Prevalence of thyroid dysfunction in patients with diabetes mellitus.
BACKGROUND
Diabetes mellitus (DM) 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 investigate the prevalence of TD in patients with type 1 and type 2 diabetes mellitus (T1DM and T2DM).


METHODS
This is an observational cross-sectional study. Three hundred eighty-six (386) patients with T1DM or T2DM that regularly attended the outpatient clinic of the Diabetes unit, Hospital Universitário Pedro Ernesto, participated in the study. All patients underwent a clinical and laboratory evaluation. Thyroid dysfunction was classified as clinical hypothyroidism (C-Hypo) if TSH > 4.20 μUI/mL and FT4 < 0.93 ng/dL; Subclinical hypothyroidism (SC-Hypo) if TSH > 4.20 μUI/ml and FT4 ranged from 0.93 to 1.7 ng/dL; Subclinical hyperthyroidism (SC-Hyper) if TSH < 0.27 μUI/ml and FT4 in the normal range (0.93 and 1.7 ng/dL) and Clinical hyperthyroidism (C-Hyper) if TSH < 0.27 μUI/ml and FT4 > 1.7 μUI/mL. Autoimmunity were diagnosed when anti-TPO levels were greater than 34 IU/mL. The positive autoimmunity was not considered as a criterion of thyroid dysfunction.


RESULTS
The prevalence of TD in all diabetic patients was 14,7%. In patients who had not or denied prior TD the frequency of TD was 13%. 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%. Forty-four (11.2%) new cases of TD were diagnosed during the clinical evaluation. The forty-nine patients with prior TD, 50% with T1DM and 76% with T2DM were with normal TSH levels.


CONCLUSIONS
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 possible aggravation the classical risk factors such as hypertension and dyslipidemia, arising from an undiagnosed thyroid dysfunction.
Diabetes Unit, State University Hospital of Rio de Janeiro (UERJ), Avenida 28 de setembro, 77, Serviço de Diabetes, Terceiro andar, Vila Isabel, Rio de Janeiro, Brazil. catiasousapalma@gmail.com.
Cátia Cristina Silva Sousa Vergara
CC
Palma
Marco
M
Pavesi
Verônica Guedes
VG
Nogueira
Eliete Leão Silva
EL
Clemente
Maria de Fátima Bevilacqua Motta Pereira
Mde F
Vasconcellos
Luiz Carlos
LC
Pereira
Fernanda Faissol
FF
Pacheco
Tássia Gomide
TG
Braga
Ludmila de Faria
Lde F
Bello
Juliana Oliveira
JO
Soares
Stefanie Cathren Fenizola
SC
Dos Santos
Vinícius Paes Leme Cavalcante
VP
Campos
Marília Brito
MB
Gomes