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Insulin effect delayed?

C

Chimon

Member
Messages
5
Type of diabetes
Type 1
Hi, I've had diabetes type 1 for 26 years. Recently I got my hands on a Dexcom G5 continual glucose monitor and I noticed that after every meal my BG spiked up to around 18, it stayed there for 2-3 hours and then it crashed down to around 2. I read online that Novorapid can have this side effect and so I talked to my nurse and asked for a new insulin type. My doctor gave me Fiasp and the only difference now is that my BG doesn't spike to 18 anymore which is great but now it instead stays around 10 for 2-3 hours then it crashes down again. Now it could be because of an infection which makes my body require more insulin but I am not sick and I feel fine except for the mood swings because of the high BG. I'm wondering if this happens to anyone else here?

It's hard for me to find the correct dose of Fiasp if the effect of the insulin is delayed..
My long-lasting insulin is Lantus and I wake up with the same BG as when I go to sleep.
 
You say you crash to around 2 on your dexcom 3 hours after a meal. The lowest a dexcom will read is 2.2, less than that it just says LOW. Dexcom won't be especially accurate at low or high ends of the spectrum, so it is worth checking whether the lows you are seeing in CGM are confirmed by finger prick testing.

If you are having lows 3 hours after your bolus that suggests you bolus is too much for your meal. To see if your insulin:carb ratio is working correctly for you you are advised to have a reasonable carb contend meal with not too much protein or too much fat, something simple like meat and 2 veg + potatoes. Then test 2 hrs after eating and 4 hours after. The four hours after should be about when your bolus has finished (although it may be lasting up to 5 hrs). If you are hypoing in that period, then you are taking too much insulin to cover the meal.

When are you taking your bolus? Are you taking it immediately before/with your meal? Or are you pre bolusing? My understanding is fiasp doesn't need really need a pre bolus by much more than 10 min & even that should be done with caution. But novorapid needs about a 15-20 or even 30 minute pre bolus. Timing your insulin correctly can help avoid a post prandial spike. And if you are taking your insulin at the right time for the meal, then that can mean you don't have to take so much to deal with a post prandial spike, so you avoid crashing down and ending up with a hypo at 3hrs post meal.
 
Have you actually basal tested?
 
catapillar said:
You say you crash to around 2 on your dexcom 3 hours after a meal. The lowest a dexcom will read is 2.2, less than that it just says LOW. Dexcom won't be especially accurate at low or high ends of the spectrum, so it is worth checking whether the lows you are seeing in CGM are confirmed by finger prick testing.

If you are having lows 3 hours after your bolus that suggests you bolus is too much for your meal. To see if your insulin:carb ratio is working correctly for you you are advised to have a reasonable carb contend meal with not too much protein or too much fat, something simple like meat and 2 veg + potatoes. Then test 2 hrs after eating and 4 hours after. The four hours after should be about when your bolus has finished (although it may be lasting up to 5 hrs). If you are hypoing in that period, then you are taking too much insulin to cover the meal.

When are you taking your bolus? Are you taking it immediately before/with your meal? Or are you pre bolusing? My understanding is fiasp doesn't need really need a pre bolus by much more than 10 min & even that should be done with caution. But novorapid needs about a 15-20 or even 30 minute pre bolus. Timing your insulin correctly can help avoid a post prandial spike. And if you are taking your insulin at the right time for the meal, then that can mean you don't have to take so much to deal with a post prandial spike, so you avoid crashing down and ending up with a hypo at 3hrs post meal.
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I do check with my acccu-chek aviva when I get low values to be sure. Ok so it's normal to have high BG for hours after bolus? I take my fiasp right before eating.
Even if I take a higher bolus than normal my BG simply won't go lower than my pre bolus BG for 2-3 hours. This is what I don't understand.
 
Chimon said:
Yes exactly. Yes, I check my BG every 5 minutes with my Dexcom G5 and I'm certain this is not caused by my basal
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You might want to do some basal testing as suggested by @donnellysdogs to check that out, it's a good idea to be sure the basal dose is correct before tinkering with bolus ratios to check the bolus isn't having to make up for too much/too little basal.

Here's a nice guide on how to basal test - https://mysugr.com/basal-rate-testing/
 
Certain isnt the same as "yes" I have basal tested during the day..

Many people find that basals change with seasons.. mines with clock changes.
 
donnellysdogs said:
Certain isnt the same as "yes" I have basal tested during the day..

Many people find that basals change with seasons.. mines with clock changes.
Click to expand...
I recently had an epilectic episode due to hypo. Me and my nurse lowered my basal dose in reaction to this and we both agreed my new basal dose is good. This is why I'm certain. But thank you for your input!
 
Sounds like you have to pr bolus as your food is getting there before your insulin. We have to try to marry them and catch the food. For me, my insulin action starts around 20 min. If I bolus and eat without waiting I will go high. Insulin isn’t immediate and if you’re eating before your insulin starts working you will see a spike.
 
My current Dexcom is not the most reliable device. It shows things that are not actually happening like a line of dots skimming the top of the screen and rapid crashes into the red. Checking these anomalies with a meter reveals numbers that are well adrift. When the transmitter gets the reading within a Mmol of the meter reading it is useful for trends.

I always check transmitter recorded highs with a meter before treating with insulin. Heading to a hypo is physically obvious and I don't wait for the receiver to alert me. When I treat a hypo the receiver readings continue to fall for several minutes before a rise is recorded.
 
For true basal testing during the day you need to actually have a meal/bolus and then not eat for 10hours... unless hypo.

I would also agree with @Kristin251 and @Ambersilva.

Is your bolus/basal still running around 50/50 ratio or do you manage on a different ratio?
 
donnellysdogs said:
For true basal testing during the day you need to actually have a meal/bolus and then not eat for 10hours... unless hypo.

I would also agree with @Kristin251 and @Ambersilva.

Is your bolus/basal still running around 50/50 ratio or do you manage on a different ratio?
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Hi Chimon,

I suffer from similar post-prandial spikes and with good knowledge it’s definitely not my basal. Over the years, there have been some improvements with taking insulin before eating and that - and a reduction in carbs is the only thing that works for me. However, I’ve had regular horrific hypos where the insulin sporadically hits before the carbs (despite low protein/fat) and decided that I can’t take it more than 5-10min max before eating due to risk of random hypos/slow digestion/whatever is causing erratic insulin working times.

Like you, I’ve now switched to Fiasp but only started today so too early to ‘review’....I was a bit gutted to see a spike to 14 after only 15 carbs in the form grapes (always a killer for me) but I’m really, really hoping it might just be related to the new set (also always a prob for me despite a 4.25 cannula 6mm fill).

Other carbs were 24 for chicken noodle soup, I went to 10 for about an hour which is good for me.

Based on my similar experience, I’d say try to have a good mix of protein / fat when you eat. Eg I don’t eat baked beans now without popping cheese in too in the microwave. Maybe try something like two pieces of toast with little low fat spread and then try two pieces of toast with tuna mayo and see the spike differences. Tuna mayo with jackets/bread/pasta is one of my few low spike, magic foods.

I’d love to move from spikes in 18s to 10s too so well done for asking for different insulin. It’s a HUGE improvement.

Sometimes I feel like a totally different diabetic compared to what medical research suggests should be the case, or the info from others - when looking at my awful post-prandial highs so thanks for posting; I don’t feel like it’s just me now.
 
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