Endocrine Abstracts

Background: Hypertension is one of the widespread cardiovascular pathology in patients with primary hyperparathyroidism (PHPT).The renin-angiotensin-aldosterone system (RAAS) is a key system in the regulation of blood pressure and its interactions with mineral metabolism are described. Our previous study* of PHPT patients revealed a significant decrease in plasma renin activity (PRA) and serum aldosterone levels in the early postoperative period and also positive correlations of calcium and PTH with RAAS parameters.

The aim of this study was to investigate follow-up changes of the RAAS activity in PHPT patients one year after surgery.

Material and Methods: We have examined 27 patients with PHPT (24 women, 3 men; median age 55 years [37; 59]) within a year (12 ± 1.3 months). All patients underwent biochemical and hormone evaluation before, in 3 daysand 1 year after surgical treatment for PHPT. The exclusion criteria were the glomerular filtration rate <75 ml/min/1.73 m², severe cardiovascular pathology, obesity, diabetes mellitus, using drugs affected calcium balance before and in 12 month after radical surgery. Control group was sex- and age-matched without cardiovascular pathology and any mineral disturbances (median serum calcium 2.45 mmol/l [2.42; 2.49], PTH 32.94 pg/ml [27.2; 41.6]).

Results: All patients initially had symptomatic PHPT (median serum calcium level 2.74 mmol/l [2.66; 2.9], PTH 123.8 pg/ml [85.8; 203]). Hypertensionwas observed in 37% and corrected with ACE-inhibitors or angiotensin II receptor blockers. PHPT patients had lower plasma renin activity (PRA) and higher serum angiotensin II (AT II) level comparing to control group (0.49 [0.11; 1.8] vs 1.23 [0.74;2.24] ng/ml*h, P = 0.02 and 38 [30;42.2] vs 25.64 [20.14;35.44] pg/ml, P = 0.04 respectively). At the 3rd day after surgery the blood evaluation revealed a significant decrease in PRA (P = 0.001), whereas at 12th month there were decrease in AT II (P = 0.03) and increase in PRA (P = 0.018). Serum aldosterone level did not show any significant changes (P = 0.62). There were no differences in the RAAS components between PHPT and control groups. However wefound a positive correlation of intact PTH with aldosterone in 3 days (P = 0.04) as well as intact PTH with AT II levels at 12th month (P = 0.03) after parathyroidectomy in non-therapy subgroup.

Conclusion: Our resultsdemonstrated the interaction between RAAS activity and PHPT, but further studies are required.

*The impact of impaired calcium-phosphorus metabolism on the renin--angiotensin-aldosterone system in patients with primary hyperparathyroidism. Mokrysheva N, Dobreva E, Bibik E, Eremkina A Endocrine Abstracts (2019) Vol 63. DOI: 10.1530/endoabs.63.GP24