October - December 2007, Volume 3, Issue 4

Trifanescu RA, Fica S, Dimulescu D, Barbu C, Sirbu A, Rotaru M, Florea S, Purice M, Coculescu M

Thyroid hormones and proinflamatory cytokines' profile in amiodarone-induced thyrotoxicosis

Acta Endo (Buc) 2007, 3 (4): 417-436
doi: 10.4183/aeb.2007.417

In this study we aimed to assess amiodarone&#8217;s effects on thyroid hormones, C reactive protein (CRP), interleukin 6 (IL-6) and tumor necrosis factor (TNF-&#945;) profile in amiodarone-induced thyrotoxicosis (AIT) and their relationship with arrhythmias. In 60 patients with AIT (29M/31F), aged 59.7 ? 1.5 years and 105 hyperthyroid patients (25M/80F), aged 59.4 ? 1 years, TSH, total T3, total T4, free T4 were measured by IRMA or microenzymatic immunoassay. In 11 AIT patients and 26 patients with common hyperthyroidism, without significant Graves&#8217; ophthalmopathy, CRP, IL-6 and TNF-&#945; were measured by chemiluminescent immunoassays. AIT patients showed significantly lower T3 levels (273.82 ? 18.76 ng/dL) as compared to common thyrotoxicosis (361.89 ? 13.47 ng/dL), p<0.001, while T4 and FT4 were similar. AIT patients showed similar CRP, IL-6 and TNF-&#945; levels to common hyperthyroidism (10.22 ? 3.03 mg/L vs. 6.31 ? 2.33 mg/L, p=0.11, for CRP, 17.46 ? 13.09 pg/mL vs. 6.46 ? 1.14 pg/mL, p=0.65, for IL-6, and 9.9 ? 1.76 pg/mL vs. 12.85 ? 2.22 pg/mL, p=0.22, for TNF-&#945;, respectively. Patients with arrhythmias (n=19) showed significantly higher CRP, IL-6 and TNF-&#945; levels as compared to patients without arrhythmias (n= 18): 10.81 ? 3.35 mg/L vs. 3.96 ? 1.08 mg/L, p=0.05, for CRP, 15.15 ? 7.52 pg/mL vs. 4.02 ? 0.74 pg/mL, p=0.007 for IL-6, and 15.16 ? 3.33 pg/mL vs. 9.2 ? 0.82 pg/mL, p=0.037 for TNF-&#945;. In conclusion, AIT showed a similar pattern of proinflammatory cytokines to common hyperthyroidism. Increased CRP, IL-6 and TNF-&#945; are found only in patients with thyrotoxicosis associated with atrial fibrillation or other arrhythmias.

Keywords: amiodarone, thyrotoxicosis, proinflammatory cytokines, arrhythmias

Correspondence: Mihail Coculescu, Endocrinology Department, &#8220;Carol Davila&#8221; University of Medicine and Pharmacy, 34-36 Bd. Aviatorilor, 011863, Bucharest, Romania, Phone/Fax: + 4021 3198718, e-mail: m.coculescu@uni-davila.ro