Increased plasma levels of thioredoxin in patients with coronary spastic angina

To determine whether plasma levels of thioredoxin are associated with coronary spasm, we measured the plasma levels of thioredoxin in 170 patients who had <25% organic stenosis in coronary arteriography. According to the results of cardiac catheterization, we divided the patients into two groups: a coronary spastic angina group (n = 84) and a chest pain syndrome group (n = 86). The plasma levels of thioredoxin were significantly higher in the coronary spastic angina group than in the chest pain syndrome group (40.7 +/- 4.1 versus 18.2 +/- 1.1 ng/ml, p < 0.0001). Furthermore, the increased plasma levels of thioredoxin were associated with high disease activity indicated by the frequency of angina attacks (p = 0.0004). In multiple logistic regression analysis, the higher levels of thioredoxin [relative risk 14.8, 95 % confidence interval (5.13-42.9), p < 0.0001] and current smoking [relative risk 3.39, 95 % confidence interval (1.31-8.75), p= 0.012] were significant and independent variables associated with coronary spasm. We demonstrated that the plasma levels of thioredoxin were increased in the coronary spastic angina group, and increased levels of thioredoxin were associated with high disease activity. The plasma levels of thioredoxin and current smoking were risk factors for coronary spastic angina, and they were independent from other traditional risk factors.