PON1 and Insulin resistance: Moreover, the activity level of PON1 in T2DM inversely correlates with the duration of the disease and with metabolic parameters such as plasma glucose concentration, glycated hemoglobin (HbA1c) and homeostatic model assessment of insulin resistance, which is a method for assessing β-cell function and insulin resistance based on fasting glucose and insulin or C-peptide concentrations [16,17].