Prevalence of thyroid disease, thyroid dysfunction and thyroid peroxidase antibodies in a large, unselected population. The Health Study of Nord-Trondelag (HUNT).
OBJECTIVE
To examine the prevalence of thyroid disease and dysfunction including thyroid autoimmunity in Norway.


METHODS
All inhabitants 20 years and older (94009) in Nord-Trondelag were invited to participate in a health survey with a questionnaire and blood samples.


RESULTS
The prevalence of former diagnosed hyperthyroidism was 2.5% in females and 0.6% in males, hypothyroidism 4.8% and 0.9%, and goitre 2.9% and 0.4% respectively. In both sexes the prevalence increased with age. In individuals without a history of thyroid disease the median, 2.5 and 97.5 percentiles for TSH (mU/l) were 1.80 and 0.49-5.70 for females and 1. 50 and 0.56-4.60 for males. The TSH values increased with age. When excluding individuals with positive thyroid peroxidase antibodies (TPOAb) (>200U/ml), the 97.5 percentiles dropped to 3.60 mU/l and 3. 40 mU/l respectively. The prevalence of pathological TSH values in females and males were TSH >/=10mU/l 0.90% and 0.37%; TSH 4.1-9. 9mU/l 5.1% and 3.7%; and TSH</=0.05mU/l 0.45% and 0.20% respectively. The prevalence of positive TPOAb (>200U/ml) was 13.9% in females and 2.8% in males. In females the lowest percentage (7.9%) of positive TPOAb was seen with TSH 0.2-1.9mU/l and increased both with lower and higher levels of TSH. The percentage of males with positive TPOAb was lower than in females in all TSH groups except for those with TSH>10mU/l (85% TPOAb positive).


CONCLUSIONS
In spite of a high prevalence of recognised thyroid disease in the population a considerable number of inhabitants have undiagnosed thyroid dysfunction and also positive TPOAb.
Bjoro
T
T
Hormone Laboratory, Aker University Hospital, Oslo, Norway. trine.bjoro@ioks.uio.no
Holmen
J
J
Krüger
O
O
Midthjell
K
K
Hunstad
K
K
Schreiner
T
T
Sandnes
L
L
Brochmann
H
H
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000032:analysis*; D005260:Female; D006042:Goiter / Q000453:epidemiology; D006801:Humans; D006980:Hyperthyroidism / Q000453:epidemiology; D007037:Hypothyroidism / Q000453:epidemiology; D007453:Iodide Peroxidase / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D012737:Sex Factors; D011795:Surveys and Questionnaires; D013959:Thyroid Diseases / Q000453:epidemiology* / Q000276:immunology*; D013960:Thyroid Function Tests; D013972:Thyrotropin / Q000097:blood
D001323:Autoantibodies; D013972:Thyrotropin; D007453:Iodide Peroxidase