Study: Insulin Pumps Decrease Quality of Life and Increase A1c in CGM Users

This is a minor conclusion from the DIAMOND study, whose major conclusion was that CGM use in MDI is better than fingerstick use and MDI as far as A1c, time in range, hypo and hyperglycemia events and quality of life.

But they also found that quality of life and A1c were negatively affected by pump use with CGM use.

The article can be found here:

I did not find a study link, but found this article.

I think that the cohort used in this study in no way correlates to the FUD cohort, but I did find the conclusions interesting.


This is a must read article

More expenses. Clinically measurable decreased quality of life. Higher A1C and more hypoglycemia. Hmm no wonder I don’t want one.


A total of 75 participants with type 1 diabetes who were already using CGM technology were randomly assigned to insulin pump vs. multiple daily injection (MDI) therapy.

I think anyone starting pump therapy has to want pump therapy a lot. It’s more work than MDI in many ways (and less work in a few). Anyone who is ambivilant or opposed to pump therapy is not going to like it much.

When I started, I had very specific ideas about why MDI was not working for me and how a pump could help address those issues. I took a year in making the decision to switch from MDI to the pump, and I always had my long-term goals in mind. It was frustrating in the beginning at times, in part because I didn’t fully appreciate how much more work pump maintenance was. Had I just randomly decided one day to try the pump for the heck of it or because someone (doctor, researchers) had suggested it, without giving it much planning and forethought, I imagine my experience could have been much more negative.

It also, of course, depends on the individual. There are some people for whom MDI just does not work well, and there are other people for whom the pump just does not work well. Everyone needs open choice in the therapies they have access to and decide to use. Studies like this make me nervous because I get wary that insurance companies or governments might use the results to limit access to pumps, which are already difficult to access in some cases.


Totally agree, and this makes the conclusion of study invalid. Most people need several months just to get settings right and be comfortable with set changes, etc. Tubing could be major issue for some, unless study offered omnipod as option.

But there are probably many real life examples where patient was talked into pump as being 100% great, without including the cons, and later returned to MDI.

I switched from injections of NPH and Regular, to using pump (with Regular). So big improvement for my QOL and A1C. Might have been different if using pens and newer insulin prior to switch.


Everyone should find the best regimen for what they need. Find what works for them.

Unless you have tried them both, you will really never know.

If you trust what a study shows - being lumped in with a bunch of people who are not you - and you want to base anything off of that, fine.

I have done all of it. So I have the right basis for comparing all the pluses and minuses for any of it.

There is no perfect system. But unless you have done both MDI and pump, you can never be sure what is best for you.

I think you could easily create a study that showed the opposite. You can weight all kinds of things differently that affect the quality of life score.

This was determined by assessing the “quality-adjusted life-years (QALYs) via a modified Sheffield T1D model.” Theoretically, there may be many potential reasons why someone may experience a reduced quality of life on an insulin pump, such as worrying about pump site problems, associated financial concerns, the considerations of wearing an additional device, etc.

For example, the Sheffield model they are referencing uses a reference A1C of 10%. Does an A1C of 10 apply to you? Not really a factor I am worried about.


I did MDI for 3-4 days last week and I am so much happier being back on the pump :grinning:

Now that I gave my opinion I will read the article.


I agree…I always feel so grateful to be back on the pump after a period of MDI.


As the resident pump hater I don’t see any reason to disagree with this study, but I have extreme personal bias and hatred towards the pump due to horrible experiences with infusion sets bending and the pump overall being defective and not trustworthy. It failed almost every day, left me with possibly permanent scar tissue due to running out of space (due to infusion set failures, which may of caused the permanent scar tissue) in one week or so of use let alone the whole 2 weeks (I can’t inject in my right side of my tummy, haven’t been able to ever since i used the pump and I only used it for weeks worth of time and haven’t used it for 4 years, one attempt recently lead to a hyperglycemic episode because it didn’t work and I HAVEN’T injected there in years!!!) . I also always regret not getting a dexcom or something at the same time, I feel PERSONALLY using a pump with a cgm is really …risky and dangerous due to the lack of all day coverage insulin like lantus leading to dka really easy if your site fails. I still totally WISH i didn’t fall for the basically peer pressure on the internet to feel that was the only way to manage my diabetes when I was new…as it wasn’t. Have had great luck with MDI, have always had an a1c in the 5.5-5.8% range, rarely go hypo (did that all day when I was on the pump, when it worked. Novolog is a crappy basal for me, even on the lowest setting, when 10 units of lantus would keep me good all day???) rarely go hyper either.

I agree with the following things: Pumps are expensive, pumps put you at risk for dka way easier than mdi (lantus, tresiba, etc will cover you even with an imperfect dose , if you use a pump and it fails you have no insulin coverage, huge dka risk, especially if you’re using it without a dexcom or libre that is just asking for trouble) not to mention just hyperglycemia as well (which I see as more dangerous and avoid in every way possible) ,they are more wasteful (if the infusion set fails, you have to redo EVERYTHING!) , they’re more likely to fail and you may or may not get insulin from them at some point because how flawed teflon is as an infusion set (metal infusion sets are way safer but still carry the same scar tissue risk), also the scar tissue from pumps make it harder to deliver insulin and it’s less likely you’ll easily scar yourself up with injections as it’s something smaller and easier to rotate around.

I wouldn’t tell anyone to stop using the pump, but I basically feel like it was a major detriment to my health so I’m glad to see at least a few others being like nope I didn’t like it either , and more studies backing it up that mdi is safe for a lot of people , and not everyone needs a pump.


Wow. Sounds like you had a rough experience that’s scared you for life where usage of pumps and cgms…but for many folks their experiences are the exact opposite of yours. The statement above makes little sense to me though. If you are on a CGM, you can always know your BG. So the only way you’ll go into DKA is if you have totally inaccurate pump settings, are not paying attention at all to your CGM numbers, pump fails AND you just don’t change it out.

You said you tried it only a week. Sorry, that’s not enough time to evaluate or judge either product. For my son and our family, both devices have been Lifesavers.

If MDI works for, great! Sounds like you’re doing just fine without pump and MDI.


We were reluctant to go with a pump as well, as we were doing very well, pre-puberty, on MDI + CGM. But looking at how we now have to deal with extreme hormonal peaks every day, and daily temp basal of +30 to +40% a good part of the day, it is impossible for us to conceive of decent control for what we see without a pump. Although we would rather be on MDI if we could, for some of the reasons given by @Sensorium139.

I agree with the feeling. Our CGM, to us, is more important than our pump. We will trade the pump in before the CGM. In fact, you’d have to pry the CGM from the rigid frozen fingers of my dead body before you can separate us from it. I also think that it us even more important with a pump due to the failure risks. But there are other issues with MDI that are exceedingly hard to address, such as for those, like us, with variable basal and high daily hormone peaks.

That said, I agree with @ClaudnDaye that a pump trial required a good bit of time—and commitment as well. It took us a several months to get much out of it. Today, many of our control techniques are only possible with a pump.

I think MDI with good control requires a certain type of diabetes with more repeatable BG curves and less change, within a day and from day to day. It is great that MDI works so well for some! And certainly, it would be nice if that was true for us. In the end, as always YDMV: what works great for some does not work well for others, and we have to be careful not to proselytize any control model too hard :slight_smile:


What I see time and time again though, in the doc (of course there are exceptions), is people having pretty good results with modern mdi options, particularly with a cgm, but then becoming convinced by, as @Sensorium139 says; essentially peer pressure, that pumping is inherently superior… then having worse results and far more frustration but still being unable to consider that possibly it’s not superior for them… I think that is an unfortunate tendency we have as humans—- to think that because a treatment protocol is more expensive and more complex that it must be superior. I think that in the case of pumping vs mdi we have a tendency to continue to think that sometimes in light of evidence, or even personal experience to the opposite…

There is no doubt in my mind that pumping is a far superior option for some people. There is equally no doubt in my mind that it’s a much worse option for a lot of people who, given the environment
and circumstances, aren’t able to recognize that… and that’s why I welcome objective research on the subject… because I think we as humans are incapable of being objective on the subject


I agree with you @Sam: those who can do MDI with very good control, in many most cases, would be best served on MDI if they don’t get significantly better control with a pump: less complexity, less risk, much less cost.

I also think, though, that one cannot expect people randomly thrown into a pump to get the most out of it. The fact is, it is a sophisticated device that does require a good bit of work to understand and exploit.

I guess I am making the very point you are after: it is only for those who need more than MDI can offer :slight_smile:

Of course, you can’t really know until you try it. My son did not want to pump. Now it does not want to stop.


Are you guys seeing better results on the pump than you did with MDI? And keep in mind you were using a 30 year old basal technology on mdi…

Agreed. The missing link for me when hearing pump advice is assessing one’s compatibility with expensive tech. In my 3+ years of CGM usage I have already broken 1 G5 receiver, 2 iphone screens and 1 apple watch. I consider these accidents a cost of doing business (for me) with my combination of a fairly hectic and physically rough lifestyle. That said, I have never broken an insulin pen. Not sure how long a pump would survive if it was riding along on my belly!

Also, some days I do enough MDI corrections where I consider it manual pumping.

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With a CGM and pump my A1C is about 5.6.
With a CGM and MDI I could never get below 6. It was in the 6.3 to 6.5 range. (And that is using 13 year old basal technology.)

It took me a month to get the pump dialed in. Once it was setup it has been pretty low stresa.

Also, I use an omnipod which does not have the tubing. It really just feels like a slightly larger extra CGM sensor. I may feel differently with a tubed pump.


So I found the actual paper this was based on and here are a few notes

  • They appear to have used the Omnipod and Dexcom G4 for this trial
  • 37 people were on the pump and 38 on MDI
  • They had two subgroups based on A1C, whether participants were above or below 7.5% at the start of the experiment.
  • All people with higher A1Cs to begin with had an increased time in range (70-180) although pumpers increase was greater (+10 MDI vs +153.6 pump). All people with lower A1Cs had a decreased time in range to approximately the same degree (-49.98 MDI vs -47.31 pump)
  • Average A1c changes from starting point were listed as +0.06 for high A1c on MDI, -0.09 for high A1c on pump, +0.24 for low A1c on MDI and +0.82 for low A1c on pump
  • All pumpers had a pretty dramatic decrease in the amount of insulin they were taking per day (-16.8u for high A1c folks and -19.13u for low A1c folks)
  • it was across 20 different endo clinics and it claims that they made no attempt to standardize pump training
  • most of the quality of life information appeared to be based on mathematical modeling, with increased A1c predicting more future complications = lower quality of life, and more time spent managing the disease counting as lower quality of life

I have - but that was probably 18 years ago when Lilly was making some truely crap plastic insulin pens :grinning:

Isn’t this the whole name of the game? To avoid complications?

Yes, I agree. With those notes I was really just trying to list info that maybe wasn’t super clear in the summary linked above.

I also just noticed something very interesting… for the change in A1c they have averages (which I listed above) and medians, which include the range. The medians w/ ranges are a little suspect to me

Lower A1c MDI: 0.2 (-0.10, 0.8)
Lower A1c Pump: 0.9 (-0.4, 3.3)

Higher A1c MDI: 0 (-0.8, 1.3)
Higher A1c Pump: 0 (-1.6, 0.8)

They don’t give info on the A1c results beyond the means, medians and the range so it is hard to say whether a single 3.3% A1c increase is skewing the results or if multiple people in the group with tight control experienced dramatic A1c increases.


What these study results seem to imply to me is that people who are already maintaining low A1c results on MDI should probably just stick with MDI. I know that for me personally, when I’m interacting with people in forums, and someone with a great A1c asks about pumping, I tend to not hype the pump. It doesn’t make sense to me to switch up something that is already working.

Where the pump really has an impact is for people who just cannot get a low A1c on MDI. The pump offers many more potential strategies than MDI does. I’m one who has never, ever, had good control on MDI regardless of what I’ve tried.

The whole quality of life issue is (I think) quite subjective. Some may find failed infusion sets a deal-breaker. I changed my site this morning and about an hour and a half later tested at 23.8 mmol/L (428 mg/dl). I was at work and clearly my new site was not working. I popped into the bathroom, moved my needle set to a new location and re-taped it (I didn’t actually change sets), gave myself an IM correction with Fiasp in an insulin pen, and in under an hour I was down to 13.3 mmol/L (239 mg/dl) and within an hour and a half was back in range. To me, that was not a major quality of life issue. But for people who handle it differently, it could be a much bigger deal.