The spectrum of thyroid disorders in adult type 1 diabetes mellitus.
BACKGROUND
Thyroid disorders such as goiter, nodules, autoimmune thyroid disease and thyroid dysfunction have rarely been investigated in adult type 1 diabetes mellitus. Our aim was to study the spectrum of thyroid disorders in adult type 1 diabetic subjects and compare them with results obtained from a sample of the general adult population.


METHODS
The study population comprised 224 type 1 diabetic and 3481 non-diabetic subjects aged 20-69 years. Thyroid function (TSH, FT3 and FT4) and serum autoantibodies to thyroperoxidase (anti-TPO-Ab) were evaluated from blood samples. Thyroid structure and size were measured by ultrasound.


RESULTS
Type 1 diabetic subjects had a higher risk of known thyroid disease [odds ratio (OR) 1.78, 95% confidence interval (CI) 1.11-2.85], a lower risk of goiter (OR 0.73; 95%-CI 0.54-0.99) and nodules (OR 0.54; 95%-CI 0.35-0.85), and a higher risk of anti-TPO-Ab >200 IU/mL (OR 1.94; 95%-CI 1.28-2.95) compared to the reference population. Furthermore, diabetic subjects had lower serum FT3 levels than the non-diabetic references (adjusted mean 5.00 pmol/L; 95%-CI 4.88-5.12 pmol/L versus 5.27 pmol/L; 95%-CI 5.24-5.30 pmol/L).


CONCLUSIONS
Adult type 1 diabetes mellitus is associated with a decreased risk of goiter and nodules and an increased risk of thyroid autoimmunity. A diabetes-related low T3 syndrome may contribute to the differences in thyroid function between type 1 diabetic and non-diabetic subjects.
Völzke
Henry
H
Institute of Epidemiology and Social Medicine, University of Greifswald, Greifswald, Germany. voelzke@uni-greifswald.de
Krohn
Ulrike
U
Wallaschofski
Henri
H
Lüdemann
Jan
J
John
Ulrich
U
Kerner
Wolfgang
W
D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000032:analysis; D001324:Autoantigens / Q000276:immunology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006042:Goiter / Q000453:epidemiology; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013959:Thyroid Diseases / Q000209:etiology*; D013960:Thyroid Function Tests; D016606:Thyroid Nodule / Q000453:epidemiology; D013972:Thyrotropin / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D001323:Autoantibodies; D001324:Autoantigens; D033862:Iron-Binding Proteins; D014284:Triiodothyronine; D013972:Thyrotropin; C056658:TPO protein, human; D007453:Iodide Peroxidase