Why has my Insulin-Carb Ratio changed so much?

[JontyW]

Hello,

Some background
I've been a Type 1 diabetic for 43 years, diagnosed in 1969, but have managed my diabetes pretty well over that long period, and as a consequence have experienced no complications. Being scientifically trained as a physicist has helped me since I am good at maths and making adjustments and monitoring the outcome etc. I have never been on a DAFNE course, and up until recently just used common sense, experience, plus guesswork to get the required insulin dosage. Although having found this excellent document has made me fully aware of what basal/bolus regime means (nobody told me about that) ...

Carb Counting & Insilun Adjustment:
Carbs count e-book ? An introduction to carbohydrate counting and insulin dose adjustment

https://shop.diabetes.org.uk/store/literature/information-books/carbs-count-e-book.aspx
and that IC ratios are the key to adjusting the bolus (why would you need to go on a DAFNE course once you've read and understood that?)

I am on a basal/bolus regime of Lantus (am) plus carb related Humalog for breakfast and dinner. I don't have a carb lunch or bolus in order to keep my weight down, although my BMI at 24 is just in the normal range. I weigh 74Kg but the amount of bolus that I require is very high compared to the 'normal' range. My typical insulin doses are as follows:-

Lantus (9am): 12
Humalog (Bfast): Ratio = 12! (this is VERY high) Carb: 30g, so 30g CHO needs 36u bolus
Humalog (Lunch): Ratio = 3 10g CHO needs 4u bolus (usually don't carb/bolus at lunch) .. just have 10g CHO
Humalog (Dinner): Ratio = 4 Carb:45g so 45g CHO needs 18u bolus

My HbA1C's over the last 12 years have been within the range 7.0% - 8.0% with an average of 7.5%. Last one (Aug-12) was 7.2% (55) and is the lowest since I've started learning about basal/bolus and IC ratios etc and inputting all readings to a complex Excel spreadsheet. This spreadsheet 'predicts' what my bolus should be for:-
1) average of last 3 days readings/results
2) last day's results
3) based on these 2 suggestions I will input required bolus (plus add any correction does needed)
... to predict what bolus input for next meal assuming the ratio may need to be changed based on past results (this is quite advanced monitoring .. but remember my background 🙂

Long-term issue
I have for many years experienced large overnight BG drops (up to 8 mmmol/l, with an average of 4 mmol/l) for no apparent reason, even with a correct basal level. So my pre-bedtime BG is always about 10 - 11 to prevent having an early morning hypo on the few occasions when a large BG drop is experienced. As a consequence my diabetes consultant has set my target HbA1c to be slightly higher than normal at <7.5%, and this is what I achieve.

My current question - why has my breakfast Insulin:Carb Ration changed?
See the attachment (don't think the website will get this) for a graph over the last 6 months showing the IC Ratio for both Breakfast and Dinner and how it has changed. You will see that the Dinner ration has been relatively steady around 1:4, but the breakfast ratio has gone from 1:5.5 in Oct-12 to a value of 12.5:1 NOW. I have been trying out different Lantus doses during this period and they are shown on the graph. Many fasting tests have been very variable but I believe that a Lantus dose of 12 seems OK, based on many fasting tests, but this is only about 15% of total insulin dose (well below the norm of 50% .. but that is what I need!).

My question to all the experts on this excellent forum .... why has my IC Ratio for breakfast gone up by a factor of x3 from ...

Feb-12: 1: 4
Feb-13: 1: 12

Any ideas would be welcome .. since although I'm an experienced Type 1 with good analytical skills .. I'm still stumped: :-(

All suggestions are welcome!

Jonty

 

[HOBIE]

A DAFNE course would be good for you & others on the same corse. With your experience to share with others. I also have been T1 since the sixtys & you will pick some little bit of info off the corse. Theres no harm in doing a DAFNE ! Keep at them bgs & hope you find an answer 🙂

 

[pgcity]

Great post. I love your analysis. The increased ratios coud be due to your lantus not lasting 24 hours. As the long as the ratio works though I would be happy.

You could try moving your injection to the evening to test the theory if you need to know.

 

[trophywench]

Well most people are more insulin resistant of a morning; and most people see their BG rise from the early hours or from when their feet hit the floor, sometimes all the way up towards lunchtime.

Have you considered splitting your Lantus so that you can have as little as you need at bedtime to avoid going hypo or having to go to bed in double figures, which ain't good, is it? - overnight then whang some more in as soon as you wake up?

I did this after a fashion as I never found Lantus to split satisfactorily for me so I swapped to Levemir and had 14u of a morning and 4u at approx 9.30 pm at night. However my A1c was still between 7.5 and 8.5 ..... Now I'm pumping I can see exactly what I need and when I need it, and believe you me there's no long acting insulin that has a profile anywhere near my ACTUAL basal requirements. And within 3 months without me doing anything particularly difficult or different, just close attention to basals - my A1c dropped to 6.5 where it's stayed ever since. I'd like to say it was ME but it really wasn't. It was the fact that NOW I'm getting the insulin I need exactly when I need it.

Have you ever considered a pump?

OR some people wake up and have a jab of fast acting to tackle the rise that's gonna happen if they don't, then sort themselves out, and have their brekkie after say half an hour, jabbing again for the carbs - and get by like that.

 

[JontyW]

Thanks for the feedback, but I think it is unlikely it is due to Lantus not lasting 24 hours since my BG regularly DECREASES rapidly once I have awoken, often 2 - 3 mmol/l in just 2 hours. I awake at 7am, test to see the BG drop since bedtime at 12pm, then test again before breakfast at 9am. It nearly is always heading south, not north!

I have also have Addison's disease and take 10mg Hydrocortisone at 7am to get my cortisol level up to normal, so that may be having some affect .. but I don't really understand how that can impact BG level in early morning. But I am going to have a trial at splitting the Lantus dose am and pm to see what happens.

BUT .. today has been one of those .. "what's going on .. my BG keeps dropping". Here is the data ....
1) Previous two night drops have been 5.9 and 6.0 .. higher than average of 4
2) Last night .. pre-bed was 10 (spot on my target) .. woke at 5:20am (too hot, we have a fully insulated house) so tested just in case .. 3.1 .. blimey what's going on?
3) 5:20am: had 12g CHO (2 jelly babies)
4) 6:00am: 3.8; had another 18g CHO (3jelly babies)
5) 7:00am: 7.2; so BG seems OK .. get some more sleep 🙂
6) 8:20am: 3.1; BG still dropping .. what the 'ell is going on? had another 18g CHO (3 jelly babies)
7) 9:30am: 2.6 .. what IS going on .. BG keeps crashing .. WHY? had another 18g CHO (3 jelly babies);
8) 10:15am: 4.7 .. Bfast. Did normal bolus ratio (11u to 10g CHO+ plus Lantus 12)
9) 12:00pm: normal BG would be ~9 .. it was 3.7!!! had 20g CHO
10) 13:30: 3.6 AGAIN .. what the 'ell is going on? Had 30g scone with jam and no bolus to cover it
11) 17:00: 3.0 ... will the crashing BG never stop today?

Everything today was as usual, with no extra excercise or anything .. just a normal day. It would seem that my pancreas may have started working after 43 years .. I don't think so!

So this is an excellent example of what occasionally happens to my overnight + daytime BG . it just never seems to stop dropping .. and dropping. Last time this happened during mid morning 18 months ago, I woke up on the garage floor with 3 yellow jackets peering down at me .. not nice .. and it took them 2 hours to get my BG > 5!!

I don't know whether such an extreme episone relates to the breakfast ratio increasing or not, but it sure is not nice .. but I'm so relieved that I woke at 5am, by chance, and did a BG test.

Any ideas are welcome as usual ..

Jonty

 

[pottersusan]

sudden change in need for insulin

I'm pumping now, but used to have real probs with bg dropping like a stone overnight. This was due to too much basal.
I've recently had a sudden change (basically happened overnight) in my need for insulin in the morning - I need about half as much (and I wasn't having much to start with!). Also I need more later in the day than previously. Very strange... none of the 'experts' has a good reason why this has happened! Ideas please

 

[pgcity]

It does look like your basal is out. Have you done any basal testing? It's not just for people on pumps. I found it impossible to get my basal correct using long acting insulin and am now on a pump. I couldn't recommend it highly enough and with your analytical skills you would make a great candidate.