The association between hypoechogenicity or irregular echo pattern at thyroid ultrasonography and thyroid function in the general population.
OBJECTIVE
Patients with overt hypothyroidism show decreased echogenicity of the thyroid at ultrasonography (US). The aim of this study was to investigate the association between echogenicity of the thyroid/irregular echo pattern, and thyroid function in the general population, i.e. subjects without overt thyroid disease.


METHODS
A cross-sectional investigation of 4649 randomly selected adult subjects.


METHODS
Blood samples were analysed for serum TSH, thyroid hormones and thyroid autoantibodies. US of the thyroid was performed.


RESULTS
Participants with decreased echogenicity (n=379) had a higher mean TSH (1.65 mU/l) compared with subjects with normal echogenicity (1.21 mU/l, P<0.0001). The association was stronger in subjects with markedly decreased echogenicity (4.20 mU/l, P<0.0001). A similar association was seen when the subjects were divided into subgroups according to the level of TSH; more subjects with high levels of TSH had decreased echogenicity (P<0.0001). Likewise, more subjects with high levels of TSH had an irregular echo pattern (P<0.0001). Subjects with decreased echogenicity had a higher risk of having thyroid autoantibodies than subjects without decreased echogenicity (P<0.0001). This association was stronger when echogenicity was markedly decreased.


CONCLUSIONS
We demonstrated an association between hypoechogenicity at thyroid US and higher levels of serum TSH even in subjects without overt thyroid disease, suggesting decreased echogenicity as an early sign of thyroid dysfunction. Irregular echo pattern, whether accompanied by hypoechogenicity or not, was another possible marker of thyroid failure. This indicates a possible use of thyroid US in detecting early and subclinical thyroid dysfunction.
Vejbjerg
Pernille
P
Department of Internal Medicine I, Bispebjerg Hospital, University of Copenhagen, Bispebjerg Bakke 23, 2400 Copenhagen NV, Denmark. pervej01@glostruphosp.kbhamt.dk
Knudsen
Nils
N
Perrild
Hans
H
Laurberg
Peter
P
Pedersen
Inge Bülow
IB
Rasmussen
Lone B
LB
Ovesen
Lars
L
Jørgensen
Torben
T
D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D001324:Autoantigens / Q000276:immunology; D003430:Cross-Sectional Studies; D003718:Denmark; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000000981:diagnostic imaging; D007037:Hypothyroidism / Q000000981:diagnostic imaging; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D013959:Thyroid Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000502:physiology*; D013972:Thyrotropin / Q000097:blood; D014463:Ultrasonography
D001323:Autoantibodies; D001324:Autoantigens; D033862:Iron-Binding Proteins; D013972:Thyrotropin; C056658:TPO protein, human; D007453:Iodide Peroxidase