Geographic variations in the frequency of thyroid disorders and thyroid peroxidase antibodies in persons without former thyroid disease within Germany.
OBJECTIVE
To investigate regional variations in the frequency of undiagnosed thyroid disorders among 25- to 88-year-old men and women in two communities in the northeast and the south of Germany. In addition, autoantibodies to thyroperoxidase (TPO-Abs) and urinary iodine excretion were determined.


METHODS
Two population-based surveys of men and women using a common standardized protocol, the Study of Health in Pomerania (SHIP) in the northeast of Germany (2505 participants) and the Kooperative Gesundheitsforschung in der Region Augsburg (KORA) in the south of Germany (2316 participants), were compared with regard to the frequency of undiagnosed thyroid disorders.


RESULTS
Compared with the northeast of Germany, urinary iodine excretion and serum thyroid-stimulating hormone (TSH) levels were significantly higher in the south. The median urinary iodine concentration was 110 μg/l (64; 169 μg/l) in SHIP and 151 μg/l (97; 214 μg/l) in KORA, and the median TSH value was 0.81 mIU/l (0.56; 1.15 mIU/l) in SHIP and 1.22 mIU/l (0.84; 1.80 mIU/l) in KORA. The frequency of elevated TSH (TSH ≥ 2.12 mIU/l) was 4.3% in SHIP and 14.1% in KORA (P<0.001); the corresponding values for suppressed TSH (<0.25 mIU/l) were 3.5 and 1.7% (P<0.001). The proportion of ultrasonographic findings was 55.5% in SHIP and 68.0% in KORA. The frequency of serum TPO-Abs did not differ significantly between northeast and south Germany.


CONCLUSIONS
There were considerable regional disparities in the frequency of thyroid disorders within Germany. These differences can be explained not only by different regional histories of natural iodine deficiency but also by current differences in the iodine supply under an identical nationwide iodine fortification program.
Helmholtz Zentrum München, Institute of Epidemiology II, German Research Center for Environmental Health (GmbH), Neuherberg, Germany. christa.meisinger@helmholtz-muenchen.de
C
C
Meisinger
T
T
Ittermann
H
H
Wallaschofski
M
M
Heier
H
H
Below
A
A
Kramer
A
A
Döring
M
M
Nauck
H
H
Völzke
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000096:biosynthesis*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods; D013959:Thyroid Diseases / Q000201:enzymology* / Q000453:epidemiology / Q000276:immunology*
D001323:Autoantibodies; D007453:Iodide Peroxidase