In 2006, when I was diagnosed with prediabetes, I wasn’t overweight, and I had a hemoglobin A1c score of five percent, squarely in the middle of the nondiabetic range of four percent to six percent. This test measures the glucose attached to red blood cells. These cells stay in your body for three months or so, making the A1c a running average of your blood-sugar levels. If your score is high, then your blood sugar frequently has been elevated during that timeframe. As a test of glucose control, many doctors and experts herald the A1c as nearly infallible, precisely because it isn’t a one-off number like a random or even fasted glucose test.
This made my prediabetes condition difficult to diagnose, though. In my case—and in the cases of many others, I fear—the A1c included many very high and very low scores which, when averaged, created an illusion of normalcy. My blood sugar would often spike to a level well into prediabetes after I consumed a lot carbohydrates, especially simple sugars; and then crash after my pancreas secreted too much insulin. I only realized this after taking what’s called a glucose tolerance test, where the doctor or nurse gives you 75 grams of pure sugar to drink, after which your blood glucose and insulin levels are measured at various intervals over the next few hours.
The rollercoaster of a condition and its name, reactive hypoglycemia, aren’t new. In fact, they’ve both been around for many decades, falling in and out of fashion, as strange as that sounds. Debate has swirled around both the prevalence of the condition and the harm it causes. I’ve seen it described as both “the most common health problem in the country” and as a “rare condition.” Some doctors argue that it’s a quixotic but ultimately harmless blood-sugar pattern unrelated to diabetes. Others say it reflects a diabetic or prediabetic condition, depending on how high the spike goes.
Typical of the confusion and contradictions is a web page on reactive hypoglycemia published by the McKinley Health Center of the University of Illinois at Urbana-Champaign. It states that reactive hypoglycemia occurs in two to three out of every 10 young women. It goes on to say, “Reactive hypoglycemia does not lead to more severe conditions.” Except a score of 140 or higher on a glucose tolerance test is used to diagnose prediabetes, while 200 or higher marks full-on diabetes. (Results must be duplicated on a different day for an official diagnosis to be made.) It’s puzzling, then, that some say reactive hypoglycemia doesn’t lead to serious health problems when the blood sugar curves it produces are diagnostic of a disease, one that’s both chronic and progressive.
Where diabetes is concerned, the effects of the environment, nutrition and exercise upon the body are incredibly fluid and complex. Static snapshots tell only a fraction of the story. Even an average, like the A1c, misses much of the dynamic. Volatility—the moves between extreme highs and lows—is the unexplored frontier of blood sugar and diabetes. We won’t have a full grasp of the diabetes epidemic, and the role reactive hypoglycemia plays in it, until we place more emphasis on how, why and at what speed blood glucose levels move, rather than simply recording where they wind up and what the long-term average is. I’m living proof that you can have a perfect A1c, and seldom actually be there.