This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fisher, D. A. Articles by Goshi, J. H. Search for Related Content PubMed PubMed Citation Articles by Fisher, D. A. Articles by Goshi, J. H.

The Hypothalamic-Pituitary-Thyroid Negative Feedback Control Axis in Children with Treated Congenital Hypothyroidism

Quest Diagnostics, Inc.-Nichols Institute (D.A.F., J.C.N., E.I.C.), San Juan Capistrano, California 92690-6130; Kaiser Permanente Medical Care Program of Northern California (E.J.S., J.H.G.), Oakland, California 94611; Oregon Health Sciences University Center (S.L.F.), Loma Linda, California 97201-3011; and Kaiser Permanente Northwest (S.H.M.), Beaverton, Oregon 97005

Address correspondence and requests for reprints to: D. A. Fisher, Quest Diagnostics, Inc.-Nichols Institute, 33608 Ortega Highway, San Juan Capistrano, California 92690-6130.

Measurements of serum concentrations of free T₄, T₃, TSH, and thyroglobulin (Tg) were conducted in 42 infants (2–9 months of age) detected and treated through the Northwest Newborn Regional Screening Program and 63 children and adolescents (1–18 yr of age) with congenital hypothyroidism (CH) detected and managed in the Northern California Kaiser Permanente Medical Care Program. Normal feedback control axis data were developed by Quest Diagnostics, Inc. - Nichols Institute Diagnostics and Loma Linda University, from free T₄ and TSH measurements in 589 healthy subjects, 2 months to 54 yr of age; 83 untreated hypothyroid patients; and 116 untreated hyperthyroid patients. Twenty-four of the 42 CH infants and 57 of the 63 CH children manifested serum TSH concentrations appropriate for the measured free T₄ level. In the remaining 18 infants and 6 children, serum free T₄ values were increased 0.2–1.4 ng/dL (2.6–18.0 pmol/L) for the prevailing TSH level, suggesting a state of mild to moderate pituitary-thyroid hormone resistance. In the treated children, the mean T₃ concentration was lower (by 32%, 102 vs. 150 ng/dL; 1.57 vs. 2.31 nmol/L) than in normal children, in agreement with earlier data in hypothyroid adults treated with exogenous T₄. Serum Tg concentrations were normal or elevated in 90% of the 19 children with ectopic glands and 93% of 27 children with eutopic glands in whom measurements were available. There was a positive correlation between serum TSH and Tg concentrations (P < 0.001), suggesting significant endogenous thyroid hormone production in these children. Our results suggest that the majority of infants and children with CH have a normal hypothalamic-pituitary-thyroid negative feedback control axis during treatment and that the measurement of serum TSH is a useful marker complementing the free T₄ measurement in the management of children with CH. A minority have variable pituitary-thyroid hormone resistance, with relatively elevated serum TSH levels for their prevailing serum free T₄ concentration. The prevalence of resistance is greater (43%) in young infants (<1 yr of age) than in older children (10%), indicating that, in most children, the resistance improves with age.

This article has been cited by other articles:

				P. S. Hansen, T. H. Brix, I. Iachine, T. I. A. Sorensen, K. O. Kyvik, and L. Hegedus Genetic and environmental interrelations between measurements of thyroid function in a healthy Danish twin population Am J Physiol Endocrinol Metab, March 1, 2007; 292(3): E765 - E770. [Abstract] [Full Text] [PDF]

				M. J. E. Kempers, A. S. P. van Trotsenburg, D. A. van Tijn, E. Bakker, B. M. Wiedijk, E. Endert, J. J. M. de Vijlder, and T. Vulsma Disturbance of the Fetal Thyroid Hormone State Has Long-Term Consequences for Treatment of Thyroidal and Central Congenital Hypothyroidism J. Clin. Endocrinol. Metab., July 1, 2005; 90(7): 4094 - 4100. [Abstract] [Full Text] [PDF]

				A. S. P. van Trotsenburg, T. Vulsma, S. L. R. van Rozenburg-Marres, A. L. van Baar, J. C. D. Ridder, H. S. A. Heymans, J. G. P. Tijssen, and J. J. M. de Vijlder The Effect of Thyroxine Treatment Started in the Neonatal Period on Development and Growth of Two-Year-Old Down Syndrome Children: A Randomized Clinical Trial J. Clin. Endocrinol. Metab., June 1, 2005; 90(6): 3304 - 3311. [Abstract] [Full Text] [PDF]

				E. J. Schoen, W. Clapp, T. T. To, and B. H. Fireman The Key Role of Newborn Thyroid Scintigraphy With Isotopic Iodide (123I) in Defining and Managing Congenital Hypothyroidism Pediatrics, December 1, 2004; 114(6): e683 - e688. [Abstract] [Full Text] [PDF]

				G. Van Vliet, B. Larroque, L. Bubuteishvili, K. Supernant, and J. Leger Sex-Specific Impact of Congenital Hypothyroidism due to Thyroid Dysgenesis on Skeletal Maturation in Term Newborns J. Clin. Endocrinol. Metab., May 1, 2003; 88(5): 2009 - 2013. [Abstract] [Full Text] [PDF]

				P C Hindmarsh Optimisation of thyroxine dose in congenital hypothyroidism Arch. Dis. Child., February 1, 2002; 86(2): 73 - 75. [Full Text] [PDF]

				O M P JOLOBE Thyroid disorders{---}an update Postgrad. Med. J., February 1, 2001; 77(904): 144 - 144. [Full Text]