Jonathan's fasting glucose: 85 mg/dl
His HbA1c: 6.7%
Jonathan's high HbA1c reflects blood glucose fluctuations over the preceding 60-90 days and can be used to calculate an estimated average glucose (eAG) with the following equation:
eAG = 28.7 X A1c – 46.7
(For glucose in mmol/L, the equation is eAG = 1.59 × A1C - 2.59)
Jonathan's HbA1c therefore equates to an eAG of 145.59 mg/dl--yet his fasting glucose value is 85 mg/dl.
This is a common situation: Normal fasting glucose, high HbA1c. It comes from high postprandial glucose values, high values after meals.
It suggests that, despite having normal glucose while fasting, Jonathan experiences high postprandial glucose values after many or most of his meals. After a breakfast of oatmeal, for instance, he likely has a blood glucose of 150 mg/dl or greater. After breakfast cereal, blood glucose likely exceeds 180 mg/dl. With two slices of whole wheat bread, glucose likewise likely runs 150-180 mg/dl.
The best measure of all is a postprandial glucose one hour after the completion of a meal, a measure you can easily obtain yourself with a home glucose meter. Second best: fasting glucose with HbA1c.
Gain control over this phenomenon and you 1) reduce fasting blood sugar, 2) reduce expression of small LDL particles, and 3) lose weight.