RESUMO
Objective: To explore the value of serum parathyroid hormone (PTH) in the diagnosis of primary aldosteronism (PA) and to investigate an optimal cut-off of serum PTH to distinguish PA from nonfunctional adrenal tumor (NFA). Methods: The clinical data of patients with adrenal incidentaloma in Chinese PLA General Hospital from January 1, 2017 to December 31, 2019 were collected. The data of PA and NFA by clinical characteristics and evaluation on endocrine function were retrospectively analyzed. The logistic regression model was used to find the potential risk factors of elevated PTH. The receiver operating characteristic(ROC) curve was used to evaluate the efficacy of PTH in diagnosis of PA and to explore the best cut-off value. Results: A total of 773 patients were included. There were 356 PA patients (203 males, 57.0%), aged (50±11) years and 417 NFA patients (219 males, 52.5%), aged (51±12) years. The serum PTH level in patients with PA was significantly higher than that in patients with NFA [63.1 (48.4, 80.3) ng/L vs 41.7 (34.1, 51.7) ng/L, P<0.05], as well as the proportion of patients with elevated PTH level (47.8% vs 7.2%, P<0.05). Logistic regression analysis showed that having PA and deficiency of Vitamin D were risk factors for PTH elevation (both P<0.05). The ROC curve showed that the best cut-off value of PTH for the diagnosis of PA in patients with vitamin D deficiency was 56.44 ng/L, with a sensitivity of 66.5% and a specificity of 83.0%, and that in patients with normal vitamin D was 48.81 ng/L, with a sensitivity of 70.5% and a specificity of 72.6%. Conclusions: Patients with PA tend to show increased levels of serum PTH compared with NFA patients. The level of serum PTH can be used as one of the valuable indexes in screening of PA.