Objective: To determine whether coronary artery calcification (CAC) is increased in patients with primary hyperparathyroidism (pHPT) because of the presence of hypercalcemia, which has been shown in vitro to promote vascular calcification.
Methods: Electron beam computed tomography of the coronary arteries was performed on 20 patients with pHPT referred to our endocrinology clinic for evaluation of hypercalcemia. All patients were nonsmokers, with normal renal function, no history of diabetes, and no history of coronary artery disease. CAC in the patients with pHPT was compared with that in population-based control subjects from the Multi-Ethnic Study of Atherosclerosis (MESA). Two methods of analysis were used: (1) calculation of the odds ratio of CAC and (2) a nested case-control (1:4) study.
Results: One patient with pHPT had a history of nephrolithiasis; the other 19 patients were asymptomatic. The mean age (+/- SD) of the patients with pHPT was 57.3 +/- 9.1 years, the mean serum calcium concentration was 2.68 +/- 0.18 mmol/L, and the mean intact parathyroid hormone level was 119 +/- 76.5 pg/mL. Of the 20 patients, 14 had CAC scores of zero. The odds ratio for measurable CAC in the presence of pHPT in comparison with that in the MESA control subjects was 0.17, which was not significant. In the matched analysis, the CAC scores for the patients with pHPT did not differ significantly from those for the MESA control subjects (P = 0.25 with use of the Wilcoxon test).
Conclusion: We found no evidence for a difference in CAC in patients with pHPT in comparison with the population-based control subjects in this small pilot study.