Novorapid. How long does it take to take effect and what's its duration?

[tim2000s]

One of the great things about the Libre is your ability to test things like correction doses and whether they are right. But in tandem, you can also discover interesting things about the insulins you use...

This morning, by overnight level was higher than I wanted it to be, all be it flat (the Levemir doing a fabulous slow release job). When I awoke I checked my glucose level and it was too high, so I decided to correction dose of 1.5u, which according to my calcs should reduce my BG level by 4.5 mmol/l. As I was doing it from fasting, I thought it would be a good test.

Here's the result:

Overnight, the level ran at 9.4 (too high for my liking, but sometimes it happens - misadjustment for protein from the previous night). I tested at 4.45 and found this result.

The timeline is then as follows:

4.45am - Test - 9.4mmol/l
4.47am - Inject - 1.5u Novorapid into upper arm
5am approximately - Novorapid takes effect
7.07am - Test - 4.7mmol/l

I ate no food during this period, so this is a fasted test.

So what are my results from this test? The glucose drop was 4.7 mmol/l over the 2hr 20 mins period, confirming that my correction dose of 1u:3mmol wasn't far out. It's actually 1u:3.1mmol/l. That was the result I was looking for.

What I also learned is that in the injection site I used, the Novorapid kicks in within 15 minutes of injection. I know that other sites definitely take longer, so this was an interesting observation.

The second conclusion is that I get about two hours duration out of Novorapid in my system. We are told that the rapid insulins hang around for five or so hours, but the graph isn't suggesting this. From taking effect, it is clear that the Novorapid is no longer having a noticeable effect somewhere between 6.30am and 7am where the graph flattens out again (and more importantly, seems to stay flat).

So the conclusions I have taken from this little test were actually threefold.

1. With no food in my system, my correction ratio is confirmed at 1u:3.1mmol/l
2. NovoRapid can and does act within 15mins when fasted, in specific injection sites. Note the caveats.
3. NovoRapid, when injected in these locations, endures for no more than 2.5 hours within my body.

An interesting little start to the morning!

 

[iHs]

On a pump, I set my acting time for Novorapid to be 4.5hrs and adjusted my correction factor using the 100 rule which if I set using that rule, would take 4hrs to get my bg back to my target of 6mmol. If I want to get back to my target a bit quicker, I adjust the correction but then keep an eye on the IOB and adjust the carb bolus.

Looking at yr msg, it may be that yr correction factor works ok during the day but that depends on how quick you want to get back to yr target? If you get back to yr target within 2 to 3hrs, then some of the correction will still be active and unless youve adjusted the csrb bolus to allow for this, then hypo you will feel. Many pumpers adjust their correction factor during the night using bg testing trial and error.

 

[tim2000s]

Hi @iHs , I know what happens if I adjust my correction to a higher dose. Not only does my glucose level come down slightly more quickly, it also drops farther. This was a good example of how it works in isolation. Effectively, my body response was to drop my BG level to where I wanted it in less than two hours.

Whilst we talk about the duration of short acting insulins, and that there is an amount that endures for 4-5 hours, I've yet to see that myself, and I would expect there to be decline in my BG level accordant with it on this occasion, but there doesn't seem to be. It could be called out that this is towards the end of my levemir lifespan so it is possible that this is why, so I intend to undertake a similar experiment more towards the middle of the day, when levemir impact could be lessened.

 

[iHs]

I think even though people do a bit of basal rate testing and trying to adjust it to give better stability, they also adjust the bolus to the action if the basal and try not to worry too much about perfection.

 

[noblehead]

Sure I read that QA insulins such as Novorapid and Apidra peak at around 90-120 mins after injecting whereby 80% of the insulin is used, the rest continues to work over the following 2 hours at a rate of 10% each hour, could have been the book Think Like a Pancreas where I read it.

 

[tim2000s]

I'm sure they do. This wasn't really trying to achieve perfection, more experimenting on myself because I could! I wanted to see if what I thought was true based on not really paying a massive amount of attention to it, is with more thorough observation.

 

[noblehead]

@tim2000s, certainly worth experimenting again when you know that your levemir dose is still active.

 

[tim2000s]

Sure I read that QA insulins such as Novorapid and Apidra peak at around 90-120 mins after injecting whereby 80% of the insulin is used, the rest continues to work over the following 2 hours at a rate of 10% each hour, could have been the book Think Like a Pancreas where I read it.

Looking at the graphs in Bernstein, you see a peak at 60-90 mins, then a fall off after that over the next 90 mins, to a very small concentration for the remaining time. The thing is that in a fasted state, I would expect that an active component would work to reduce BG levels post that end point, but it doesn't seem to make a huge amount of difference in me. I would hasten to add that this is observations of myself though and using very small injections.

 

[noblehead]

Looking at the graphs in Bernstein, you see a peak at 60-90 mins, then a fall off after that over the next 90 mins, to a very small concentration for the remaining time. The thing is that in a fasted state, I would expect that an active component would work to reduce BG levels post that end point, but it doesn't seem to make a huge amount of difference in me. I would hasten to add that this is observations of myself though and using very small injections.

But as you question that your levemir might be running out around the time that you did the test last night it would be difficult to say........if you get what I mean.

 

[tim2000s]

But as you question that your levemir might be running out around the time that you did the test last night it would be difficult to say........if you get what I mean.

I do. Based on the observations over time that aren't as acute though, what I tend to see is the sharp drop, which doesn't tend to be followed by a noticeable impact when using low doses. On higher doses there is a very definite hangover effect.

 

[novorapidboi26]

Ill say it again, I need to get myself one of these puppies............

 

[Bogusman]

Where do you get all this info? Peak times, duration, % rates, etc. etc. etc. I have been type1 for exactly 30 years and inject before I eat and before I go to bed, that's it. As we all know Diabetes has a malevolent mind of it's own and to try and work it out is, imo, futile. Maybe not the right attutude but it seems to have worked for me...so far.

 

[tim2000s]

I've been diabetic for 26 years and I have am enquiring, nosey mind. If I have some rudimentary tools it amuses me to experiment to find things out. This, plus liberal use of Google presents a vast amount of data that one can use as one sees fit. The down side of having a very engineer's approach to life.

I like to absorb knowledge about stuff that I do. That doesn't mean that others have to though!

 

[Tranly]

I'm diabetic for 6 months, is pumping Novorapid. Thanks so much for your interesting observations and sharing Tim2000s!

My sugar was quite ok throughout the day until one night 4 hypos woke me up, so I decided to reduce the TDD and do the basal test and other tests as well. But after working out a smaller basal rate that worked during fasting, the whole thing started to clash.. My sugar have behaved very unexpectedly and out of control for a week now. And now I am back with the basal rate before the tests.. I think that I failed totally and my efforts were down right wasted!
---> Do fasting and testings result in loss in balance and unexpected BG readings?
---> According to my little experience, the body is such a interrelated system that one change will make the whole thing crash, including your sensitivity to insulin..

One wired thing I experienced during these rough days is, while wearing a CGM, I observed that after bolusing and eating, my sugar refused to rise but stayed low to even go hypo for 2 to 3 hours after eating, and then all of a sudden spurt to 16.x and stayed there for hours without going down.
---> How can this be interpreted? was my bolus dose too large? was my liver involved in the glucose spike?

Have you ever experienced a higher BG reading 2 or 3 hours after a correction bolus that is meant otherwise? Like I corrected the 10.3 reading and 3 hours afterwards it was 11.8!

Hope someone is kind enough to help me clear this our a little bit!
Huge thanks! ---Ly

 

[donnellysdogs]

The need for changes to basals from one week to another can be due to many things.. Different shifts, being on holiday, periods, having lie ins...So many things.

First off have you sat down and thought uf there was anything different going on when you were having lows? Or now that you're having higher readings.

Any changes in levels on a pump 2-3 hours after having either a food bolus or correction bolus is likely to be your ratio's needing fine tuning.

However, this is not always the case. You can go higher as you just described despite corrections due to other reasons of say the type of food you are eating... Did it need a multiwave bolus when you ate?

If you are going low straight after food (0-120 mins) that would indicate a basal change is needed.

Making adjustments is also analysing your activities, your foods, your sleep patterns, your stress, any illness, your happiness....so many factors besides the pump settings....

 

[LucySW]

I've been diabetic for 26 years and I have am enquiring, nosey mind. If I have some rudimentary tools it amuses me to experiment to find things out. This, plus liberal use of Google presents a vast amount of data that one can use as one sees fit. The down side of having a very engineer's approach to life.

I like to absorb knowledge about stuff that I do. That doesn't mean that others have to though!

Thank goodness for your enquiring nosey mind! And for other people who think out if the box and pursue it.

 

[RuthW]

I'm diabetic for 6 months, is pumping Novorapid. Thanks so much for your interesting observations and sharing Tim2000s!

My sugar was quite ok throughout the day until one night 4 hypos woke me up, so I decided to reduce the TDD and do the basal test and other tests as well. But after working out a smaller basal rate that worked during fasting, the whole thing started to clash.. My sugar have behaved very unexpectedly and out of control for a week now. And now I am back with the basal rate before the tests.. I think that I failed totally and my efforts were down right wasted!
---> Do fasting and testings result in loss in balance and unexpected BG readings?
---> According to my little experience, the body is such a interrelated system that one change will make the whole thing crash, including your sensitivity to insulin..

One wired thing I experienced during these rough days is, while wearing a CGM, I observed that after bolusing and eating, my sugar refused to rise but stayed low to even go hypo for 2 to 3 hours after eating, and then all of a sudden spurt to 16.x and stayed there for hours without going down.
---> How can this be interpreted? was my bolus dose too large? was my liver involved in the glucose spike?

Have you ever experienced a higher BG reading 2 or 3 hours after a correction bolus that is meant otherwise? Like I corrected the 10.3 reading and 3 hours afterwards it was 11.8!

Hope someone is kind enough to help me clear this our a little bit!
Huge thanks! ---Ly

Ly, in a word, yes. I recently reduced my basal rate because I was dipping into hypos too often. That was followed by quite a few high blood sugars, probably because before my basal rate was also working to bring down my post-prandial blood sugars, and now it isn't. I have to recheck my insulin:carb ratios on my boluses, I think.

On you delayed rises, it is possible that it is your basal rate that's wrong. It is also possible that you have delayed stomach emptying. It is also possible that it is the timing of your boluses that is wrong (too long before eating.) you really need to look at each of them in turn. The quickest one to test is timing. You can only know if the real problem is delayed stomach emptying after you have checked the other two. If it is stomach emptying then you can delay insulin delivery in various ways with your pump.

 

[LucySW]

Ly, in a word, yes. I recently reduced my basal rate because I was dipping into hypos too often. That was followed by quite a few high blood sugars, probably because before my basal rate was also working to bring down my post-prandial blood sugars, and now it isn't. I have to recheck my insulin:carb ratios on my boluses, I think.

On you delayed rises, it is possible that it is your basal rate that's wrong. It is also possible that you have delayed stomach emptying. It is also possible that it is the timing of your boluses that is wrong (too long before eating.) you really need to look at each of them in turn. The quickest one to test is timing. You can only know if the real problem is delayed stomach emptying after you have checked the other two. If it is stomach emptying then you can delay insulin delivery in various ways with your pump.

Delayed stomach emptying possibly less likely because Dx only six months ago? (Bar very bad luck ... )

 

[Squid]

How on earth do you get such a lot of information about your diabetes control?
The only thing I can get is my levels using my meter!
Is there a better way of knowing more details than that, perhaps with another type of instrument?
I'm 70 years old, diagnose in 1986, but now realising that I had been suffering since about the age of 28 or so. I'm a T2 by the way and am having a devil of a time keeping up, mostly my hypers!
Thanks

 

[_dja20]

Where do you get all this info? Peak times, duration, % rates, etc. etc. etc. I have been type1 for exactly 30 years and inject before I eat and before I go to bed, that's it. As we all know Diabetes has a malevolent mind of it's own and to try and work it out is, imo, futile. Maybe not the right attutude but it seems to have worked for me...so far.

I have been reading all this with interest. I have had type1 for almost 50 years. Beginning with 2 injections of soluble insulin (fast acting) then going on to Lente zinc suspensions which was only one injection a day. Seemed ideal but unfortunately was not very successful. Urine tests of the time mostly bright orange. Beef insulin was the main one of the time, things move on, I tried the human ones, not suitable, so have used porcine for many years. During all this time I have tried to find a pattern. This has proved to be totally impossible. In some ways I would like to be using all that is now available like Tim, but I have actually concluded, as is suggested in some of these posts, that ones systems vary and react in different ways, that all circumstances will probably never repeat themselves exactly, and that therefore though very interesting, it is just not worth taking on doing extra injections, ie. going on to a basal/bolus system is just not worthwhile. However, I do wish that I could get hold of a c.g.m. for just a couple of weeks to give my fingers a break.