The protocol was approved by the local Helsinki Committee for experiments on Humans and all patients gave informed consent. The exclusion criteria were recent (less than 6 months) myocardial infarction, cerebrovascular event or angiography with stent placement, serious infection in the month before recruitment, any use of contrast media in the last 6 months, loss of more than 5% of body weight during the last 6 months, cardiac arrhythmias, ejection fraction of less than 40%, active malignant diseases, previous thyroid disease and pregnancy.