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Help deciphering readings

G

gogobroom

Well-Known Member
Messages
73
Location
Hampshire
Type of diabetes
Type 2
Treatment type
Diet only
I've just started using my Libre GCM and trying to get a handle on what the numbers mean, I am currently trying to go lower carb (under 100gsm a day, previously was about 160) started off with breakfast with a carb content of 12g = no considerable rise in BG at 8.09 this morning (reading was already high at 8mmol, by 10.13 there wasn't much change at 7.9 at this point I ate an apple, circa 16g carbs, within an hour my reading had gone up to 10.2, and was still over 9 at midday - where I went for a run, post run back down to 7.7.

What I am trying to understand is why after the apple it rose by 2mmol when I thought that an apple was unlikely to cause a BG rise ? Does this seem normal or correct ? Double checked with finger pricks and readings about the same.


For info my usual morning FBG reading is between 7 and 8 currently

Any insight will be helpful Thanks
 
Apples vary considerably in sugars, though they all contain carbs. A medium sized apple contains around 14gms of carbs - so more than your breakfast and depending upon the variety much of those carbs will be in the form of sugars.

I suppose you can think of apples as being a medium carb fruit - not as bad as the same weight of banana, grapes etc. But many of us Type 2 diabetics don't eat them unless they are small and of a less sweet variety. I will eat a small slice of apple, but otherwise I eat only the low carb fruit such as berries but not blueberries - they are still too high in carbs for me.
 
Coincidentally, I forgot my lunch today. Grabbed an apple and a small handful of grapes from the office fruit bowl at about 2.30pm and my bg went from about 5 to about 7.5
 

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Thanks all - it appears apples can be naughty after all ... will leave them for now and maybe test again another day or maybe nearer to the time of my exercise. It can be very confusing, when you google things like apples and diabetes it general comes up as a low/medium GI food that shouldn't increase BS much.
 
gogobroom said:
when you google things like apples and diabetes it general comes up as a low/medium GI food that shouldn't increase BS much.
Click to expand...
It's the carbs that makes you rise, all carbs turn to glucose in the body.
GI only tells you something about how quickly those carbs hit, so a high GI food gives a sharp, shorter peak, low GI gives you a slower and likely lower but longer rise.

That said, I regularly use apple to treat a mild hypo, usually a couple of bites is enough for me. So while apple doesn't make me rise just as quick as sweets or glucotabs, it does get me out of a low within minutes.
 
For me the secret is not to eat fruit as a snack or meal replacement, if you just grab an apple your body has got nothing else to do except extract the glucose from it.
Far better to sneak it in as part of a meal or just after as desert, it's almost as if while your body is dealing with the protein and fats from your meal, the sugars in the apple go mostly unnoticed.
 
Agree with @catinahat - I can manage perfectly with half an apple as part of a meal in salads sauces or part of a dessert etc but not on its own as a snack
 
Another question or 2 regarding rises in readings. Whenever i search for the information it generally comes up with the 2 hours post food readings, not much information on what happens within that 2 hours... so :

1) If I get a rise from 6.5 to 11 or 12 or even 13 mmol/l in the first hour post food but the reading returns back to around 6.5 or 7 after 2 hours is that a bad reaction to the carbs

2) which is better (if there is a better) A high rise then drop within 2 hours post food or a minimal rise but still higher than before 2 hours after ?

3) should there be a maximum rise I am looking to stay under even if that rise is only for 40 mins or so ?


Still trying to understand the peaks and troughs and what does or doesn't effect my bloods. I have another 2 weeks before my doctors appointment so trying to get a good handle on thing knowledge wise before then.

Thanks in advance
 
The two-hours-after-food is to gauge the reaction of your body to what you put in there: is the insulin response enough, to cope and bring your levels back down to acceptable numbers. Generally this does mean you miss the actual highest peak, which depending on how fast the carbs hit the body (fruit juice in minutes is faster than bread in half an hour or so, for instance), will be somewhere in the first hour and a half after the meal, most likely. So that's why the two hour thing is a rule of thumb: Rise no more than 2.0 mmol/l, means your insulin response and sensitivity were adequate and you could deal with the meal, even if there was a steep spike somewhere in the 2 hours after the meal. Do keep in mind that anything that rises and drops fast, can make you feel decidedly unwell. So while technically all is good if the numbers return to normal after two hours, it'd still be preferable not to spike, if you do feel wobbly when spiking/dropping suddenly.
What do you call a minimal rise? If it's minimal, it's still in the normal range, under 8,5? Then it's not something I'd worry about if it lasts a little while. If it's higher though, then to me it would not be acceptable, but that's a personal choice. (Mind you, I tend to not go over 6,-something-or-other-after-the-point, as anything over that I'll feel ill with. Sluggish and such, but usually solved with a brisk walk.).
I'm sure others here can throw a lot of numbers at you, but all in all... Keep it simple, don't overthink it. Stick with the no-more-than-2.0mmol/l-rise-after-2-hours as a rule of thumb, and don't stress if it doesn't work out every once in a while. Like when eating out and having misjudged the ingredients of a meal, or when down with lurgy. Don't get strangled by the numbers. Keep in range as much as you can, be forgiving when you can't, and just keep trying to improve. Because with so many variables at play that can influence your blood sugars, setting hard numbers and limits is basically setting yourself up to fail. And this is something you'll be doing for a loooong time, so best to keep it a little forgiving, or you'll throw your hands up at some point and go "I give up", while it's just a restless night or a cold wreaking havoc, not something you have a whole heck of influence over. Do what you can, and keep at it.

Dunno if that helps at all, but there you go.
Jo
 
Testing is not about seeing how high you go. If it was, you'd be testing 20 minutes to 60 minutes after you ate. And if you eat carbs, you should expect a rise in blood glucose. That is what happens - the carbs are digested to glucose and that passes into the bloodstream.

The issue for diabetics is how quickly our systems can clear the glucose out of the bloodstream. Consistently high blood glucose levels over time is what causes damage. Food is one source of glucose, the other is your liver, which will manufacture glucose from stores and move it into your bloodstream in response to any number of things.

Personally, I know that even a small latte will take me over 9mmol/l very quickly. I'll be back to around 5.3 after one hour. I'd personally not choose to eat anything that took me above 11 or 12 even for a short time (eg pastry).

I'm attaching a CGM graph from a non-diabetic person. You'll see that blood glucose rises and falls normally and constantly. The green X marks meals, and the red squiggle shows a drop in BG in the early mornings.
 

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Thanks both for the info, I think I understand, I am just trying to get a handle on what causes rises and try and limit them to a degree, but if that rise is dealt with ok within 2 hours then not so much of an issue, but I still think that if it goes to say 12 from 6.5 then it can't be good <<<< this is what I am trying to get my head around.

Thanks for the non diabetic graph, I kind of thought that may be the case.

When testing or on my libre I generally run between 6 and 8 at any point when viewing, so currently for me a 2 point rise would generally take to at least 8 or 9, whereby those in remission or with bloods "under control" wouldn't want to go higher than that at any point. I can see numbers upwards of 11 at times post food was just wondering what effect this was happening. As I say currently my average is around 7.4 - when I speak with docs later in month I should be able to get a handle on it a bit better, aiming for less than 100g carbs a day, and those carbs are usually veg non starchy.

Heres a couple of days from last week to show you what I mean. I am not overly concerned I am just of the mind to try and understand as much as possible, once this "phase" passes I will likley be more relaxed, but currently trying to get the most out of the libre data.

 
I have no experience of using a CGM, but can see that some of your intermediate highs after eating and before 2hrs after first bite are higher than most of us would like.
I also note that on Thursday you did exercise which raised your blood glucose (more intense exercise does this- though it isn't a bad thing.

It's too bad we can't see the notes for Friday. But our BG shows reactions to the bacon cheese muffin & ketchup (both contain carbs). Bacon and eggs (or either) would be a good low carb breakfast. Then again gravy peas and mash (which probably all contain carbs) - not sure about the sausages since you don't say if they were high meat content or not - high meat content = low carb.

On Friday you had a much bigger reaction to dinner than on Thursday despite there being very little difference in total carbs eaten in those meals. You need to look into this - was the Thursday meal higher in fat, or did it have more complex carbs ('brown' rather than refined white ones)?

In any case it seems that you need to aim for breakfasts more like Friday's (perhaps include the snack in with the breakfast) and aim for dinners more like Thursday's.
 
These are interesting - your "baseline" is pretty steady at mid fives to high sixes/sevens. You're seeing rises into double figures after eating, but the levels are coming down to baseline around the two hour mark. If this pattern was starting from a lower baseline - at say 5.0 rather than 7.0 - you might not get quite such big rises to your present peak levels. You'll always get rises from carbs, but in my book it's better spending 20 minutes above 8.0 than 60 minutes above 9.0.

Thing is, the baseline is usually set by your liver, and it takes time for the liver to adjust to accepting lower levels as a "new normal". It took my liver months. If you're continually adding glucose via carby food, it's not going to help persuade your liver that lower glucose levels are normal.

If we're looking for suspects - the muffin, maybe the ketchup, the mash, some sausages have a lot of carbs via oatmeal filler (these are usually the "low fat" ones) peas, and gravy. It's not just the level of carbs in the individual foods, it's the quantity as well. A food at 20% carb that you have 10g of - total 2g carb - will probably have a smaller BG impact than a food at 5% carb that you have 200g of - total 10g carb.
 
ianf0ster said:
I eat only the low carb fruit such as berries but not blueberries - they are still too high in carbs for me.
Click to expand...
For reference to anyone interested in blueberries (they're my favourite), 25g is approximately 3.6g of carbs. Sounds good, they'll fit right in with low carb or keto, right? Unfortunately 25g of blueberries works out to about 11-12 blueberries - not exactly a fulfilling portion size.

Best bet is to combine them with @catinahat's suggestion if you're inclined to up the portion size, seems to work for me too...
KennyA said:
You'll always get rises from carbs, but in my book it's better spending 20 minutes above 8.0 than 60 minutes above 9.0.
Click to expand...
@gogobroom - Takes a while to get your head into this mode of thinking from Kenny, but this is how I approached my diet design too. It's all about minimising elevated BG level durations, not keeping them on a low flat line. One meal causing a spike for a short time won't affect an hba1c result, but a majority of meals spiking BG levels for extended periods (especially where these levels don't reduce before the next meal and become a rolling high that's topped up) will affect an hba1c - plus it's likely where most of us T2's unknowingly were for a period of time before we were diagnosed.
 
Hi @gogobroom, welcome to the forum. To me it looks that you are doing great. Looking at your graphs, your BG values rise when you eat, but two hours later these are down again. This is normal. I would caution not to overinterpret these results, in particular the baseline values for several reasons: 1) CGM have an uncertainty of 15% so 7 could actually be 6 or 8. To lower the baseline you need either change your diet, i.e. reducing carbs or medication (which we try to avoid), but this can take time as @KennyA says. I don't know your HBA1c but you say you have pre-diabetes, so possibly only small adjustements are required, assuming that you are healthy otherwise. I think you are doing the right thing, e.g. with a CGM you can experiment with food and see what causes spikes, which are larger than 2 to 3 as for non-diabetic and more importantly if they do not return to the baseline or take much longer than 2 hours. Personally I like apples, but I often only eat one half of an apple. e.g. by or chopping 1/2 into full-fat yoghurt for breakfast and taking the 2nd half the next day or by cutting them in slices and sharing with my partner.
 
Appreciate the responses, I will digest them and work through. Things are getting clearer thanks to the responses I have received on here.

With regard to HbA1c I am 52, awaiting doc appointment at the end of the month and expect to be diagnosed Type II. I think it will be an interesting conversation though, I am athletic, into endurance sport, healthy weight and other than the HbA1c and of course my glucose readings, and age been 49, not really on the radar for type II even though I have been prediabetic for almost 10 years.
 
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