Helping T2 Hubby with ISF Pump Adjustment

Hello Friends,

Thank you for all the "Welcome" messages that I received when I first signed on. Since this is my first post, I hope you'll forgive me if it's in the wrong place and let me know where it should be posted.

My husband’s I:C ratio, ISF and Basal settings on his pump are pretty well spot on; however, he needs very little insulin at night and if I do need to give him a correction bolus at night, he needs less insulin than the pump suggests or he’ll go too low. (Normally his night time blood sugars are between 70 and 80 and I don’t need to bolus him.)

Here’s an example: The other night he checked his blood sugar at 1:00 a.m. and it was 237. (He had not eaten anything for the previous 4 hours.) Although the pump suggested that I should give him a correction bolus of 2.10 Units, I only gave him 1.50 Units. At 7:02 a.m. when he awoke and again checked his blood sugar, it was down to 63.

Questions: 1. Does the ISF only affect the correction bolus and not the basal? 2. If so, how would I adjust the ISF to keep him from going so low? 3. Should the ISF be adjusted for the time period between 1:00 a.m. and 5:00 a.m.? 4. If his ISF is already at 60 for the night time period, it would seem that adjusting it to 120 or greater would make sense. What do you think?

Thank you in advance for your help. :)

All of my pump settings are more conservative after midnight, including basal, I:C, target and ISF. I give up a little ground and get aggressive again in the morning, night time target (110-130) and daytime is (90-100). the target change has no impact unless you do a correction.

I have more questions than advice. I think you should watch and see if there is a pattern rather than make an adjustment on what happened the other night. The duration of action for your Hubby needs to be considered in this as well as the ISF. You can certainly raise the ISF to avoid the low, but I would not. I love to wake with a 63...the day is off to a good start then.

You don't say what pump he's using, but most pumps allow you to set multiple I:C ratios, sensitivity factors, and basal patterns for different times of the day.

Question #1: Generally speaking, yes the ISF is used for bolus only, as are (obviously) I:R ratios. Of course one may have a different level of sensitivity thus needing more/less basal at a given time frame but that is a predetermined setting in the pump.

Personally, I need significantly more insulin from 8:00 PM to 1:30 AM, and then about half that amount until 5:00 AM.

Is the need for extra (non-meal related) bolus corrections a frequent one? If so, that could suggest the basal settings need adjustment.

When I need to do a correction, which is very rare anymore unless I'm sick, I always check 30 minutes, then one and two hours later and depending on the reading continue to check, or trust that I've 'guessed' correctly. Yes even if that means setting the alarm every hour all night long!

Have you/hubby read either Think like a Pancreas or Pumping Insulin? Both are good reference books for all things pump. They will teach you how to figure out/test to identify what needs adjusting. Will help you look for trends/patterns in BG readings to assess how things stand.

I have a little bit different angle on this.

Why are you doing the monitoring and bolusing? I don't mean to be nosy, and you certainly don't need to share sensitive medical info. Just something like, "his health situation requires me to manage this for him" is sufficient.

However, absent some compelling reason causing him to be incapable of managing this, you should have a much more passive role in routine treatment of his diabetes. If he needs a bolus, he should be delivering it, every time, if he is able to (i.e. not in a state of confusion from an extreme hypo or something).

I know you love him and want to protect him. I must say that, in my opinion, doing these things for him if he is perfectly capable will result in the exact opposite. He must be the expert on his pump and treatment, more than you. You will not always be around when a correction is needed, or a hypo needs to be treated.

That is, unless there's more to this than you've shared already.

As a T2, he may not need the basal at all (very likely, especially with his apparent high sensitivity to insulin, although I can only infer that from what you've posted).

Bolus timing is very, very important as well. Bolusing when you eat, or shortly after, can result in the sort of BG response you saw that night: Eat a snack at 10pm, bolus for it right after eating it. BG will generally peak much higher 2-3 hours after eating (like you saw), and then nosedive as the insulin really gets kickin'.

In contrast, bolus 30-45 minutes ahead, and the peak can be dramatically reduced.

Example: I'm a T2, on an insulin pump. If I eat an In 'n Out Double Double (my once a week food treat) for lunch and bolus when or immediately after eating, starting at a BG of 85, I'll peak somewhere around 200 at the 1-2 hour mark. Then it will work its way back down over the next 2-3 hours.

If, instead, I bolus for it 45 minutes ahead, implement a partial TAG strategy adding extra insulin for the protein on a combined extended bolus, my BG starts at 85, kisses 130 at the 2 hour mark, and is back down in the 80s after 4 hours.

All this speaks further to the point I made in my other post: Your hub needs to be the expert on this, not you. To manage it successfully, he has to be the one in the driver's seat. The only time it's better to have a caregiver running things is if the subject is incapable of doing so (elderly, children, mentally infirm, severely disabled, etc.).

How far in advance to pre-bolus is a very individual parameter, one that needs to be shaken out with some experimentation. Also depends on the insulin. He is surely using a short-acting analog of some sort, like the rest of us. His pre-bolus timing should fall somewhere in the range 15-45 minutes. A little controlled experimentation on the weekend, with relatively small amounts of insulin and carbs, can uncover his unique physiology in this regard pretty safely.

Thank you so much for all your replies and suggestions!

My husband is using the “Animas Ping” pump and is on U-500 insulin.

The last few years while I was working and he was on MDI's, I would even load the syringes for him and write down the times that he needed to check his blood sugar and when to take his insulin, but he would forget to check and also forget to take his insulin before eating.

At 5'5 1/2" his weight blossomed up to 215 and he had a heart attack and Congestive Heart Failure in June, 2013. Because of the amount of insulin that he needed, his Dr. put him on U-500 insulin, and then on the pump. Last February he went "blind" in one eye and is unable to read the pump even with glasses; however, his distance vision is still pretty good. He does take his own Blood Sugar readings when I remind him to. Sometimes he'll eat first before checking and bolusing and then I'll find out later and that makes things complicated. Generally, it’s all I can do to get him to wait for even 10 minutes after “pinging” him before eating.

To make a long story short, I had to quit my job to stay home and care for him. Since getting the pump in June of 2014, he has lost around 26 pounds and his blood sugars (instead of being in the 300's and 400's are now mostly in the range between 80 - 115 except when he had the occasional low. Also his A1C has come down from a 10.1 to around 6.5.

I very much agree with you that he should be taking charge and managing his own pump (and I would love to see that happen) but he has difficulty seeing the pump screen as well as having memory problems. I was trying to show him how to do the audio bolus but even that's too difficult for him as he's also hard of hearing. My concern is that if something happens to me and I'm not able to be with him, that he'll end up with renal failure, stroke, or another heart attack and be totally incapacitated. He already has very painful Neuropathy and has difficulty with walking.

I’m really thankful for the “Ping” remote because it enables me to give him a bolus without using a syringe.

Does anyone know if there's a magnifier that could fit over his pump screen? At present I’ll try to show him something simple like hitting the “OK” button to turn off the “Low cartridge” alarm and he cannot see the “Confirm” on the pump.

With the U-500 insulin, we were told that he should bolus 30 minutes before eating. However, we weren’t told what to do if he goes ahead and eats something without checking his blood sugar and then I find out 15, 30, or even 60 or more minutes later. What is the proper procedure for that situation? If it’s only 15 minutes, do we bolus him for both carbs and a correction bolus if needed? If it’s 30 or more minutes, should we only give a correction bolus? Or should we reduce the carb bolus by half of the suggested amount and also give the correction bolus? I realize that the correct answer is not to allow this to happen in the first place, but unfortunately this happens quite often and it would really help to have some sort of criteria to go by in deciding what to do.

We’ve tried experimenting with small amounts of insulin and carbs to come up with a pattern; however, the more weight he loses the more sensitive he is to insulin. So each time we think we’ve got it figured out, and then he loses a few pounds, we have to reduce his basals again. By the time we get a hold of his Endo and then she gets back to us with his new adjustments, he needs to have them adjusted again. At present his numbers are doing okay since he’s reached a plateau in weight loss.

Dave, what do the initials “TAG” stand for where you mentioned “partial TAG strategy”? We’ve done some 4-hour testings during the day (without hubby eating anything) and during that period just the basal is keeping him in the 80‘s or 90’s. Is this ok? Like you mentioned, he hardly needs any basal during the night. Before going on the U-500 and the pump, he would wake up with high numbers (200 or above) but that’s really changed now for the better. Also he was taking up to 240 total daily Units of U-100 NovoLog and Levemir and that’s also drastically changed with using the U-500 since now he’s only pumping 8.55 Units daily of basal and between 1 and 1.5 units daily for carb boluses.

Please forgive the rambling and somewhat disjointed thoughts.

Again, thank you in advance for your help. :)

First, thank you for sharing, and especially thank you for taking my comments in the spirit they were intended (and not taking offense!). That sort of maturity is refreshing.

From what you shared, it's clear he needs assistance. However, it also sounds like you can help him become more independent as well, and I'd offer the encouragement to make that one of your joint goals: Achieve as much independence as can safely be achieved. Not only will it make the entire situation more safe and under control when, inevitably, you can't be there, but also has a very positive impact for your hub too.

TAG stands for "Total Available Glucose". It's a strategy to more completely account for the glucose impact from eating, including effects that protein and fat have on blood glucose. It's a technique that becomes increasingly important (and effective) the more one shifts their diet to low-carb, higher protein/fat for calories.

Given yours hub's situation, I'd recommend you all do some serious research, and experimentation, with low-carb diet mix. U500 implies some severe insulin resistance, so every gram of carbohydrate you can eliminate from the daily intake will have a huge impact on insulin needs. There may be a low carb dietary mix that can get him back on U100 insulin concentrations, which would allow the use of fast-acting insulins, making BG management much much easier.

I eat a "moderate carb" diet -- I try to stay under 100g of carb a day, <60 when I can pull it off. So, when I eat, I always program a extended (also called a "dual wave") bolus to cover the carb count, and the protein count, in the meal. The "immediate" (delivered all at once) portion covers the carbs. The extended part (a.k.a. "square wave") delivers the insulin to cover glucose generation from the slower digesting proteins. Rule of thimb is about half the protien by weight is converted to glucose by the liver, over a slower period of digestion. Example: Chinese chicken salad, 40g carb, 40g protein. My insulin:carb ratio is 1:4. Take half the protein and add it to the carbs to calculate bolus: 40 + (40/2) = 60. Apply ratio, 60/4 = 15 units. However, I want 10 units immediately to cover the 40g carb, and 5 units over a longer period (I use 3 hours). So I program an extended bolus to deliver 10U immediately, and then the balance of the 15 total (5U) over 3 hours. This keeps my BG under great control. The math and strategies change a little with U500 because of it's longer "tail" in staying active, and longer time for insulin action to peak. However, the basic idea is the same.

What is the proper procedure for that situation? If it’s only 15 minutes, do we bolus him for both carbs and a correction bolus if needed? If it’s 30 or more minutes, should we only give a correction bolus? Or should we reduce the carb bolus by half of the suggested amount and also give the correction bolus?
This answer is, fortunately, pretty simple: Bolus for the anticipated glucose load any time between 60min prior to 3hr after eating. More than 3 hr, bolus based on a correction calculation rather than a TAG load.

Reasoning: Within the non-fasting window, you can pretty much ignore any BG that has been covered by endogenous insulin. I'd say given your hub's situation, this is even more the case, with such high insulin resistance. So the amount of insulin needed to cover what was eaten is the same, regardless of how much of the sugar has made it from digestive tract to blood stream. It all still needs to be "processed".

Once he's back into fasting mode (i.e. no longer absorbing carbs from digestion -- it's all done) his endogenous insulin production -- weak as it may be -- has and is continuing to whittle away very slowly at some of that sugar. Also, basal metabolism is messing up the in/out part of the picture, insofar as glucose processing is concerned. At this point, the actual BG level is the best indicator of how much insulin is truly needed to get things back in line.

Keep in mind though that BG peaks are a matter of getting ahead of the sugar before it gets digested and in the blood. With U500, if it were me, I'd be bolusing a full hour ahead of eating, and eating a very precision diet (i.e., accurately quantified nutritional components, particularly carbs, protein, and fat).

All that said, what you're doing now is working very well. An a1c of 6.5 with very few (and sounds like no serious) hypos is really good.

Also he was taking up to 240 total daily Units of U-100 NovoLog and Levemir and that’s also drastically changed with using the U-500 since now he’s only pumping 8.55 Units daily of basal and between 1 and 1.5 units daily for carb boluses

Hmmm... based on these numbers, sounds to me like he should be able to get back on Novolog (or equivalent) with some further weight loss, and low-carbing if he isn't already. Being on a fast-acting insulin makes a lot of this so much easier. The Ping has a 300U cartridge, I believe -- get it down to 150 a day, and he can go two days on a set, which is not bad.

As for the basal: Research "Dawn Phenomena" on the site, if you aren't already familiar with it. I basically have my basal turned off during the day, and most of the night while I'm sleeping. The two times it kicks in, pretty substantially, is the few hours before I wake up to combat DP, and then in the evening for a few hours starting around 5pm to head off a fasting rise I seem to always get then.

When I first replied to your post I had no idea Your Hubby was pumping U500R....With this insulin you will need to stay on a strict meal plain and bolus only proven doses that comply with the diet...U500R can last 24 hours and is not a good insulin for doing corrections like someone who is on a fast acting short duration insulin. Although some indaviduls are pumping U500R it is a long lasting insulin which is OK for basal use but doing corrections will be very reality you are probably stacking each meal and by the middle of the night it will be easy for him to have too much IOB....

Many of the suggestions that have be made simply do not apply to a insulin that has as long tail like U500R...Many of us old timers have some experience with slow insulin, and we controlled our BG with 1,2, or 3 injections each day, along with a very regimented diet there is no room for error like with fast insulin that burns off in a few hours.

The pump is better for his basal requirements, but each meal bolus will need to be almost perfect, because each meal bolus is stacked on the last one and your pump cannot correctly calculate IOB for a correction when your using U500.

Is the action profile of U500 different than U100 Humulin R? I thought it was the same thing, just 5x concentrated.

U100 Humulin R is fine for pumps and their software handles it without problems. Of course, regular doesn't have a 24 hour tail -- it has an 8 hour tail, more or less. Hence my question about the difference between U500 and U100, other than the concentration.

Form the product information:

Humulin R U-500 is unmodified by any agent that might prolong its action. Clinical experience has shown that it frequently has time action characteristics reflecting both prandial and basal activity. It takes effect within 30 minutes, has a peak similar to that observed with U-100 regular human insulin and has a relatively long duration of activity following a single dose (up to 24 hours) as compared with U-100 regular insulins. This effect has been credited to the high concentration of the preparation. The time course of action of any insulin may vary considerably in different individuals or at different times in the same individual.

Thank you so much for all your replies to my many questions.

Guess what happened this afternoon? Because of your encouragement, I gave the remote meter to my hubby along with a magnifying glass and then walked him through the steps of inputting his carbs and his BG and Voila! he was able to give himself a carb and BG bolus via his pump for the first time! However, even with the magnifier he still had a difficult time seeing the numbers. If we can find some sort of magnifier that clips over his meter, there's a chance that he might be able to do this.

Since he has his favorite mini meals, to make it easier for myself, I've written down the carb amount of each meal along with the portion sizes. This saves time because I'm not having to add up the carbs in each food item and this will also benefit him if he is able to use the remote.

Dave, I really appreciate the way you explain things with examples and then give the reasoning behind your answers.

My hubby's Endo is really wanting to get him off of the U-500 and start him on the U-100 but we've been asking her to let him stay on the U-500 permanently because he's been losing weight and his numbers have been the best that they've ever been. Before the pump he had a couple of months doing MDI's with the U-500 and we were noticing an improvement even then.

When he was on the U-100 before, his weight and numbers were totally out of control! So we're really concerned that going back to the U-100 will really mess things up.

Question: In view of the fact that he will not wait (after bolusing) for more than 5 or 10 minutes before eating, will switching to the U-100 insulin be better for that fact alone? If I understand your explanations, then this would appear to be true. However, if switching would be better, I'm having difficulty understanding why the U-500 is working out so well for him at this time??

Would it shed more light if I were to post his pump settings, BG's and boluses as well as the carb amounts and the times that these events happen? I keep a fairly detailed log of what he does daily and if more info would be beneficial, I'll gladly share it with you.

As we are scheduled to see his Endo this coming Thursday, anything we can learn before that time will help us to make an informed decision when she brings up the matter again of switching back to the U-100 which we're still not wanting to do. Added to the concern of switching is the fact that we'll have to change insets more often. Now we can go 5 or 6 days before changing which is really nice. Also, we're concerned about having to start all over again with the fine tuning and tweaking in order to get us to the same "good" place that we are at this time.

What this all boils down to is that I really want to do what is best for my husband who is a snacker and doesn't want to wait for a bolus before he eats.

Again, thank you in advance for any and all suggestions. :)