In addition, the plasma XOR activity showed correlations with parameters of insulin resistance, such as fasting immunoreactive insulin (IRI) (R = 0.54, P < 0.001), homeostasis model assessment of the index of insulin resistance (HOMA-IR) (R = 0.47, P < 0.001) and urinary C-peptide excretion during the day (R = 0.41, P = 0.01). Here, INS is linked to Insulin resistance.