Oxidative status in plasma, urine and saliva of girls with anorexia nervosa and healthy controls: a cross-sectional study

Anorexia nervosa (AN) is a serious psychosomatic disorder with unclear pathomechanisms. Metabolic dysregulation is associated with disruption of redox homeostasis that might play a pivotal role in the development of AN. The

This is the first study assessing wide range of markers of oxidative status in plasma, urine and saliva of the patients with AN. We showed that both, higher levels of markers of oxidative stress and lower antioxidants play a role in redox disruption. Restoration of redox homeostasis might be of the clinical relevance. Anorexia nervosa is a serious psychosomatic disorder with increasing incidence worldwide. Numerous general medical complications affecting most major organ systems are caused by progressive malnutrition and rapid weight loss. However, precise pathomechanism involved in the pathogenesis of anorexia nervosa remains to be elucidated. A potential role of oxidative stress caused by metabolic disruption in the etiology of anorexia nervosa was already described in plasma or blood components. This study aimed to investigate whether redox imbalance could be detected even in alternative body fluids of patients with anorexia nervosa - urine and saliva. Samples from female patients (n = 111) with anorexia nervosa and healthy controls (n = 29) were collected and analysed in this study. Our results indicated that changes in redox homeostasis could be detected not only in plasma, but also in urine and saliva of patients with anorexia nervosa. This was shown by higher markers of oxidative stress - advanced oxidation protein products, fructosamines and advanced glycation end-products. Oxidative damage of biomolecules might have direct cytotoxic effect associated with increased expression of proinflammatory cytokines, growth factors etc. Thus, many medical complications of anorexia nervosa might be directly connected to the accumulation of oxidatively damaged biomolecules.

Plasma, spot urine, and saliva were collected from 111 girls with AN (aged from 10 to 18 years) and from 29 age-matched controls. Markers of oxidative stress and antioxidant status were measured using spectrophotometric and fluorometric methods.

Plasma advanced oxidation protein products (AOPP) and advanced glycation end products (AGEs) were significantly higher in patients with AN than in healthy controls (by 96, and 82%, respectively). Accordingly, urinary concentrations of AOPP and fructosamines and salivary concentrations of AGEs were higher in girls with AN compared with controls (by 250, and 41% in urine; by 92% in saliva, respectively). Concentrations of thiobarbituric acid reactive substances (TBARS) in saliva were 3-times higher in the patients with AN than in the controls. Overall antioxidants were lower in plasma of girls with AN compared to the controls, as shown by total antioxidant capacity and ratio of reduced and oxidized glutathione (by 43, and 31%, respectively). Conclusions: This is the first study assessing wide range of markers of oxidative status in plasma, urine and saliva of the patients with AN. We showed that both, higher levels of markers of oxidative stress and lower antioxidants play a role in redox disruption. Restoration of redox homeostasis might be of the clinical relevance. Anorexia nervosa is a serious psychosomatic disorder with increasing incidence worldwide. Numerous general medical complications affecting most major organ systems are caused by progressive malnutrition and rapid weight loss. However, precise pathomechanism involved in the pathogenesis of anorexia nervosa remains to be elucidated. A potential role of oxidative stress caused by metabolic disruption in the etiology of anorexia nervosa was already described in plasma or blood components. This study aimed to investigate whether redox imbalance could be detected even in alternative body fluids of patients with anorexia nervosa - urine and saliva. Samples from female patients (n = 111) with anorexia nervosa and healthy controls (n = 29) were collected and analysed in this study. Our results indicated that changes in redox homeostasis could be detected not only in plasma, but also in urine and saliva of patients with anorexia nervosa. This was shown by higher markers of oxidative stress - advanced oxidation protein products, fructosamines and advanced glycation end-products. Oxidative damage of biomolecules might have direct cytotoxic effect associated with increased expression of proinflammatory cytokines, growth factors etc. Thus, many medical complications of anorexia nervosa might be directly connected to the accumulation of oxidatively damaged biomolecules.