Insulin Resistance Among Children and Adolescents with Subclinical Hypothyroidism: A Case-Control Study

Background: Subclinical hypothyroidism (SCH) is marked by elevated thyroid-stimulating hormone (TSH) levels while maintaining normal thyroxine levels. Although the link between insulin resistance (IR) and overt hypothyroidism is well-established, less is known about this relationship in children and adolescents with SCH.Objectives: This study aimed to explore the association between insulin resistance and SCH in individuals aged 4 to 18 years. Methods: In this case-control study, 30 patients with SCH aged 4 - 18 from the Endocrinology Clinic at Imam Reza Hospital, Shiraz, Iran, were chosen as the case group through convenient sampling. Additionally, 30 healthy children and adolescents from the same clinic were randomly selected as controls. Exclusion criteria included positive Anti-TPO, goiter, previous thyroid disease, systemic diseases, chronic or acute diseases, diabetes, and a BMI ≥ 85%. Levels of TSH, insulin, fasting blood sugar (FBS), triglycerides, cholesterol, low-density lipoprotein, and high-density lipoprotein were compared between the groups. Data were analyzed using SPSS 25. Results: The study found that levels of FBS, insulin, and Homeostatic Model Assessment for IR (HOMA-IR) were significantly higher in the SCH group than in the control group. There was a significant correlation between TSH levels and both insulin levels and IR in the SCH group. Subclinical hypothyroidism was found to significantly increase the risk of developing IR among pediatric patients compared to healthy controls. Conclusions: Overall, our findings indicate a positive correlation between TSH levels and IR in children with SCH. Additionally, HOMA-IR levels were significantly higher with elevated TSH in the SCH group compared to healthy children. It is recommended that IR be evaluated and treated timely in SCH patients to prevent future complications.