Testing strategies

By idamtnboy Latest Reply 2010-10-31 12:03:12 -0500
Started 2010-10-30 20:32:25 -0500

I've read several comments on here by folks who focus on testing after meals. Testing after meals can be very informative, but I don't think that it should be the basis of your control strategy unless you are on a multiple times per day insulin injection protocol. This is because there are two aspects of BG levels that matter, the long term average level of BG, and the short term insulin production from the pancreas.

A1C readings are a measure of the 30 day half life of your BG level. It is high continuous levels of BG that cause the most damage to your physiology because that forces higher continuous insulin production, eventually "burning out" your pancreas. Insulin at continuous high levels is actually somewhat of a poison to your body, thus you want to keep your continuous average BG levels as low as practical. The best testing strategy for the diabetic to know what your A1C level is, is the post sleep test, morning for most people. In fact, diabetes is defined as fasting blood glucose levels greater than 110, not by after meal readings. Morning readings, of all the readings you can take during the day, most accurately reflect this.

Now, all that being said there is a place for after meal testing. One, it gives you an indication of how quickly the food you consumed converts into blood glucose. But more so I believe, it is an indicator of how healthy your short term insulin response is. A significant spike in your after meal BG, particularly, I believe, 2 hours after eating indicates your insulin response is sluggish or weak. A spike about an hour after, with readings dropping after that, to me, indicate a fast conversion of the carbs to BG followed by a quick insulin response. If the spikes are mostly about the same level regardless of what type of carb you've eaten, then I believe that is a indicator of a good solid pancreas response and insulin production.

I am skeptical that reliance only on after meal testing is a good strategy, since the long term, meaning weeks, months, and years, BG level is the vital measure of concern.

I suspect there are a variety of opinions of doctors about the value of reviewing your personal regular test results. My first doctor looked at my graphs and numbers and filed them in my medical folder. I really think his interest was mostly an encouragement to me to closely monitor my BG for myself. My current doc has no interest in seeing my personal data, although he regularly renews my prescription for test strips. His focus is on the every 4 month lab test of my A1C level. Clinically, that is the most reliable measure.

A high long term BG level indicates the body is not doing an adequate job of absorbing glucose into muscle cells and converting it into the energy that keeps you moving. The pancreas tries to compensate by boosting the insulin level, forcing the cells to absorb the glucose, which is not good as I note above. Continuous high levels of glucose and insulin circulating in your blood is what eventually kills you, not glucose and insulin spikes after eating. That's why I believe post sleep testing on a regular basis is best.

Now, to add some more to this long post, and to change direction a bit. I spent many years in the field of quality assurance. One of the things I learned, as have many manufacturers, is the concept of process control. If you are limited in how much you can buy for diabetes supplies I recommend you try this approach. Test your BG every day at the same time for 7 days. Then calculate the average of those readings. Do no testing for 3 or 4 weeks, and then do the 7 day testing again, then keep repeating the cycle. What this gives you is information about two important aspects of all processes. The 7 day average number factors in natural variation that occurs day to day, which is normal. Then comparing the averages of each subsequent test period will give you a good measure if there are long term changes taking place. If the 7 day average number is gradually increasing over several months that is a warning flag. If it's going down, then by joyful! If the average number jumps up and down significantly over a few months that indicates your BG control program isn't working properly and is a flag that your medication and diet protocol may need tweeking.

Sure hope this rambling is of some value to some of the forum members. Let me know. Thanks.

2 replies

GabbyPA 2010-10-31 12:03:12 -0500 Report

The issue with using the A1c to judge your BG health only is that there are many things it doesn't tell you. It doesn't tell you if you are dropping low. People who drop low frequently may have a "good" A1c, but they are not in control of their levels. Also things like infections or chronic stress will raise your numbers and reflect in a higher A1c even if your diet and exercise programs are working. Then if you are a regular donor of blood, this too can lower your A1c, but doesn't reflect how your control is doing. I believe that you need to be using both to determine what it is that is making your A1c what it is.

Harlen 2010-10-31 01:04:03 -0500 Report

For me I needed to take my BS befor eatting and two Hr after meals.
this let me get to know what my ratio of carb to insulin is
After getting that # I was much better able to ajust my meds.
I use a scale as well to know what I am eatting
As for your post
I like it short and sweet but that may be for I can not spell lol lol
Best wishes

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