On the one hand, a low concentration of testosterone is connected to hyperinsulinemia and insulin resistance in men, and testosterone replacement therapy improves the insulin sensitivity in hypogonadal men [52,53]; on the other hand, in women, androgen excess is correlated with insulin resistance, and free testosterone level in adolescent girls was suggested as a risk factor of metabolic syndrome development [54]. The gene discussed is INS; the disease is hyperinsulinism.