Conversion to hypothyroidism in treatment with I131 * due to hyperthyroidism secondary to severe disease: Hospital de San José, January 2005 - December 2008 Conversión a hipotiroidismo en tratamiento con I131* por hipertiroidismo secundario a enfermedad de graves: Hospital de San José, Enero 2005 - Diciembre 2008

Abstract

Hyperthyroidism has a high prevalence and incidence in Colombia and requires adequate diagnosis and treatment due to the cardiovascular and ophthalmological risks involved. Due to the different results of the conversion time to hypothyroidism after administration of I 131 found in the literature, a retrospective cohort study was performed in patients with Graves' disease who received I 131 in the services of endocrinology, internal medicine and nuclear medicine of the Hospital of San José, from January 2005 to December 2008. The main objective was to establish the median time of conversion to hypothyroidism and the secondary was to determine if age has influence. Ten bibliographical references, fourteen journals and three guide texts were reviewed. The survival analysis was based on Kaplan-Meyer curves using the STATA 10 statistical program; 89 medical records met the inclusion criteria. 76% of patients with Graves' disease managed with I 131 presented conversion to hypothyroidism in the first six months, the rest over the following six months with a peak at nine. The median time was six months. Efficacy is recorded at six months and is a marker of therapeutic efficacy for hypothyroidism due to Graves' disease. When there is no conversion, strict monitoring of patients is recommended in order to choose the appropriate therapy.