Effect of hyperparathyroidism on endothelial functions and atherosclerosis.

Background: Primary Hyperparathyroidism (PHPT) is associated with an increased mortality risk of cardiovascular disease, and this appears to decrease with time after parathyroidectomy. Our study aimed to determine the association between endothelial function, Carotid Artery Intima Media Thickness (CIMT), and Flow Mediated Dilatation (FMD) in hyperparathyroidism and their effects on cardiovascular disease. Methods: The study included 20 patients each with PHPT and Secondary Hyperparathyroidism (SHPT) and 12 healthy subjects. All groups were matched with respect to age. Patients with diabetes mellitus, hypertension, and cardiovascular diseases were excluded from the study. Levels of serum calcium, Parathormone (PTH), and Daily Urinary Calcium Excretion (UCE) were calculated; furthermore, FMD and CIMT were evaluated for all subjects. Results: Serum calcium levels were significantly higher in the PHPT group than those in the SHPT and control groups (P<0.001 and P<0.001, respectively). As expected, UCE levels of PHPT group were higher than those of both the control and SHPT groups (P<0.001, P<0.001 respectively). FMD and CIMT levels were not significantly different between the groups. There was a negative correlation between FMD and serum calcium and PTH levels in the PHPT group (P<0.05).