Lipid Metabolism Abnormalities in Obese Children and Adolescents with Subclinical Hypothyroidism

Introduction: Subclinical hypothyroidism (SH); is a condition in which serum free T4 (fT4) levels are within normal limits and thyroid stimulating hormone (TSH) levels are above age-related levels. In obesity, serum TSH levels increase with the increase in body mass index; Thus, the frequency of SH is reported to be high in obese patients. Hypothyroidism and obesity are the main causes of secondary dyslipidemia. In this study; in overweight / obese children and adolescents; the frequency of SH and its relationship with lipid metabolism abnormalities were investigated. Materials and Methods: The clinical findings and laboratory results of 291 overweight/obese children and adolescents (169 girls, 122 boys) were evaluated retrospectively. Lipid and lipoprotein levels of the patients were compared according to the reference values according to age and gender and were recorded as low, normal and high. Patients with normal serum fT4 levels and TSH levels: 4.5-10 mIU / ml and not receiving sodium L-throxin treatment comprised the SH group (n = 53), and patients with normal serum T4 and TSH levels constituted the control group (n = 238). These two groups were compared in terms of lipid metabolism abnormalities. Results: The frequency of SH in the whole study group was 18.2%. When compared with reference values according to age; in the whole study group and as well as in both the groups with and without SH were found borderline high levels of median total cholesterol and LDL-C levels, high median TG levels and normal-high median HDL-C levels. Median TG/HDL-C levels were>2 in these three groups. In the SH group compared to the group without SH; serum total cholesterol levels, the frequency of hypertriglyceridemia and TG / HDL-C ratio>2 were higher (p<0.05). Serum TSH levels were positively correlated with TG (r = 0,13, p<0,05). Conclusions: There is a high frequency of SH in obese children and adolescents. It was understood that obese patients had dyslipidemia and this situation became more pronounced in the presence of SH and SH contributed to the development of atherogenic lipid profile. These findings made us think that weight loss of obese patients can also improve both SH and lipid metabolism abnormalities.