In conclusion, the current Korean nationally representative population-based study showed that high TSH within the reference range was significantly associated with increases in serum fasting glucose, HbA1c and TG, whereas low FT4 within the reference range was related to increases in serum fasting insulin and an insulin resistance index (HOMA-IR) even after controlling for possible confounders in euthyroid children and adolescents aged 10–18 years. The gene discussed is INS; the disease is Insulin resistance.