Single blood tests rarely provide meaningful information on their own. There are very few places in science—or life, for that matter—where a single piece of data gives a meaningful and certain conclusion. The HgbA1c test is one of those results that needs the other values from your Blood Code Discovery Panel or Progress Panel.
HgbA1c, also known as glycosylated hemoglobin, is a subset of the hemoglobin molecule and a calculation reflects your eight- to twelve-week average blood glucose. It is a calculation that measures a chemical reaction, directly related to glucose concentrations, to hemoglobin (Hgb) in your bloodstream.
- 4.5–5.7% is normal (26–39 mmol/mol)
- < 5.6% is optimal (< 38 mmol/mol)
- 5.8–6.4% indicates significant insulin resistance (40–46 mmol/mol)
- >6.4% indicates diabetes (>46 mmol/mol)
Fasting blood glucose measures your blood sugar only at the moment of the draw; HgbA1C measures the prior eight- to twelve-week average blood sugar. In 1990, most labs reported anything below 6.5% as normal. Now, the top edge of acceptable normal is 5.7% (39 mmol/mol). This lower acceptable limit is due to mounting evidence over the years that nondiabetic individuals with HgbA1C between 5.5% and 6% (37–42 mmol/mol) had significantly greater stroke and cardiovascular disease than those who maintained numbers between 5% and 5.5% (31–37 mmol/mol). Furthermore, as HgbA1C numbers went above 6% (42 mmol/mol), heart disease risk correspondingly increased with each level of elevated average glucose.[i]
But, the lifespan of hemoglobin varies from person to person and the longer the hemoglobin remains in the bloodstream, the higher HgbA1c will go because it is in the presence of glucose for a longer time frame.
How do you know whether you carried your hemoglobin for 12 weeks as opposed to 8? Well, you don’t really. We all accept that this test is batting greater than 90% accuracy but we need to see the result as one piece of the Blood Code for everyone. It does not stand alone.
Look at this blog post for the interpretation guideline from Step Three in The Blood Code. You will notice that one result does not stand alone, The HgbA1c needs to be seen along with fasting glucose, Insulin and HOMA-IR to better grasp your expression of insulin resistance.
[i] Matsushita, K., et al. The association of hemoglobin A1c with incident heart failure among people without diabetes: The Atherosclerosis Risk in Communities Study. Diabetes. 2010; 59:2020–26.