The more I read, the more I realize that people have to be their own advocates concerning their health. There's a lot of information out there, but a lot of it is contradictory--even information that comes from doctors. Without medical training, how do you sort it out?
Lately I've been reading The Power of Logical Thinking by Marilyn vos Savant. Readers of a certain age may remember the Monty Hall dilemma from her column in Parade magazine in 1990. She correctly answered a reader's question about probability. The problem was so simple that grade-school age children could--and did--test it for themselves. Yet vos Savant got mountains of mail from professors and Ph.D.s telling her she was wrong.
There's a section in her book about averages. "You can drown in a river with an average depth of two feet," she observes. This reminded me of a woman I met last weekend. As she and I talked, the conversation turned to health. She was quite a bit overweight and said she had fibromyalgia, suffered from depression sometimes, was often tired, and was beginning to get peripheral neuropathy. Sounded like diabetes to me. I asked her if she was diabetic, and she said no, her A1c was too low for that. (A1c is blood glucose average over the past three months or so.) I asked her about blood glucose levels an hour after a meal, and she said that it sometimes got up to 190, but that was fine because of her good A1c.
With all due respect to this nice lady, let's examine the fallacies. I've named them as best I can.
- Using the wrong tool for the task. Is an average is a good measure of blood glucose? It depends on your purpose. According to Jenny Ruhl, "The A1c might be a helpful screening tool for finding people with full fledged diabetes who are unaware that they have it." But if your purpose is to avoid diabetes-induced damage, Ruhl says you need to avoid high blood glucose levels, which cause the damage--not just have a good average.
- Not accounting for testing limitations. If your highest post-meal blood glucose reading is below 200, could you still have diabetes? The official definition of diabetes is, in fact, having a reading of 200 or more. My acquaintance's highest reading was 190. However, all instruments have a margin of error. If her meter was accurate within 5%, her real level was between 181 and 200. If her meter was accurate within 10%, her real level was between 171 and 209.
- Appeal to authority and improperly hedging your bets. Without an official diagnosis, do you have a condition? Diabetes isn't like pregnancy, where you either are or you aren't. Blood sugars beyond a certain level--around 140 an hour after blood sugar challenge--indicate possible pre-diabetes. Damage can occur at this level. I suppose that either waiting for your family doctor to say "you have diabetes" or using the researchers' criteria and a BG meter is appealing to authority, but to my mind, the bigger downside comes with waiting around when one can take safe, simple measures to avoid high blood glucose levels.