Psychoneuroendocrine characteristics of common obesity clinical subtypes

OBJECTIVE: To relate psychological profiles, cerebral asymmetry and the hypothalamus-pituitary-adrenal axis (HPA) reactivity to clinical characteristics of common obesity. METHODS: Sixty consecutive adult female overweight and obese patients attending the outpatient endocrine department were included in this study. Clinical evaluation specifically selected a priori the following indexes: obesity age of onset, parenthood obesity, carbohydrate craving, binge eating with purging, obesity degree (defined by the body mass index (BMI)-weight (kg)/height (m2)), body fat distribution (defined by the abdominal-thigh ratio (A/T)) and initial weight loss after medical treatment. Psychological evaluation was performed with the Minnesota Multiphasic Personality Inventory (MMPI). In the last 30 patients, the Edinburgh Inventory of Manual Preference (EIMP) and the corticotrophin-releasing hormone (CRH) test were also performed. RESULTS: Clinical characteristics defined a priori were independent variables as evaluated by contingency table analysis. Factorial analysis of variance (ANOVA) revealed a significantly different MMPI profile, according to parental obesity, with post-hoc significantly higher scores on the hypochondriasis (Hs), paranoia (Pa), psychasthenia (Pt) and schizophrenia (Sc) scales in patients with obese parents. Obese patients presented significantly higher dichotomized manual preference indexes in relation to overweight patients. Parental obesity, binge eating behaviour with purging, body fat distribution and the dichotomized manual preference index were independent significant factors for the ACTH response in the CRH test, together explaining 41% of the response variability. Age of onset of obesity and the dichotomized manual preference index were independent and significant factors for the cortisol response, together explaining 37% of its variability. A non-normal distribution was found for the ACTH response: high- and low-responders presented significantly different MMPI profiles, with high-responders presenting higher scores on all clinical scales except masculinity/femininity (Mf). CONCLUSION: Overweight/obese subjects with parental obesity present a distinctive personality profile and a higher ACTH response in the CRH test. Cerebral asymmetry may be a relevant factor for obesity development and is associated with the HPA reactivity. HPA reactivity is a sensitive index integrating clinical, psychological and neural asymmetric factors.