INS and Insulin resistance: HOMA-IR was used as a valid surrogate indicator of insulin resistance and was calculated according to the equation: Fasting insulin (μU/L) x fasting glucose (nmol/L)/22.5 (39), while HOMA-B was calculated as follows: (20x insulin in mIU/ml)/(glucose in mmol/L – 3.5) and it has been suggested to be an effective indicator of B-cell function (40).