Effect of daily zinc supplementation for 12weeks on serum thyroid auto-antibody levels in children and adolescents with autoimmune thyroiditis- a randomized controlled trial.

Abstract

To assess the effect of daily zinc supplementation for 12weeks on thyroid auto-antibodies- thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb), and oxidative stress in children with autoimmune thyroid disease (AITD) compared to standard therapy. This open-labeled, parallel, randomized controlled trial was done in a tertiary care teaching institute in south India. Children aged 3-18 years with AITD were randomized to receive 25 mg elemental zinc daily for 12weeks or standard therapy alone. The change in thyroid function tests (thyroid stimulating hormone, free T3, free T4), thyroid auto-antibody (TPOAb, TgAb) titers, oxidative stress markers (glutathione peroxidase, malondialdehyde, superoxide dismutase, and total antioxidant capacity) were compared. Forty children, 20 in each arm, were recruited in the study. We observed a female-to-male ratio of 7:1. Median duration of disease was 2 (0.25, 4.25) years. A total of 37 (92.5 %) children were hypothyroid, two hyperthyroid, and one euthyroid at enrolment. A total of 13 children (32.5 %) had associated co-morbidities, most commonly type 1 diabetes mellitus and systemic lupus erythematosus, three(7.5 %) each. We did not find any significant change inthyroid function tests, thyroid auto-antibody titers, andoxidative stress markers. However, the requirement of levothyroxine dose was significantly increased in the control arm, compared to the zinc group (p=0.03). Only four (20 %) children had minor adverse effects like nausea, metallic taste, and body ache. Zinc supplementation did not have any effecton thyroid auto-antibodies and oxidative stress. Zinc-supplemented children did not require escalation in levothyroxine dose.