Change Pump?

Hi everyone! My name is Pam and I’m a T1D currently on a Medtronic pump, but am thinking of switching to either a T-slim or Animas pump. I’m wondering whether either of these pumps has more accurate dosing than the Medtronic. Even though my current pump works okay, I feel like I can’t quite get regulated on it. Before I was on a pump my A1c’s were 6.0; then I started to have some hypoglycemia unawareness due to constantly changing schedules at work. That’s why I went on a pump. Since going on it my A1c has been at a 6.2 or higher and it took me almost 3 years to get it to a 6.2! I’m thinking that I need to be able to dose a smaller amount of insulin to get back my 6.0, hence my considering one of these two other pumps. Any thoughts?

Hi Pam @PamcKlein,

I’ve only used Minimed Medtronic pumps [three models] so I’m not offering comparisons to the other brand pumps. I currently use a Minimed Paradigm #523 - real old technology by current standards - but with this pump I am able to set basal rates to the one-thousands of a unit in increments of 0.125 and bolus rates in increments of 0.025. Settings like this have helped me avoid hypoglycemia.

I’m not a medical professional but I’ll relate some of my experience and advice I received from two endocrinologists acting independently. For many years I maintained an Hb A1c between 5.9 and 6.1 until I had two extreme hypo where EMS had to revive me - one with a BG reading of 9. Since then both attending endocrinologists have ordered me to keep A1c at 6.5 or above - currently at 6.3. “Unawareness” is serious and it may become more pronounced as your years go on.

I understand how a constantly changing work schedule will affect your body’s insulin needs and this is where the “Pattern” pump feature comes into play. Also, I suggest that periodically you validate your basal rates by extended periods of fasting from food just to see if your basal will maintain your work schedule BG within a fixed rang, such as between 100 and 120 mg/dl. I know that I must constantly tweak my rates.

Hi @PamcKlein Pam!

accurate dosing: I guess it depends on your current model but let’s pretend it’s an older one and accurate to 0.1 units (as was my first medtronic)… the new medtronic ones claim 0.05 units either way - it is incredibly tiny compared with any form on pen injection or any syringe of any kind. do any of the current latest pumps have superior accuracy in any form that matters? My opinion is no. Of course if your sensitivity (carb ratio) to insulin was lets say less than 1 unit of lispro (fast acting) insulin for 50 grams of sugar, then that would be a different story I think. my ratio is 10:1 or 12:1 and so I wouldn’t care if my pump accuracy was 0.5 or even 1.0 units. so what is your carb ratio?

the last time i actually read the engineering specs, medtronic had the best (by an incredibly tiny amount) basal clock. that was 2 or 3 years ago.

now if you take a look at where inaccuracies take place that are large enough to matter, I think you’ll find that estimating carbs has a good amount of uncertainty to it, as does product labeling. you can be off by 25% to 50% on your actual carb intake unless you weigh take notes and probably eat exactly the same thing every single time.

the other huge source of error is your meter. your bs meter has an accuracy of +/-20% when your bs is above 75 mg/dl. so that reading you just got for 160? well your actual blood sugar is between 192 and 128. how bout that? when you have a pump dosing accuracy of 0.1 units and then get a meter reading that could be off by that much… who would care?

I think 6.2% hba1c is great work. I think shooting for a 5.9 or lower it puts you at a statistical risk of hypos. If you want a new pump please get one - the dumb buttons on the medtronic pumps are pre-historic at this point and you deserve a new pump even if it is change for change’s sake. all the pumps are pretty good but you should check with your insurance in case they have a “formulary” opinion. cheers and good luck!

look at that @Dennis beat me by a minute. I agree with the hypo dangers!

Dennis and Joe: Thanks for your thoughts! Dennis, I do check my basals periodically by fasting and have found that I need to change them from time to time. I was thinking that maybe it was my pump. Now I’m thinking maybe not! Oh, and Dennis, yes I am aware of the variables in accuracy. That’s why I use a One Touch meter, it’s always been the most accurate - - for me at least!

On that note, I currently use a Dexcom CGM and was thinking about getting a pump that is integrated with it. The Medtronic CGMs didn’t work for me, unfortunately, and I have found the Dexcom to be much more accurate. Both the Animas and T-slim work with the Dexcom and One Touch as far as I can tell. One thing I am concerned about is accidental dosing. Do either of you know if there is a way to lock the screen on either of the two pumps I’m considering? I don’t want to worry about accidentally giving myself a bolus if I were to bump my pump against something! Thanks!

hi Pam, neither medtronic or animas pump will deliver a bolus on an accidental single bump. both pumps need you to enter a bolus by pressing a button several times, then confirm the bolus with a different button before it delivers. anything out of sequence cancels the bolus. you can also disable “audio bolus” on the animas or the “e-z bolus” on the medtronic if you really want to . I don’t know enough about t-slim to comment.

I agree with Joe, there is always a certain amount of inaccuracy both in pump insulin dosing and in meter readings. An endo that I know who also has T1D really doesn’t believe in using dosing that is so small (ie 0.05 units).

I use a T-slim and is does do the really small bolus amounts if you decide to go that route. The screen automatically locks after a few seconds of unuse. You have to hit 1,2,3 in consecutive order to unlock it. I’ve never had an accidental bolus. When I wore an Animas pump there were a few times that I hit the quick bolus button but it requires confirmation and beeps so I always knew when I’d hit and was able to clear it and avoid an accidental bolus. That was a few years ago, not sure about the new animas pumps.

Don’t get too caught up in the numbers. 6.2 is an awesome A1C. I was also told by the same endo that there is a percentage of error in A1C’s as well depending on how the test is taken and who runs it. Slight changes aren’t really a big deal as long as your in a good range and are stable.

I think you are worrying too much about your A1c. I have had type 1 for 53 years and have been on MiniMed, Cosmo, Roche and for the last 2 years T-Slim G4 with CGM thru Dexcom G4. I am very pleased with the T-slim. I do think that anyone who is really active can’t possibly avoid frequent lows when they maintain a 5-6 A1c. I usually keep mine at 6.6 to 7.1. My doc is not happy when I get 7.5 or higher. Some docs push 5-6 A1c but they don’t tell you how to live a normal life. I was in the ER 4-5 times in a 12 month period when I was with such a doc. I couldn’t play golf, hunt or do anything that required lots of physical or even mental activity. I have gotten nothing but great check-ups since I started staying in the high 6’s. You may want to talk to your Endo about your concerns.
Good luck

Thank you all for your thoughts and responses. @joe: when I was on shots 1 unit would drop my BG 50 mg/dl. My carb ratios, as currently set, range from 14:1 up to 21:1, most are in the 14-17:1 range. I’m still not in good control at these settings though. In fact, the doctor who first got me to use a pump had them set much differently and I kept having lows. Now, I have an occasional low, but have noticed some spikes as well. So, it’s still a work in progress. Also, thank you for the info on the different pumps. I was ready to go with Animas, and then they decided to stop selling the pumps. So then I thought I’d stay with Medtronic and upgrade (I really want a water proof pump that I can swim with and the are the only two that offer that). Unfortunately, Medtronic couldn’t guarantee delivery before the end of the year due to the hurricane damage. So, I’m still using my older Medtronic for now. I’ll try again to upgrade once I meet this year’s deductible!
@mimo: Yes, an A1c of 6.2 is pretty good, I agree. It’s just I’ve only seen that reading once in over 4 years. I want a 6.0 or even 6.2) consistently like I use to be and am trying to figure out how to get back there. I may just have to go back on shots, but I’m trying to make it work on the pump.
@jayarr: I have also had T1D for 53 yrs and have no complications. Throughout my early 20’s up until my late 40’s my A1c’s were a 6.0. Then they crept up to a 6.2 and then a 6.4. Still decent, I know, but I asked my doctor of over 10 years if he thought I should be concerned. He suggested I try the “new” insulins, Lantus and Humalog. He said they should keep my BGs more steady throughout the day. I tried them, and that’s when my A1c’s went crazy. I went up to a 6.8 and it kept climbing. By the time I found a new doctor my A1c was over a 12! I have always been well controlled and this scared me. I’m happy to be back down in the 6’s, but most of my A1cs are still 6.6-6.8. I want them back at a 6.0. I’m not looking to get them lower than that. The 5.75 A1c I had was in college, but I’m not looking to get it there again.
As for your experiences with lower A1c’s, I’m sorry you had to go through that. I’m not sure why you “couldn’t play golf, hunt or do anything that required lots of physical activity…” I never found that to be the case. I simply adjust my dose and/or eat an extra snack and I’m fine. For me, when my BGs run higher than 105mg/dl I’m thirsty and running for the bathroom every hour or so when I’m at 135mg/dl or above. So, I need to keep them down. We are all different in that way. So, what works for you and I are different things. It is what it is! :slight_smile:

Hi Pam @pamcklein,
I’m happy with my HbG A1c at 6.3 - 6.4 after going a “lifetime” ranging generally between 5.9 and 6.1; two different endocrinologists who know my history well individually "ordered me to get my A1c up to 6.5 when I began to develop hypo-unawareness. And now with the higher A1c I feel better and actually have much better management of BG. With the higher A1c, the standard deviation of BG checkpoints is >25 whereas with the lower A1c my SD often exceeded 50. An A1c of 6.0 means that you have an average BGL of 106 which could include many, many 30’s and 40’s along with a few 400+; what I’m saying that aiming for a “low” A1c is not my goal and in itself does not tell the whole story.
Don’t get me wrong, I believe the A1c may be our best single “sign post” for diabetes management; I was part of the glycosylated hemoglobin llater called HG A1c and then Hb A1c] study in the early 1970’s.

A thought on your pump settings: have you tried long-term fasting [15 - 18 hours] to validate your basal settings? After changing my pump settings I will do this fasting and see if I can stay in a range [100 - 140] without needing to eat or take a correction bolus. I’ve always done my own pump settings - right from the beginning with my MiniMed 515. The only guidance the endo gave me was “… add your daily Lantus to your daily Humalog and figure out how to balance 70% of that total in your new pump”. After a gazillion changs I’ve gotten it correct - whoops, let’s wait another couple of days and see if my current settings are working.

Thank you Dennis for your reply. I too, have been working on my pump settings. Just when I think I’ve got it “right” something goes wrong. I think part of it is menopausal hormonal changes. I also wonder about my “sensitivity” settings. The doctor I was with when I got my pump set them and I have never changed them, but I sometimes wonder if I should. I know that on Humulin my BG would drop @50 for every unit taken. I’ve never figured out how much one unit of Humalog drops me though. The sensitivity settings on my pump are 80 or 90 depending on the time of day. I just don’t know how that corresponds. If you, or anyone knows how to calculate this, I’d appreciate any info you can provide!

As for the A1c levels, I was able to maintain a 6.0 for years with only 1-2 severe lows/year. I actually went several years with no severe lows. Severe lows, meaning lows I could not treat myself, were very rare. I know when I am running 6.6 - 6.8 I don’t feel right and am always thirsty, which is where I’ve been for a while now. That is why I am working hard to get my A1c’s back down.

My pump settings are a work in progress. I don’t often have the opportunity to long-term fasting. I do try on weekends to do so, especially for my overnight readings. One day each year, on Yom Kippur, I fast for @27 hours (and yes, my doctor approved this beginning when I turned 13!). I check my BG frequently and will eat if necessary. It is a great way to figure out when I’m dropping though!

Thank you again, Dennis.

Pam you are very welcome for any bit of information and guidance I can provide; most of my diabetes “wisdom” has come to me through trial and mistakes. Yes, I am very cautious when doing anything that will affect my body and well being and I do discuss all but changes in ratios, basal and other pump stuff with knowledgable doctors before doing anything.

I recently recalculated my insulin sensitivity using this method:
Choose a time to test when:
• Your blood glucose value is at least 50 mg/dl above your target
• You have not taken a meal bolus or correction bolus for at least 4 hours
• You have not eaten any food for the last 4 hours
• You can go without eating for the next 4 hours

Don’t test your correction factor during any circumstances that might affect the results, such as:
• After performing strenuous exercise
• If you have an illness or infection
• After a serious low blood glucose
• During major emotional stress

I prefer setting my correction factor on the conservative side - especially the sensitivity for evening and over night knowing I can do another correction later or at breakfast.

Some doctors use a medical book formula for calculating insulin sensitivity; they divide 1700 [some use 1500 and soe use 1800] by total daily insulin dose - but I believe the more complex method I used is more accurate. I always log all insulin and later compare how effective my correction dose worked - but I very rarely change my sensitivity factors.