title: The Impact of Subclinical Hypothyroidism or Thyroid Autoimmunity on Coronary Vasospasm in Patients without Associated Cardiovascular Risk Factors.
abstract: OBJECTIVE
  Subclinical hypothyroidism is associated with endothelial dysfunction and impaired coronary flow reserve. However, the effect of subclinical hypothyroidism or thyroid autoimmunity on variant angina has yet to be determined.
  
  
  METHODS
  Among 385 consecutive patients without associated cardiovascular risk factors who underwent coronary angiography with the ergonovine provocation test (EPT), 165 had a positive EPT {EPT(+)} and 220 had a negative EPT {EPT(-)}. The relationship between coronary artery spasm and the presence of subclinical thyroid dysfunction as well as serum thyroid peroxidase autoantibody (TPO Ab) was evaluated.
  
  
  RESULTS
  The proportion of patients with subclinical hypothyroidism among those who were EPT(+) was significantly higher than that in those who were EPT(-) (18% vs. 11%, p=0.001). However, there was no significant difference in the proportion of patients with subclinical hyperthyroidism between the groups. Moreover, EPT(+) patients showed significantly more positive TPO Ab (33% vs. 14%, p<0.001) than those with EPT(-). There was a positive correlation between EPT(+) and TPO positivity (r=0.226, p<0.001), subclinical hypothyroidism (r=0.112, p=0.033), and body mass index (r=0.123, p=0.018). Binary logistic regression analysis revealed that the significant predictors of EPT(+) were body mass index {adjusted odds ratio (OR)=1.042, 95% confidence interval (CI)=1.005-1.080}, presence of subclinical hypothyroidism (OR=3.047, 95% CI=1.083-8.572), TPO Ab titer (OR=1.028, 95% CI=1.015-1.041), and the presence of TPO Ab (OR=4.904, 95% CI=1.544-15.567).
  
  
  CONCLUSIONS
  Subclinical hypothyroidism and the presence of TPO Ab are significantly associated with coronary vasospasm in patients without cardiovascular risk factors.
authors: Division of Cardiology, Department of Internal Medicine, Busan Veterans Hospital, Busan, Korea.
authors: Sea-Won
authors: SW
authors: Lee
authors: Division of Cardiology, Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea.
authors: Kyoung-Im
authors: KI
authors: Cho
authors: Division of Cardiology, Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea.
authors: Hyun-Su
authors: HS
authors: Kim
authors: Division of Cardiology, Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea.
authors: Jung-Ho
authors: JH
authors: Heo
authors: Division of Cardiology, Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea.
authors: Tae-Joon
authors: TJ
authors: Cha
keywords: Autoimmunity; Coronary vasopasm; Hypothyroidism