title: Significance of elevated serum thyrotropin during treatment of congenital hypothyroidism.
abstract: Serum thyrotropin concentrations are frequently elevated during treatment of children with congenital hypothyroidism. It is unclear if elevated thyrotropin during early treatment indicates non-optimal treatment. In a cohort of 49 children with congenital hypothyroidism, we studied the decline in serum thyrotropin concentration after initiating L-thyroxine treatment, the relationship between elevated thyrotropin and treatment variables, and non-compliance with the treatment as a possible cause of elevated thyrotropin. The initial mean dose of thyroxine was 8.5 (SD 3.3) micrograms/kg body weight/day: 71% of the serum samples obtained 15-21 days after the start of treatment had serum thyrotropin concentrations < 10 mU/l. Six children had no samples with serum thyrotropin < 10 mU/l during the first 3 months of treatment. These children had a lower thyroxine dose prescribed, and serum thyrotropin was normalized when the dose was sufficiently increased. During treatment, from 6 weeks of age, serum thyrotropin > 10 mU/l was related to a lower dose of thyroxine and lower serum thyroxine, and was not due to non-compliance with treatment.
authors.affiliation: Department of Pediatrics, Rikshospitalet, Oslo, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Heyerdahl
authors.forename: B F
authors.initials: BF
authors.lastname: Kase
mesh_terms: D015331:Cohort Studies; D003409:Congenital Hypothyroidism; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000188:drug therapy; D007231:Infant, Newborn; D008297:Male; D010349:Patient Compliance; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use
chemical_list: D013972:Thyrotropin; D013974:Thyroxine