Diabetes, glucose, and food -- Oh my!

June 28, 2009 4:39 PM

Type II Diabetes filter: How do measured glucose levels vary depending on how long it has been since eating?

My husband was just recently diagnosed with Type II diabetes, based on an A1C reading of 7.3. He has made numerous lifestyle changes: careful food choices, no binging, regular exercise, eating three meals a day instead of one. (I nag very effectively, as you can see!) This has brought his second A1C reading down to 6.1, without any medication, so we feel like we're definitely on the right track.

But I keep wondering what the "curve" looks like if blood sugar readings are plotted against the hours since eating. A search of the internets hasn't turned up any generic curves we can use as a reference.

For example: His after-dinner blood sugar readings are usually done about 1 - 1-1/2 hours after having a Dannon Light Yogurt for dessert, instead of the 2 hour delay the doctor recommends. If he were to wait until the 2-hour mark before testing his blood, would the reading be higher or lower than the one he gets at the 1-1/2 hour mark?

If he were to take his blood sugar readings hourly, over several days, we could discover the curve empirically. This is not an option, though -- he would never go for it.

So I'm hoping one of you wonderful MeFi folks either knows the answer to my specific question or perhaps can point me to a generic curve that exists somewhere on the 'net.

posted by DrGail to Health & Fitness (7 answers total)

My blood glucose level peaks about an hour after eating and then goes down to "normal" after the two hour mark (but I take medication). Depending on the amount and type of carbs I had at a meal, the 1.5 hour is lower than the peak, but higher than the two hour mark. It depends on the time of day and amount of exercise I've had as well. My blood sugar level in the evening is higher post meal than after lunch even though I may have eaten a similar number of carb grams, etc. However it can vary even when I follow the exact same routine and meals. I've lost a lot of weight and that has impacted what happens. In other words, I don't think you've found a generic plot of glucose levels is because there's too much noise that would make things different.

You don't need to have a formal hourly reading over days to get to this finding. But you can get some valid information on by doing a test after dinner one night, after breakfast another time, and after lunch another time. If numbers seems wacky you can do it again on another day. For me, the key was finding out the effect of different foods and time on my glucose levels. It was totally worth sticking myself and testing. Once you have this type of information you know your body's reaction to the food and not some generic levels that aren't tuned to your situation.
posted by birdherder at 4:56 PM on June 28, 2009

What you're looking for is info on postprandial glucose levels. There is no normal curve because there are a lot of factors to consider - was the meal sugary? Mostly protein? This article is old (2003) but interesting.
posted by selfmedicating at 5:02 PM on June 28, 2009 [1 favorite]

This might be close to what you're looking for. It's from an article on the glycemic index put out by the Food & Agriculture Organization of the UN. Who knew such an organization existed?
posted by selfmedicating at 5:06 PM on June 28, 2009 [1 favorite]

The closest thing to this is the meal glucose tolerance test described here. If you scroll down there are figures showing what their healthy volunteers glucose looked like after their standardized meal.

Of course in real life it depends on what you ate and the degree of your disease. I have a bunch of data sitting around on this, but that's pretty much what it's going to come down to.
posted by a robot made out of meat at 6:51 PM on June 28, 2009

But I keep wondering what the "curve" looks like if blood sugar readings are plotted against the hours since eating. A search of the internets hasn't turned up any generic curves we can use as a reference.

Is HE wondering? It's his disease, he needs to deal with it.

Here's the number I use: Two hours after eating the BG should be under 140 and probably closer to 120. That's the curve. During the day, it should be be between about 70 and 140, with 140 being after meals. Waking BG should be under 120.

As selfmedicating says, the graph can vary, based on a number of factors. For myself, it can depend on what I've eaten, how much I've eaten of carbs, protein and fat, whether the carbs are slow or fast acting, whether I've exercised, what kind of exercise (cardio vs weightlifting), how much of it I've done, whether I've been doing it regularly vs took a few days off, how much stress I'm under (high stress just shoots the numbers way up), whether I've been sleeping enough, whether I'm depressed, what time of day (those morning highs suck) and what type of meds I'm taking and in what amounts.

I'm part of a program that gives me free strips and encourages me to use them often and for kicks I've tested every hour, on the hour, just for kicks. The graph varies based the factors above.
posted by Brandon Blatcher at 6:53 PM on June 28, 2009 [1 favorite]

Oh, in that chart the gray area is the range of variability they saw in 100 people. If you're used to thinking in mg/dL instead of mMol, multiply the values on the y-axis by 18.
posted by a robot made out of meat at 6:59 PM on June 28, 2009

Everyone above is correct in saying it depends on multiple factors. With yogurt, 1.5 hours is probably going to be higher than 2 hours. You say he would be unwilling to test each hour for an entire day, but testing at one and two hour marks after each meal for a couple days could be nearly as informative.

Does he hate testing per se? Is it the pokiness? Some lancing devices are better than others; I've heard good things about the Softclix.
posted by molybdenumblue at 7:37 PM on June 28, 2009