Bobbing for Apples

[There is no Spoon]

Can somebody satisfie my curiosity,

Blood Glucose reading and testing with monitors.
From years of doing calculus I don't think of a single reading as having any significant meaning it tells you noting about what is happening. A reading of 80 tells me nothing about whether that number is climbing or dropping.

I understand that testing is an invaluable tool for many but what is it telling you?
Why do I hear that one should test 2 hours after a meal. I completely understand that you don't want to have to prick your finger 5 time to get 5 readings after a meal but where does the 2 hours come from is this the time period that bg should have peeked and now be on the decline?
If so then does that take into account peoples different basal metabolic rates?

A few people have raise the subject today of exercise raising blood sugar readings and to me that's what's supposed to happen more energy is released into your system but at the same time you system is primed to syphon of that energy over the next few hours.
IF
This is the case then unless you are feeling any ill effects relying on a single number that is "meaningless" seems ill advised.

Just trying to educate myself

 

[miahara]

The bottom line is that testing before and after a meal gives an indication of how what you've just eaten has affected your blood glucose level. It gives you an indication as to what foods you can eat and what foods are best avoided. You are correct in so far as a single reading doesn't tell you much in itself, though single readings at the same time every day may show a trend over time. I doubt if anyone attaches much importance to a single reading.

 

[Guzzler]

At first single readings can educate on specific foods. As readings mount then trends are observed rather than single readings. Trends can indicate improved IR and can get us back on track after a slide.
I think the two hour mark has more to do with the average time of digestion/uptake of fuel source. For instance, if you took a glass of orange juice on an empty stomach you are not going to have to wait two hours to see the start of the peak but if you had a low carb mixed meal then the two hour mark is a relatively good place to measure. As you say, we are all different so unless you have a CGM if you wanted to see exactly how your food affects you then it means testing with finger pricks more often.

 

[LouWilk059]

This link should answer questions about why you should test and when.
https://www.diabetes.co.uk/blood-glucose/eat-to-your-meter.html

 

[There is no Spoon]

You are correct in so far as a single reading doesn't tell you much in itself, though single readings at the same time every day may show a trend over time.

I hear what your saying,
lets assume its the same identical meal for 7 days gives you approximately the same result it still does not tell you if bg is going up or down at that moment in time. You just have 7 readings that look the same.
Or have I picked that up wrong is it always going up (never down) at the 2 hour mark, and it indicates how much its gone up. And has noting to do with what speed its going up?

I get that 7 different meals and one of them is way higher than all the others should indicate you have eaten something that doesn't agree with you. And can help you identify the culprit.

But as you said no one attaches much importance to a single reading, but every reading is a single reading, a point in time where the value is X.
X tells you nothing in of itself. especially if you do not know what X was before the meal. I don't think I have heard anyone say they test before a meal. Have I picked that up wrong?

 

[bamba]

It should not be a single reading, but a pair bracketing a meal at zero/2 hours.

The diffrence in the two readings tells you how your body responded to that meal on that day.

Repeat to build a data set of safe/unsafe meals.

Overlong term hopefully difference, and perhaps absolute values will go down.

 

[There is no Spoon]

This link should answer questions about why you should test and when.

Thanks I did read that and it kinda of underlined my point

In the example of the table given
"To assess the best meal for blood glucose levels, we need to look at the columns marked ‘2 hour rise’ and ‘4 hour rise’."

The 4 hour rise in case is now up to 8 which is an increase of 1unit it has really dropped from 11 to 8 which show that the blood sugar is falling when the reading says it has risen.

Taking this back 2 hours to the reading of 11 it has risen by 4 units
But although this seems to be rising and it is definite proof that it has risen it dose not tell me if it is still continuing to rise or has already peeked at say 15 and is now on its way back down.

Is it just a case of it's the only tool available to us and can help you make and educated guess?

 

[There is no Spoon]

The diffrence in the two readings tells you how your body responded to that meal on that day.

Sometimes its not until you hear the responses that it helps you do define the crux of the question.
"tells you how your body responded " but not how its responding.

I've read a few posts citing that exercise raises blood sugar and this is a bad thing and I have wanted to argue that this is not the case the argument should be that this is what you want, because it does not just sit around doing nothing it is syphoned of quite quickly. Relatively speaking of course.

But I'm still learning.

 

[There is no Spoon]

As you say, we are all different so unless you have a CGM if you wanted to see exactly how your food affects you then it means testing with finger pricks more often.

More data is always better.
But its more in conjunction to how quickly bg is syphoned of particularity with eating after exercise.

Which I get is not a simple question it brings in the factors of how food effects people individually, how strenuous the exercise is, overall levels of fitness and muscle mass compared to body fat to name but a few...

Trying to understand
IF your body is primed to syphon of that bg energy quickly over the next few hours and will continue to do so at a lesser rate for the rest of the day, and you are not feeling any ill effects,
NOW
Add in to this that the meal after exercise should be protein to repair micro damage to muscles
AND
Protein is a slower conversion process to bg
THEN
raised bg in this case is a desirable result.

 

[Indy51]

I read this advice many moons ago on how to establish your own peak response time by Dr Lois Jovanovic, Diabetologist:

"determine the best time for postprandial SMBG by testing 45, 60, 75, 90, 105, and 120 minutes after a meal to detect their peak postprandial glucose concentration"

Her advice to physicians on self-monitoring of blood glucose below:

Educate your patients on the risks associated with high peak-postprandial glucose concentrations (≥150 mg/dL) (8.3mmol)

Ensure patients understand that postprandial glucose concentrations are determined by the total amount of carbohydrates consumed

•• Encourage patients to measure their carbohydrate consumption

•• Recommend that patients keep a food diary

Remind patients of the benefits of monitoring their blood glucose levels with SMBG and construct a testing plan that optimizes these benefits

•• Have patients determine the best time for postprandial SMBG by testing 45, 60, 75, 90, 105, and 120 minutes after a meal to detect their peak postprandial glucose concentration

•• Using preprandial and postprandial SMBG, together with a food diary, patients can understand how certain foods influence their glucose concentrations

•• If preprandial glucose concentrations are already high, there is no room for carbohydrates in the upcoming meal

Review recent SMBG and food diary data with your patients to help them recognize trends in out-of-target readings

•• Use this information to recommend a specific SMBG testing schedule including number of tests per day and appropriate testing times

•• Have patients meet with a nutrition specialist if they are having trouble identifying or controlling their carbohydrate consumption

 

[bulkbiker]

X tells you nothing in of itself. especially if you do not know what X was before the meal. I don't think I have heard anyone say they test before a meal. Have I picked that up wrong?

Very much so.. test before and after a meal.. otherwise as you say the reading is pretty useless in isolation.

 

[There is no Spoon]

Very much so..

Yeah your right I couldn't be more wrong here if I tried.

And if I had read @miahara post properly it was the very first thing he said.
In my defence it was late and I'm old.

 

[There is no Spoon]

Diabetologist

I didn't even know that was a word.

Since joining have read a lot of post where the subject matter was "my reading is X its so high what's going on"
I completely understand the stabbing yourself 18 times a day with a very sharp pointy thing is not high on anybody's agenda and this is why people only take one reading.

But it's the advice I have seen posted a few times recently exercise will raise your bg so test your bg after exercise.

I'm suggesting, and I get that everyone is different, unless your feeling the symptoms of Hyperglycaemia, which is bad. Then raised blood glucose is exactly what your aiming for.
OR
To look at it in reverse Hypoglycaemia which is worse is exactly what your not aiming for.
PERHAPS
As with many things in life it boils down to finding a cheerful psychic.
A happy medium.

 

[Mike d]

Exercise drops mine big time so that assumption is flawed. It's ridiculous from my perspective and I'm not alone with that

 

[There is no Spoon]

Exercise drops mine big time so that assumption is flawed. It's ridiculous from my perspective and I'm not alone with that

Ah come on now Mike don't be like that.
I did say

its more in conjunction to how quickly bg is syphoned of particularity with eating after exercise

specifically "the meal after exercise should be protein to repair micro damage to muscles " take 1/2 an hour after exercise.

I spoke with some one yesterday who posted weights were not a good idea because they "stress the muscles" and stress means raised bg. But they had misunderstood that "stress the muscles" means making them contract. Same word different meaning when taken out of context leading to the wrong advice.

Because you personal experience "Exercise drops mine big time" does not mean the assumption is flawed.
http://www.joslin.org/info/why_do_blood_glucose_levels_sometimes_go_up_after_physical_activity.html
"When you exercise your muscles need more glucose to supply energy. In response, your liver increases the amount of glucose it releases into your bloodstream... , your blood glucose levels can increase right after exercise."

"Basically, stimulated by the demand from your exercising muscles, your body is pouring glucose into your bloodstream"
( anyone can quote 1 sentence from something they pulled up from google to support and argument doesn't make it true.)

And because its not your experience dose not make it ridiculous either.