The Overnight Blood Sugar Conundrum

Another great post by Adam Brown! In our case, Nighttime management is tough due to all the physical training and games my son plays, we have more than 1 basal program depending on how the day went.

How do I stay in range while sleeping?

" What makes nighttime BGs profoundly difficult is that they are influenced by a number of factors: food during the day; dinner and nighttime snacking (size, type, timing); daytime exercise; insulin dose and timing; and more. Basal insulin requirements can also change drastically from night to night – in studies of automated insulin delivery, people with diabetes sometimes need half as much basal insulin on some nights and twice as much insulin on other nights. This makes repeatable perfection challenging!"


I have that problem. Some nights i’m low and other nights, like last night I’m around 200. Had it not been for my wife waking me up (G5 alarm), I’d have spent another 3 hours being way too high. One way to help stay in range at night is be more proactive at eating supper at similar times and snacking some evenings but not others. What I eat after supper tends to influence my overnight bg’s a lot. Getting low before bed messes me up because they I’ve got to eat to fix the low. So starting several hours before bed, try like heck to be stable and don’t let bg’s get out of hand. I know, it’s easier said then done, but the hours preceding bedtime are so important to having good luck during the nighttime.

Next up is using a pump should help immensely as opposed to MDI.

Last and definitely NOT least, is use a CGM such as a Dexcom and set the alarms as tightly as you can get them w/o waking you up excessively. Mine are set 150/70.

Agreed, but I also think the problem is that many people on MDI take the same amount of basal every night, regardless of circumstances, and use basal insulins that can’t be easily adjusted from night to night.

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Which goes to my point that using a pump is very helpful for maintaining better bg levels–day OR night.

I use MDI, and have very few problems at night. In 60 yrs, I have never used a pump and I have great control. I find that my great control is achieved by discipline, which I did not have at all during my first 22 yrs with urine testing.

Now that I am retired, it is fairly easy to get the same amount of heavy exercise daily, and I try to eat the same amount of carbs everyday. I also never eat after dinner unless I am low. Once in awhile I will have a glucose reading that surprises me, but I can usually figure out why. If I find I am going to high or too low over a period of time and it isn’t connected to my pre meal shots I change my dosage of Tresiba.

I know that retirement has given me the freedom to really think about everything I do, but even while working and raising a child, I was able to keep a low A1c.

A teen can’t be that disciplined nor do I think that they should be.

For me a pump has never been necessary.

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FWIW, I didn’t mean to imply every T1 needs to have a pump to have decent control. But for those that have DP, it’s a godsend, if for no other reason. For those who have varied schedules, do shift work, it’s great not to have long-acting insulin floating around in one’s bloodstream for about 24 hours with no way to “remove” it. I could list a number of other very legit reasons to choose a pump over MDI. One being, it’s great to have a pump when dining out, instead of having to inject using a pen/syringe.

Dave I do have DP, so I give an early morning shot to combat it.

Imagine for a moment how much easier DP would be to handle if you had a pump. :slight_smile: Don’t answer: I know you don’t want a pump. I got it.

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What is early morning for you?

For lots of people, DP hits at 2-4 AM. When I was on shots, the only way to wake up with a normal BG level was for me to wake up every night at 3:00 AM to take a few units of rapid insulin. Therefore, the pump has helped me actually be able to sleep through the night.

I’ve been taking metformin for several years, and recently I began splitting the dose into twice a day doses. I’ve found this has been hugely successful in levelling out my overnight blood sugars. I’m getting overnight flatlines more often than not now. But I’m also on a pump so do have a variable basal rate overnight and throughout the day.

Having started using the Tandem pump last month, I really enjoy the Basal IQ which suspends the basal rate when BGs are going low. For me this would be once or twice a week overnight. No overnight lows since.

Keeping the fasting BGs under 120 is more of a struggle but Victoza taken at 6pm tends to dampen the DP as it’s peak effect is 8-12 hours after taking.

Looking forward to trying the X2. I’d get it now but Tandem rep suggested I wait until Control IQ comes out to be sure that I would get one with that included. They said there is a contractual issue with Medicare and upgrades. If i get the pump now,it is possible that Medicare won’t provide the upgrade and then I couldn’t get a code or whatever it is, to upgrade a “pre-Control IQ” X2. Craziness, eh?

I think you are wise to hold out for the Control IQ. I am looking forward to seeing how it works for me once it’s rolled out.

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I wish I could trust that their wariness for me to buy now, turns out to be justified. I just don’t see the logic in a current X2 owner being denied the upgrade to Control IQ as a Medicare patient over some fine print in a contract. And it’s not like they told me it won’t be covered–just that they were afraid it MIGHT NOT be. It’s all rather nebulous.

I find Adam Brown’s advice to avoid eating after dinner ends is crucial for me. I am lucky to use an automated insulin dosing system and usually wake up between 70-99 mg/dL. Good BGs overnight usually lead to good BGs during the day.

While I prefer a pump over MDI for overnight control, I know I can make MDI work for me reasonably well. I’m sure I would get much better at it if I spent more time doing it.

I would not willingly give up my automated system, however. It is far superior to any system I’ve used over the years. I expect to read many comments in the years ahead with people expressing astonishment at how they ever lived without their closed-loop systems. It’s addicting in that you get much better control with half the effort. It’s not perfect and you still have to maintain good eating, sleeping, and exercise habits.

The gold standard in glucose metabolism is still one that includes a healthy functioning pancreas. Even a well-adjusted closed-loop system is crude by comparison. Since that exquisite and elegant system is not on our life’s menu, we need to look for a reasonable approximation.


Jen, it usually is when I get up to pee. This morning it was at 4:30. At that time my glucose reading was 115, so I took one unit in order to wake up at 7:00 with a reading of 89. As soon as I get up in the morning I give my pre breakfast shot.

According to an email from Tandem in November, we Medicare people will get access to Basal IQ. I think that since it is a no-cost software upgrade, we can get it.

“It was recently announced that Medicare plans to cover Dexcom G6 CGM supplies. Dexcom expects to begin shipping to Medicare patients beginning in April 2019. At that time, you will be able to remotely update your t:slim X2 Pump to integrate with the Dexcom G6 CGM System. This update will also include a predictive low-glucose suspend feature called Basal-IQ™ Technology. As with Dexcom G5 Mobile CGM integration, continued Medicare coverage for Dexcom G6 CGM supplies when integrating with your t:slim X2 Pump will require that you occasionally use your Dexcom receiver to view your data.”

Control IQ will be another issue as you mentioned because I expect that they will charge for the update and Medicare doesn’t allow people to participate in such upgrades. TBD for sure. I just keep reminding myself that 2-1/2 years ago Medicare wouldn’t cover CGM’s and we have come a long ways since then. It is not perfect but things aren’t perfect for most people on private insurance either. I refuse to spend my senior years being mad and frustrated so I advocate where I can and work to be patient for advances in my care. Since I started my diabetes career with urine testing, things in my diabetes tech life are pretty darn good…


I think you primarily have “feet on the floor” phenomenon, which isn’t too difficult to manage with MDI. My experience is similar, which is why MDI or pump work well for me. For others, they will experience extreme blood sugar rises starting at 3-4am even while they are sleeping, which makes MDI more difficult than a pump.

Yep, this was my experience. I had to get up at around 3:00 AM to take 2-3 units of Humalog just to be able to wake up below 10 mmol/L. If I didn’t do that, I could go to bed with a blood sugar of 5.5 mmol/L, have a blood sugar of 5.5 mmol/L at 3:00 AM, and wake up at 7:00 AM with a blood sugar of 17 mmol/L. I was not willing to wake up every night for the next 50 years, so went on a pump. :slight_smile: Even on a pump, staying level overnight has been a major challenge until I started splitting my metformin extended-release dose (which basically shuts off the liver’s production of glucose); that seems to have made a major difference, and now the majority of my overnight periods are flat and in range.

I used to also experience the “feet on the floor” phenomenon where I’d start rising soon after getting up. That was not as large a rise as the dawn phenomenon and was not as big a deal to manage. Metformin has also largely eliminated that issue for me, which was only a major issue if I tried to skip breakfast and would experience a big spike.

No, mine isn’t feet on the floor, but is DP according to what Richard Bernstein has said. I know that a couple of yrs ago, he too was giving a shot in the early morning or by morning his readings would be high and take hours to bring back down. That is my pattern too. Once it gets too high in the early morning, my control is shot for hours.

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Jen, when you get to be as old as I am, sleeping through the night without having to urinate at least once is not an option. :grin:

I am glad that you have found what works for you.

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