Evidence-Based Medicine
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World J Clin Cases. Jul 16, 2014; 2(7): 257-264
Published online Jul 16, 2014. doi: 10.12998/wjcc.v2.i7.257
Association between resting energy expenditure, psychopathology and HPA-axis in eating disorders
Giovanni Castellini, Walter Castellani, Lorenzo Lelli, Carolina Lo Sauro, Carla Dini, Lisa Lazzeretti, Lorenza Bencini, Edoardo Mannucci, Valdo Ricca
Giovanni Castellini, Lorenzo Lelli, Lisa Lazzeretti, Lorenza Bencini, Valdo Ricca, Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, 50134 Firenze, Italy
Walter Castellani, Department of Respiratory Physiopathology, Palagi Hospital, 50134 Firenze, Italy
Carolina Lo Sauro, Department of Health Science, University of Florence, 50134 Firenze, Italy
Carla Dini, Nutrition Service, University of Florence, 50134 Firenze, Italy
Edoardo Mannucci, Non Invasive Cardiology, Department of Heart and Vessels, University of Florence, 50134 Firenze, Italy
Author contributions: Castellini G, Lelli L and Ricca V contributed equally to this work; Castellini G, Lelli L, Lo Sauro C and Ricca V designed the research; Castellani W, Dini C, Lazzeretti L and Bencini L performed the research; Castellini G and Mannucci E analyzed the data; Castellini G, Lelli L and Ricca V wrote the paper.
Correspondence to: Valdo Ricca, MD, Psychiatric Unit, Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Largo Brambilla 3, 50134 Firenze, Italy. valdo.ricca@unifi.it
Telephone: +39-055-7947487 Fax: +39-055-7947487
Received: April 14, 2014
Revised: May 30, 2014
Accepted: June 18, 2014
Published online: July 16, 2014
Abstract

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

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

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

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

Keywords: Anorexia nervosa, Bulimia nervosa, Cortisol, Psychopathology, Resting energy expenditure

Core tip: We have investigated the relationship between resting energy expenditure (REE), eating psychopathology, and hypothalamus adrenal axis in EDs. Twenty two anorexia nervosa (AN) and 21 bulimia nervosa (BN) patients were assessed. Both AN and BN showed a reduced REE as compared with predicted REE. AN and BN showed an opposite pattern of association between REE and Body Mass Index (BMI) which was positively associated with REE in BN, whereas a strong, negative association between BMI and REE was observed in AN. In AN only, a higher REE was associated with a more severe eating disorder psychopathology, and higher cortisol levels. The data supported a mediation model where cortisol levels mediated the relationship between eating psychopathology and REE.