Background Insulin re Bedtime Testing

[mum2westiesGill]

Before i have my each of my main meals ie breakfast, lunch & dinner i always test first then either inject & eat or eat & inject.....i'm on Humalog QA.
When it comes to supper time sometimes i have supper sometimes not, depends if i'm hungry or not. If i'm having supper i always have it downstairs whilst watching tv then do my test a bit later when i go to bed. Am i doing this the right way round or should i be testing before i have my supper? i'm on Lantus BI, which i believe lasts approx 24hrs.

Thank you for any help about this. 🙂

 

[Robster65]

Hi Gill.

I've never seen supper as something I can have unless I test and find I'm not high enough for bedtime (eg. 5/6ish).

If you're going to eat supper anyway, I would try and factor this in with either your teattiem humalog, depending on when you eat, or with your lantus, if you can, to cover the supper and overnight basal needs.

It's a drawback of T1 that you can't just eat when you feel hungry, but have to factor it in with the insulin and lifestyle effects.

Rob

 

[mum2westiesGill]

Hi Gill.

I've never seen supper as something I can have unless I test and find I'm not high enough for bedtime (eg. 5/6ish).

If you're going to eat supper anyway, I would try and factor this in with either your teattiem humalog, depending on when you eat, or with your lantus, if you can, to cover the supper and overnight basal needs.

It's a drawback of T1 that you can't just eat when you feel hungry, but have to factor it in with the insulin and lifestyle effects.

Rob

Thanks for the reply Rob.

I usually have tea & humalog about 7pm - 8pm ish then supper (a sandwich) about 1030pm - 1100pm ish.

 

[Robster65]

Your supper would be within the action time of the teatime humalog. You really need to test before your supper and only eat the sandwich if you're low.

Your basal may be artificially high to cover for the supper, which would make it difficult to get your daytime BGs right.

If it were me, I'd try and factor in the sandwich with the teatime humalog and try and time the supper right to be covered by the humalog.

That way, your basal only needs to cover the glucose from your liver and not additional meals, which it isn't really intended for.

I've only ever seen a supper as a boost before bedtime if needed, when I've been more active or under estimated teatime carbs.🙂

Hope this helps.

Rob

 

[mum2westiesGill]

Your supper would be within the action time of the teatime humalog. You really need to test before your supper and only eat the sandwich if you're low.

Your basal may be artificially high to cover for the supper, which would make it difficult to get your daytime BGs right.

If it were me, I'd try and factor in the sandwich with the teatime humalog and try and time the supper right to be covered by the humalog.

That way, your basal only needs to cover the glucose from your liver and not additional meals, which it isn't really intended for.

I've only ever seen a supper as a boost before bedtime if needed, when I've been more active or under estimated teatime carbs.🙂

Hope this helps.

Rob

Thank you for the help Rob 🙂

 

[trophywench]

I agree with Rob.

You have to inject fast acting whenever you eat carbs. So you need to test - if your BG is high or if it's low you'd have to adjust the insulin you have for the snack, and you won't have a clue. However if it's within 4 hours of your last jab, there will still be some fast-acting left in your system which you need to factor in to your jab for the snack.

Think DAFNE say you can have a snack under 10g carbs and not inject, just correct next mealtime, but it's rare I'd do that. 10g increases my BG by 3 mmol so to have that without insulin my pre-snack BG needs to be no more than 4.0. Rare!

However, why have carbs? if you eg had a lump of cheese instead of anything bread you'd not have to bother, and anyway the mental arithmetic factoring in what might be left over from previous jabs etc is just too complicated ......

 

[Ellie Jones]

Sorry but I disagree with what Rob is saying..

Whiskeymum

You need to keep background and quick acting completely separate, use quick acting insulin for the food you are about to eat..

If you incorporate your supper insulin with your tea, it is likely that you will hypo before you eat your supper if you don't then this would suggest one of two things, either your carb ratio is out or your basal is out... But either way it will mean that you won't have enough insulin to either prevent your supper spiking or enough to cover the supper and your BG is likely to raise to high,

If it doesn't do this this suggest that your basal insulin at this point of the night is way too high, and that if you didn't have the supper you would have had a hypo..

You need to ensure that your basal is correct first otherwise all your other working out will be incorrect..

Then you work out your correct carb/insulin ratio's for meals/time of day. and also how long your quick acting insulin is working in you, a general rule of thumb to start with is humalog/novorapid.. takes 10-15 minutes to kick in, peaks at the 2 hour mark, at this point around about 80% of the dose has been used and the tail end burns out with mim impact on BG over another 2 hours... But this can be different for individuals.. So needs working out.

You then use this information and your pre-food BG, carbs amount, to calculate your dose, with taking into consideration a couple of other factors, such as exercise etc..

 

[Robster65]

Sorry but I disagree with what Rob is saying..

Whiskeymum

You need to keep background and quick acting completely separate, use quick acting insulin for the food you are about to eat..

If you incorporate your supper insulin with your tea, it is likely that you will hypo before you eat your supper if you don't then this would suggest one of two things, either your carb ratio is out or your basal is out... But either way it will mean that you won't have enough insulin to either prevent your supper spiking or enough to cover the supper and your BG is likely to raise to high,

If it doesn't do this this suggest that your basal insulin at this point of the night is way too high, and that if you didn't have the supper you would have had a hypo..

You need to ensure that your basal is correct first otherwise all your other working out will be incorrect..

Then you work out your correct carb/insulin ratio's for meals/time of day. and also how long your quick acting insulin is working in you, a general rule of thumb to start with is humalog/novorapid.. takes 10-15 minutes to kick in, peaks at the 2 hour mark, at this point around about 80% of the dose has been used and the tail end burns out with mim impact on BG over another 2 hours... But this can be different for individuals.. So needs working out.

You then use this information and your pre-food BG, carbs amount, to calculate your dose, with taking into consideration a couple of other factors, such as exercise etc..

That's why I said it's best to avoid carb snacks unless needed. The teatime humalog will still be acting 3 or 4 hours after tea, so to give extra humalog for a snack would be dangerous so close to bedtime, unless you're absolutely certain you know how much to give.

Which, as trophywench says, is too complicated to work out for sure.

If the supper can be within a couple of hours of tea, depending on what was had for tea, it could possibly be factored into the teatime bolus with care. 🙂

Rob

 

[Ellie Jones]

Aren't you insulting whisky mum's intelligence?

Sorry but I find it very insulting to she can't be given information because you deem that she hasn't got the intelligence to make a calculation!

What you are suggesting is putting whisky mum at great risk of hypo before she has supper, plus leading to a possibility of a night-time hypo.. But also it doesn't teach her the complexities involved in prompting good control.. And makes finding out where a problem lays and how to best resolve it..

The calculation isn't that complex that you need to be genesis to calculate it, and if you've got a dash of common sense (and I can't be the only genesis or holder of common sense about) then you use a cautious approach..

 

[Robster65]

Ellie, we seem to have got some crossed wires somewhere.

I was merely pointing out to whiskysmum that to eat a snack 3 or 4 hours after tea, she would still have active humalog on board, her BG might still be dropping and being so close to bedtime, she might not be able to do another test after 2 hours to check it.

I have had much trouble with this in the past and was trying to pass on my experience to WM who had asked about supper and testing.

I don't profess to be an expert, merely a long in the tooth diabetic, like yourself and trophywench, who have largely been there and done that.

I apologise if I upset you or whiskysmum. That wasn't my intention, but I stick by my original postings.🙂

I believe that eating carb snacks of more than 10-15g before bed, if they're not needed for correction, can cause problems with basal calcs and I wouldn't want to give a bolus for them.🙂

Rob

 

[trophywench]

OTOH EJ if it's me you think is insulting intelligence, please can you tell me the formula of calculating 'bolus on board' if it's withing whatever the active time for you personally?

Say it's 4 hours and you take 5 units - after 3 hours, how much do you have left, bearing in mind it's had a peak before 3 hours. When and how much did it peak? It will be less than 1.25 units anyway, won't it?

If there is a way of calculating that precisely enough, I would genuinely be pleased to know it - no sarcasm whatever - it would help no end.

Plus - sorry! - I can't actually fathom what you mean by 'genesis' in this context? - it generally means beginning, birth, commencement, creation, dawn, origin, root, source blah blah blah - nor can I think of a similar word that would seem to fit the bill?

 

[mum2westiesGill]

Hi,

Can i just say to Robster65 that it's ok you've not insulted my intelligence. When i come on here to ask any questions (which is all that i seem to do on here) i always read & try to take on board any advice.....Just hope now that i've not upset anyone 😱

 

[Robster65]

I can't imagine anyones upset WM. 🙂

With the limitations of writing replies, some of the meaning or intention can get lost in translation.

And we all have slightly different opinions and sometimes like to defend them to the hilt !

Keep asking and we'll keep shouting the answers back.

Rob

 

[mum2westiesGill]

I can't imagine anyones upset WM. 🙂

With the limitations of writing replies, some of the meaning or intention can get lost in translation.

And we all have slightly different opinions and sometimes like to defend them to the hilt !

Keep asking and we'll keep shouting the answers back.

Rob

Cheers Rob & don't worry i'll keep on asking cause you never stop learning 🙂

 

[Northerner]

I do agree that, as has been said, I would rather not get into calculations about insulin on board and bolusing for late-evening snacks before bed, so have always avoided supper unless my evening meal bolus was overestimated and sent me uncomfortably low before bed - then I would eat something, of course. For me, it's not a matter of complex calculations, but simply a matter of safety. I live alone and have always tried to ensure that I have no (or as little as possible) active fast-acting insulin before bed, because the consequences of a night-hypo could be dangerous. As I've never done it, I don't have the experience to know how sleep might affect my ratios, and this is difficult to learn anyway as you would have to wake regularly to test.

So, I would always test before eating close to bedtime, and only eat if my levels required me to do so - not necessarily hypo, as I wouldn't go to bed on a 4.5, for example.

I think if you do want to eat close to bedtime you have to be prepared to inject for it and test that the injections will not send you low - too much uncertainty for me there. Alternatively, you don't inject and yet still wake to normal levels, which may mean your basal is too high overnight if it can also deal with the food as well as the liver. 🙂

Yes, you can probably work all these things out, but there will always be an element of risk - it is diabetes, after all! I prefer to keep my risky times to when I am likely to be awake and able to react quickly.

 

[Ellie Jones]

Calculating your bolus needs...

Pretty easy really or I find that it is..

I use a pump now, so the calculation is slightly easier for me, as I don't have to consider on what part of the basal wave I'm on...

I know that my insulin duration is 4.5 hours, from the peak at 2 hours to 4.5 hours my BG will drop a futher 1mmol/l give or take a 0.1mmol/l or 2...

I also know that if I had a high fat meal or eaten pasta I'm going to get around a 2mmol/l raise in BG between 5 hours and 7 hours after I've eaten it..

So when it comes to eating a snack 2 hours after eating a meal that I've taken 5 units of insulin, I will have 1 unit on board, (3 hours after I'm going to have just under 0.5 unit..)

So if my BG is 5.6 mmol/l I know that my BG is unlikely to fall below 4mmol/l before it burns out.. If it's in the 4's then I take the lowest point it would go, and work how much I reduce or add carbs to correct.. Then work out my dose from that... And if I was due to be going to bed not long after eating, I would further reduce my dose to give myself a safety net..

I then consider what I've been doing that and what I'm going to do, I know that if I've been out with the dogs or working in the cold, then my bolus for the afternoon needs to be reduced... And certain types of exercise will lag into the next day so I have to make between 5-16% reduction for these..

So yes it can be worked out, but you've got to do the foundation work to find out the information and understand your diabetes... Which I find a lot of people including my own husband can't be bothered to do..

 

[Northerner]

...So yes it can be worked out, but you've got to do the foundation work to find out the information and understand your diabetes... Which I find a lot of people including my own husband can't be bothered to do..

It's not necessarily a case of 'can't be bothered', it might just not matter enough. I rarely want anything to eat after my evening meal so it's not an area for me to spend time investigating. I remember when I broke my leg and the physio asked me what I wanted to do - I replied that I wanted to be able to run marathons again, so he gave me a much tougher programme to follow to achieve this. He explained that, for some people just being able to walk to the pub might be their limits, so their rehabilitation was much simpler! 🙂

But thank you for your explanation Ellie, you never know and things might change for me and now I will know how it might be approached 🙂

 

[Robster65]

There's also the point that for many people, their diabetes isn't so predictable, and on MDI isn't so controllable.

But again, well done for working it all out and thank you for explaining it to us. 🙂

Rob

 

[trophywench]

There's also the point that if 1u drops your BG 3 mmol or more and you don't have the luxury of a half unit pen let alone a pump - you have to be very very very careful indeed.

Best not to risk it IMHO.

 

[Ellie Jones]

@northener

I agree it's not the case that all fall into a 'can't be bothered' there is a lot out there that just don't know as nobody tells them!

That was my gripe..

Whiskmum was being done a disfavour because other people were making an assumption that either they couldn't do the calculating or perhaps that the individual might by chance be in the 'can't be bothered to' group..

@Robert

No my diabetes wasn't always predictable and I wouldn't know why one day I would have a hypo less than 2 hours after having breakfast but the next day be as high as a kite😱 Nothing made sense.. But I now know that this was purely down to ignorance I actually fundamentally didn't have a clue what I was doing... Once I starting learning then it started to become clearer where my problems lay and I could work out insulin adjustments to compensate for the excess peaks and trough's of an unstable basal profile, to a certain degree.. And it highlighted my need for an insulin pump, to make life a lot easier for me as I the ability to flatten my roller coaster of a basal profile in a decent working line to work from.. And deliver a dose of insulin to suit my needs and not up carbs to match the minimum dose of an insulin pen!

And on forums I do find that a lot of people who say I've got 'unpredictable' or 'Brittle diabetes' fundamentally their control problems lay in that they don't have the knowledge to work out what's what..

I know that I can't even now or when I was on MDI tag insulin on to tea for a supper I intended to eat a couple hours later as my BG would land in my boots very quickly.. By doing this mixing one lot of insulin from one meal and/or snack with another meal/snack ends up with my control becoming unpredictable..