The changes in CAVI from baseline to after exercise were negatively correlated with changes in TSH (r = - 0.32, p = 0.038) in the subclinical hypothyroidism group.
Mutations in TSH receptor (TSHR) are associated with TSH resistance, a genetic defect characterized by a heterogeneous phenotype ranging from severe hypothyroidism to subclinical hypothyroidism (SCH).
In the present study, a novel TSHR mutation (V87L; confirmed to be a loss-of-function mutation) was identified in a 59-year-old Chinese woman, as the potential cause of the patient's subclinical hypothyroidism.
Loss-of-function mutations in the thyrotropin receptor (TSHR) gene lead to resistance to TSH (RTSH) presenting with either congenital hypothyroidism (CH) or subclinical hypothyroidism (SCH).
Inactivating mutations in the TSHR gene have been demonstrated to be responsible for subclinical hypothyroidism, a disorder characterized by elevated serum TSH concentrations despite normal thyroid hormones levels.
The second one had a neonatal persistent moderate TSH levels increase associated with a thyroid gland hypoplasia and was treated with L-T4 since the first months of life.These two cases support the recent association of TSH-R mutations inheritance as an autosomal dominant pattern with variable expressivity and suggest that the decision to start replacement therapy in patients with persistent SH due to TSH resistance should be individualized.
Overweight/obesity, thyroid hypoechogenicity, and nonsynonymous mutations in the TSH-R gene are characterizing features of a large portion of SH children.
To date, this study demonstrates the highest prevalence (29%) of TSHR gene mutations in children and adolescents with non-autoimmune subclinical hypothyroidism not selected by neonatal screening.
To establish the role of new TSH receptor (TSHr) variants (P27T, E34 K, R46P, D403N, W488R and M527T) recently identified in children with congenital hypothyroidism (CH) or subclinical hypothyroidism (SH) with a thyroid gland of normal size.
In conclusion, our results seem to exclude the role of TSHr or Gs(alpha) gene mutations in the pathogenesis of the non-autoimmune SH observed in some children with DS.
Strain JP26 Chinese hamster ovary (CHO) cells, stable transfected with the human TSH receptor, were incubated with unfractionated plasma (1/10 diluted in hypotonic incubation medium) of 10 DS children with subclinical hypothyroidism and nine euthyroid children with insulin-dependent diabetes mellitus as controls. cAMP released in the incubation medium was measured by RIA.
Median TPO antibody titer was not different between those with and without thyroid IRAEs but was higher in those with overt as compared to subclinical hypothyroidism (5 vs. 0.3 IU/mL, p=0.003) and those prescribed thyroid hormone replacement as compared to observation (5.5 vs. 0.3, p=0.008).
According to the TSH reference range recommended by American Thyroid Association (ATA), the prevalence of subclinical hypothyroidism, subclinical hyperthyroidism, hyperthyroidism, hypothyroxinemia, and thyroid peroxidase antibody-positive were 12.42%, 0.50%, 0.99%, 1.61%, and 11.80%, respectively, prevalence according to the trimester-specific reference range were 1.99%, 0.25%, 1.61%, 0.37%, and 1.61%, respectively, which showed elevated hypothyroxinemia incidence and declined incidence of subclinical hypothyroidism and hyperthyroidism.Trimester-specific reference range varied from that of ATA's recommendation, influencing the diagnosis, and treatment of pregnant thyroid disorders.
The study population included 47 045 pregnant women (mean age, 29 years; median gestational age at blood sampling, 12.9 weeks), of whom 1234 (3.1%) had subclinical hypothyroidism (increased thyrotropin concentration with normal FT4 concentration), 904 (2.2%) had isolated hypothyroxinemia (decreased FT4 concentration with normal thyrotropin concentration), and 3043 (7.5%) were TPO antibody positive; 2357 (5.0%) had a preterm birth.
Twelve infertile women with thyroglobulin antibody (TGAb) and thyroid peroxidase antibody (TPOAb)-negative nongoitrous SH were referred to our department of endocrinology between September 2007 and September 2015.
Currently, there is no consensus on universal thyroid screening and levothyroxine (LT4) treatment of pregnant women with subclinical hypothyroidism (SCH) who are negative forthyroid peroxidase antibody (TPOAb-).
Subclinical hypothyroidism at 12 weeks occurred in up to 60% of class 3 women and was accompanied by elevated thyroid peroxidase antibodies (TPO-Ab) titers (50%) and a parental history of thyroid dysfunction (23%).
The aim of this research was to determine the optimal thyroid-stimulating hormone cut-off point to screen for subclinical hypothyroidism in the first trimester of gestation in a population of our clinical area and to determine the diagnostic value of this screening test for detecting anti-thyroid peroxidase antibodies.