Thyroid disorders are common in first-degree relatives of individuals with type 1 diabetes mellitus

Débora Batista Araujo,Melanie Rodacki,Mario Vaisman,Joana Rodrigues Dantas,Rosangela Prendim Tortora,Natasha Ferreira Teixeira Melleti,Lenita Zajdenverg,Adolpho Milech,Bianca Barone,Marcus Miranda Dos Santos Oliveira,José Egídio Paulo De Oliveira

doi:10.1590/2359-3997000000022

Abstract

Thyroid diseases are common in individuals with type 1 diabetes mellitus (T1DM) and should be investigated annually in these individuals. The aim of this study was to evaluate the frequency of thyroid diseases in first degree relatives (FDR) of patients with T1DM. Eighty individuals (40 patients with T1DM and 40 FDR) were interviewed and blood was sampled for thyroid-stimulating hormone (TSH), free thyroxine (FT4) and thyroid peroxidase (TPO) antibodies measurement. Autoantibodies against glutamic acid decarboxylase 65 (GAD65), islet antigen-2 (IA2) and autoantibodies against insulin (AAI) were measured in FDR. We found a similar prevalence of thyroid dysfunction in patients with T1DM and their FDR (22.5% vs. 27.5%; p = 0,79). There were no differences in serum TSH levels (p = 0.29), FT4 (p = 0,45), frequency of abnormal TSH (p = 0.28), positive TPO antibodies (p = 0.13), titers of TPO antibodies (in positive cases) between patients with T1DM and their FDR (p = 0.94). Thyroid abnormalities seem to be common not only in patients with T1DM but also in their FDR, which suggests that screening strategies for thyroid diseases might also be useful to these individuals.

Highlights

Patients with type 1 diabetes mellitus (T1DM) are at increased risk for other autoimmune disorders, such as autoimmune thyroid disease (ATD), celiac disease and Addison’s disease [1,2,3]
We identified a similar frequency of thyroid dysfunction and autoimmunity in patients with T1DM and their first degree relatives (FDR)
Current guidelines indicate that thyroid disorders should be screened annually in individuals with T1DM based on the high risk of the development of these abnormalities [14,15,16]

Summary

Introduction

Patients with type 1 diabetes mellitus (T1DM) are at increased risk for other autoimmune disorders, such as autoimmune thyroid disease (ATD), celiac disease and Addison’s disease [1,2,3]. Current guidelines recommend that all patients with T1DM should undergo an annual screening for thyroid disease with at least a serum TSH measurement [2,6,7,8]. Previous studies have shown that first degree relatives (FDR) of patients with T1DM have an increased prevalence of thyroid abnormalities than the general population [2,3,9,10,11,12], ranging from 8 to 25% [2,3].

Results

Conclusion