Endocrine Abstracts

Purpose: The hormonal thyroid changes related to obesity, even when in the euthyroid state, may contribute to the unfavorable cardio-metabolic profile of obese patients. In this retrospective study we aim to investigate the biochemical thyroid changes and the association between serum TSH, FT4, FT3 and cardio-metabolic risk factors in euthyroid obese youths.

Methods: Four hundred ninety-one Caucasian euthyroid obese children and adolescents aged 9.93±2.90 years were recruited. Each patient underwent clinical and auxological examination and laboratory workup including an OGTT and the measurement of thyroid function and lipid profile. Homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride to high density lipoprotein cholesterol ratio, total cholesterol to HDL ratio, atherogenic index of plasma, insulinogenic index, area under the glucose and insulin curve were calculated.

Results: We found that TSH was positively correlated with BMI-SD values, increasing FT3 levels was associated with increasing degree of obesity whereas FT4 levels resulted negatively associated with BMI-SD values. TSH values were associated with increasing LDL levels. A significant association between serum TSH, hypercholesterolemia and hyperinsulinemia was found. In addition, FT4 level resulted negatively correlated with fasting plasma glucose and FT3 levels positively correlated with the area under the curve of insulin and negatively correlated with HDL levels.

Conclusions: Taken together, our data showed that thyroid hormones influence obesity, lipid and glycemic parameters in euthyroid youths. These findings could carry implications regarding optimal TSH levels in obese children and confirm the importance of evaluating the thyroid function as possible adjunctive cardio-metabolic risk factor related to obesity.