Correlation of circulating interleukin-10 with thyroid hormone in acute myocardial infarction

In patients with acute myocardial infarction (AMI), euthyroid sick syndrome (ESS) has been reported to be linked to increase in interleukin (IL)-6 and activation of its receptors. Recent reports have shown that IL-10, an anti-inflammatory cytokine, also plays a key role in the pathogenesis of AMI. Therefore we investigated the relationship between thyroid state and IL-10 in patients with AMI. We measured thyrotropin (TSH), free triiodothyronine (FT3), free thyroxine (FT4), IL-10, and IL-6 in plasma from 20 patients with AMI and 20 healthy controls. All 20 AMI patients showed significantly lower concentrations of FT3 than in controls accompanied by normal or subnormal levels of TSH, characterized ESS. Concentrations of IL- 10 and IL-6 were higher in patients than in controls. Both IL-10 and IL-6 significantly (p<0.05, respectively) correlated with thyroid hormone in patients with AMI. Time course of IL-10, IL-6, and FT3 seemed to be tightly linking. In conclusion, IL-10 and IL-6 appears to affect thyroid hormone homeostasis in patients with AMI.