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Spiking Post Meal

indyjholtzmann

Well-Known Member
Messages
54
Type of diabetes
Type 1
Treatment type
Pump
Hi everyone!

Long-time stalker of the forum, first-time poster. I'm a Type 1 diabetic and diagnosed when I was 7 (17 years and counting!). I went for the DAFNE course over the summer and started testing my BG levels more often. Recently I got myself a Freestyle Libre and found myself testing even more now.

One thing I have found with me testing more is that my BG levels seem to spike when I test 2 hours after my meals (it was recommended by my diabetic nurse that I do this during the DAFNE course). I always figured that my levels would probably increase slightly after meals but a lot of the time I'm seeing increases of around 6 - 10mmol and it pushes me out of my target range and sometimes straight into a hyper. I don't give myself a correction dose as a few hours later, I'll be back down into my target range and I don't want to dose because I'll probably end up in a hypo (I'm on insulin injections).

I've got an appointment with my nurse soon so I'll be bringing it up with her then but I was just wondering if anyone else has found this happening or if I should be worried? It's very disheartening to see these spikes on my Libre graph...
 
So the fact your coming back to pre meal levels shows that your ratio and carb counting is spot on (assuming you are calculating and adjusting) do you pre bolus at all? xx
 
Are you doing finger pricks when you are high, or just trusting the libre? I had a lot of trouble with libre accuracy - sometimes it would be out by 3+mmol/L, so I would give unnecessary boluses and end up low. I found that it tends to exaggerate high blood sugar and the rate of increase.

How much do you eat in a typical meal? Perhaps you could reduce the amount of carbs you eat, and split it across multiple meals in order to spike less during each meal.
 
Do you pre-bolus? Taking insulin 20-30 minutes before eating can lower spikes.
 
Thanks for the advice, guys! Honestly, I didn't even know that pre-bolus was even a thing but I've just looked it up and it might be something I need to try. It seems like a lot of planning and working out how long I need to inject before my meal.

As for finger pricking, I've only done one prick since I got the Libre last week. Perhaps I shouldn't be relying on it as much as I am? I'd say a typical meal for me is about 70-90+ grams.

Might look into pre-bolus and see how that goes.

Thanks again!
 
Hi @indyjholtzmann,

I'd definitely recommend trying pre-bolusing a good 20-30 minutes before meals. I have had T1 for 23 years and naively didn't realise this was a 'thing' and retrospectively can see why my HbA1c is far from where I want it to be. The spikes were masked by relatively okay readings pre-meal.

Also try not to rely on your Libre 100%. I was encouraged to always finger prick before I eat due to the potential inaccuracy. I use my libre for trends and direction I'm heading rather than actual figures.

You might find you need to adjust your diet now you have the Libre. I've had to cut out certain types of food that I thought were generally healthy - healthy for most of the population but healthy for diabetics no!

Best of luck
 
It generally takes insulin 15-20 min to start working so prebolusing can help catch the spike before the carbs get there.
 
@indyjholtzmann , I'd definitely second pre-bolusing. It makes an extraordinary difference. After you inject, novorapid typically takes about 20 minutes to start working and then peaks after about an hour or two. If you inject then eat immediately, the carbs will often break down and end up as glucose long before the insulin starts getting to work, so it'll have an uphill struggle against an already rising sugar.

Whereas, if you inject then wait a bit, the insulin has a chance to actually get into the bloodstream so it can deal with the glucose head on.

Takes a bit of experimentation to figure out how far in advance to pre-bolus and it'll also depend on various factors like whether you're already trending down or up or stable, how low or high you are and, importantly, the GI of the meal, for example, with me, white rice breaks down pretty fast so I'll maybe need 20 mins for that, but brown rice, presumably because of the fibre, is slower so maybe only 10 mins for that. Fat content also plays a part, generally slowing down absorption so maybe a bit less for that.

You're basically trying to match the pattern of insulin over time to the pattern of food digestion.

Stephen Ponder's book Sugar Surfing gives a lot of hints and tips on getting the most out of cgm and libre. My local hospital recommends it, so he's not a quack.

That includes throwing away the DAFNE notion of not taking correction doses between meals. The pancreas does it, so why shouldn't I? DAFNE rules are based largely on strip testing, for understandable safety reasons, but cgm makes it a different game where you can be more proactive and deal with developing situations as they start, instead of dealing with it after the event.

Just as an example, in the screenshot below, the graph appeared to be on an upward trend from 13:00 to 15:00 so took a 1u shot to pin at about 16:00 as I knew from past experience that moving about as I went home around 17:00 would generally raise me by 1 or 2. Turns out it didn't on that occasion, or maybe the 1u was too much (looking at it again, graph was starting to flatten out, so my bad for missing that clue), so I then start sliding towards 4 as I'm getting ready for tea, took 12u about 20 mins before a 90g meal, ravioli on 3 slices of toast and some raspberries at about 18:00. Net result, there's a slight bounce up from 4 to 6 before it flattens off.

Incidentally, I'm getting that graph live from libre - put a £100 blucon transmitter from Ambrosia Systems on top of it, it sends results every five mins to xDrip+ on my phone, so I get not only a much more informative graph, but also high and low alerts. Sorry, it's my new toy, so I can't help babbling on about it!

Good luck with libre - it makes this unpredictable game much fairer!

 

It's a guess, but is your insulin to carb ratio 1:7...ish?

Graphs do look nice and easy enough to understand. Love the idea of the alerts. Main concern is the size of the lump on your arm, with the sensor and the bluecon attachment.
 
Thank you so much for the advice, guys! I certainly will look into pre-bolus now, I think. I might attempt it on a meal or two (I'll inject about 20 minutes before my meal to start with), see if it does make a difference, and go from there.

I'm beginning to see why my hba1c is not where I want it to be as well although it has been dropping since I took the DAFNE course. I'll look up the Sugar Surfing book as well, thank you @Scott-C. And I wish my graph looked that neat!
 
JoeT1 said:
It's a guess, but is your insulin to carb ratio 1:7...ish?

Graphs do look nice and easy enough to understand. Love the idea of the alerts. Main concern is the size of the lump on your arm, with the sensor and the bluecon attachment.
Click to expand...


Good guess! I've got the carb ratio in the predictive simulations settings set to exactly that! After I first got libre, I spent some time looking through the graphs looking for situations where there was very little spike post-meal, I'd entered the carb amount and insulin dose and the best ones seemed to pan out at beteeen 1.3 to 1.7 u per 10g, so I'll generally do a carb count and take about 1.5 u per 10g, with the occasional tweak depending on time of day, exercise, GI, food type etc - strict carb counting and rigorous application of ratios is a good starting point, but after a while, native T1 intuition plays a major part too.

I wouldn't worry about the size of it. It's fractionally wider than a sensor and about the height of two and a half sensors stacked on top. I barely notice it. They've got a stock photo which gives an idea (the holder is from a separate company, I just tag mine on with a 7 by 8 plaster):



The graphs are indeed excellent. Here's another which gives a better idea of the power of it:



Blue dots are the readings, but you can see also red dots which is where it thinks I'm heading, hence the "Low predicted in 36 mins" at top left. But I then have 18g and the purple dots is an estimation if where that'll take me. The green lines are estimations of how much insulin I've got on board, so can be useful if you end up insulin stacking.

I don't treat any of the predictions as writ in stone, but they can provide some very useful pointers or clues as to what might happen in the next few hours, so I can then decide if action is required. Some of the predictions have been remarkably accurate. They'll update every 5 mins. Shortly after that 18g on the graph, the low prediction disappeared.
 
@Scott-C

Have you ever tested the predictions out to see if the hypo does occur.....

and if it did from a graph similar to the one above, what would you conclude as the reason for the hypo....?

carb count? dose timing? physical activity?
 
Excellent. You know what, I think I'll give it a shot.

I think there's a post from you with the links etc to this stuff.
 
novorapidboi26 said:
@Scott-C

Have you ever tested the predictions out to see if the hypo does occur.....

and if it did from a graph similar to the one above, what would you conclude as the reason for the hypo....?

carb count? dose timing? physical activity?
Click to expand...

There's been a couple of occasions where it's predicted a low, so have taken some sugar, but it's been a fast dropper and the hypo has arrived before the sugar gets in stream. So, yes, the predictions work. So haven't avoided hypos altogether with fast droppers but I'm still getting a heads up so get a much softer landing because I've already taken some sugar before the hypo rather than after.

I think the reason for the prediction in tbe graph above was just me being dumb by taking the 3u at 8pm! Can't remember the reason for that, maybe thought that I'd under bolused for the meal at 6:30
 
I totally agree with @tiredoftrying2017 trying about not relying on the Libre.
I found the values vary significantly from my finger pricks (which I trust much more). I have learnt to use the Libre for historical trend analysis only. For example, it is great to spot when your BG starts to rise after eating and when you spike. But don't forget the Libre is typically 15 minutes behind finger pricks.

Not sure if @indyjholtzmann is in the UK and whether you are driving. If you drive, you must test with finger pricks - the DVLA do not accept anything else.
 
JoeT1 said:
Excellent. You know what, I think I'll give it a shot.

I think there's a post from you with the links etc to this stuff.
Click to expand...

Yes, the thread here has links and notes on setting it up:
http://www.diabetes.co.uk/forum/thr...h-libre-blucon-and-xdrip.127195/#post-1614057

I have a look at Ambrosia's facebook once in a while and they say they'd sold out but seem to be getting on top of it. They're a tiny little start up and organisationally shambolic so you might have a bit of a wait after ordering!
 

I am in the UK but I don't drive so that's not a worry. I'll try not to rely on the Libre so much, I think it's just the convenience of it! I travel a lot and I don't really sit around on my trips so I've always found it hard to stop and test my BG. It becomes more of a problem when my surgery doesn't prescribe me with enough test strips either so normally with my finger prick I was only testing three times a day before each of my meals and if I'm feeling either hypo or hyper.

I might test with my finger prick and see how much the discrepancy is compared to the Libre now.
 
I've only had diabetes since 1984. Which is when the first glucose meters became available for personal use. (Mine was about the size of a small stack of magazines!) And I don't check by blood sugar 2 hours after I eat. I check it when I get up, before lunch and dinner, and at bedtime, and if I feel low. That's about it. My average A1C has always been between 5.8 and 6.5. My average glucose on my meter at home is between 4.4 and 6.4. The reason I haven't checked postprandial blood sugars is because if it's pretty good (4.0-5.0) before I eat 2 what would I do differently? It's like the OP said. Since starting on this forum I've been exposed to the concept of "pre-bolus", which makes a certain amount of sense IF YOU ARE SURE what you're going to eat for that meal. But to be honest I doubt is it will improve a person's A1C. Just my 0.02.
 


A few years behind you, dx'd in 1988. If you've found a way of dealing with it without pre-bolusing, testing etc etc, good on you, carry on with what suits you.

But, like the OP, I've found that if I don't pre-bolus, I'll end up sky high in the mid teens, I'd prefer not to be there because it can take a bit of rage bolusing to get it back down, so a bit of careful pre-bolusing takes care of that.

I'm not fussed about my a1c at all. My docs are. They just about threw a fit when my last one came in at 36, convinced I must be hypo all the time. Err, no, I can understand their concern - low a1c, you're either stable or averaging lots of highs and lows. So I'm going to ask them how much an a1c actually tells them compared to an agp (with some docs , you need to explain what an agp is) and then chuck this at them:

 
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