July 25, 2003
Tight Control
Question from Warner Robins, Georgia, USA:
I have type 2 diabetes, and while I have always managed to keep my A1c between 5-6%, I’m not sure that’s good enough. The way I see it, patient A’s glucose may only vary from 80-150 mg/dl [4.4-8.3 mmol/L] throughout the day, and patient B’s glucose may vary from 30-200 mg/dl [1.7-11.1 mmol/L]. Although both would have a mean reading of 115 mg/dl [mmol/L], wouldn’t more damage be done because of the greater fluctuations or does it simply not matter?
I ask this question because I have a bad habit of stuffing myself at evening meals, then starving myself the rest of the day. When I get up in the mornings (after 10 hours of fasting) glucose is still around 150 mg/dl [8.3 mmol/L]. Then, I skip breakfast and exercise until I get weak. Only then will I eat something. However, my doctor is pleased because he only sees the A1c reading. If/when he requests a fasting glucose, I simply starve for about 20 hours and exercise hard before having my blood drawn.
Answer:
You pose an interesting question, and there is actually some truth to what you fear. You could conceivably have a normal hemoglobin A1c that represents extremes of highs and lows. The A1c rises with the elevations only, so every time you are low it is not glycosylating (or coating with sugar).
Your health care provider should be considering the A1c and the daily testing to see if they match. In your case, although your A1c is great, I would be concerned about daily highs over time. In other words, the lows would not counteract the highs in terms of risk of complications. My advice to you is to try to find ways to eat less in the evening or at least switch your exercise to after eating too much.
JS
