title: Effects of thyrotrophin, thyroid hormones and thyroid antibodies on metabolic parameters in a euthyroid population with obesity.
abstract: OBJECTIVE
  To investigate whether thyroid function in the euthyroid range and thyroid autoimmunity status would affect metabolic measures in individuals with obesity.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  We retrospectively evaluated 5300 consecutive obese (BMI ≥30 kg/m(2) ) subjects attending the Obesity Outpatient Clinic. Subjects with overt or subclinical thyroid disease, diabetes mellitus, chronic disease or using any medication were excluded. After exclusion, 1275 euthyroid [TSH values >0·4 and <4·5 μIU/ml, free triiodothyronine (FT3), free thyroxine (FT4) in the normal reference range] obese subjects (aged 18-65 years) were eligible for the study.
  
  
  METHODS
  The physical and biochemical records of the subjects at first admission to the obesity outpatient clinic were examined.
  
  
  RESULTS
  Eighty-three per cent (n = 1063) of the study population were women. Antithyroid peroxidase (anti-TPO) positivity was 14%, and antithyroglobulin (anti-TG) positivity was 15%. TSH was 1·8 μIU/ml (1·3-2·4) in antibody-negative subjects and 2·1 μIU/ml (1·4-2·9) in antibody-positive subjects. Neither TSH nor thyroid antibody positivity was associated with insulin resistance (IR) and atherogenic dyslipidaemia after adjustment for confounders. FT3 was positively associated with IR (P < 0·001) and atherogenic dyslipidaemia (P = 0·03); however, this association lost its significance after adjustment for age, gender and BMI. FT4 was negatively associated with IR and this association remained even after adjustment for confounders (P < 0·001).
  
  
  CONCLUSIONS
  TSH and thyroid antibody positivity were not related with metabolic measures. Low-normal FT4 had an inverse association with HOMA-IR even after adjustment for confounders.
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Kartal Dr. Lutfi Kirdar Training and Research Hospital, Istanbul, 34890, Turkey. suletemizkan@yahoo.com.
authors.forename: Sule
authors.initials: S
authors.lastname: Temizkan
authors.affiliation: Department of Family Medicine, Kartal Dr. Lutfi Kirdar Training and Research Hospital, Istanbul, 34890, Turkey.
authors.forename: Bilgken
authors.initials: B
authors.lastname: Balaforlou
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Kartal Dr. Lutfi Kirdar Training and Research Hospital, Istanbul, 34890, Turkey.
authors.forename: Aysenur
authors.initials: A
authors.lastname: Ozderya
authors.affiliation: Department of Family Medicine, Kartal Dr. Lutfi Kirdar Training and Research Hospital, Istanbul, 34890, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Avci
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Kartal Dr. Lutfi Kirdar Training and Research Hospital, Istanbul, 34890, Turkey.
authors.forename: Kadriye
authors.initials: K
authors.lastname: Aydin
authors.affiliation: Department of Family Medicine, Kartal Dr. Lutfi Kirdar Training and Research Hospital, Istanbul, 34890, Turkey.
authors.forename: Selin
authors.initials: S
authors.lastname: Karaman
authors.affiliation: Department of Family Medicine, Kartal Dr. Lutfi Kirdar Training and Research Hospital, Istanbul, 34890, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Sargin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism*; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000276:immunology*; D013963:Thyroid Hormones / Q000378:metabolism*; D013972:Thyrotropin / Q000378:metabolism*; D013974:Thyroxine / Q000097:blood; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D013963:Thyroid Hormones; D013972:Thyrotropin; D013974:Thyroxine