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

Abstract

Objectives: 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, cortisol, salivary alpha-amylase (sAA) and secretory immunoglobulin A (sIgA), in saliva of patients with restrictive-type 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 (enzyme-linked immunosorbent assay, 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 body-weight indexes were observed. Opiorphin levels were neither correlated to stress and immune biomarkers, nor to salivary flow rate.

Conclusions: The effect of stress responses can be reliably assessed in saliva in AN patients. The difference between sIgA and cortisol indicate that they can both be used for mental stress assessment in saliva. Modulation of opiorphin by chronic stress was not confirmed. Unchanged sAA indicates a partial adaptation of human organism to severe condition during malnutrition.

Keywords:

• Anorexia nervosa
• cortisol
• stress
• saliva
• opiorphin

Acknowledgements

The authors would like to thank all those who participated in this study for their enthusiastic involvement and hard work. The authors would like to thank the Poznan University of Medical Sciences for supporting the study. The funders had no role in study design, data collection and analysis, the decision to publish, or the preparation of this manuscript.

Ethical approval

This article does not contain any studies with animals performed by any of the authors. All procedures involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Disclosure statement

Elzbieta Paszynska, Monika Dmitrzak-Weglarz, Magdalena Roszak, Yves Boucher, Agata Dutkiewicz, Maria Gawriolek, Justyna Otulakowska-Skrzynska, Szymon Rzatowski, Marta Tyszkiewicz-Nwafor, and Agnieszka Slopien declare that they have no conflict of interest.

Additional information

Funding

The work was supported by Poznan University of Medical Sciences.