Because you're measuring two different things, like an apple and an orange - HbA1c is the average level of blood sugar (glucose) over the past 2 to 3 months. Insulin (I'm assuming fasting insulin) measures, well, insulin.Torimintz wrote:I am confused at how my insulin can be lower than my a1C
Unlike glucose, as Mike said, insulin is a hormone. Insulin does many things, among which it helps glucose as a fuel to get into the cells where needed. When there's too much glucose, more insulin is produced to store/shove the glucose (as fat) into fat cells and then where ever it can find a spot. If the insulin finds storage spots for the extra glucose/fat, blood glucose levels can be said to be "normal" even though the body is pumping out insulin, is stressed out, and inflamed with fat overfiling the fat cells and spilling over into places it shouldn't be like in the abdomen, organs, and muscles. When exposed to too much glucose, the body pumps out more and more insulin to control the glucose even though the glucose measurements are "normal" (but the person is insulin resistant). If this continues, the body finally cries "uncle" and insulin production becomes dysfunctional in the body and that's the extreme end of insulin resistance - Type 2 diabetes, although other chronic diseases develop from insulin resistance without T2 diabetes developing, for example Alzheimer's is colloquially referred to as Type 3 Diabetes.
Another way to measure insulin resistance is with HOMA-IR (Homeostatic Model Assessment of Insulin Resistance). That can be calculated by taking the fasting glucose (not A1c, fasting glucose is a snapshot in time, the A1c is an average over 2-3 months, more like a movie) times fasting insulin divided by 405. (FG x FI/405). Desired range is 1.0 or lower. Over 2.5 is insulin resistance.
I should note fasting insulin is not a very static number, if your fasting insulin tests at 4, 15 minutes later it might go down to 1 or up to a higher number. So take a fasting insulin number as a general guide, not an exact figure. Nevertheless, 4 is a very good fasting insulin measure.
Many of these terms/concepts are discussed in the wiki: Insulin Resistance and Blood Sugar