Thyroid dysfunction with the continued use of beta interferon in the treatment of multiple sclerosis

Abstract

Introduction: The treatment of multiple sclerosis (MS) with beta interferon has been shown to be effective in reducing the number of relapses and the inflammatory activity of the disease, as well as slowing its progression. Although there are controversies in the literature, recent studies have pointed to the possibility of thyroid dysfunction as a side effect of prolonged use of beta interferon. Objectives: To analyze the presence of thyroid dysfunction due to the use of beta-interferon in patients with multiple sclerosis. Methods: That is a documentary, observational, and analytical study, with a quantitative, retrospective, and cross-sectional approach. Sociodemographic variables, thyroid function laboratory tests, and medication usage time present in medical records were analyzed. Results: From 118 medical records evaluated, after applying the exclusion and inclusion criteria, 35 were included in the study. 80% of the sample were female, mean age was 32.43. The mean values for TSH and free T4 before starting treatment with beta-interferon were 1.66 mIU/L and 0.96 ng/dL, respectively. After 6 months, the values for TSH and free T4 were 2.20 mIU/L and 0.91 ng/dL, respectively. It can be concluded that the continuous use of beta-interferon did not lead to significant changes in TSH and free T4 levels compared to baseline (P = 0.061 and P = 0.102, respectively). It is worth noting that there were two cases of subclinical hypothyroidism developed during the study. Conclusion: MS patients using beta-interferon are mostly young women. No significant changes in their thyroid function were observed. Therefore, based on this information, the need for routine periodic laboratory tests to evaluate thyroid function in patients using beta-interferon is questioned. Further studies are needed with a larger sample size to definitively clarify this topic.