Suspending the pump to treat a low blood sugar

I’ve been trying to lose weight, but it seems the more I do, the more I am getting low blood sugars. Total daily dose of insulin has been reduced from an average of 60 units a day to about 40 units a day. I have been trying to lose weight for over a year now, and have only lost about 8 pounds. So, i think maybe my weight loss would be helped if i didn’t have to correct with sugar and calories.

So, i started experimenting with suspending the pump, and it has been difficult. Yesterday night, i was humming along at 80 for about 2 hours before the blood sugar started dropping. It was 62 when i suspended, continued to fall to just under 55, and then stopped and stayed that way. I thought it was just taking some time, and waited, and waited. It stayed at around 55 for over an hour! The pump was suspended for over 2 hours before I got up to 118. This is how long it has been every time I try to suspend to correct lows. Is this normal? I read the tandem pump will suspend for a maximum of 2 hours, which sometimes is not enough to get the sugar back up. Maybe if I caught it earlier? But I don’t want to treat an 80 like a low blood sugar.

Has anyone successfully used the suspend feature to treat lows? Do you have any tricks you use?

suspending doesn’t “treat” a low; it can merely (maybe) reduce the further dropping of one’s bg’s when it’s on it’s way down from a safe value, IF one’s basal rate is quite high. For relatively low basal rates (relative to the particular person), suspending is kind of a joke. the treatment for low bg’s is to EAT CARBS.


A reduction in the amount of food you are eating will reduce your overall basal needs. I suggest cutting your overall basal a little bit to help prevent the lows. I think reassessing basal needs when you are on a diet is very helpful.

I think a zero basal (ZB) for an extended time can cause a big rebound, because a few hours later you have been with no insulin for a while. I don’t like lengthy ZB’s. If it is going to be for several hours, I’d much rather do a 20%-50% or something like that, so my body still has a slight background of basal going.

If you have access to glucagon, you can do a mini-dose to help bring you up. Like only 5-10 units. And the benefit is that you are not adding calories, you are just using some of the glucose that is already stored in your liver.


I use Fiasp in my pump (which I find faster-acting than other rapid Insulins),and I frequently suspend to prevent lows, but not to treat lows. By the time you’re low, it’s too late because a suspend works quite slowly. But if you can catch a downward trend and suspend with at least 30 (preferably more) minutes warning, then it often does help prevent a low or at least decrease its severity. The key is knowing what circumstances tend to make you go low and watching the CGM closely for developing lows so that you can catch them before they happen.


I have never been a fan of suspending insulin even when you are experiencing a low BG. Here’s why. A basal and a bolus are both insulin and although a basal is a very small drop of insulin every few minutes, it takes hours for that drop to be fully effective. That is the same for a bolus which is a much larger dose but is usually given for a meal. It takes hours for the bolus to be fully effective. So when you suspend insulin (basal) you are suspending very small portions for a period of time but it does very little to increase your BG. Rather it will increase you BG for hours. In my opinion it is much better to eat as fast acting carb than to suspend your basal. And you won’t be going higher later for no apparent reason.


I have already cut my basal needs by about 33 percent, as well as bolus. I try to eat between 1500 and 2000 calories, and my smartwatch estimates that I burn between 2200 and 3000 every day. At first, I was thankful I wasn’t gaining anymore because my weight jumped up by 50 pounds when I wasn’t paying attention, but now I’m just super frustrated. I haven’t been this fat since high school (I lost 50 pounds in college). I feel like the only thing left to cut is the low blood sugar treatments. Yesterday was particularly frustrating because I cut all my bolusing by 50 percent so I could take a run, and then 7 hours later, I was still dropping. I ate 160 grams of carbs, and only used 9 units of bolus, when my normal ratio is 1:8.5.

If I have to choose between losing weight and a good hba1c, I will obviously choose a better hba1c, but I would like to do both. Sometimes I worry that the only reason I lost weight the first time was because my hba1c was over 10 and I was literally ■■■■■■■ the sugar away.

I will try your glucagon suggestion. I just hate the idea of taking even more medication to achieve equilibrium. Still, I guess I have to try something different if I want a different result.

Thanks for all your replies

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The weird thing is, there was no spike later. It actually started to head down again after reaching 118. I don’t think my run was very energetic. I kept a 16 minute pace over 1.6 miles, so not fast at all. I have no idea what happened.

Glucose tablets (4 gr. Of carbs each) are a great way to treat lows. It is also better to count carbs than calories - the two are not comparable.


Suspending a couple of hours before exercise to keep from going low is something I do pretty frequently. Right now, as a matter of fact. But yeah, like everyone says, not much use once you’re already low–the effect is too delayed.

The original post mentioned trying to lose weight. And for losing weight, you should look at both.

For losing weight, ideally you should know how many calories are coming from carbs, fat, and protein so that your diet is balanced correctly, and to make sure the total calories is within range.

If you are not counting calories and instead only counting carbs, and you eat a big fatty steak, your carb count for that meal would be zero, but it could still be contributing to weight gain.

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I thought I had accounted for the run already. I ran at 2.30, took 3.5 units of insulin at 4.30, ate 75 grams of carbs (fruit salad) between 4.45 and 5.30, rose up to 130 before dropping to 80 and staying there until about 8.45 when it suddenly dropped. I guess I could reduce the basal rate for 6 or 7 hours after I run, but that seems dangerous given the unpredictable nature that exercise seems to have. Also, I think 80 is a good number to be at, but it didn’t leave me much warning when it started to drop. It was 80, and then 15 minutes later it was 62, with no, or very little, insulin on board.

I just feel like my best blood sugar days, the ones where I take least insulin and stay in range mostly, are my worst diet days because I’m taking half the insulin, but constantly eating extra sugar because it keeps bottoming out. I have been reducing insulin like crazy, but I still cant figure out why some days, I eat 90 grams of carbs and have to take 45 units of insulin to stay in range, and others I will take 29 units of insulin (yesterday), eat 160 grams or more of carbs, and be hovering around 80 with dips all day. I know diabetes is unpredictable, and that’s why I adjust my carbs and insulin intake to accommodate the sugars (currently 85 percent in range of 70-140), but it’s so hard to balance that with my strong desire to lose weight (I am obese, with a BMI around 35).

Maybe I should have just asked for tips to lose weight, lol. I just don’t know how i can cut back much more while still being a lifelong sustainable way of eating because i don’t want to diet hard for 6 months, get burnout, and gain more weight, so i thought maybe if i could cut the calories i use to treat low blood sugars it would have some small effect.

I am trying to lose weight as well I got lows just like u.
I cut the basal rate. It did not do much. I readjusted bolus for the first 2 meals That cut the lows.
After exercise I would eat a protein bar or fruit just because and that helped bottoming out. I am using Weight Watchers program with modifications for diabetes (less fruit etc.) and have realized that I am eating too much food with high calories. Mostly low carb. like peanut butter, eggs in butter, etc. Your daily calorie count could be too high. You have to count calories as well. Do not eat canned soups. It will put weight on with a blink of an eye. Drink a lot of water and high fiber to keep the bowels moving. I lost 7 pds in 3 weeks

“The weird thing is, there was no spike later. It actually started to head down again after reaching 118. I don’t think my run was very energetic. I kept a 16 minute pace over 1.6 miles, so not fast at all. I have no idea what happened.”

That is enough to make your insulin more sensitive. u have to account for insulin sensitivity,. I am trying to stay between 1200- 1500 cal. `Good luck. I use Hammer Gel for lows. it works faster that than tabs and generally sustains longer if you add some protein It takes me up 75 units 1 pack and 35 units half a pack and is easily portable


I don’t use the suspend feature of the pump, instead I’ve used the temporary basal rate (TBR). The big difference is that with suspend, the user must remember to come back and cancel the suspend function. Forget and the next thing you know, you’re fighting a high instead of a low.

I like setting the TBR to 30 minutes and then setting a follow-on zero TBR for another 30 minutes, if needed. This way the temporary basal rate times out, so forgetting about it doesn’t penalize you.

Congrats on reducing your total daily dose of insulin. My experience with this is that fewer units of insulin actually work better with more time in range, a lower average, and less glucose variability. Less is definitely more.

How many carbs do you use to correct hypos and what glucose level triggers that action? I don’t treat for hypos until my glucose drops to 65 mg/dL (3.6) because that’s the level where my body starts counter-regulation. I like using the BG level where my body actually enters hypoglycemia instead of some textbook level. Your experience will likely be different.

Some people use 80 mg/dL and that, by itself, may be an inappropriate level to take a carb correction. If insulin on board is zero or low and the trend is flat to mildly down, I’ll often treat with just two carbs, one half of a glucose tab.

Many people still use the more coarse 15/15 rule. That old rule says to treat any hypo under a fixed level, say 70 mg/dL (3.9), with 15 grams of quick acting carbs, wait 15 minutes, test and repeat as needed. For me, I found that this rule not only over-corrected in many situations but also added needless calories. You’ll need to experiment to find the right correction carb dose to see what works for you.

I’ve been amazed at how effective TBRs are using Loop. What I’ve learned, however, is that the usual basal rates must be close to actual needs or the TBRs don’t work as well. It’s also amazed me at how quickly TBRs can effect some BG change. I often see BG response in my glucose trace within 15-20 minutes following a TBR.

Now I know the full effect of any basal rate change is not felt for about 60-90 minutes, but the leading edge can drive some impact a lot more quickly than you would think. I think it’s important for the usual basal rates to be calibrated well for TBRs to be effective. It’s like a balance point. When two opposing forces are equal, then slight changes in either of these two opposing forces can change blood glucose direction.


I treat when the blood sugar reaches 65 normally, but I set the low threshold to 70 so I have some warning if its dropping quickly. It depends on the circumstances how I treat the low. If its dropping slowly, and I’m at home, I’ll drink 1 or 2 oz of Pepsi from a marked glass. If the drop is quicker, than I will eat glucose tablets if I absolutely have to, or drink 4 oz of Pepsi if my stomach cant handle the tablets. If I’m not at home, I have individual packets of gummi bears because if I’m not at home im probably either at work or exercising and I need bigger jump to finish whatever it is I’m doing, and gummi bears don’t melt. They have 18g of sugar. The most confusing lows for me to treat are either when it drops at the end of exercise, because it will probably bounce back up, but I don’t know when, and an hour after eating, because it will probably go back up, but I don’t know when. Pre-bolusing has been great for reducing post-prandial spikes, but sometimes waiting a half hour isn’t enough, sometimes it’s too long, and sometimes it’s just right. I feel like a very confused goldilocks lol. It also reduces insulin needed,in my opinion, but the amount of reduction is unpredictable.

I’m jealous that suspending works so well for you. My recent experiments have left me feeling pessimistic about the likelihood that a closed loop system will work for me without either taking too long to prevent lows, or keeping me at a higher number for more cushion. I’m also starting to suspect that the insulin is taking longer to absorb in my body than others because sometimes I bolus, and the dip doesn’t happen until an hour later. If the insulin is absorbing slowly it would make sense why I have more low blood sugars in the evening and early night, and less frequent lows around breakfast because the insulin is building up in the body later in the day. However, even without eating, and taking the same amount of insulin in the morning, I notice some mornings the dip comes after 15 minutes, most of the time between 45 and 50 minutes, and sometimes as long as 90 minutes. With this level of unpredictability it’s hard to prevent lows and stay in range, which is why I was looking for a way to treat without packing on calories as well.

I started tracking everything I eat in my fitness pal, and I already weigh everything, so I’m pretty sure the calorie count is accurate. Then again, they say people are 40-70% inaccurate at measuring their own calorie consumption. There also might be inaccuracies with how many calories burned as estimated by my smartwatch.

After tracking for a week, I cut back on packaged soup just because there was way too much sodium. I don’t have any blood pressure problems, but I was stunned when I realized I was eating 5000 or more mg of sodium.

Good luck with your weight loss journey! You’re doing way better than I am. I’ll just continue reducing insulin and hope that eventually everything pays off.

I have a few thoughts - first, I just started on the T’slim with Basal IQ, and it’s working really well to reduce my lows, suspending the basal often when I’m still in the 80’s or even much higher, but trending down. I’m surprised to see how often it’s doing that, and yet I’m not having rebound highs, and am overall having fewer lows and highs! It’s pretty amazing.

My basal rate is only .35, so in response to a comment above, it works fine with low basal rates.

I also find that eating fewer carbs, about 100/day total, helps to both keep my weight down/steady, and helps to prevent some of the bigger lows that happen when you’re taking larger amounts of insulin. I only use about 1.5-2 units for each meal. So even if I’ve over-bolused, I’m not likely to have a fast and big drop…

Good luck - it’s a day by day process, different for each of us!

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Suspending does not raise BG quickly enough to help (for me).

Exercising is going to make your sugars unpredictable. Period. Some days will be better than others.

A 33% drop in basals is heavy duty. Is there any chance you can lower a bit more? Perhaps cut the basals to the point where you have definitely cut it too far (and cant get by on non-exercise days), and then slowly increase to fine tune it. You might need a different basal pattern completely for exercise vs non-exercise days. If your really bottoming out, you might be safest finding a happy medium and just knowing that your going to need to increase your basal on non-exercise days. You can figure out what makes you feel safe and comfortable so that your not getting super low if your a heavy exerciser.The best thing you can do for yourself is have the basal rate as ‘perfect’ as you can for survival - whatever that means to you.

I bet that you will still loose weight if you are exercising (even if your eating more). If you are building muscle, then you will burn more calories all day, every day.

I know that I would destroy a closed loop system with what I do physically. It simply cannot account for the variability that I see with physical activity. It would be dangerous. I need to wait until its more developed.

QUESTION: How tolerant are you of lows? Do you handle them well? Whats your make or break number where you expect to loose your ability to function? Sounds like you can handle BG = 60, but you must be getting some 30’s, yes? I’d like you to exercise caution about those because exercise might make it drop rapidly and those 30’s could really throw you for a loop. If I start to see many 30’s, I drop the basal no matter what. That’s my, personal, make or break number.

Bingo. agreed.

OK. Losing weight if you are a type 1 is almost impossible. I do not know why. I have gained 20 lbs and eat 600 cals a day. No cheating. I have been D since the age of 22 mts . Good luck to anyone who actually does. i am on a Medtronic 630G; have been on a pump since I was 16. I am a woman; the hormones, lows all come into play. I find suspending doen not ever work for weight loss

Well, I must have done the “impossible”. I went from 242 to 203 (an excellent weight for me, at 6’4"). I started in December 2017 and reached 203 in April 2018. A few years ago, I did the same thing. It’s all about calories in/calories out. No magic, No tricks.