Endocrine Abstracts

Background and aim: Obesity is associated with a dysregulation of the immune system which can result in a predisposition to the development of autoimmune diseases. The aim of this cross-sectional study was to evaluate anti-pituitary antibodies (APA) in severe obese patients, in order to identify a possible role of the immune system in obesity and to correlate these antibodies with pituitary hormone changes found in obese patients.

Matherials and methods: 36 obese patients from the Bariatric Surgery Unit and 50 non-obese subjects as control group were recruited. Weight, body mass index, blood pressure, heart rate, glycemic and lipid profile and insulinemia were measured in all subjects participating in the study. Basal levels of pituitary hormones (FSH, LH, TSH, GH, ACTH) and peripheral glands hormones (cortisol, testosterone, estradiol, free T4, free T3, IGF-1) were evaluated in all patients. APA were evaluated by indirect immunofluorescence method on cryostatized sections of the pituitary gland of a young baboon.

Results: 10 patients (28%) resulted APA positive while no APA positive subject was found in the control group. Therefore, the obese patients were divided into two groups, based on the presence or absence of APA (APA +, APA-); we compared the clinical characteristics and we found a significant lower cortisol level in obese APA + subjects than in obese APA- subjects (P=0.045). The anti-pituitary antibodies titer was inversely correlated with cortisol and growth hormone (GH) levels.

Conclusion: we found a higher prevalence of APA in obese patients than in control group and this result is in line with studies that suggested a higher risk and prevalence of autoimmune diseases in obese patients.

References: 1. Tsigalou C, Vallianou N, Dalamaga M. Autoantibody Production in Obesity: Is There Evidence for a Link Between Obesity and Autoimmunity?. CurrObes Rep. 2020;9(3):245-254.

2. Versini M, Jeandel PY, Rosenthal E, Shoenfeld Y. Obesity in autoimmune diseases: not a passive bystander. Autoimmun Rev. 2014;13(9):981-1000.

3. Bellastella G, Maiorino MI, Longo M, et al. Impact of Pituitary Autoimmunity and Genetic Disorders on Growth Hormone Deficiency in Children and Adults. Int J Mol Sci. 2020;21(4):1392. Published 2020 Feb 19.