[Recurrence of Graves-Basedow disease: the influence of treatment schedule]

Abstract

Background: The aim of the present study was to evaluate the possible influence of 2 different methods of treatment (antithyroid drugs and antithyroid drugs plus levothyroxine) on the number of recurrences in Graves' disease, as well as to study the possible prognostic factors for the evolution of the disease.

Methods: Seventy-six patients allocated in to 2 treatment groups were studied. Group A included those patients treated with decreasing doses of carbimazole and group B included patients treated with high doses of carbimazole plus levothyroxine. The follow-up of these patients was carried out over a minimum of 36 months after discontinuation of treatment.

Results: No significant differences were observed in either the clinical characteristics or hormonal or antibody values in both groups on initiation and at the end of treatment. The percentage of recurrence in group A patients during the first 12 months of follow-up was significantly greater (65% vs 23%, p < 0.001) than in group B. The percentage of recurrence equalled (62.8% vs 60.7%, p = NS) on prolongation of follow-up of up to 36 months. Recurrence was not correlated with either the clinical or biochemical parameters evaluated, although it did correlate with goiter size with recurrence observed in 100% of the patients with goiter greater than or equal to II.

Conclusion: The association of levothyroxine to treatment with carbimazole in Graves' disease delays the appearance of recurrence but does not significantly decrease it in comparison with the treatment with carbimazole in decreasing doses. Only the size of goiter on initiation of treatment may be a prognostic factor for disease evolution.