Prevalence of amiodarone-induced hypothyroidism; A systematic review and meta-analysis

Amiodarone is a common anti-arrhythmic agent mostly used to treat and prevent different kinds of arrhythmia with several considerable side effects, most commonly on the thyroid gland. We aimed to assess the frequency of hypothyroidism among chronic amiodarone users. PubMed/Medline, Web of Science, and Scopus databases were screened in the title and abstract sections with no time limitation. Relevant published records reported amiodarone-induced hypothyroidism (AIH) among patients with normal thyroid function at baseline were recruited with further analysis according to gender and study locations. We found 29 records on 14143 individuals. Total population age ranged from 18 to 92 years (males: 58.2% (8158 out of 13,999)). The AIH prevalence was found to be 14% (95% confidence interval (CI): 12-17%). Further gender stratified showed an insignificant higher AIH frequency in females versus males (17%, 95% CI: 13-22% vs. 14%, 95% CI: 11-19% P= 0.304, respectively). Despite no significant difference in AIH prevalence according to different continents, African subjects had marginally lower AIH frequency compared to Asian (7%, 95% CI: 4-13% vs. 15%, 95% CI: 12-19%, P= 0.012) and South American persons (7%, 95% CI: 4-13% vs. 54%, 95% CI: 9-93%, P= 0.038). This review suggests the occurrence of AIH is quite considerable regardless of gender and area of residence, and several periodic thyroid assessment strategies should be developed for earlier recognition and therapeutic interventions in clinical settings.