Association between aldosterone and parathyroid hormone levels in patients with adrenocortical tumors.

Abstract

BACKGROUND\nPatients with primary hyperaldosteronism (PA) may present with high parathyroid hormone levels and negative calcium balance, with some studies speculating that aldosterone could directly stimulate PTH secretion. Either adrenalectomy or mineralocorticoid receptor blockers could reduce PTH levels in patients with primary hyperaldosteronism. The aim of this study was to assess the relationship between aldosterone levels and PTH-vitamin D-calcium axis in a cohort of patients with PA, compared to patients with non-secreting adrenocortical tumors in conditions of vitamin D sufficiency.\n\n\nMETHODS\nWe retrospectively enrolled a series of 243 patients of whom 66 with PA and 177 with non-secreting adrenal tumors, and selected those with full mineral metabolism evaluation and 25(OH) vitamin D levels greater than 20 ng/mL at the time of initial endocrine screening. The final cohort was composed of 26 patients with primary hyperaldosteronism and 39 patients, used as controls, with non-secreting adrenal tumors. The relationship between aldosterone, PTH levels and biochemistries of mineral metabolism was assessed.\n\n\nRESULTS\nAldosterone was positively associated with PTH levels (r=0.260, P<0.05) in the whole cohort and in the PA cohort alone (r=0.450; P=0.02). In the multivariate analysis, both aldosterone concentrations and urinary calcium excretion were significantly related to PTH levels, with no effect of 25(OH) vitamin D or other parameters of bone metabolism.\n\n\nCONCLUSIONS\nPTH level is associated with aldosterone probably independent of 25(OH) vitamin D levels and urinary calcium. Whether aldosterone directly interacts with the parathyroid glands remains to be established.