Is there a link between stress and immune biomarkers and salivary opiorphin in patients with a restrictive-type of anorexia nervosa?

AbstractObjectives. Opiorphin is a salivary peptide with analgesic and antidepressant properties. Its relationship with the hypothalamic-pituitary-adrenal, autonomic nervous and immune systems may provide understanding of chronic stress, especially in anorexia nervosa (AN). This study investigated a possible correlation between opiorphin and stress/immune biomarkers, respectively cortisol, alpha-amylase (sAA), secretory IgA (sIgA) in saliva of patients with restrictive-type of AN.Methods. A case control clinical trial was conducted in 92 AN patients (+75 healthy controls). Unstimulated salivary samples were taken during the acute stage of AN, measurements of cortisol, sAA, sIgA and opiorphin were performed with a quantitative assay (Elisa, p < 0.05).Results. AN patients displayed an increase in cortisol (p < 0.001) and sIgA (p < 0.001) but not in sAA (p = 0.279) levels. Distinct correlation between these two parameters and bodyweight indexes were observed. Opiorphin levels were neither correlated to stres...