A Prospective Study of the Effect of Nonionic Contrast Media on Thyroid Function

Abstract

To observe the effect of iodine in nonionic contrast media on thyroid function, we measured free thyroxine (FT4) and thyroid stimulating hormone (TSH) following nonionic contrast radiography in 73 patients (49 males; 24 females) aged 50 to 84 years, mean 65.7 years. FT4 was significantly (p < 0.01) raised above baseline at 8 weeks but not 4 weeks following contrast injection (mean +/- standard deviation, 17.1 +/- 5.9 and 14.3 +/- 4.0 vs 13.3 +/- 2.7 pmol/L at baseline); however, TSH was significantly (p < 0.03) depressed at both 4 and 8 weeks (1.09 +/- 0.68 and 1.21 +/- 1.56 vs 1.40 +/- 0.90 mIU/L). T3 did not change significantly. FT4 rose by more than 20% in 15/73 and TSH fell by more than 20% in 41/73 compared to a fall of FT4 in 3/73 and a rise in TSH of 8/73 (p < 0.005 and < 0.001, respectively). Two patients became hyperthyroid and in four others either FT4 was elevated or TSH suppressed, one of whom developed atrial fibrillation. Although frank hyperthyroidism following contrast radiography was uncommon, there was a significant trend towards thyroid stimulation rather than suppression after iodine exposure. This may be related to the age of the patients studied.

Thyroid functions after contrast agent administration for coronary angiography: a prospective observational study in euthyroid patients

“…It was seen in that study that T4 level increased, TSH value decreased and no significant change occurred in T3 level. Two of these subjects developed hyperthyroidism and one subject was reported to develop atrial fibrillation (30). Rhee et al (22) report the findings of a nested case-control study examining associations between exposure to iodinated radiologic contrast media and development of incident thyroid dysfunction.…”

“…Subclinical hyperthyroidism poses serious risk of morbidity and potential mortality in the elderly and especially in those with cardiac conditions (30). Cardiovascular effects of subclinical hyperthyroidism include an increase in average heart rate, increased risk of atrial arrhythmias, increased left ventricular mass, and reduced heart rate variability (38).…”

“…Cardiovascular effects of subclinical hyperthyroidism include an increase in average heart rate, increased risk of atrial arrhythmias, increased left ventricular mass, and reduced heart rate variability (38). Thus, it must be kept in the mind that subclinical hyperthyroidism may develop following injection of contrast agent especially in the elderly population (30,39).…”

Thyrotoxicosis in a 13‐year‐old girl following pituitary adenectomy for Cushing′s disease

“…In this case, the first symptoms of thyrotoxicosis developed approximately 2 months after the use of iodinated contrast medium, and according to Conn et al. 16, the contrast may affect the thyroid as long as 8 weeks postinjection. Contrast medium injection does however not affect thyroid function tests (TFT) in patients with a normal thyroid.…”

Examining The Effect of Iodized Contrast Agent of Coronary Heart Angiography in People Without Thyroid Gland Disorders

“…Two patients suffered hyperthyroid and 1 suffered AF. 29 In Iran, two studies have been conducted in this area. The first study was conducted in Shiraz on 48 patients, who underwent coronary angiography with urografin contrast agent.…”