Establishment of a serum thyroid stimulating hormone (TSH) reference interval in healthy adults. The importance of environmental factors, including thyroid antibodies.
It has previously been shown that thyroid antibodies affect thyroid stimulating hormone (TSH) concentrations in men and women and that TSH levels are predictive of future thyroid disease. We investigated the validity of the National Academy of Clinical Biochemistry (NACB) guidelines regarding the TSH reference interval by studying 1512 individuals. Two hundred and fifty had at least one thyroid antibody, 121 were taking medications other than estrogens and occasional analgesics, and 105 reported a family history of thyroid disease. Serum TSH, thyroid peroxidase antibodies (TPOab) and thyroglobulin antibodies (Tgab) were determined on AutoDELFIA and TSHRab by a radioreceptor assay (RRA) from Brahms Diagnostica. For individuals without thyroid antibodies and other risk factors, no effect of age and gender was seen for serum TSH. Neither medication nor the presence of Tgab alone had any influence on serum TSH. TPOab alone or in combination with Tgab were associated with an increased serum TSH level. The 'cumulative percentage distributions' of subgroups, as well as the combined population, was In-Gaussian distributed. The central 95% of the population was within the 95% CI in rankit-plots. Consequently, a common reference interval for serum TSH of 0.58-4.07 mlU/l for all adults between 17 and 66 years of age was established. This reference interval is much higher than expected from the NACB-guidelines.
Department of Clinical Biochemistry, Odense University Hospital, Odense, Denmark. Esther.Jensen@ouh.fyns-amt.dk
Esther
E
Jensen
Per
P
Hyltoft Petersen
Ole
O
Blaabjerg
Pia Skov
PS
Hansen
Thomas H
TH
Brix
Kirsten Ohm
KO
Kyvik
Laszlo
L
Hegedüs
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D005192:Family Health; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D008297:Male; D008875:Middle Aged; D016011:Normal Distribution; D012016:Reference Values; D012307:Risk Factors; D012737:Sex Factors; D013954:Thyroglobulin / Q000276:immunology; D013959:Thyroid Diseases / Q000097:blood; D013972:Thyrotropin / Q000097:blood / Q000276:immunology / Q000592:standards*
D001323:Autoantibodies; D013972:Thyrotropin; D013954:Thyroglobulin; D007453:Iodide Peroxidase