Background: Hyperparathyroid condition might influence endothelial cells. The aim of this study was to assess flow mediated dilatation (FMD) in patients with primary hyperparathyroidism (PHPT).
Methods: We prospectively evaluated 21 patients with PHPT (9 women, 12 men; aged 50 +/- 11 years, serum calcium 11.6 +/- 0.7 mg/dl, intact parathyroid hormone (iPTH) 489 +/- 495 pg/ml) and 27 healthy control subjects (13 women, 14 men; aged 49 +/- 10 years, serum calcium 9.4 +/- 0.5 mg/dl, iPTH 28 +/- 8.5 pg/ml). Endothelial function, measured as FMD of the brachial artery using ultrasound, was calculated in two groups. To avoid confounding factors, conditions known to affect endothelial function like diabetes mellitus, hypertension, dyslipidemia, smoking, coronary and peripheral artery disease were excluded from both groups.
Results: FMD was lower in patients with PHPT than that in those without (10.2 +/- 5.8 vs. 19.8 +/- 5.8, P = 0.0001). FMD negatively correlated with serum calcium (r = -0.55, P = 0.002).
Conclusion: Endothelium-dependent FMD may impair in patients with PHPT compared to controls. Endothelial dysfunction can contribute to the deleterious cardiovascular effects of PTH excess. Therapy to reduce or retard endothelial dysfunction in patients with PHPT may lead to decreased cardiovascular morbidity and mortality.