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Risk factors for amiodarone-induced thyroid dysfunction in Japan.
Sayoko Kinoshita1, Tomohiro Hayashi2, Kyoichi Wada1
1Department of Pharmacy, National Cerebral and Cardiovascular Center, 5-7-1, Fujishiro-dai, Suita, Osaka 565-8565, Japan.
Journal of Arrhythmia
|December 7, 2016
Summary
This study investigated amiodarone-induced thyroid dysfunction in Japanese patients. Dilated cardiomyopathy and cardiac sarcoidosis are risk factors for amiodarone-induced hyperthyroidism, while baseline TSH and free T4 levels predict hypothyroidism.
Area of Science:
- Cardiology
- Endocrinology
- Pharmacology
Background:
- Amiodarone is linked to adverse effects like thyroid dysfunction.
- The precise mechanisms of amiodarone-induced thyroid dysfunction are not fully understood.
- This study focused on Japanese patients to determine prevalence and risk factors.
Purpose of the Study:
- To investigate the prevalence of amiodarone-induced thyroid dysfunction.
- To identify risk factors associated with amiodarone-induced hyperthyroidism and hypothyroidism.
- To explore the role of baseline thyroid hormone levels and cardiac conditions.
Main Methods:
- Retrospective analysis of 317 patients treated with amiodarone from January 2012 to December 2013.
- Patients included those with euthyroidism, subclinical hyperthyroidism, or hypothyroidism.
- Statistical analysis to identify predictors of thyroid dysfunction.
Main Results:
- 9.5% developed amiodarone-induced hyperthyroidism, 18.9% developed amiodarone-induced hypothyroidism.
- Dilated cardiomyopathy (DCM) and cardiac sarcoidosis were significant predictors of hyperthyroidism.
- Lower baseline free T4 and higher baseline TSH levels predicted hypothyroidism.
Conclusions:
- DCM and cardiac sarcoidosis are risk factors for amiodarone-induced hyperthyroidism.
- Higher baseline TSH and lower baseline free T4 levels are risk factors for amiodarone-induced hypothyroidism.
- Subclinical hypothyroidism may predispose patients to amiodarone-induced hypothyroidism.
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