitive-behavioral underpinnings of compulsive exercise from a multi-faceted perspective. The objectives of this study were threefold: (1) to validate the Spanish version of the CET; (2) to compare eating disorder diagnostic subtypes and a healthy control group in terms of the factors that drive compulsive exercise as defined by the CET; (3) to explore how the dimensions evaluated in the CET are associated with eating disorder symptoms and general psychopathology.

Methods: The CET was administered to a total of 157 patients with an eating disorder [40 anorexia nervosa, 56 bulimia nervosa (BN), and 61 eating disorder not-otherwise-specified (EDNOS)] and 128 healthy weight/eating controls. Patients were assessed via a semi-structured interview to reach a DSM-IV-TR diagnosis. Additionally, all participants completed the Symptom Checklist-90-Revised (SCL-90R) and the Eating Disorders Inventory-2 (EDI-2).

Results: Confirmatory factor analysis demonstrated adequate goodness-of-fit to the original five-factor model of the CET. BN and EDNOS patients scored higher in the avoidance and rule-driven behavior, weight control, and total CET scales in comparison to the healthy controls, and higher across all scales apart from the exercise rigidity scale compared to the anorexia nervosa patients. Mean scores of the anorexia nervosa patients did not differ to those of the control participants, except for the mood improvement scale where the anorexia nervosa patients obtained a lower mean score. Mean scores between the BN and EDNOS patients were equivalent. The CET scales avoidance and rule-driven behavior, weight of control and total CET scores were positively correlated with the clinical assessment measures of the SCL-90R and EDI-2.

Conclusion: Compulsive exercise is a multidimensional construct and the factors driving compulsive exercise differ according to the eating disorder diagnostic subtype. This should be taken into account when addressing compulsive exercise during the treatment of eating disorders.

Problematic Exercise in Anorexia Nervosa: Testing Potential Risk Factors against Different Definitions

“Hyperactivity” has a wide prevalence range of 31% to 80% in the anorexia nervosa literature that could be partly due to the plethora of definitions provided by researchers in this field. The purpose of this study was two-fold: 1) To assess the variance across prevalence rates of problematic exercise encountered in patients with anorexia nervosa, in relation to seven different definitions found in the literature. 2) To examine how core eating disorder symptoms and the dimensions of emotional profile are associated with these different definitions and the impact of these definitions on the assessment of patients’ quality of life. Exercise was evaluated in terms of duration, intensity, type and compulsion using a semi-structured questionnaire administered to 180 women suffering from severe anorexia nervosa. Seven different definitions of problematic exercise were identified in the literature: three entailing a single dimension of problematic exercise (duration, compulsion or intensity) and four combining these different dimensions. Emotional profile scores, obsessive-compulsive symptoms, eating disorder symptomatology, worries and concerns about body shape, self-esteem and quality of life were assessed using several established questionnaires. The prevalence of problematic exercise varied considerably from, 5% to 54%, depending on the number of criteria used for its definition. The type and level of eating disorder symptomatology was found to be associated with several definitions of problematic exercise. Surprisingly, a better self-reported quality of life was found among problematic exercisers compared to non-problematic exercisers in three of the definitions. The different definitions of problematic exercise explain the broad prevalence ranges and the conflicting associations generally reported in the literature between problematic exercise and eating disorder-related psychological parameters. There is an urgent need for a valid consensus on the definition of problematic exercise in anorexia nervosa. This will support the development of further research on the etiology and treatment of problematic exercise.

Physical activity in anorexia nervosa: How relevant is it to therapy response?

OBJECTIVE

Elevated physical activity has been observed in some patients with anorexia nervosa (AN) despite their emaciated condition. However, its effects on treatment outcome remain unclear. This study aimed to examine objectively measured physical activity in this clinical population and how it might be related to a partial hospitalization therapy response, after considering potential confounders.

METHOD

The sample comprised 88 AN patients consecutively enrolled in a day hospital treatment program, and 116 healthy-weight controls. All participants were female and a baseline assessment took place using an accelerometer (Actiwatch AW7) to measure physical activity, the Eating Disorders Inventory-2 and the Depression subscale of the Symptom Checklist-Revised. Outcome was evaluated upon the termination of the treatment program by expert clinicians.

RESULTS

Although AN patients and controls did not differ in the average time spent in moderate-to-vigorous physical activity (MVPA) (P=.21), nor daytime physical activity (P=.34), fewer AN patients presented a high physical activity profile compared to the controls (37% vs. 61%, respectively; P=.014). Both lower levels of MVPA and greater eating disorder severity had a direct effect on a poor treatment outcome. Depression symptoms in the patients were associated with lower MVPA, as well as with an older age, a shorter duration of the disorder and greater eating disorder psychopathology.

CONCLUSIONS

There is a notable variation in the physical activity profile of AN patients, characterized by either low or very high patterns. Physical activity is a highly relevant issue in AN that must be taken into account during the treatment process.

High Levels of Physical Activity in Anorexia Nervosa: A Systematic Review

High level physical activity is a frequent symptom in patients with anorexia nervosa (AN), influencing the development, maintenance, complications, treatment success, relapse rate and severity of the disease. Accelerometry is assumed to be an objective method to assess physical activity (PA) in AN. We aimed to review objectively measured levels of PA in AN and to give an overview for clinical practice and future research. Data were searched in PubMed and PsychINFO until April 2015 following the preferred reporting items for systematic reviews and meta-analyses statement. Twenty studies fulfilled the inclusion criteria. A notable heterogeneity of measurements, outcomes, participants and settings was found. Overall, HLPA is not adressed enough by current evidence. A common valid terminology of HLPA is not available, and accurate criteria of different levels of PA must be defined to create comparability of future studies. Further objective PA assessments are needed to improve treatment outcome and relapse rate.

Adolescent eating disorders: update on definitions, symptomatology, epidemiology, and comorbidity

The prevalence of eating disorders among adolescents continues to increase. The starvation process itself is often associated with severe alterations of central and peripheral metabolism, affecting overall health during this vulnerable period. This article aims to convey basic knowledge on these frequent and disabling disorders, and to review new developments in classification issues resulting from the transition to DSM-5. A detailed description is given of the symptomatology of each eating disorder that typically manifests during adolescence. New data on epidemiology, and expanding knowledge on associated medical and psychiatric comorbidities and their often long-lasting sequelae in later life, are provided.

20 years of leptin: role of leptin in human reproductive disorders

Leptin, as a key hormone in energy homeostasis, regulates neuroendocrine function, including reproduction. It has a permissive role in the initiation of puberty and maintenance of the hypothalamic-pituitary-gonadal axis. This is notable in patients with either congenital or acquired leptin deficiency from a state of chronic energy insufficiency. Hypothalamic amenorrhea is the best-studied, with clinical trials confirming a causative role of leptin in hypogonadotropic hypogonadism. Implications of leptin deficiency have also emerged in the pathophysiology of hypogonadism in type 1 diabetes. At the other end of the spectrum, hyperleptinemia may play a role in hypogonadism associated with obesity, polycystic ovarian syndrome, and type 2 diabetes. In these conditions of energy excess, mechanisms of reproductive dysfunction include central leptin resistance as well as direct effects at the gonadal level. Thus, reproductive dysfunction due to energy imbalance at both ends can be linked to leptin.