SAT-253 Association between TSH and Cardiovascular Risk Parameters in Obese Children and Adolescents

Introduction: Hyperthyrotropinemia is common in overweight and obese patients and has been hypothesized that high TSH, even within the normal limits, could be associated with an adverse metabolic profile. Objective: Aim of the study was to evaluate the association between TSH and cardiovascular risk parameters in a large group of obese children and adolescents. Patients and Methods: 1402 obese patients (median age 9.7 (2.2-17.8) y, 646 boys) were included in this retrospective analysis. All patients were euthyroid or had mild isolated hyperthyrotropinemia with TSH <10 µU/ml and normal fT4. Waist circumference (WC), systolic and diastolic blood pressure (SP and DP), fasting glycemia, insulin and lipids were measured in all subjects. An Oral Glucose Tolerance Test (OGTT) was also performed (glucose load of 1.75 g/kg of ideal body weight, max 75 g). Insulin resistance was evaluated by Homeostatic Model Assessment (HOMA index, glycemia (mmol/L) x insulin (mU/L) / 22.5). Patients were subdivided into 3 groups according to their TSH level: normal-low TSH (group A, 930 patients, TSH: ≥0,5 - <2.5 µU/ml), normal-high TSH (group B, 432 patients, TSH: ≥2,5 - <4.5µU/ml), mild isolated hyperthyrotropinemia (group C, 40 patients, TSH: ≥4.5 - <10 µU/ml). Results: Median BMI, WC, and fT4 were similar between the 3 groups. The prevalence of patients with high SP, hypertension (high SP and/or DP), and abnormal LDL was higher in patients with hyperthyrotropinemia versus euthyroid patients (p≤0.01), but no differences were found between normal-low and normal-high TSH patients (abnormal SP prevalence: group A 12.6%, group B 14.7%, group C 30.1%; hypertension: group A 14.3%, group B 18.1%, group C 36.1%; abnormal LDL prevalence: group A 14.6%, group B 16.3%, group C 37.5%). Median insulin and HOMA and the prevalence of patients with abnormal HOMA were higher in group C (17 mU/ml, 3,87, and 65%, respectively) than in group A (12.4 mU/ml, 2.64, 39,6%, p≤0.007), and were higher in group B (14 mU/ml, 3,07, 49%, respectively) than in group A (p≤0.001). DP, basal and post-OGTT glycemia, total cholesterol, HDL and triglycerides were not different between the three groups. Conclusions: In our large cohort of obese children and adolescents, increasing TSH was associated with hypertension, insulin resistance and increased LDL, regardless of BMI and fT4 level. These results confirm that TSH, even if in the normal range, could be associated with an adverse metabolic profile. Further studies are needed to define if TSH could be involved in the pathogenesis of cardiovascular diseases in obesity.