Thyroid function tests in children with congenital hypothyroidism on L-thyroxine treatment.
The plasma levels of thyroxine (T4), triiodothyronine (T3), free T4 (FT4), free T3 (FT3), reverse T3 (rT3) and immunoradiometrically assayed thyrotropin (IRMA TSH) have been measured in 28 L-T4-treated children with congenital hypothyroidism as well as in a control group (group C). The patients were subdivided into 2 groups according to the nonsuppressed (group A) or suppressed (group B) TSH response to TSH-releasing hormone (TRH). Basal IRMA TSH correlated with the TSH increment after TRH and it was significantly lower in group B vs. groups A and C, while no difference was present between groups A and B in regard to T4, FT4 and rT3, all higher than in group C. FT3 levels were similar in the 3 groups. In children, as in adults, basal IRMA TSH seems to be a reliable index in monitoring overtreatment.
Volta
C
C
Department of Pediatrics, University of Parma, Italy.
Ghizzoni
L
L
Davoli
A
A
D'Amato
L
L
Panza
C
C
Bernasconi
S
S
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003409:Congenital Hypothyroidism; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D011863:Radioimmunoassay; D013960:Thyroid Function Tests; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood / Q000627:therapeutic use*; D014284:Triiodothyronine / Q000097:blood; D014285:Triiodothyronine, Reverse / Q000097:blood
D014284:Triiodothyronine; D014285:Triiodothyronine, Reverse; D013972:Thyrotropin; D013974:Thyroxine