INS and obesity due to melanocortin 4 receptor deficiency: Insulin resistance is defined as a reduced sensitivity to the action of insulin, and a lower glucose uptake and utilization in the liver, being exacerbated by obesity and the intake of dietary fats [4, 5].Homeostasis Model Assessment of insulin resistance(HOMA-IR) is a common efficient way to assess insulin resistance [6], which has been proven to be equally good as the gold standard for measuring insulin resistance.