Ketones more likely on pump?

Hello Everyone,

I have recently transitioned to a pump(tandem t slim) and yesterday I had ketones. My cde wanted me to check for them due to not eating as much and not many carbs for a few days my appetite has been lower. She thought this could be causing my liver to release glycogen and spike me at various times. I was surprised and kind of alarmed to find medium ketones. I was also not feeling well either by that point(dizzy, weak, stomach upset) bg was in range but eventually spiked and I had a low fever later. Eventually I started to feel better and ketones went to low and then trace levels.

This is the first time I've ever had them since dka or even had my bg rise when I've been sick. It was scary when I started spiking. I'm wondering if that may be more likely when you're only on fast acting insulins since this never happened to me while on lantus and levemir?

Huh? Naturally when you eat very low carb or fast your body will generate ketones. Ketones are generated when you burn fat. Ketones are not involved with your liver releasing glycogen although they may occur at the same time as your liver releasing glycogen. I think your CDE may be confused.

ps. And being sick can also cause your blood sugar to go high.

Hi Brian, I think her theory is not eating enough, less fuel, also causes fat burning which produces ketones, and when you don't eat enough the liver then produces glycogen because you're not getting enough from whatever you're eating- I don't know I will have to ask her. Although eating low carb shouldn't cause moderate ketones, maybe trace ketones. I'm aware that being sick can cause high bg, however, as I said, my bg has never spiked when I've been sick while on the long acting insulins and I've never had any ketones since dka( when sick or from eating low carb). I'm wondering if being on the fast acting only could have played a role here.

Using only rapid insulin in a pump makes it more likely that you'll get ketones because there is always the chance that a mechanical problem that lasts for several hours such as a blockage or a very, very large air bubble may result in having no insulin delivered which would mean that you wouldn't have enough insulin on board to take care of your basal requirements.

How high was your blood sugar when you had medium ketones?


Thanks Maurie,

Yes I know about that and thought of it, there were no air bubbles, not occlusion alerts etc. I did have some really big air bubbles one day last week but I primed them out and called tandem. They said I was doing everything right and sometimes air bubbles occur in the cartridge that aren't injected in but they took the inset information also. I was low high for a long time and corrections weren't working and started working as soon as I primed them out so I think it was air bubbles in that case.

My bg was 134 the first 2 checks after discovering medium ketones then went to 189 later at which point I checked again for problems and thought maybe I should just change the set but I was told to do this if I'm over 250, however with that many ketones I was more worried. My cde told me to eat some fruit which I did to help hydrate me. I was doing corrections and basal rate of 110% by that point and drinking water. Then I went to 190 for a bit and eventually came down to 121 fortunately. I felt much better and ketones had reduced to moderate and then to trace then. I ended up spiking up again later from a small meal but ketones didn't go up again. I was using ketone sticks which aren't as accurate but they obviously went from higher levels to lower levels. I have one of the meters which tests for ketones in blood so I will get some test strips for that now.

I guess what I'm wondering is if maybe the fast acting insulin, due to the way it is delivered in the pump, may metabolize differently and therefore be more likely to result in ketones depending on what levels you have available at any given time in a situation where you're sick, dehydrated or for whatever reason. I had also done a 23 hour fast for basal testing 2 days before so that could have affected things too.

"Low high for a long time" describes too many bad days as far as I'm concerned. I've never seen anything about fast acting metabolizing in a way that makes one more prone to ketones and have never had that sort of problem since I started pumping about 6 years ago. If I had to blame it on something, I would blame it on coming down with something.

From my experience, if you need to bump up your basal to help fight a sticky high 110% is often to conservative to do much good. I'm willing to take a mild low (60-65) to get down quicker and often pump the basal up to 140 or 120% dropping it back to 100% when I get back below 150 or so.

Eating low carb and/or fasting can cause moderate ketones, at least for me. This is one reason I stopped eating really low carb - I had a bad site once when I was eating about 50g a day (and had ketones constantly as a result) and ended up with the ketone strip turning darker than the darkest possible colour. That totally freaked me out, so I haven't tried eating that low carb again. I've also developed high ketones when attempting to exercise while disconnected from the pump for any longer than about 30 minutes.

I do think you are more prone to ketones and DKA on a pump if you have a bad site or insulin is not being delivered properly since, as you said, there is no long-acting insulin in your system. But I don't think just the fact that you're on a pump would cause ketones, unless you set a temporary basal rate too low or something like that.


Ketones are the byproduct of fat metabolization. This metabolization is not the preferred method of receiving energy (the brain and red blood cells run purely on glucose, but they can tolerate ketones also), and typically occur for one of two reasons in diabetics:

  1. 1. A low-carb diet will trigger ketosis. By restricting the carbs consumed, you are essentially forcing your body to metabolize fat. This is why ketosis diets, such at Atkins, tend to be popular dieting options for people who want to lose weight. For most people, carbs need to be restricted to really low amounts (such as below 20g of net carbs) for ketosis to begin.
    2. You are not producing enough insulin (or are not receiving enough insulin) to metabolize the carbs that are in your blood through consuming carbs and your liver releasing glycogen stores (this is why we need basal insulin -our basal dose should closely match the amount of insulin we need to counteract the liver breaking down glycogen and releasing it at glucose into the blood). Pumpers are at a really high risk of experiencing ketosis because of having very little to no insulin in their bodies. Pumps use rapid-acting insulin, and unlike long-acting insulin used in MDI, it is metabolized within 4-6 hours. If there is an issue wrong with the pump, you are not receiving any insulin, which triggers ketosis (remember that "insulin is the key that allows glucose into the cells" -if there is little to no insulin, the cells can not use carbs for energy and must rely on burning fat for fuel).

I personally develop ketones really easy, and I cannot feel them. I typically test for ketones if there is any reason for me to believe that I am not receiving insulin, especially when I have done a site change within the past 12 hours. In the two instances where I have had pump issues with ketones, one of my readings was at 280, and the other one was at 210 (both instances with moderate ketones). If I am suspecting that I am experiencing pump issues with a below 250 BG, I tend to correct for my BG through my pump and set a reminder to test in an hour. If my BG is higher at the one-hour test, I can assume that something is affecting insulin delivery, I take a pen correction, test for ketones, change everything out on my pump, and keep myself hydrated.

Actually, the brain does not "run purely on glucose". See, for example, the published work of Volek and Phinney among others. For a quick primer, see this article. Or do some searches -- the literature on this is extensive and growing.

Some brain cells -- the ones too small to possess mitochondria -- do depend exclusively on glucose. But large parts of the brain are quite capable of burning ketones for fuel. So it's not accurate to say categorically that the brain can run only on glucose and nothing else.

I understand that ketosis occurs in anyone that fasts; even overnight fasts produce some level of ketosis. It makes sense that the body uses alternate methods of metabolism to keep it alive. I also understand that the brain can easily use ketones for energy. Think about people that go on multi-day extended fasts. Humans can survive many days without food and the brain's use of ketones is one of the reasons why this is possible. In fact, people who fast often report a heightened cognitive clarity.

Many people confuse ketosis with diabetic ketoacidosis (DKA). That is analogous with confusing a 10 knot breeze with hurricane force winds. I've seen people against low-carb diets with attendant ketosis (deliberately confusing it with DKA) as a reason why diabetics should not eat low carb.

As diabetics we need to be concerned with the combination of high ketone levels and high blood glucose like 300 mg/dl (about 17 mmol/L). It is the combination of high ketones and high BGs that can be lethal.

I've never used the urine ketone test strips but have used the blood ketone strips. It's my understanding that the blood ketone strips are much more accurate.

You're right to be concerned about this issue, meee, now that you're on the pump. Insulin pumpers need to be more vigilant about unintended interruptions of insulin since they do not take long acting injected insulin.

+1, Terry.

Confusing ketosis with DKA is a widespread -- even predominant -- misunderstanding. It's fallacious, like confusing apples with oranges, and harmful, like mistaking natural gas (a useful fuel) for octol (a powerful military explosive).

I'm not sure what happened, it could have been something else, but huge air bubbles are worryisome. Now I'm questioning if I really had ketones or not because I tested again yesterday and the first test showed low levels while a second test 20 minutes later was clear, after drinking a bit of water. I wasn't dehydrated, but I wonder if concentrated urine effects them or not or if the sticks just aren't that reliable. I'm being very cautious now since I have only been on insulin in the pump for 8 days, and we don't know how it will effect me yet with my lows, but I will try a higher percentage if that happens again.I prefer not to even hit 60 now if I can avoid it.

Thanks Jen, I never want to see that high ketone result again- saw that in dka. I have never had any when on mdi but the lowest I ate was 30g which isn't enough for most people to have them. My brother(nonD) had low levels when he did the atkins diet. I'm still not sure what happened here really.

Thanks, I have never gone that low so had no ketones except when in dka with very high levels due to lack of insulin.

I agree, protein is converted to glucose.

Thanks Terry, No confusion for me....I think it was the fast that started it maybe if I did really have them, and not eating that much.. I worry if I see that combo at lower levels because I was in early dka at 279, even before that it was starting. I felt horrible and I'm still dizzy on and off, not sure what's up maybe a virus.

I'm horrible in that I've never tested for Ketones. I haven't had that many BG> 300 since I started pumping, or even that often before as I have always been very aggressive about getting rid of elevated BG.

I'd never heard that pumps have increased risk of ketones, maybe it's a Tslim peculiarity? I'm very particular about holding my pump up when I prime, with the "bubble" at the top of the reservoir so that it gets blown out while I'm priming it. I've never noticed a high from bubbles although if my BG starts to run up, I'm usually sort of hyper about fixing it.

I don't test usually, only 1 or twice when I was high to see if I had them and I didn't. I can't remember the last time I did before being asked to do it. But they told me to carry ketone sticks now with the pump. Kind of nerve racking because I really never worried about this on mdi that much.

What I was also thinking was maybe due to the slowly released supply of the basal that if something happened which resulted in lower levels of insulin and you suddenly became ill or dehydrated it could overwhelm you quickly. When I was in dka and it became more severe my bg was rising very rapidly, of course I was already in dka then so a different situation. I'm not sure what other pumps are like but I can't see inside the cartridge at all, it is a plastic bag inside they told me. I plan to take one apart and see. Due to my lows I have become not as hyper about it and more cautious.

can't believe you're on a do you think? I get ketones from not eating enough early in the morning, very common, especially overnight fasting. I've had ketones from high blood sugars too but I was really high close to 300's.

Well, I'm still adjusting but I haven't been feeling well at all through my training. I'm not sure what it is and now I'm so dizzy on and off I haven't been out for two days except for a walk last night. I had a horrible high when I ate a low fat meal for the first basal test and I had to cancel it: 110 to 289 in 1/2 hour with half the insulin I would normally take according the what the pump told me to do- I felt so horrible I thought I was going to pass out and I could barely think. Then I was high for a few hours due to air bubbles probably and now this. So far the basal was very flat in my 23 hour test- I went hypo at the end. And now this. My a1c will definitely be higher because I'm running higher but hopefully I will get the hang of it eventually. I just wish I knew what else is going on with feeling so off. I didn't test for ketones at 289, just got on the phone with tandem, checked out possible problems, corrected etc. It had nothing to do with the pump, it was the food apparently. I have never had them while on mdi even at the times when I spiked up a lot. But now I wonder how accurate the strips really are.

It's hard to make a judgement about it just yet with feeling this way and all these various episodes.