Compared to patients without IR, the IR group was characterized by significantly higher BMI values and more frequent occurrence of obesity and significantly higher fasting glucose and insulin concentrations, as well as more common IFG, lower median SHBG levels (30.8 vs. 49.1 nmol/L; p < 0.001), and a more frequent occurrence of SHBG concentration below laboratory's lower limit of the normal range for women aged 18–50 years (<26.1 nmol/L). The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.