Serum Insulin

Function

Insulin is a vital hormone produced by the beta cells of the pancreas. Its primary role is to regulate the amount of glucose (sugar) in the blood. It facilitates the transport of glucose from the bloodstream into the body's cells, where it is used for energy or stored for future use. The Serum Insulin test measures the concentration of this hormone in the blood, usually after a period of fasting.

Why it is Ordered

Doctors order this test to investigate the cause of hypoglycemia (low blood sugar), to monitor insulin production in patients with Type 2 diabetes, and to diagnose insulin resistance. It is often paired with a glucose test to calculate the HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) score.

Associated Conditions

• Insulin Resistance: A condition where the body's cells do not respond effectively to insulin, leading to Metabolic Syndrome and Type 2 Diabetes.
• Insulinoma: A rare, usually benign tumor of the pancreas that secretes excessive insulin, causing severe hypoglycemia.
• Polycystic Ovary Syndrome (PCOS): Often associated with hyperinsulinemia and insulin resistance.
• Type 1 Diabetes: Characterized by very low or absent insulin production due to autoimmune destruction of pancreatic cells.

Monitoring and Health

Tracking insulin levels is crucial for managing metabolic health. High fasting insulin is often an early warning sign of metabolic dysfunction long before blood sugar levels actually rise to diabetic ranges.