Why are IC Ratios different throughout the day?

[JontyW]

I have had Type 1 diabetes for 43 years and have been generally well controlled with an average HbA1c of < 7.5%, and as a consequence have experienced no complications. My good control has been achieved by generally having the same amount of carbohydrate for the same meal each day (as was the technique needed in the days before MDI basal/bolus) and dosing based on previously achieved blood glucose results. I eat a lowish-carb diet of about 110 - 130g per day.

More recently I have started reading some diabetes websites to get a better understanding of how to manage my MDI basal/bolus regime since I had been provided limited information on how to optimise this. From these websites I found out about carb counting and the concept of Insulin-Carb Ratios (ICR). So for the last 8 months I have been recording on a daily basis, in a detailed Excel spreadsheet that I have developed myself, all the required data (BG before each meal, carbs, basal each day and bolus each meal, plus comments as needed) to get a better understanding on what might be changing.

Note: I have a degree in Physics so am used to conducting controlled experiments and recording/plotting/reviewing the data. I think this background has indeed helped in achieving my good control so far.

In the spreadsheet I have developed a traffic light system (green - in target,amber - just out, red - out of target) which helps to highlight ongoing changes. In addition I have multiple graphs displaying the daily, 3-day or 5-day average values for all the key metrics. So you can see I have an extremely comprehensive recording and reviewing system. This also predicts the carb bolus required for next meal based on previous BG results (prev day and 3-day ave) and ICR used, and also adds on any correction dose. So carb bolus is always calculated very accurately using the IC Ratio.

Now to my main question: one piece of information that I found from my web searches was about the IC Ratio, and in particular how it can change throughout the day, so each meal (breakfast, lunch and dinner) has a different ratio. I previously had no idea about this concept, and the fact the difference can be so large!

Here are my ratios: Insulin units per 10g CHO

Breakfast:- 11 (40g needs 44u)

Lunch:- 3 (40g needs 12u)

Dinner:- 4 (40g needs 16u)

Questions I would like you to answer:-

1. Why is my breakfast ICR so much higher than the other meals? Bfast -> Dinner = 11 -> 4 (2.8 times MORE bolus needed at Bfast).

2. What is the 'mechanism' in the body that is changing in the first part of the day to require so much more bolus?

2. Up until mid-Nov 2012 the breakfast ICR was about 5, then for no apparent reason it escalated to ~ 10, and has been about this level ever since. See attached screenshot "ICR - JontyW" which shows the 5-day average graph. The Bfast ICR had to be increased to overcome high BG levels pre-lunch. Note that the Dinner ICR has remained constant in the range 3.5 to 4.5, with no dramatic change.

Note: my basal is 12u of Lantus taken in morning and unchanged during the above period.

I would welcome anyone's ideas on this subject .. thanks.

Jonty

 

[Northerner]

1. Why is my breakfast ICR so much higher than the other meals? Bfast -> Dinner = 11 -> 4 (2.8 times MORE bolus needed at Bfast).

2. What is the 'mechanism' in the body that is changing in the first part of the day to require so much more bolus?

2. Up until mid-Nov 2012 the breakfast ICR was about 5, then for no apparent reason it escalated to ~ 10, and has been about this level ever since. See attached screenshot "ICR - JontyW" which shows the 5-day average graph. The Bfast ICR had to be increased to overcome high BG levels pre-lunch. Note that the Dinner ICR has remained constant in the range 3.5 to 4.5, with no dramatic change.

Note: my basal is 12u of Lantus taken in morning and unchanged during the above period.

I would welcome anyone's ideas on this subject .. thanks.

Jonty

Hi Jonty, you sound a lot like me (and many other people) in that you need much more insulin in the morning than later in the day. I inject 8 units fr 12g carbs at breakfast, around 4 units for 50g at lunch, and around 8-10 units for 80-100g evening meal.

The reasons for the high morning dosage is because of the high levels of cortisol that your body produces in the morning as you wake (also known as Dawn Phenomenon). The cortisol stimulates your liver to release glucose from its stores to give you a boost to start the day, but as a diabetic you need to cover this activity with insulin. So, in reality you are not just injecting for carbs, but also for this extra glucose. Also, people tend to be more insulin resistant in the mornings, so the insulin you inject will not be as 'potent' in removing the glucose from your bloodstream and storing it for energy in your cells and liver. Pumpers get round this by setting special basal rates to cover those early hours, but it's not as simple(!) on MDI.

As the day progresses you will become more insulin sensitive, so less insulin needed per 10g, plus there will usually be much less glucose being produced by your liver. 🙂

 

[gabriele]

Hi Jonty W,

I did some experiments some years ago and found out even if I'm not eating , I still neet to inject some units insulin to cover the dawn phenomenom .

 

[PattiEvans]

Jonty

I agree that we do mostly need higher ratios in the mornings when we are most insulin resistant and a lot of us are fighting Dawn Phenomenon, however I see that you're eating approx 110 - 130g carb per day, so I'm assuming that those carb counts you give as an example are fairly typical and therefore you're taking approx 72u bolus per day, yet only 12u basal? This to me suggests that your boluses are propping up your basal and the clue may be found in the fact that in November your insulin needs changed. That's the sort of time of the year (when it gets colder) that many of us find that we need to increase our basal insulins. Have you ever done a basal test? i.e. gone without food to see whether your basal is holding you steady? Apart from what I said earlier, it's normal for basal/bolus balance to be somewhere in between 40/60 to 60/40 whereas your current balance is way way out from that. It's usual for basal insulin to need tweaking every few months, but normally bolus ratios remain more or less static (even though they will vary by time of day).

As you are so analytical may I suggest you obtain a copy of either Gary Scheiner's "Think like a Pancreas" or John Walsh's "Using Insulin" both of which are really really helpful with this sort of conundrum.

 

[JontyW]

Hi Pattidevans,

Thanks for your reply and you have made some good points and in particular about why the breakfast ratio increased dramatically in Nov.

But in that case why didn't the dinner ratio increase and stay higher? Is the temperature that you say affects diabetics, due to the outside temperature and if so how does that work if I'm not outside? Please explain more about " ..when it gets colder... many of us find that we need to increase our basal insulins." .. since I don't understand the logic of this.

Regarding the basal/bolus ratio, I take 12u basal & about 55u bolus (don't normally carb/bolus at lunch, so total 67 with a 18/82 ratio .. much lower than the normal range, as you have pointed out). I have done many, many fasting tests on a variety of basal levels from 20u to 6u, but found varying results when repeating them. But 12u seemed to give a good result (changes during fasting of no more than +/- 1.7 mmol/l). These tests have been typically from 7am until 2pm, some up to 7pm.

And off course I have lots of overnight fasting tests (last carb/bolus at 7pm) then test hourly starting at 7am, which always show a large BG drop (ave 5 mmol/l with a range of 2 - 8 mmol/l) for all basal levels. A drop of 8 mmol/l would mean a hypo at 7am so I have to ensure pre-bedtime BG is always at least 10. This big overnight BG drop is my biggest diabetes problem and I've had this for many many years and the cause in unexplained. My consultant suggested adding Lantus many years ago - made no difference, so I had large variable drops even with no Lantus, then change to Apidra - also made no difference.

I purchased both Gary Scheiner's (have sent my original message to him to get his response) and John Walsh's books back in July and have read several sections many times and now have a good understanding about basal/bolus regime and how to optimise both insulins ..... excellent detailed books!

There is one other issue that you should be aware of, that is I have Addison's Disease http://www.addisons.org.uk/, and I will give more information about this in my reply to Northerner regarding cortisol levels.

Hope that this is not too much to take it but I have presented the information to make it as clear as possible.

Thanks again for all your inputs ...

Jonty

 

[MeganN]

Just an idea but you could move your basal to the morning instead if the evening to avoid the night time drops

 

[everydayupsanddowns]

Just an idea but you could move your basal to the morning instead if the evening to avoid the night time drops

I think Jonty is already taking basal in the morning (I think I read that in previous posts) however the significant drop overnight troubles me - if I have read your posts correctly, you are artificially boosting BGs at night to compensate for a major drop during the early hours (when cortisol and other counterregulatory hormones can be seen to 'dip'). In your shoes Jonty I would want to look at the effect of a split dose of basal, possibly Levemir (or even NPH) which tend to be more responsive and shorter in profile, with less active insulin overnight and more during daylight hours.

It may be that in order to properly/accurately reflect your individual basal requirements an insulin pump is the only real option - but that's a whole different thread!

 

[JontyW]

You are correct .. I take my basal in the morning.

Regarding trying split dose basal, I recently did a 4 day trial on this with 8u at 9am and 4u at 9pm, and the average drop was 5.2, so no real change, with drops of 5.5, 2.4, 6.6, and 6.4.

The drop BG value is measured between 12pm (bedtime) and 7am (on waking) and the attached file (file will not attach .. sorry) shows a graph of the daily value since late Sep-12 and also one of the 3 day ave to smooth out the extremes. So you can see there are quite a few nights when it dropped 7 to 8 mmol/l which meant I awoke (just) at 3.5 or less. Hypo wise I'm still with it just below 3.0 and will wake up OK, although I do have a wife next to me who would assist if needed.

Luckily this hasn't happened since 12 Feb when I went to bed at 10.9 and dropped 9.1 and ended up at 1.8 in a very confused state! On the next few nights I then changed my pre-bed target to 14, and luckily I did since it then dropped 10.5, 9.0, 8.6 .. then all changed back to normal type drop levels again. So you can see my problem ... something appears to change in my body every few weeks or so (no definite frequency) which affects my blood sugar levels.

Another trial I started on Wed (3 days so far) was to ELIMINATE the basal to see what would happen. Drop results on last 2 nights have been 4.2 and 3.7, but on both evenings I have had to eat extra carbs of 10g & 30g (not too sure why this was) to ensure starting BG was near to my target of 10. It is too early to draw any conclusions on this but will let you know when 7 nights have elapsed. But I don't expect any big difference since when Lantus was introduced about 5 years to overcome this problem ... it didn't.

One other comment:- about my BG dropping "AFTER I wake up". I often record what happens between 7am (waking) and 9am (breakfast) and often see rapid drops of up to 2 to 3 mmol/l over those 2 hours. Let's take last night & this morning as an example:-

7pm Dinner: 54g CHO - 23u bolus ICR = 3.9
(no snacks .. I no longer need snacks since using accurate carb counting and ratios!)
12pm - 10.8
7am - 7.1 (overnight drop of 3.7)
9am - 4.4 (drop of 2.7!) ... WHY when last bolus was 14 hours ago and no basal?
- had breakfast & bolus, but pre-lunch (4 hrs later) was low below target of 5.5 at 3.9, (so will have to reduce ratio tomorrow to correct this)

Note: when I test during the night it is always a steady BG drop, with no increases.

You can see I am a very data driven person and I find my spreadsheet so useful 🙂

Thanks for all your help on this rather unusual problem .. I'm determined to find out what is happening & solve it, but have no desire to go on a pump.

BG NOW: 12:15pm - 13.2 (so let's see what tomorrow brings) ....

Jonty

 

[PattiEvans]

Hi Jonty

I think you have just given us all the reason for many of your problems. You have Addisons disease which puts all normal insulin ratios and basal requirements into a completely different dimension and would explain the drops overnight you are seeing.

I fear any suggestions/comments we could make wouldn't be as helpful as normal given the additional problem of Addisons which affects your cortisol levels. I know that Sue who posts on this forum has Addisons disease and is therefore possibly the only person I know who can make any pertinent comments that would address your levels. She is pumping and I believe she has excellent control.

 

[JontyW]

Trying to attach two graph screenshots .. not sure if it will work ....

Jonty

 

[Northerner]

Trying to attach two graph screenshots .. not sure if it will work ....

Jonty

Jonty, I would suggest using photobucket to put graphic images in your posts as there are some very tight restrictions on attaching images via the forum. With photobucket you upload your image then copy and paste the 'IMG' code into your post. The service is free.

http://photobucket.com/

 

[JontyW]

Here are the three graphs that I wanted to share .... (with thanks to Northerner for the tip about using Photobucket ...)

1. Night Drop (top graph is every night, seond one is 3-day average)

2. Waking BG ... where you can see quite a few mornings it was .. hypo time :-(

 

[JontyW]

The reasons for the high morning dosage is because of the high levels of cortisol that your body produces in the morning as you wake (also known as Dawn Phenomenon). The cortisol stimulates your liver to release glucose from its stores to give you a boost to start the day, but as a diabetic you need to cover this activity with insulin. So, in reality you are not just injecting for carbs, but also for this extra glucose. Also, people tend to be more insulin resistant in the mornings, so the insulin you inject will not be as 'potent' in removing the glucose from your bloodstream and storing it for energy in your cells and liver. Pumpers get round this by setting special basal rates to cover those early hours, but it's not as simple(!) on MDI.

As the day progresses you will become more insulin sensitive, so less insulin needed per 10g, plus there will usually be much less glucose being produced by your liver. 🙂

Hi Northerner,

Firstly, I didn't mention that I had Addison's Disease (although my profile does state that) because I wanted to see what suggestions came up.

I have now completed last night -> early this morning regular blood tests to show you what is a typical trend. Here are the BG taken roughly an hour apart ... (last bolus was 7pm for dinner)

12:15 - 13.2
5am:- 9.1 (drop of 4 in 5hrs)
6am:- 8.6
7am:- 8.8 (drop of 4.4)
(took 10mg hydrocortisone to boost cortisol level as per Addison's treatment .. see below)
8am:- 6.9
9am:- 8.1 (increase possibly due to hydrocortisone dose at 7am?)
10am:- 6.4 (stopped test .. had breakfast)

Here is the graph to show the trend. You can see the BG just keeps on dropping throughout the night and into the early morning.

For a 'normal' - non Addison's person, the Dawn Phenomenon should release cortisol which would cause the liver to secrete glucose back into the bloodstream and the BG would rise. But the opposite happens with me, and I guess this is because I'm not creating any cortisol and so have to take hydrocortisone tablets three times a day to artificially create cortisol to match the normal creation during the day.

THE NATURAL DAILY CYCLE OF ADRENAL HORMONE PRODUCTION (from Addison's manual)
In a person with healthy adrenals, cortisol levels start to rise around 4am, are at their maximum around the time you wake up in the morning (7am in my case) and then gradually taper off during the day. That is why you will be advised to take your largest divided dose (hydrocortisone) first thing in the morning.

My Addison's hydrocortisone dosage: 7am: 10mg; 2pm: 10mg; 6pm: 5mg

So why is the BG dropping during the night/early morning when the last insulin (bolus) was at 7pm the previous evening, and so should be used up after 5 hrs .. by 12pm? That is the key question to answer I think....

What would happen if I did not have an evening meal carbs or bolus ... what would BG do overnight?
Well I did this test in May, without planning it, when I has a sickness/vomiting bug during the day.
Sick during day so no carbs or insulin (Lantus or Humalog).
Results:-
Fasting test over night:- 1am - 6.1, 4am - 6.7, 6am - 5.7, 7am - 5.2, 8am - 6.0, 9am - 7.2 (had Hydrocortisone)
Conclusion:- Steady BG with no significant drop. Since I still get a big drop without Lantus (as per last night), the big BG drops I usually get must be due to the 7pm bolus which seems to last up to 15 hours ... is that possible?

I welcome your comments...

Jonty

 

[Northerner]

Conclusion:- Steady BG with no significant drop. Since I still get a big drop without Lantus (as per last night), the big BG drops I usually get must be due to the 7pm bolus which seems to last up to 15 hours ... is that possible?

I welcome your comments...

Jonty

A couple of possibilities: perhaps when you did the test without having food/bolus appeared different to the normal trend because of increased insulin resistance due to the illness? Another possibility, given that you have been diagnosed for over 40 years, is that your insulin absorption is poor or 'pooling' at your injection site, giving you a much delayed drop overnight?

 

[JontyW]

I think you have just given us all the reason for many of your problems. You have Addisons disease which puts all normal insulin ratios and basal requirements into a completely different dimension and would explain the drops overnight you are seeing.

I fear any suggestions/comments we could make wouldn't be as helpful as normal given the additional problem of Addisons which affects your cortisol levels. I know that Sue who posts on this forum has Addisons disease and is therefore possibly the only person I know who can make any pertinent comments that would address your levels. She is pumping and I believe she has excellent control.

Hi Patti,

I think you have reached a very reasonable conclusion in Addisons being the controlling factor. That is why I have stopped the basal and have now found that it did not make any difference. Only change one thing at a time ... or else it can get confusing.

Am I correct in assuming it is "PumperSue" that has experience of managing diabetes & Addisons?

Thanks for your helpful comments ...

 

[pgcity]

How about testing your basal by skipping your evening meal a few times when you are not ill. If it is stable then you know that you need to look at your evening meal. What kind of things do you eat? Are they low gi or hgh fat? The night time drop may just be your body digesting the food and the hypos coud be activity or alcohol related.
Alternatively things just change and you never find a reason.

 

[trophywench]

Just wondering here - I know very little detail about Addisons.

To make you mimic a non-A person, you would need to take your first tablet about 4am or just before, wouldn't you? so that's ridiculous.

But no longer acting insulin has yet been invented that actually caters for a person with Addison's.

Do you not fancy a pump?

 

[PattiEvans]

Am I correct in assuming it is "PumperSue" that has experience of managing diabetes & Addisons?

Yes she is. Honestly I can't see how we can advise given the hormones in play which we, as T1s don;t have to cope with.

 

[JontyW]

Just wondering here - I know very little detail about Addisons.

To make you mimic a non-A person, you would need to take your first tablet about 4am or just before, wouldn't you? so that's ridiculous.

Last night I decided to do a trial to test this out. So by taking the hydrocortisone 3 hours earlier (at 4am) to see how the BG changes from 4am to 10am. I also decided to double the dose to 20mg because my current 10mg at 7am shows a steady BG decrease even after 7am (blue line).

The starting BG at 12am was more like the normal of 9.8, and this graph shows how the two trials worked ....

Conclusion: the BG was essentially flat from 4am to 8am (red line), but then started to rise rapidly. Even so, looking at the Change values in table on left up until (9am; 5hrs after hydrocortisone tab) the max change is -1.9. In comparison, for the 7am - 10mg test, the change to 9am was much greater -6.3. So a really big improvement and this shows that the earlier cortisol is triggering the liver to release glucose at a time/rate more matched to the residual bolus. I think I've got that right .. haven't I?

I'm still trying to get my head around what could be going on because there are three potential conflicting parameters that are trying to change the BG.

1. Residual bolus from evening meal, trying to reduce BG.
- I need to understand what it is about my evening meal and insulin sensitivity which could cause this
2. Background balas (although currently removed), trying to reduce BG
3. Hydrocortisone cortisol, causing liver to raise BG (but only from 7am or 4am)

In addition I have to ensure that:
4. Cortisol level throughout the day .... must be optimised to ensure 'near normal' cortisol needs

So I can fully understand how it is probably only a pump that could address this complex situation.

Tonight I will try one further trial using 10mg at 4am to see what happens. And also look into my evening meal GI which is an area I have not explored as yet. But I do eat pretty healthy food, all cooked by myself and which is grilled rather than fried, all fat removed, lots of vegetables etc.

But no longer acting insulin has yet been invented that actually caters for a person with Addison's.

Do you not fancy a pump?

Regarding a pump, if I was just a normal (non-A) T1, I strongly believe that I could achieve improved HbA1c (from last one of 7.2% to ~ 6.5%). This is based on my previous long term experience but enhanced by my recent gain in knowledge about carb counting, using IC ratios to calculate bolus plus my detailed spreadsheet.

However ..... having Addisons adds a new control dimension, and my current situation has two disadvantages:-

1. Risk of early morning hypos due to occasional large overnight BG drops
2. Higher than ideal HbA1c due to targeted high BG (10 mmol/L) in evening and first few hours of sleep, to protect from 1. above from happening

I always go for the simplest and most effective solution, so I need to do a few more trials to see what conclusion I come to.

But it has certainly made it much easier for me to understand and explore the various issues, by having such knowledgeable and helpful forum members ... many thanks

Jonty

 

[Anna1]

Hi JontyW
What symptoms did you get for Addisons disease? My BG always goes down by itself in the evening same time every night and like you I have to go to bed on 11 or 10 to wake up on about 7 by 7 am. I am on Tresiba. Recently the drop in the evening has been more substantial and I seem to be much more insulin sensitive then I used to be. I have lost 1 1/2 stone in weight (which was by choice so I know this can have an affect on insulin sensitivity) but I have gone from 48 units of Levemir in the morning to just 17 units of Tresiba. I take about 19-20 of Novo per day and like you the Novo seems to stay in my system for ages as just keeps clocking down towards the evening and overnight. Seem to be ok most of the time during the day and up to about 3pm. Generally feel tired, sometimes feel dizzy for about 2 seconds on standing quickly, had lowish blood pressure last check 97/71 and just feel generally tired climbing the stairs but disappears once I'm up and moving around again. Could Addisons be possible and the lack of Cortisol causing my drop in BG do you think? Or are symptoms more severe then that? Any advice would be appreciated as struggling with sudden drop in the evenings and if I reduce my basal further my ratios in the morning would need to increase meaning more novo in my body - sorry I know this is an old post but thought I would try Thanks