Effect of successful parathyroidectomy on 24-hour ambulatory blood pressure in patients with primary hyperparathyroidism.

OBJECTIVE: The pathogenesis of hypertension in patients with primary hyperparathyroidism (PHPT) is unclear, and the prevailing opinion is that parathyroidectomy does not affect the blood pressure (BP). Most previous studies have been based on BP measurements at rest in a clinical setting. The aim of this study was to get additional information by 24-hour ambulatory measurements. DESIGN AND PATIENTS: Forty-nine consecutive patients with PHPT (age 63+/-12 years, 44 women) were examined before and 6 months after curative parathyroid surgery. MEASUREMENTS: Serum concentrations of calcium and PTH, and 24-hour ambulatory mean, minimum, and maximum systolic (S) and diastolic BP, and mean arterial BP. RESULTS: On average, the patients showed no BP change after parathyroidectomy. However, those with a history of hypertension (n=20) showed generally increased BP values after parathyroidectomy, with significantly increased minimum and average SBP (P=0.02 and P=0.04, respectively), whereas patients without a history of hypertension (n=29) showed unchanged or slightly reduced BP values after parathyroidectomy, with significantly decreased maximum SBP (P=0.04). Serum concentrations of PTH and calcium were not significantly related to any of the BP variables measured. CONCLUSIONS: The novel finding that patients with both PHPT and hypertension may show increased BP after parathyroidectomy warrants intensified BP control postoperatively in these patients, and motivates early treatment of PHPT in order to prevent the development of complicating hypertension.