Increased markers of inflammation and endothelial dysfunction in patients with mild primary hyperparathyroidism

Objectives: The association between primary hyperparathyroidism (PHPT) and cardiovascular disease is incompletely understood. The aims of this study were to evaluate how cardiac function and markers of inflammation and endothelial dysfunction correlate in patients with mild PHPT, and how these markers are influenced by surgical cure of the parathyroid disease (PTX). Material and methods: Forty-five patients with PHPT were examined before and 1 year after PTX. Serum/plasma concentrations of calcium, PTH, highly sensitive C-reactive protein (CRP), interleukin-6 (IL-6), vascular adhesion molecule-1 (VCAM1), E-selectin, and NT-proBNP were measured as well as erythrocyte sedimentation rate (ESR) and creatinine clearance. Cardiac function was evaluated by equilibrium radionuclide angiography. Results: The baseline serum level of IL-6 correlated negatively with baseline parameters of cardiac function (exercise capacity, p < 0.001, left ventricular ejection fraction at exercise, p < 0.01). The mean serum concentrations of IL-6 and CRP and the ESR had increased 1 year after PTX (p < 0.001, p < 0.01, and p < 0.001, respectively) in parallel with a decrease in cardiac function and an increase in circulating NT-proBNP. The mean serum level of VCAM1 was above the upper normal range at baseline and had not changed significantly 1 year after PTX. Conclusion: Patients with mild PHPT and normal renal function displayed signs of subclinical inflammation and endothelial dysfunction. One year after PTX, the inflammatory markers were increased in parallel with a subclinical decrease in cardiac function. Further studies are warranted to clarify the natural course and clinical implications of these changes.