TY - JOUR
T1 - Disturbance of the fetal thyroid hormone state has long-term consequences for treatment of thyroidal and central congenital hypothyroidism
AU - Kempers, M. J. E.
AU - van Trotsenburg, A. S. P.
AU - van Tijn, D. A.
AU - Bakker, E.
AU - Wiedijk, B. M.
AU - Endert, E.
AU - de Vijlder, J. J. M.
AU - Vulsma, T.
PY - 2005
Y1 - 2005
N2 - Background: During T-4 supplementation of patients with thyroidal (primary) congenital hypothyroidism (CH) TSH concentrations are frequently elevated despite free T-4 (FT4) concentrations being well within the reference range. To examine the thyroid's regulatory system, we analyzed thyroid function determinants in children with congenital and acquired thyroid disorders and in controls. Methods: Retrospectively, plasma FT4, TSH, and T-3 concentrations were analyzed in T-4-supplemented children aged 0.5-20.0 yr with thyroidal CH, central (secondary or tertiary) CH, or autoimmune thyroid disease and in control children with type 1 diabetes mellitus. Results: When TSH was within the reference range (0.4-4.0 mU/liter), mean FT4 in thyroidal CH [1.65 ng/dl; 95% confidence interval (CI), 1.62-1.67] was significantly higher than in autoimmune thyroid disease (1.15 ng/dl; 95% CI, 1.11-1.19) and diabetes (1.08 ng/dl; 95% CI, 1.06-1.10). In central CH, when TSH was less than or equal to 0.02 mU/liter, mean FT4 was 1.27 ng/dl (95% CI, 1.24-1.29). When FT4 was within the reference range (0.78-1.79 ng/dl), 43% of the TSH measurements in thyroidal CH were more than 4.0 mU/liter, compared with 18% in autoimmune thyroid disease and 0% in type 1 diabetes mellitus; in central CH, 95% of TSH measurements were less than 0.4 mU/liter. Conclusions: In T-4-supplemented patients with thyroidal CH, when TSH concentrations are established within the reference range, FT4 concentrations tend to be elevated, and vice versa. Because this phenomenon could not be observed in acquired thyroidal hypothyroidism, we hypothesize that a pre- and/or perinatal hypothyroid state shifts the setpoint of the thyroid's regulatory system. In central CH, when FT4 concentrations are established within the reference range, the pituitary secretes only minute amounts of TSH. For monitoring T-4 supplementation, reference ranges for FT4 and TSH should be adapted to the etiology of hypothyroidism
AB - Background: During T-4 supplementation of patients with thyroidal (primary) congenital hypothyroidism (CH) TSH concentrations are frequently elevated despite free T-4 (FT4) concentrations being well within the reference range. To examine the thyroid's regulatory system, we analyzed thyroid function determinants in children with congenital and acquired thyroid disorders and in controls. Methods: Retrospectively, plasma FT4, TSH, and T-3 concentrations were analyzed in T-4-supplemented children aged 0.5-20.0 yr with thyroidal CH, central (secondary or tertiary) CH, or autoimmune thyroid disease and in control children with type 1 diabetes mellitus. Results: When TSH was within the reference range (0.4-4.0 mU/liter), mean FT4 in thyroidal CH [1.65 ng/dl; 95% confidence interval (CI), 1.62-1.67] was significantly higher than in autoimmune thyroid disease (1.15 ng/dl; 95% CI, 1.11-1.19) and diabetes (1.08 ng/dl; 95% CI, 1.06-1.10). In central CH, when TSH was less than or equal to 0.02 mU/liter, mean FT4 was 1.27 ng/dl (95% CI, 1.24-1.29). When FT4 was within the reference range (0.78-1.79 ng/dl), 43% of the TSH measurements in thyroidal CH were more than 4.0 mU/liter, compared with 18% in autoimmune thyroid disease and 0% in type 1 diabetes mellitus; in central CH, 95% of TSH measurements were less than 0.4 mU/liter. Conclusions: In T-4-supplemented patients with thyroidal CH, when TSH concentrations are established within the reference range, FT4 concentrations tend to be elevated, and vice versa. Because this phenomenon could not be observed in acquired thyroidal hypothyroidism, we hypothesize that a pre- and/or perinatal hypothyroid state shifts the setpoint of the thyroid's regulatory system. In central CH, when FT4 concentrations are established within the reference range, the pituitary secretes only minute amounts of TSH. For monitoring T-4 supplementation, reference ranges for FT4 and TSH should be adapted to the etiology of hypothyroidism
U2 - https://doi.org/10.1210/jc.2005-0197
DO - https://doi.org/10.1210/jc.2005-0197
M3 - Article
C2 - 15827096
SN - 0021-972X
VL - 90
SP - 4094
EP - 4100
JO - Journal of clinical endocrinology and metabolism
JF - Journal of clinical endocrinology and metabolism
IS - 7
ER -