title: Thyroid Function in Obese Children and Adolescents and Its Association with Anthropometric and Metabolic Parameters.
abstract: Fat accumulation leads to dysfunction of hypothalamic-pituitary-thyroid axis and to changes in thyroid function. A higher serum level of thyroid stimulating hormone (TSH), with normal levels of thyroid hormones, suggesting subclinical hypothyroidism, is often found in obese individuals. The influence on lipid and glucose metabolism of thyroid dysfunction in obese patients remains unclear. This retrospective study encompassed 110 obese children and 38 healthy non-obese children aged 5-18. Anthropometric measurements, including bioelectrical impedance, were taken in all children. Fasting TSH, fT4, glucose, lipid profile, and a glucose tolerance test in case of the obese individuals, were evaluated. The obese children demonstrated a significantly higher mean concentration of TSH compared with their peers with proper body weight: 2.1 ± 1.0 μIU/ml vs. 1.5 ± 0.6 μIU/ml, p = 0.001. The fT4 was not different between the two groups. In the obese children, TSH correlated with body mass index (BMI) and waist circumference after controlling for age and gender. A multivariate regression analysis showed a relationship of TSH with total cholesterol, LDL cholesterol, triglycerides, and non-HDL after adjusting for BMI. None of these relationships were revealed for fT4. The level of TSH correlated with the degree of abdominal obesity. We conclude that the serum TSH concentration, even remaining within the norm, could adversely affect the lipid profile, irrespective of obesity.
authors.affiliation: Department of Pediatrics and Endocrinology, Warsaw Medical University, 63A Żwirki i Wigury St, 02-091, Warsaw, Poland. mruminska@wum.edu.pl.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Rumińska
authors.affiliation: Department of Pediatrics and Endocrinology, Warsaw Medical University, 63A Żwirki i Wigury St, 02-091, Warsaw, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Witkowska-Sędek
authors.affiliation: Department of Pediatrics and Endocrinology, Warsaw Medical University, 63A Żwirki i Wigury St, 02-091, Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Majcher
authors.affiliation: Department of Pediatrics and Endocrinology, Warsaw Medical University, 63A Żwirki i Wigury St, 02-091, Warsaw, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Pyrżak
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood; D008297:Male; D009765:Obesity / Q000503:physiopathology*; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000503:physiopathology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
chemical_list: D008055:Lipids; D013972:Thyrotropin; D013974:Thyroxine
keywords: Body mass index; Children; Cholesterol; Lipid profile; Metabolism; Obesity; Thyroid stimulating hormone