The HOMA-IR (Hotline-Assessed Insulin Resistance Rating Scale) is a mathematical index derived from two values: fasting plasma glucose (FPG) and fasting plasma insulin. It is calculated using the formula: (Fasting glucose (mg/dL) × Fasting insulin (µU/mL)) / 405. This index reflects the degree of insulin resistance in the liver and peripheral tissues. The higher the HOMA-IR value, the greater the cellular resistance to insulin, meaning the body needs to produce more insulin to maintain normal blood sugar levels.