title: Frequency of isolated maternal hypothyroxinemia in women with gestational diabetes mellitus in a moderately iodine-deficient area.
abstract: OBJECTIVE
  To investigate frequency of isolated maternal hypothyroxinemia (IMH) in women with gestational diabetes mellitus (GDM) using both the method specific trimester range (MSTR) and the standard reference range (SRR).
  
  
  METHODS
  Our study included 50 GDM patients (case group) and 60 non-GDM pregnant (control group). Glucose, insulin, HOMA-IR, fT4 and TSH values were measured when pregnancy was confirmed in all participants. Thyroid function tests were measured in each trimester using the SRR and the MSTR.
  
  
  RESULTS
  In the second and third trimesters, mean fT4 levels were significantly lower in the case group compared to the control group, based on the SRR (p < 0.001). Mean fT4 levels were within the normal reference range in both groups, based on the MSTR; however, the levels were significantly lower in the case group (p < 0.001). Using the SRR, IMH frequencies in the second and third trimesters, in the case group were 56 and 86%, respectively, and were 13.3 and 46.7%, respectively, in the control group (p < 0.001). Using the MSTR, the IMH frequencies in the second and third trimesters were 8 and 14%, respectively; there were no instances of IMH in the control group.
  
  
  CONCLUSIONS
  This study shows that changes in glucose metabolism may affect the thyroid hormone levels (fT4). Additionally, evaluating thyroid function tests in GDM patients using the MSTR can give more accurate results.
authors.affiliation: a Department of Endocrinology and Metabolism, Faculty of Medicine , Kahramanmaras Sutcu Imam University , Kahramanmaras , Turkey .
authors.forename: Ayten
authors.initials: A
authors.lastname: Oguz
authors.affiliation: a Department of Endocrinology and Metabolism, Faculty of Medicine , Kahramanmaras Sutcu Imam University , Kahramanmaras , Turkey .
authors.forename: Dilek
authors.initials: D
authors.lastname: Tuzun
authors.affiliation: a Department of Endocrinology and Metabolism, Faculty of Medicine , Kahramanmaras Sutcu Imam University , Kahramanmaras , Turkey .
authors.forename: Murat
authors.initials: M
authors.lastname: Sahin
authors.affiliation: b Clinic of Endocrinology and Metabolic Diseases, Dr. Ersin Arslan State Hospital , Gaziantep , Turkey .
authors.forename: Alper Celil
authors.initials: AC
authors.lastname: Usluogullari
authors.affiliation: c Clinic of Obstetrics and Gynecology, Cengiz Gokcek Obstetrics and Children's Hospital , Gaziantep , Turkey , and.
authors.forename: Betül
authors.initials: B
authors.lastname: Usluogullari
authors.affiliation: d Department of Biochemistry, Faculty of Medicine , Kahramanmaras Sutcu Imam University , Kahramanmaras , Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Celik
authors.affiliation: a Department of Endocrinology and Metabolism, Faculty of Medicine , Kahramanmaras Sutcu Imam University , Kahramanmaras , Turkey .
authors.forename: Kamile
authors.initials: K
authors.lastname: Gul
mesh_terms: D000328:Adult; D001786:Blood Glucose; D016640:Diabetes, Gestational / Q000097:blood / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000453:epidemiology* / Q000503:physiopathology; D015994:Incidence; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D007455:Iodine / Q000172:deficiency*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000503:physiopathology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood*; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin; D013972:Thyrotropin; D007455:Iodine; D013974:Thyroxine
keywords: Gestational diabetes mellitus; isolated maternal hypothyroxinemia; thyroid peroxidase antibody