Endocrine Abstracts

Introduction: Recent studies seem to support a bidirectional positive interaction between aldosterone and parathyroid hormone (PTH). Understanding the normal physiological relationship between renin-angiotensin-aldosterone system (RAAS) and PTH is of clinical interest because their inappropriate activity may negatively impact cardiovascular and skeletal health.

Objective: To evaluate the presence of an interaction between aldosterone and PTH in a cohort of patients assessed for suspicious hyperaldosteronism or hyperparathyroidism.

Material and Methods: We retrospectively evaluated consecutive patients followed in our Endocrinology Department between January 2014 and December 2016. We collected data about renin-angiotensin-aldosterone system and calcium metabolism from clinical and laboratorial records and selected patients whenever both data were available.

Results: We identified 97 patients evaluated for suspicious hyperaldosteronism or hyperparathyroidism. 51 patients were excluded due to insufficient data. From the 46 patients included, 8(17%) had confirmed primary hyperparathyroidism and one had confirmed primary hyperaldosteronism; 74% (n=34) were women, mean age of 60.0±13.2 years and mean BMI of 27.8±4.1 Kg/m². This group had a mean aldosterone level of 141.9±74.6 pg/ml (reference range: 40–310), PTH level of 87.3±48.0 pg/ml (reference range: 9–72), 25(OH) vitamin D level of 26.5±10.2 ng/ml and plasma calcium level of 9.6±1.1 mg/dl (reference range: 8.8–10.6). PTH and aldosterone levels presented a moderate correlation in our cohort (rho=0.474, P < 0.01). After exclusion of the patients with confirmed disease, PTH and aldosterone levels presented a week correlation, though still statistically significant (rho=0.377, P=0.021).

Conclusion: Aldosterone levels were positively correlated to PTH levels in our sample. This interaction may be one of the mechanisms responsible for hypertension and increased cardiovascular risk in patients with hyperparathyroidism. On the other hand, hyperaldosteronism may indirectly impair calcium metabolism and bone health.