Functional Status of Hypothalamic-pituitary-thyroid axis and Prolactin level in Patients with First-episode of Bipolar Disorder in Mania State

Abstract Background Bipolar disorder (BD)-mania symptoms are stimulated by disease of the thyroid. Methods This study included 70 patients diagnosed with first-episode BD-mania and 70 healthy controls (HC) matched for age and sex. We aimed to determine upstream thyroid hormone interactions on the anterior pituitary, and find differences between thyroid-stimulating-hormone (TSH) and Prolactin (PRL) in the patients with first-episode of BD-mania. There were significant changes in triiodothyronine (TT3), total thyroxin (TT4), and free thyroxine (FT4) concentrations between the BD-mania and HC groups (p < 0.0167 with Bonferroni correction). Results After being grouped by sex, higher PRL in the male and female BD-mania subgroup were observed compared to each isosexual HC (p’s < 0.01). Higher FT4 in the male BD-mania group was observed compared to the HC males (p < 0.01) while the female BD-mania group showed lower TT3 and TT4 compared to the HC females (p’s < 0.01). In the female BD-mania group, correlation analysis established an inverse relationship between PRL and TSH (r2 = 0.25, F = 11.11, p < 0.01). Conclusions The findings demonstrate that sex impacts the concentration of hormones secreted by the anterior pituitary of patients with first-episode BD-mania. The increased PRL may be a putative mechanism that underlies the onset in female patients with a moderate inverse relationship between TSH and PRL.