Effects of thyrotrophin, thyroid hormones and thyroid antibodies on metabolic parameters in a euthyroid population with obesity. (26th May 2016)

• Record Type: Journal Article
• Authors: Temizkan, Sule; Balaforlou, Bilgken; Ozderya, Aysenur; Avci, Mehmet; Aydin, Kadriye; Karaman, Selin; Sargin, Mehmet
• Is Part Of: Clinical endocrinology. Volume 85:Number 4(2016)
• Page Start: 616
• Page End: 623
• Publication Date: 2016-05-26
• Subjects: Endocrinology -- Periodicals; 616.4005
• DOI: 10.1111/cen.13095
• Languages: English
• ISSNs: 0300-0664

Abstract

Summary: Objective: To investigate whether thyroid function in the euthyroid range and thyroid autoimmunity status would affect metabolic measures in individuals with obesity. Design: Cross‐sectional. Patients: 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. Measurements: 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). Conclusion: 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.