Relationship of Etiology to Treatment in Congenital Hypothyroidism

Abstract

We examined the patterns of TSH, T(4), and treatment schedules from diagnosis to 4 yr of age in 125 children (50 males anf 75 females) with congenital hypothyroidism (CH). Subjects were divided into 3 groups based on their thyroid scans: 1) athyreosis (n = 31), 2) dysgenesis (n = 54; 49 lingual and 5 hypoplastic), and 3) dyshormonogenesis (n = 40). Follow-up evaluation was carried out at 2-4 wk and 3, 6, 9, 12, 24, 36, and 48 months of age. Median gestational age, age at onset of therapy, and starting L-T(4) dose were similar in the three groups. In infants with athyreosis median screening TSH levels were higher (P < 0.02) and confirmatory T(4) levels were lower than in the other two groups (P < 0.01 vs. dysgenetic; P < 0.05 vs. dyshormonogenetic CH). During the first 6 months of therapy, mean TSH levels were highest in the athyrotic group, intermediate in the dysgenetic group, and lowest in the dyshormonogenetic group. In children with athyreosis, TSH levels normalized by 12 months of age. At 12 months dysgenetic patients had the highest TSH levels (P < 0.05). During the entire study period, TSH levels were lowest in patients with dyshormonogenesis (except at 48 months) and normalized earlier. Mean T(4) levels normalized by 2-4 weeks in all groups. At 3 and 6 months, the percentage of patients who required dose changes was highest in the athyrotic group, and at 12 months it was highest in the dysgenetic group. The athyrotic group received the highest dose of L-T(4), and dyshormonogenetic group received the lowest dose. We conclude that treatment and follow-up schedules for CH may differ in the three etiological categories based on the different hormonal patterns and responses to therapy. Children with athyreosis need close monitoring particularly early in life, whereas those with dysgenesis and dyshormonogenesis require more attention later in life.

Head circumference and linear growth during the first 3 years in treated congenital hypothyroidism in relation to aetiology and initial biochemical severity

“…Our distribution of the different aetiologies of CH was comparable with previous studies (Grant et al ., 1992; Hanakoglu et al ., 2001; Hrytsiuk et al ., 2002). Although all our patients underwent Tc‐pertechnate radionuclide scans prior to treatment, not all patients had an ultrasound scan confirmed when an iodide uptake defect was detected.…”

“…The use of radionuclide thyroid scans have enabled identification of aetiology of CH (Hanukoglu et al ., 2001; Song et al ., 2001). In studies where aetiology of CH was determined, those with athyreosis were found to have the least favourable outcome (Song et al ., 2001).…”

Dynamics of the plasma concentrations of TSH, FT4 and T3 following thyroxine supplementation in congenital hypothyroidism

“…Although in the management of hypothyroidism the plasma TSH concentration is considered a useful determinant, elevated plasma TSH concentrations are frequently encountered in the course of CH treatment (Working Group on Neonatal Screening of the ESPE, 1999; Fisher et al ., 2000; Hanukoglu et al ., 2001). To investigate which thyroid hormone determinants are most suitable to determine the achievement of euthyroidism, a retrospective analysis was made in a group of 30 CH patients with a well‐defined aetiology and in whom the plasma concentrations of TSH, free T4 (FT4), total T4 (T4) and total T3 (T3) had been measured frequently before and after initiation of T4 supplementation.…”

Congenital Hypothyroidism

“…[34] We found that in the first few years of life, children with athyreosis required more dose changes and closer monitoring than did those with the other etiologies, while children with ectopic glands showed elevated TSH values and needed dosage increases at both the end of the first and fourth years of life. [34] We found that in the first few years of life, children with athyreosis required more dose changes and closer monitoring than did those with the other etiologies, while children with ectopic glands showed elevated TSH values and needed dosage increases at both the end of the first and fourth years of life.…”