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Why a 2 hour post meal reading of BG

H

hanadr

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Does anyone know why this is the data that is recommended? It's never made sense to me to get readings approximately an hour after the level has started to fall. If anyone knows the reason, I'd be interested to know
Hana
 
I don't know the answer but I have a couple of pieces of information to add. About 40 years ago my firm volunteered lots of us to be subjects in some research being carried out by medical students. These included a bottle of sugary drink and a blood sample two hours later. My point being that it has always been two hours and that brings me to my second point.

If you want to discuss/compare your readings with others then it is essential that you all take your readings in as nearly an identical way as possible. The method does not have to be correct, it just has to be the same for everyone. Why two hours was chosen is unknown to me.

Mind you, there's nothing to stop you taking your readings after one hour if it makes you feel better.
 
Hi Hana!

I've been pondering this myself recently. I am in search of hidden highs because my recent HbA1c was higher than my testing would have predicted. Anyway, I targetted breakfast as the most likely culprit (as I have a small amount of cereal with my breakfast). I have been testing at the 1 hour (and occasionally at the 45 minutes). My results have been shocking :shock: The highest I have recorded so far was a 12.4 :shock: I'll publish the results on the forum in a couple of weeks when i've got some better data, but I'm thinking I need to pay far more attention to the 1 hour reading. My 2 hour reading after breakfast is usually around the 7s.

Smidge
 
As I understand it, the two hour was chosen because we're not trying to catch peaks. At two hours, it is considered we should be back to nearly where we were before eating in ideal circumstances. How close we are is a measure of our control. At one hour, readings can be so variable that it doesn't give a good measure of consistency - for lots of us our phase 2 insulin release hasn't had a good enough chance to be effective. One hour is ok if you're researching the effects of certain foods but is not considered a prime measure for the above reasons. As I understand it!
 
I've always been told to test before meals, that's its not necessary to afterwards. I do very occasionally check after eating.
 
Hi Sarah. There's a difference in purpose of testing here. I see you're on insulin, so although I don't know much about that, I imagine you test before eating to help you decide how much insulin to use. The original poster is on metformin only, so tests after eating to see how different foods affect her.
 
I've often wondered how high a non-diabetic persons peak at 1 hour would be after a large meal.

Is it a slippery slope with the very healthy hardly having any rise regardless of what is eaten or does everyone initially see an increase in the BS?
 
Is it not because it's not the absolute high that causes damage, but long term sustained highs. For example when pregnant I would religiously correct any highs the minute they happened (I was testing hourly towards the end) so they were never in my system for very long, and I believe this is what led me to have a successful pregnancy and a baby who was actually under the average weight (although I believe he'd have been average if I'd carried to full term) rather than over.
Interestingly whilst doing a post dinner party trick of 'what's your blood sugar' with a group of non diabetic friends, one who'd recently drank a large glass of apple juice registered 8.4. She was down to 4.something an hour later so I don't think she's diabetic or prediabetic, I think she just ingested a large amount of sugar and it took a little while for her body to play catch up.
I've been told by the DSN not to test post meal at all, and that even if I did it's ok to go up to 11. She said it is the pre meal reading that's important. As I've been having too much insulin lately, with lots of hypos, I will follow this, but I believe she meant this for everyone not just those with lots of hypos.
 
the_anticarb said:
She said it is the pre meal reading that's important. As I've been having too much insulin lately, with lots of hypos, I will follow this, but I believe she meant this for everyone not just those with lots of hypos.
Click to expand...

She might have meant it for everyone on insulin so you take the right amount, but that of course doesn't apply to those on diet only. On diet only there's no point testing unless you can change something, so we test AFTER eating to see how that food affected us. We can then omit or reduce it next time.
 
Hey Guys!

If the DSN meant it for all those on insulin she is simply wrong. If you are on insulin and trying to keep tight control you will need to test after eating. Now, you might miss a test sometimes when you've had a well-known meal and are sure your insulin dose was correct, but most of the time you will need test. I test 7 times a day usually; fasting, before each meal (using the fasting one for breakfast), two hours after each meal and before bed. I test extra if I'm going to drive at a different time, I'm trying to find a pattern in something (e.g. the hidden highs I mentioned earlier) or I have had a hypo. If you are not prepared to test so much, bolus/basal is probably not the right insulin regimen for you.

Smidge
 
SouthernGeneral6512 said:
I've often wondered how high a non-diabetic persons peak at 1 hour would be after a large meal.

Is it a slippery slope with the very healthy hardly having any rise regardless of what is eaten or does everyone initially see an increase in the BS?
Click to expand...

A non-diabetic has only a very small rise (comparitively, according to what's eaten) at one hour as they have a very good initial (phase one) insulin response that is believed to come from stored insulin left over from the previous eating episode. A type 2 diabetic typically loses their phase 1 insulin response first it is thought. We therefore have a high figure at one hour (according to what we eat). Mine can be 15% up to 40% higher at 1 hour than 2. If we are reasonably healthy Pancreas-wise, our phase two (manufactured on the hoof) insulin response comes in and drags it down. So if we are high at 1 hour and back down at 2, it means our insulin production is still working reasonably well but no insulin is left over afterwards to be stored for the next phase one response.
 
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