Please can someone explain insulin sensitivity?

[julian27ish]

I did a fasting basal test this morning by skipping breakfast and therefore not injecting any rapid insulin.

At lunch I ate the same lunch I always eat (sandwich, crisps and fruit - 90g of carbohydrate) and injected the rapid insulin I always inject (12 units). This always gives me perfect sugars through the afternoon when measured using my Libre. However today I am sky high 4 hours after my lunch (18/19).

Could the fact I didn't inject at breakfast have impacted this? Could there be some link between insulin sensitivity and the first injection of the day?

Would love to hear if others have experience or knowledge of what is happening here.

 

[tim2000s]

It would depend on timing of breakfast and lunch. Rapid acting insulin can remain in the body for up to five hours.

What did you determine about your basal from the test? Did you find your BG levels increasing towards lunch?

 

[julian27ish]

Yeah I thought about the timing. I inject for breakfast at 7am and for lunch just after 12 so I think I can rule out breakfast insulin usually being in my system still.

My basal test was very interesting. I suffer badly from the dawn phenomenon and I saw that this morning. My sugars started to rise at 6am and continued to do so until around 10am. So my sugars were elevated at lunch, but not as high as 18/19.

I believe it showed me that part of my breakfast insulin is to fight the DP and part is to cover my breakfast. So my breakfast injection will not be a simple insulin:carb ratio. Would you agree with that conclusion?

 

[Diamattic]

@julian27ish - High blood sugars reduce insulin sensitivity as well. So injecting when outside of the normal range you may need more insulin for the same effect then if you were in the normal range.

 

[julian27ish]

Diamattic- that's fascinating. So it's not just because we need some extra insulin to bring our levels down, but it actually increases our insulin sensitivity?

I wonder if that's why I am not very insulin sensitive. My sugars are always messed up

 

[SamJB]

Could be a delayed Dawn Phenomenon response. Sometime I only get DP if I eat. So, if the first time you ate was for lunch, then perhaps you had your DP then.

Doing a basal test in the morning is probably not a good idea. Overnight is best.

 

[julian27ish]

I've not heard of that before, Sam. It certainly could explain why I peaked so much.

I wouldn't usually do a basal test in the morning, but I wanted to see whether my breakfast insulin was partly being used to cover DP and, therefore, whether I can truly use the normal insulin:carb ratio. For example, if I usually eat 50g of carbs and inject 10 units, is some of the insulin being used for the carbs and some for the DP. I think maybe it is and therefore I can't always rely on a ratio of 5, eg if I ate 100g carbs for breakfast and injected 20 units, it might be way too much. Does that make any sense?

I have tested my basal overnight and it seems to keep me steady until 6am if I have a small snack before bed. If I inject less basal and don't have a small snack, I go sky high in the morning. Diabetes is so complicated and I don't have the brain power to work it all out!

Thanks everyone for your replies.

 

[SamJB]

Precisely that. If you experience DP, when you inject at breakfast, you're covering carbs from breakfast and the DP. For example, I need 2 extra units of Novorapid at breakfast to cover my DP.

 

[noblehead]

@julian27ish - High blood sugars reduce insulin sensitivity as well. So injecting when outside of the normal range you may need more insulin for the same effect then if you were in the normal range.

What @Diamattic has said is correct for many of us on the forum.

When bg levels are high (say in double digits) it takes more insulin to bring your bg levels down, so say 1 unit usually brings your bg levels down by 3mmol/l when 9 or below it may only bring your levels down by 1.5mmol/when your bg levels are 11-12 or above.

Something for you to try @julian27ish, when you wake in a morning try having your breakfast soon after, if I don't eat breakfast soon after waking my bg levels increase and within an hour can be in double figures, it's like I get a liver dump as my body doesn't think I'm going to eat, but by eating soon after waking I can stop this from happening and keep normal bg levels throughout the morning.

 

[julian27ish]

You guys are great, this is all so useful! One thing I have found recently has been confusing me and you've now explained it...

I used to inject and wait for about 45 mins to eat as it took that long for the insulin the work and I thought it avoided the spike. However recently I've been eating some of my breakfast straight away, and the rest 45 mins later. It has given me terrible lows. I put it down to my insulin sensitivity being wrong (hence the test I was doing), but actually it sounds like it was because eating straight away avoids a liver dump.

I'll adopt your suggestion and watch closely what happens. Thanks!

 

[noblehead]

Give it a try @julian27ish and see how you get on, I leave a 20 min gap between bolusing and having my breakfast which gives the insulin time to work (but is sufficient to halt the liver dump).

Good luck

 

[donnellysdogs]

When I went back to MDI after a pump my DP seriously kicked in. I just take a small bolus to counteract it. I neverbate breakfast till recently and it never gave me a hypo...
Now I add 1 unit on to my breakfast bolus which I have to have about 45 mins before it..
Also though, I do have to be specific nowadays for injecting my basal 12 hourly..

 

[linda321]

I did a basal test this morning too! I have done basal tests at night time and my blood sugars are level. I decided to do one this morning as my waking blood test was so good at 5.4, and like you I want to see if I am taking so my fast acting insulin is covering DP as well as breakfast. I had 1 mug of black coffee before walking the dog for 1 hour, then another coffee, decaff this time when I got back from the walk. Up until then my BS stayed level, but then increased to 11.8 by late morning. It has stayed pretty high all day, dropped to about 8.8 mid afternoon, but has just risen again before dinner! I haven't got a clue what is going on!!!

 

[robert72]

I did a basal test this morning too! I have done basal tests at night time and my blood sugars are level. I decided to do one this morning as my waking blood test was so good at 5.4, and like you I want to see if I am taking so my fast acting insulin is covering DP as well as breakfast. I had 1 mug of black coffee before walking the dog for 1 hour, then another coffee, decaff this time when I got back from the walk. Up until then my BS stayed level, but then increased to 11.8 by late morning. It has stayed pretty high all day, dropped to about 8.8 mid afternoon, but has just risen again before dinner! I haven't got a clue what is going on!!!

I have to bolus a few units just for getting out of bed, otherwise my basal is spot on. There's no basal insulin that could cope with that waking rise, but I treat it as part of my basal routine.

 

[richyb]

I think some of the DP symptoms might be that the long acting insulin may have run out. I used to be on Levimer which only seemed to last 20 or just about 21 hours. so in a morning for trhe first few hours my main dose had not kicked in. I am now on Toujeo which is supposed to last up to 36hours and so far my control is much better. When I did the DAFNE course it was suggested to miss out on carbs on my mid day meal and check blood sugar at about 4.30 pm to see if it had gone up or down to check basal dose.
I agree that to get sugars down with me, it seems to want slightly more bolus if sugar is high.

 

[erasmusbee]

When I went back to MDI after a pump my DP seriously kicked in. I just take a small bolus to counteract it. I neverbate breakfast till recently and it never gave me a hypo...
Now I add 1 unit on to my breakfast bolus which I have to have about 45 mins before it..
Also though, I do have to be specific nowadays for injecting my basal 12 hourly..

Hi,

I'd be really interested to know why you went back to MDI as I'm thinking of doing hte same.

 

[donnellysdogs]

Hi,

I'd be really interested to know why you went back to MDI as I'm thinking of doing hte same.

Went back to MDI as I was fed up with stainless steel set failures on the Insight pump and I was told by Accuchek that it was probably my body being too lean and mean... However I believe they have withdrawn the steel sets because of breaking needles??? Can't remember if I'm right or not on that point.
Plastic sets just do not work in my body.

I don't regret the decision. In fact I love the freedom of no machine permanently attached. I love getting in bath or shower without thinking...

I've had an op which means I can only use one arm for injections and the same hand for testing so as I also used to wear my pump on my arms it is a great relief as it would now mean that I could only use one cheek of my bum for the cannulas.

I'm also getting just as good blood readings..

Regrets none...

 

[julian27ish]

I did a basal test this morning too! I have done basal tests at night time and my blood sugars are level. I decided to do one this morning as my waking blood test was so good at 5.4, and like you I want to see if I am taking so my fast acting insulin is covering DP as well as breakfast. I had 1 mug of black coffee before walking the dog for 1 hour, then another coffee, decaff this time when I got back from the walk. Up until then my BS stayed level, but then increased to 11.8 by late morning. It has stayed pretty high all day, dropped to about 8.8 mid afternoon, but has just risen again before dinner! I haven't got a clue what is going on!!!

Hi Linda, I have had a very similar experience to you. Those on pumps vary their basal amounts for different parts of the day and I suppose our MDI approach doesn't allow this. So I have given up trying to get my fasting sugars constant and have accepted that I just need to get them as close to constant as possible.

I've found everyone's responses so helpful in that regard. My current basal amount keeps me perfectly constant in the afternoon and evening; but doesn't keep my sugars low enough in the morning. Therefore I have taken everyone's advice and treated a couple of units of my morning bolus as, effectively, part of my basal too.

Similarly, my basal causes a slight drop over night so I just counteract that with a small biscuit before bed (any excuse!). At first I thought all these measures meant my basal amount couldn't have been right but now they're becoming part of my routine I have noticed my control improving markedly.

Early days yet but it's got me out of the rut that was really beginning to get me down.

 

[linda321]

Thanks @julian27ish, I have found this thread really useful! I feel as though I am getting better at BS control. Thanks for asking the question! And thanks everyone for the helpful replies.

 

[julian27ish]

As you were all so helpful with my previous question, I'm going to be greedy and ask another...

Do you find your insulin sensitivity varies depending on the amount of carbohydrate you eat? Personally I find I need to inject a lot more insulin per gram of carbohydrate if I am having a high carb meal, especially at lunchtime. For example: 90g lunch requires 1:7 ratio; 50g lunch requires 1:10.

Any ideas why that would be so?