Study of the thyroid dysfunction prevalence in patients with diabetes mellitus treated in ambulatory diabetes of the Hospital Universitário Pedro Ernesto

O diabetes mellitus(DM) e as disfunções tireoidianas(DT) são as duas desordens endocrinológicas mais comuns na prática clínica. A DT não reconhecida pode interferir no controle metabólico e adicionar mais risco a um cenário predisponente à doença cardiovascular. O objetivo deste estudo foi avaliar a prevalência da DT em pacientes com diabetes mellitus tipo 1 e tipo 2 (DM1 e DM2) e avaliar o risco cardiovascular em pacientes com DM2 com e sem DT utilizando parâmetros clínicos e laboratoriais. Trata-se de um estudo observacional de corte transversal. Foram avaliados 304 pacientes com DM2 e 82 pacientes com DM1. Os pacientes foram submetidos a um inquérito clínico-demográfico e avaliação laboratorial para determinação do perfil lipídico, glicídico e da função tireoidiana. Os pacientes com DM2 tiveram seus escores de risco cardiovascular em 10 anos determinados pelas equações de Framingham e do UKPDS risk engine. A frequência de disfunção tireoidiana entre os 386 pacientes foi de 14,7%, sendo de 13% nos que não possuíam disfunção prévia. A disfunção mais frequente encontrada foi de hipotireoidismo subclínico, com 13% no DM1 e de 12% no DM2. A prevalência de anticorpos anti-tireoperoxidase (TPO) positivos foi de 10,8%, sendo de14,6% em pacientes com DM1.Foram diagnosticados 44 (11,2%) novos casos de disfunção tireoidiana em pacientes que negavam ou desconheciam terem DT prévia.Destes novos casos, 12,8% em DM1 e 13,1% em DM2.Dos 49 pacientes com DT prévia, 50% dos DM1e 76% dos DM2 estavam compensados. Não foi observada diferença entre as médias do escore de risco de Framingham entre os pacientes DM2 com eutireoidismo e com hipotireoidismo subclínico. Observou-se uma associação entre o hipotireoidismo subclínico e risco cardiovascular nos pacientes com DM2 demonstrado pela diferença estatisticamente significativa entre as médias do escore UKPDS para doença coronariana não-fatal e fatal, acidente vascular cerebral fatal entre os dois grupos (p=0,007; 0,005;0,027 respectivamente). As demais funções tireodianas (hipotireoidismo clínico, hipertireoidismo clínico e subclínico) encontradas não foram analisadas devido ao pequeno número de pacientes em cada grupo.Concluímos que o rastreio da doença tireoidiana entre os pacientes com diabetes mellitus deve ser realizado rotineiramente considerando-se a prevalência de novos casos de DT diagnosticados e o fato de que os pacientes com DM2 e com hipotireoidismo subclínico avaliados possuírem um risco cardiovascular maior. Todavia, concluímos que estudos prospectivos e com maior número de pacientes são necessários para o esclarecimento do impacto da doença tireoidiana no risco cardiovascular do paciente com DM.Diabetes mellitus and thyroid dysfunction (TD) are the two most common endocrine disorders in clinical practice. The unrecognized TD may adversely affect the metabolic control and add more risk to an already predisposing scenario for cardiovascular diseases. The objective of this study was to evaluate the prevalence of TD in patients with type 1 and type 2 diabetes mellitus (T1DM and T2DM) and to evaluate the cardiovascular risk of patients with T2DM with and without thyroid dysfunction using clinical and laboratory parameters. This is an observational cross-sectional study. We evaluated 304 patients with T2DM and 82 patients with T1DM. The patients underwent a clinical-demographic survey and laboratory evaluation to determine the lipid and glycemic profile and thyroid function. Patients with T2DM had their 10 years cardiovascular risk scores determined by Framingham equations and the UKPDS risk engine. The frequency of TD among the 386 patients was 14.7% and 13% who denied previous TD. The most frequently TD was subclinical hypothyroidism, in 13% of patients with T1DM and in 12% of patients with T2DM.The prevalence of anti-TPO antibodies was 10.8%, being more frequently among patients with T1DM (14.6%). Forty-four (11.2%) new cases of TD were diagnosed during the study in patients who denied or were unaware of this clinical condition. Of the 49 patients with prior TD,50% of the T1DM and 76% of T2DM were compensated. No differencies were observed between the mean scores of the Framingham risk among patients with T2DM who had normal thyroid function compared to those with subclinical hypothyroidism. An association between subclinical hypothyroidism and cardiovascular risk in T2DM patients was found by statistically significant difference between the mean UKPDS scores for non-fatal and fatal CHD and fatal stroke between the two groups (p = 0,007;0,005;0027; respectively). The other TD (clinical hypothyroidism, clinical and subclinical hyperthyroidism) found were not analyzed due to the small number of patients in each group.We conclude that screening for thyroid disease among patients with diabetes mellitus should be routinely performed considering the prevalence of new cases diagnosed and the fact that patients with DM2 and subclinical hypothyroidism evaluated had a higher cardiovascular risk. However, prospective studies and with more patients are warranted to determine the impact of thyroid dysfunction in the cardiovascular risk of patients with diabetes