A beneficial levels of 25-hydroxyvitamin D for a decrease in thyrotropin receptor antibody (TRAB) in patients with Graves' disease: a real-world study.

OBJECTIVE

This study aimed to determine whether a relationship exist between pre-therapy 25-hydroxyvitamin D levels and the remission/negative conversion rates of thyrotropin receptor antibody (TRAB) during treatment in patients with newly diagnosed Graves' disease (GD).

METHODS

171 patients were included from the Endocrinology Department of the First Affiliated Hospital of Fujian Medical University in March 2013 to April 2016. Ninety-five patients of them were diagnosed at our hospital but transferred to local hospitals for treatment. Seventy-six patients were followed and treated at our hospital with a median follow-up time of 11.03 (range 6-27) months. Patients were divided into 3 groups according to baseline 25-hydroxyvitamin D levels; <20 ng/mL (31,43.05%), 20-29 ng /mL (20,27.78%), and ≥ 30 ng/mL (20,29.17%). The TRAB remission rate and negative conversion rate was assessed among each group.

RESULTS

There was a higher TSH and lower TRAB titer in the 20-29 ng/mL group at initial diagnosis. Cox regression analysis suggested that 20-29 ng/mL group had significantly higher remission rates [RR; 95% CI: 7.505 (1.401-40.201), 8.975 (2.759-29.196),6.853(2.206-21.285), respectively] and negative conversion rates [RR; 95% CI: 7.835 (1.468-41.804),7.189(1.393-37.092), 8.122(1.621-40.688)] at the 6-, 12-, and 24-month follow-up, respectively . The level of 25-hydroxyvitamin D at the time of initial diagnosis was not associated with the re-normal of free Triiodothyronine(FT3), free thyroxineIndex(FT4) or TSH levels during the follow-up.

CONCLUSION

Newly diagnosed GD patients with appropriate baseline 25-hydroxyvitamin D levels (20-29 ng/mL) are beneficial for the reduction of TRAB during antithyroid therapy.