Associations between thyroid function, thyroid diseases, and primary aldosteronism.

Objective: Previous studies focusing on primary aldosteronism (PA) and thyroid diseases were controversial. Hence, this study aimed to examine associations between thyroid function, thyroid diseases, and PA and its subtypes.

Design and methods: This was a cross-sectional study, which enrolled 1023 patients with PA and 6138 patients with essential hypertension (EH) admitted to Hypertension Center of People's Hospital of Xinjiang Uygur Autonomous Region from August 2011 to June 2022. All patients with PA were accurately classified into aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) by adrenal vein sampling (AVS). Multivariate logistic regression analysis was used to assess the relationship of thyroid function, thyroid nodules, and PA and its subtypes.

Results: A total of 7161 patients (327 APA and 696 IHA, and 6138 EH) were included with a mean age of 48.20 ± 8.83 years. PA patients and PA subtypes showed lower FT4, FT3, TT4, TT3, and prevalence of positive TPOAb, meanwhile higher prevalence of thyroid nodules than EH patients (PA: 56.10%, IHA: 56.90%, APA: 54.80%, and EH: 48.90%, respectively). PA (adjusted OR: 1.290, 95% CI: 1.035-1.607, P = .02) and its subtype (IHA) (adjusted OR: 1.316, 95% CI: 1.005-1.724, P = .04) were significantly associated with thyroid nodules. Compared to patients with lower plasma aldosterone concentration (PAC) levels (<12 ng/dL), patients with PAC levels ≥ 12 ng/dL presented a higher prevalence of thyroid nodules.

Conclusions: PA patients had lower thyroid function and higher prevalence of thyroid nodules compared to EH patients. Therefore, the screening of thyroid function and thyroid nodules may be indispensable for PA patients.