Intima-media Thickness Measurement of the Carotid Artery in Patients with Primary Hyperparathyroidism. A Prospective Case-control Study and Long-term Follow-up

Abstract

Background: The intima-media thickness (IMT) measurement of the common carotid artery is recognized as a reliable marker of systemic atherosclerosis and may be useful in predicting the likelihood of cardiovascular events, since it is related to the extent and severity of coronary artery disease. The aims of this study were to analyze whether correlations exist between the IMT of the common carotid artery and the main clinical and biochemical parameters in patients with primary hyperparathyroidism (PHPT), and to evaluate the possible improvement of the IMT values following parathyroidectomy at long-term follow-up. Patients and Methods: Twenty-seven patients (5 men, 22 women; median age 59 years, range 36-82 years) with biochemically confirmed PHPT (Group A, cases), and 27 gender- and age-matched healthy volunteers (Group B, controls) were prospectively enrolled in the study. All patients underwent ultrasound examination and the IMT of each carotid artery were recorded, averaging all values. The measurements were repeated 18-22 months (median 20) later in all patients. Results: A significant (p<0.05) correlation between age and both systolic BP and IMT, and between IMT and fasting glycaemia was found in each Group. There was an inverse relationship between IMT and serum parathyroid hormone (R=-0.56, p<0.01), but no correlation (p=NS) was found between IMT and serum calcium (R=-0.14) or serum phosphate (R=0.07). At follow-up a slight (10.4%) improvement in the mean IMT was observed among Group A patients (0.86±0.18 vs. 0.77±0.24; p=0.12), but the difference was not significant. Conclusion: At long term follow-up, the IMT values did not improve significantly and no correlation was found between serum calcium and IMT. These results suggest that hypercalcemia does not represent a reliable risk of carotid atherosclerosis in patients with PHPT.