Abstract
Introduction: Thyroid dysfunction is observed in a number of patients with multiple sclerosis (MS) before or after starting treatment. Considering the high prevalence of autoimmune thyroid diseases in general population, the cause-and-effect relationship of MS or the treatments in patients with thyroid problems is doubtful. Present research was designed to clarify the issue in a geographical location that has not been investigated so far and to find whether the occurrence of thyroid disease is an early phenomenon or not?
Methods: Descriptive-analytical study was performed on 324 patients with MS in Tabriz, Iran. The participants were selected based on the inclusion/exclusion criteria through convenience sampling from patients referred to the neurology clinics of Tabriz university of medical sciences. Thyroid function tests were performed for the patients to diagnose thyroid problems. In these patients, the relationship between laboratory test results and the medications used for the treatment and control of MS was obtained using inferential statistical tests. P-value<0.05 was considered statistically significant.
Results: FT3 and FT4 levels consistently increased, except for interferon beta 1b. Changes in thyroid-stimulating hormone (TSH) levels were reduced for fingolimod and interferon beta 1a, while they increased for other treatments. The decrease in levels of anti-thyroglobulin and anti-thyroid peroxidase after treatments was found to be non-significant.
Conclusion: Significant changes in thyroid function may occur following pharmacotherapy of MS, at least for fingolimod and interferon beta 1a. It is recommended to periodically perform thyroid function tests before and after starting treatment.