Abusive use of thyroid hormones by athletes: A literature review

Abstract

The thyroid hormones thyroxine and triiodothyronine regulate the individual's basal metabolism. It is common among athletes to abuse thyroid hormones to promote muscle hypertrophy, aiming at better performance in physical exercise and improving body appearance. This study aims to evaluate the abuse of thyroid hormones by physical exercise practitioners, as well as the cardiovascular, metabolic and bone impact, in addition to the mortality rate associated with this use. A narrative review of the literature was conducted. The search focused on articles with a higher degree of evidence, such as systematic reviews and meta-analyses. In addition, books and guidelines from Brazilian medical societies that address the subject were used. Priority was given to the use of literature published between 2000 and 2023. Several reports of serious consequences linked to the misuse of these hormones were found, mainly cases of ventricular fibrillation causing sudden death, in addition to tachycardia, atrial fibrillation and other arrhythmias. A decrease in bone mineral density was also observed, resulting in a higher risk of osteoporosis and fractures, suppression of normal thyroid function, episodes of amenorrhea and sexual dysfunction, and a significant increase in the risk of serious complications, including thyroid storm and sudden death due to cardiovascular causes. The negative impact of the abusive use of thyroid hormones is notable; however, studies with a quantitative meta-analysis are needed to reach better conclusions.