Endocrine Abstracts

Introduction: Primary hyperparathyroidism (PHPT) is emerging as a cause of secondary hypertension. Between 20 and 50% of patients with PHPT have hypertension, this being directly proportional to the calcemia. The elevation of blood pressure in PHPT is mediated by hypercalcemia that acts directly stimulating the contraction of muscle fibers of the arterial vessel wall, and increases plasma renin levels and the release of catecholamines.

Objectives: (1) Determine the rate of normalization of blood pressure (BP) in hypertensive patients with PHPT after parathyroidectomy.

(2) Showed a reduction in the number of drugs if hypertension persists after surgery.

Materials and methods: A retrospective study of hypertensive patients with PHPT operated between 2005 and 2010. We use the Excalibur database, and look for the following key words: PHPT, hypertension, and parathyroidectomy. The following data were collected: age, sex, BMI, time with hypertension, pre-surgical PTH, calcium, phosphorus, 25OHVitamin D, creatinine, GFR, mean pre-surgery BP, pre-surgery antihypertensive drugs, mean post-surgery BP and post-surgical anti-hypertensive drugs. All patients included had to have biochemical criteria of cure PHPT.

Results: There were 88 patients with the search criteria: 18 (20.4%) were male and 70 (79.6%) were women. There was no statistically significant gender differences when comparing the other variables. The average values of the sample were: BMI: 28.2 kg/m², duration of hypertension: 8.8 years, pre-operative PTH: 124.6 pg/ml, serum calcium: 11.1 mg/dl, phosphoremia: 2.2 mg/dl, 25OH Vitamin D: 18 ng/dl. Creatinine 1.2 mg/dl, GFR 58 ml/min, pre-surgical BP 136.2/88.6 mmHg vs postoperative BP 130.3/82.2 mmHg (P<0.005), pre-surgical anti-hypertensive drugs 2.7 vs 2.2 in the post-surgery (P<0.005). 26.4% normalized their BP after surgery and did not require antihypertensive therapy. 54.4% of patients reduced the number and doses of drugs.

Conclusions: Although most patients probably had essential hypertension, PHPT appears to increase BP probably by serum calcium-dependent mechanisms. This could explain normalization tension and decrease in the number and doses of antihypertensive drugs presented by patients after parathyroidectomy.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.