MON-276 PTH Abnormalities In Patients With Primary Aldosteronism With And Without Adrenal Nodules: A Cross-sectional Single Center Study

Abstract Disclosure: N.E. Fretes Oviedo: None. M. Ortega Abad: None. L.Z. Khan: None. R. Correa: None. A. Mehdi: None. P. Rao: None. Introduction: Primary aldosteronism (PA) and primary hyperparathyroidism (HPT) are two common endocrine conditions. The Parathyroid hormone (PTH) and the renin-angiotensin-aldosterone system (RAAS) exhibit a bidirectional relationship. It is thought that PA could lead to secondary HPT. Aldosterone-induced hypercalciuria and subsequent hypocalcemia are hypothesized to trigger PTH secretion to maintain calcium homeostasis. These effects may resolve once aldosterone excess is treated. Evidence suggests that patients with aldosterone-producing adenomas (APA) might have higher PTH levels, leading to greater complications compared to those with bilateral adrenal disease. The aim of this study is to evaluate PTH levels and their potential impact on bone mineral disorders and/or kidney stones in patients with PA, with and without adrenal nodules. Methods: A single-center, retrospective observational study was conducted using an IRB-approved database that included 164 patients with a diagnosis of PA (ICD codes) and PTH levels checked from 2018 to 2023, excluding those with secondary causes of HPT. The PTH level analyzed was the one closest to the time of PA diagnosis. Patients with confirmed PA and adrenal imaging were included. Prevalence and central tendency measures were obtained and compared between groups. Results: A total of 110 patients were included with a diagnosis of PA, of whom 50 had image-confirmed adrenal nodules. Age, sex, race, and comorbidities were similarly distributed between both groups. Not surprisingly, patients with adrenal nodules had significantly higher surgery rates (p<0.001). Higher levels of PTH were noted in those with adrenal nodules compared to those without (median: 79 mg/dL vs. 46 mg/dL; P = 0.004). Regarding clinical manifestations of HPT, the prevalence of kidney stones was similar in both groups (28.3% vs. 28%), while bone mineral disorders were less frequent in the group with adrenal nodules (16% vs. 20%). Levels of calcium, albumin, phosphorus, and vitamin D were similarly distributed in both groups. Notably, a DXA scan was ordered in only 33 patients. Additionally, only 23 out of 50 patients underwent adrenal venous sampling (46%), and 15 out of 23 (65%) lateralized to the adenoma. Discussion: Similar to other studies, our data suggests that patients with PA and adrenal nodules have higher PTH levels compared to those without adrenal nodules. Interestingly, the degree of PTH elevation did not clinically correlate with a higher prevalence of bone mineral disorders or kidney stones in these patients, although the number of patients screened for these potential complications was low (30%). Conclusion: Future research is needed to further elucidate the mechanisms and gain a deeper understanding of the connection between aldosterone excess and PTH levels. This will enable more prompt screening for the deleterious effects of HPT in patients with PA. Presentation: Monday, July 14, 2025