Quality of life, clinical outcomes and safety of early prophylactic levothyroxine administration in patients with Graves' hyperthyroidism undergoing radioiodine therapy: a randomized controlled study

Abstract

Objective

While radioiodine therapy is commonly used for treating Graves' disease, a prolonged and clinical hypothyroidism may result in disabling symptoms leading to deterioration of quality of life (QoL) of patients. Introducing levothyroxine (LT ₄) treatment in the early post-therapeutic period may be an interesting approach to limit this phenomenon.

Methods

A multicenter, prospective, open-label randomized controlled trial enrolled 94 patients with Graves' hyperthyroidism randomly assigned to the experimental group ( n=46) (group A: early prophylactic LT ₄ treatment) or the control group ( n=48) (group B: standard follow-up). The primary endpoint was the 6-month QoL. The secondary endpoints were other QoL scores such as Graves' ophthalmopathy (GO) outcomes, thyroid function tests and safety.

Results

The primary endpoint at 6 months was achieved: the mental composite score (MCS) of Short Form 36 (SF-36) was significantly higher in group A compared to group B ( P=0.009). Four other dimension scores of the SF-36 and four dimension scores of the thyroid-specific patient-reported outcome (ThyPRO) significantly differed between the two groups, indicating better QoL in group A. After adjustment for variables, the early LT ₄ administration strategy was found as an independent factor for only two scores of SF-36: the MCS and the general health (GH) score. There were no differences in GO, final thyroid status and changes in the anti-TSH receptor antibodies (TRAbs) levels between the two groups. No adverse cardiovascular event was reported.

Conclusion

Early LT ₄ administration post-radioactive iodine (RAI) could represent a safe potential benefit for patients with regard to QoL. The optimal strategy taking into account administered RAI activities and LT ₄ treatment dosage and timing remains to be determined.