Introduction: Hyperthyrotropinemia is common in patients with obesity and has been hypothesized that high TSH could be associated with an adverse metabolic profile. Few studies have been performed in pediatric population and the results are controversial.
Objective: Aim of the study was to evaluate the association between TSH and metabolic syndrome (MS) in a large group of obese children and adolescents.
Patients and Methods: 1402 obese patients (median age 9.7 (2.2-17.8) years, 646 Male) were included in this retrospective analysis. All patients were euthyroid or affected by mild isolated hyperthyrotropinemia with TSH between 4.5-10 µU/ml and normal fT4. Waist circumference, blood pressure, fasting glycemia, insulin and lipids were measured in all subjects. MS was defined according to the IDEFICS criteria in 2-10 years patients and IDF criteria in patients ≥10 years. Homeostatic Model Assessment (HOMA index, glycemia(mmol/L) x insulin (mU/L)/22.5) was calculated as insulin resistance index. 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: The overall prevalence of mild isolated hyperthyrotropinemia was 2.9%.
Median BMI, WC, and fT4 were similar among the 3 groups. The prevalence of MS was higher in patients with hyperthyrotropinemia versus euthyroid patients (p≤0.01), but no difference was found between normal-low and normal-high TSH patients (group A 10.4%, group B 11.6%, group C 25%). Among the components of MS, the prevalence of hypertension was higher in patients with hyperthyrotropinemia versus euthyroid patients (p≤0.01), but no difference was found between normal-low and normal-high TSH patients (group A 14.3%, group B 18.1%, group C 36.1%). The prevalence of patients with abnormal HOMA was higher even in normal-high versus normal-low TSH patients (P<0.001, group A 39,6%, group B 49%, group C 65%).
The results were similar when the 742 patients of 2-10 years were separately analysed.
Conclusions: In our large cohort of obese children and adolescents, high TSH was associated with higher prevalence of MS, regardless of their body status and fT4 levels. These results confirm the correlation between TSH and the metabolic profile, even in children <10 years. Further studies are needed to define if TSH could be involved in the pathogenesis of cardiovascular complications in obesity.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology