Blood sugar

Glucose, the sugar in the blood at the moment of the test. HbA1c, glucose that has attached to red blood cells and built up over the months those cells live. Insulin is the hormone the pancreas releases to move glucose out of the blood and into tissues. HOMA-IR multiplies the two, giving one figure for how much insulin it takes to hold that much glucose.

Sustained exposure to glucose damages the small blood vessels of the eyes, kidneys and nerves over years, and glucose is what diabetes is diagnosed on. The four tests between them show how much glucose is in circulation and how much insulin it takes to keep it down. Glucose and insulin both move with weight and activity.