The aim of this study is to evaluate endothelial function in patients with primary hyperparathyroidism (pHT) during the preoperative hypercalcemic and postoperative normocalcemic periods and to determine whether intron 4a/b polymorphism of eNOS gene influences endothelial function. Forty-one patients with pHT (28 women, 12 men; age: 48.4±11.6 years, serum calcium: 11.4±1.0 mg/dl, parathyroid hormone: 373.3±394.5 pg/ml) who fulfilled the criteria for parathyroid surgery according to 2002 NIH guidelines, were examined preoperatively and reexamined 5.8±1.9 months after parathyroidectomy. All patients were normocalcemic after surgery. Forty-seven healthy subjects (30 women, 17 men, age: 48.03±8.9 years) were served as control group. Early atherosclerotic changes were determined by flow-mediated dilation of brachial artery (FMD). eNOS4a/b polymorphism was detected by polymerase chain reaction. FMD was significantly lower in patients with pHT preoperatively compared with controls (8.48±1.78% vs 19.52±2.26%, P<0.001). FMD improved significantly after parathyroidectomy (16.19±2.16%, P<0.001 compared with preoperative measurements), but still significantly lower than controls (P<0.01). The distribution of eNOS4a/b genotype frequencies were not significantly different between patients and controls. FMD was not significantly different among patients and controls carrying a allele or b/b genotype. Logistic regression analysis showed that presence of hypercalcemia (>10.5 mg/dl) was the only significant independent predictor of lower FMD (<9.4%). eNOS4a/b polymorphism did not enter in this model. Impaired endothelial function in patients with pHT improves after succesfull parathyroid surgery. No compelling data are evident to suggest that eNOS4a/b polymorphism modify the atherosclerotic process in patients with pHT.
03 - 07 May 2008
European Society of Endocrinology