Endothelial function and endothelial nitric oxide synthase intron 4a/b polymorphism in primary hyperparathyroidism.
OBJECTIVE
Patients with symptomatic primary hyperparathyroidism (pHT) have increased cardiovascular morbidity and mortality. Endothelial nitric oxide synthase (eNOS) intron 4a/b polymorphism is associated with coronary artery disease and hypertension in various populations. Our aim is to evaluate endothelial function in patients with pHT during pre-operative hypercalcemic and post-operative normocalcemic periods and to determine whether intron 4a/b polymorphism of eNOS gene influences endothelial function.


METHODS
Forty patients with pHT (age 48.48+/-11.64 yr) were examined pre-operatively and reexamined 5.8+/-1.9 months after parathyroidectomy. Forty-three healthy subjects (age 47.13+/-8.14 yr) were served as control group. Endothelial function was determined by flow-mediated dilation of brachial artery (FMD). eNOS4a/b polymorphism was detected by polymerase chain reaction.


RESULTS
FMD was significantly lower in patients pre-operatively compared with controls (8.48+/-1.78% vs 19.49+/-2.34%, p<0.001). FMD improved significantly after parathyroidectomy (16.19+/-2.16%, p<0.001 compared with pre-operative measurements), but was still significantly lower than controls (p<0.001). The distribution of eNOS4a/b genotype frequencies was not significantly different between patients and controls. Logistic regression analysis showed that increased serum calcium (>2.47 mmol/l) and PTH concentrations (>7.75 pmol/l) were significant independent predictors of lower FMD (<16.7%). ENOS4a/b polymorphism did not enter in this model.


CONCLUSIONS
Impaired endothelial function in patients with pHT improves after successful parathyroid surgery. No compelling data are evident to suggest that eNOS4a/b polymorphism modifies the endothelial function in patients with pHT.
Ekmekci
A
A
Department of Medicine, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey.
Abaci
N
N
Colak Ozbey
N
N
Agayev
A
A
Aksakal
N
N
Oflaz
H
H
Erginel-Unaltuna
N
N
Erbil
Y
Y
D000328:Adult; D001916:Brachial Artery / Q000033:anatomy & histology / Q000502:physiology; D002118:Calcium / Q000097:blood; D003324:Coronary Artery Disease / Q000235:genetics / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000201:enzymology / Q000502:physiology; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000235:genetics* / Q000503:physiopathology* / Q000601:surgery; D007438:Introns; D008297:Male; D008875:Middle Aged; D052250:Nitric Oxide Synthase Type III / Q000235:genetics* / Q000378:metabolism; D010281:Parathyroid Hormone / Q000097:blood; D016105:Parathyroidectomy; D011110:Polymorphism, Genetic; D014664:Vasodilation / Q000235:genetics / Q000502:physiology
D010281:Parathyroid Hormone; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D002118:Calcium