title: Abnormalities of thyroid function and glucose control in subjects with Rett syndrome.
abstract: We have identified subtle abnormalities of thyroid function and glucose control in patients with Rett syndrome. The mean serum total thyroxine (T4) concentration was significantly lower in a group of subjects with Rett syndrome (6.9 +/- 1.5 microgram/dl, n = 34; p < 0.001) than the adult reference range (8.5 +/- 1.75 microgram/dl, n = 200). This differences remained significant even for the 17 subjects not taking anticonvulsants (7.6 +/- 1.5 microgram/dl; p < 0.05 vs. adult reference). The difference was more marked when compared to age-adjusted normals, with 10 subjects having a serum total T4 concentration below normal for age including 3 of 17 of the subjects not taking anticonvulsants. This decrease in serum total T4 concentration was not due to changes in binding proteins as measured by 3,5,3'-triiodothyronine resin uptake, and was associated with a decreased concentration of thyroid-stimulating hormone (1.7 +/- 1.6 mU/l, n = 23 vs. 2.5 +/- 1.0 mU/l, n = 200; p < 0.01). Oral glucose tolerance tests were performed in 10 of the subjects with Rett syndrome. They had a delay in the peak glucose and insulin concentrations. Glucose levels were elevated at 1 and 2 hours (p < 0.05), and insulin levels were elevated at 1, 2, and 3 hours (p < 0.05). Two subjects fulfilled criteria for impaired glucose tolerance.
authors.affiliation: Department of Pediatrics, Johns Hopkins University Baltimore, Md., 21287-3311 USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Cooke
authors.forename: S
authors.initials: S
authors.lastname: Naidu
authors.forename: L
authors.initials: L
authors.lastname: Plotnick
authors.forename: G D
authors.initials: GD
authors.lastname: Berkovitz
mesh_terms: D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D001786:Blood Glucose / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D005951:Glucose Tolerance Test; D006801:Humans; D007223:Infant; D015518:Rett Syndrome / Q000503:physiopathology*; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000503:physiopathology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
chemical_list: D000927:Anticonvulsants; D001786:Blood Glucose; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine