Purpose of basal insulin

[Lucyr]

At the first day of the T1 course this week the DSN said the purpose of lantus is to drop you to your target BG overnight. On forums I’ve always read that lantus purpose is to keep you steady. Which one is true? I’m guessing it is the DSN but where does the online belief come from if so?

Here’s the two basal tests I did before the course

Test 1: 6pm lantus and dinner. 1030pm start test 14.8. Waking bg 7.5, steadily rose all morning peaking at 14.4 and dropping slightly to 11.9 by lunch

Test 2: 5:45pm lantus and dinner. 10pm 9.0, waking bg 6.0, steadily increased all morning to 11.1 before lunch.

My thought before the course would have been to reduce lantus, but following the principles of the course I checked my average morning bg which was 8.7 and so increased my lantus as well as adding some apidra when I wake up.

Since increasing lantus my waking bgs were 6.6 yesterday and 5.1 today.

So… what actually is the purpose of lantus? To drop you or keep you steady?

 

[Inka]

I remember trying to explain something similar to that here @Lucyr I’ve always been told that basal is to hold your blood sugar steady and in range in the absence of food. So I suppose that includes some blood sugar adjustment - ie slight movements up and down in blood sugar engineered by the basal if needed.

 

[Lucyr]

Thanks. The follow on question I haven’t asked yet but have written down is… if basal drops you overnight does than mean I shouldn’t correct with apidra because the lantus is already dealing with it and extra apidra would make you drop too much. Or I should because apidra is quicker and lantus will only drop you if you need dropping.

Then a question I don’t expect an answer to, if lantus drops you only to an in range bg and doesn’t drop you if you don’t need it, then why can’t we use that technology in rapid insulins so that they don’t make you low they only drop you to a normal bg?

 

[Inka]

I’m on a pump @Lucyr so it’s a bit different for me, but recently I’ve found my basal drops me a bit during the night. Really I should look at tweaking my basal rates but I can’t be arsed as I’m too busy, so I go to bed in the 7s knowing my basal will drop me into the 5s. However, I would be more wary with a basal insulin via pen and would make sure it wasn’t dropping me too low and/or have a bedtime snack.

I hope I haven’t misinterpreted what you’re saying - apologies if I have - but Lantus in and of itself doesn’t necessarily drop people (it’s not automatic, it’s dose dependent and time dependent) and there’s nothing ‘special’ about it that makes it lower blood sugar into a normal range and not further into a low range. It has no Off Switch. If somebody took too much Lantus, it could easily drop them too low overnight.

 

[Robin]

Then a question I don’t expect an answer to, if lantus drops you only to an in range bg and doesn’t drop you if you don’t need it, then why can’t we use that technology in rapid insulins so that they don’t make you low they only drop you to a normal bg?

I don’t believe any current insulin (Lantus included) has the ability to work only when needed, and I think a lot of money is currently going into trying to develop a 'smart' insulin that will only work when needed..but we aren’t there yet.

 

[Lucyr]

I’ve always been told that basal is to hold your blood sugar steady and in range in the absence of food. So I suppose that includes some blood sugar adjustment - ie slight movements up and down in blood sugar engineered by the basal if needed.

I think it’s this bit that’s confusing me… how does the “and in range” bit work? maybe I write it down as a question for the consultant when they come to the course

 

[helli]

Like @Inka my understanding has always been that basal keeps our BG steady in the absence of any other insulin or anything that could affect BG such as exercise or food. It was described to me as “mopping up” the glucose that is dripped from our liver.
This is why basal testing is done by removing these other BG affecting things and checking BG remains stable.
All injected insulins we have today follow a fixed profile. This profile may be slightly different for different people but every time I took Lantus, I would know approximately how long it would last and when the peak activity would be.
The only time is may appear to differ is if my BG was high, I would become insulin resistant to the Lantus so it would seem to have such an impact.

I do not understand why your DAFNE course suggestion that Lantus would drop you to your target BG. That makes no sense with basal testing.

 

[Lucyr]

The only time is may appear to differ is if my BG was high, I would become insulin resistant to the Lantus so it would seem to have such an impact.

Interesting that this is the opposite for me. The higher I am before bed the more I drop overnight.

 

[Inka]

I think it’s this bit that’s confusing me… how does the “and in range” bit work? maybe I write it down as a question for the consultant when they come to the course

This is where I was discussing. People often miss out the ‘in range’ bit. The aim of a basal insulin is to hold you steady and in range in the absence of food. I’ll look for my previous post about this as hopefully you’ll see what I’m trying to say.

 

[Inka]

Here:

Post in thread 'Split basal insulin question'
http://forum.diabetes.org.uk/boards/threads/split-basal-insulin-question.110635/post-1327272

Hopefully that will link to my post. If somebody’s basal held them steady at 12mmol, they would need more basal because it’s supposed to hold them steady AND in range. If someone’s basal held them steady at 3mmol, they’d need less basal even though they were steady because they were not in range. People seem to omit that last bit, and I’m wondering if that was why it was mentioned by your nurse.

 

[Bruce Stephens]

The higher I am before bed the more I drop overnight.

I imagine that suggests you still produce enough natural insulin to cause that.

 

[Lucyr]

Here:

Post in thread 'Split basal insulin question'
http://forum.diabetes.org.uk/boards/threads/split-basal-insulin-question.110635/post-1327272

Hopefully that will link to my post. If somebody’s basal held them steady at 12mmol, they would need more basal because it’s supposed to hold them steady AND in range. If someone’s basal held them steady at 3mmol, they’d need less basal even though they were steady because they were not in range. People seem to omit that last bit, and I’m wondering if that was why it was mentioned by your nurse.

Oh, I think I’ve got it with this bit now! It’s maybe something about your body naturally liking to be in a normal range too. So if you go to bed high and wake up high, it’s not enough lantus because your body will have been trying to pee out the glucose all night too. If you go to bed low and wake up low then your body will have been fighting the low eventually overnight by dumping glucose but lantus is overpowering that as well.

 

[Lucyr]

I imagine that suggests you still produce enough natural insulin to cause that.

The amount I produce is erratic, but given my average bg over the last 30 days is 13.1 and time in range of 30% don’t think my body’s insulin is currently particularly significant and wouldn’t be causing all of the extra drop when high. I’m already down to an average of 9.7 and 61% time in range over the last 7 days though and I’m only 2.5 days into changing insulin doses.

 

[Bruce Stephens]

The amount I produce is erratic, but given my average bg over the last 30 days is 13.1 and time in range of 30% don’t think my body’s insulin is currently particularly significant and wouldn’t be causing all of the extra drop when high.

How odd. I wonder what is? Maybe your liver varies a lot in how much glucose it releases.

 

[Lucyr]

How odd. I wonder what is? Maybe your liver varies a lot in how much glucose it releases.

I assume when high overnight your body sends some of the glucose to be peed out, on top of what the lantus is doing, making me drop more?

Lantus confuses me though, I think I’ve vaguely got what its purpose is now but I’ve still not really understood whether I was right to increase my lantus or whether I should have reduced it or repeated the tests more first.

 

[Tdm]

Interesting that this is the opposite for me. The higher I am before bed the more I drop overnight.

Wonder if its your own bodies insulin???

 

[Lucyr]

Wonder if its your own bodies insulin???

When I had my cpeptide test (no bolus) I was still 18 at 2hrs after eating though, which suggests the small amount I make doesn’t really cut it with highs?

 

[Tdm]

When I had my cpeptide test (no bolus) I was still 18 at 2hrs after eating though, which suggests the small amount I make doesn’t really cut it with highs?

Perhaps your body is filling it glycogen stores overnight, given it sees you have sufficient glucose sloshing around?
Or perhaps its just diabetes, diabetes-ing!

 

[everydayupsanddowns]

My own take on this is that if my Lantus was at high enough a dose to consistently reduce my BG by 4-5mmol/L overnight, then that would be fine if I went to bed at 10mmol/L.

But if I went to bed at 6.5mmol/L I’d have a hypo starting about 2-3am that continued until someone tried to wake me up in the morning.

So I definitely did NOT want Lantus to do anything but hold me level(ish), wherever that happened to be.

And I didn’t want have to eat carbs at bedtime to protect me from the risk of an overnight low either.

If I worried about being in double figures at bedtime I’d most likely have given myself a nudge of half a unit or whatever at about 10pm which would be all but finished by the early hours.

I think we all just develop systems and strategies that seem to suit us and the way our bodies work.

 

[Lucyr]

I think I’m going to call this close enough with Lantus to move onto other things? I am still dropping overnight but not having any lows and averaging 7s in the morning, lowest was 4s one day.

I think the next problem to fix is the morning rise, so now I’m trying to work out how much apidra to take when I wake up to stay level in the morning. I am feeling like I need to sort this out before I can really refine ratios? Have attached this morning so far (coffee with milk and apidra no breakfast).

Can I assume Lantus is close enough then come back to it when other things are closer to refine it? Or is everything else going to change then if I change the Lantus dose? Diabetes is constantly changing anyway.