Lows At Night

I have had diabetes 59-years, and been on a pump over 30-years. I run a consistent A1C of 6. I use a Tandem T-slim Insulin Pump. The Control IQ does a credible job. Yet I continue to struggle with night time lows. Daytime is well controlled.

It is as though my body goes into a different mode at night. This is not new, but thought I would take another stab at figuring it out.

I can go to bed at the ideal 125, but then it begins to drop. When my sugar drops; it is a nosedive, and can be 40 before I know it. Yes I use the alarms, but they are not perfect.

There is the rule that if we eat food, we must bolus, but when. I usually start with three glucose tablets. Sometimes that settles it for awhile before it drops again. Other times it sends it over 200. It is costing me valuable sleep. I stay awake and set timers to keep check on it. Milk works well, but not perfect. Much better for me than juice or crackers. I am extremely carb sensitive.

Because we are retired we often only eat breakfast and lunch, and snack for dinner. I do not like to eat before bed because of esophagus reflex.

My daytime basal rate is 1.1, my night time basal rate is 0.02. Any higher and there are more lows, any lower and there are highs. My insulin to carb during the day is 1:15, night time 1:50.

If you have snacks that work for you to keep it stabilized; I am all ears. Any suggestions will be appreciated.

Thank you.

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That’s remarkable.

I have two thoughts (both of which may be off base, but, just in case.)

  1. At what time does your basal rate drop off like that and at what time are you having the lows? That is, is there any chance that the long tail of the daytime basal is causing the nighttime drop?

  2. Are you double checking that your lows are real lows (and not compression lows)?

I suspect that you use a CGM. If so, do you keep track of your data and reports? I’m thinking about your glucose variability as measured by standard deviation. Do you know this number for say, a 14-day period?

On average, how much insulin do you take each day? What insulin duration do you use in the pump settings?

It could be that the wide difference between the day and night basal rates causes volatility in BG excursions.

My night time casual changes at 6:00 PM. My lows happen later, around 10:00 PM.

I had to look up compression liwx. But no, I sleep sitting up due to esophagus reflux.

Thank you for your input.

I do use a CGM. I know nothing about glucose variability. I have discussed this with my Endo at length. He isuggests changes, but to no avail for me.

My daily average is 28 Units.

The duration. Is 3 hours; I just changed it to 5.

I could not find a report for variability. I would need to look up what that means, and how that affects the overall picture.

I am pretty basic. I am just baffled that I am well controlled during the day, but night time is a whole different ball game.

@Nan What kind (brand & type) of insulin are you running in your pump?

Most rapid insulins have a duration of 4-5 hours, what would happen to your blood glucose if you cut your basal to zero at around 6pm (4 hours prior to lows)? If you tried this and found you spiked later during night, you could program your pump to give you a small bolus midway thru the night.

Glucose variability is reflected in the standard deviation (SD) number in CGM reports. The Dexcom overview report shows the glucose average and the standard deviation on the same screen. Here’s a sample:

The SD shown here is 20 mg/dL. Lower is better. If you have high glucose variability then corrections (either with food or insulin) can be inconsistent and volatile.

For many years I lived with a SD > 40 mg/dL. I often experienced more lows, both during sleep-time as well as during the day. People often focus on the BG average and time-in-range numbers and don’t realize just how important glucose variability is.

I think your insulin duration change from 3 hours to 5 hours is a good move.

I use Novolog. No choice. I am not sure I can do zero basal, but will find out. Well if I go below 0.2, my sugar goes high.

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I am going to try abd add my report.

I am going I try and send you my report.

Terry 4

I was able to send a screen shot of my variable report, but not to you. Sorry.

I realized that I need to get more aggressive with my carb counting. I am having highs that I should not be. I don’t like risking lows throughout the day because I am hypoglycemia unaware. I stay busy and can get distracted, then it is 40.

The change I made last night from 3 to 5 uhr may have helped. No lows, slept all night.

Have you tried TSlim pump sleep mode?

Oh…so it’s 0.2 not 0.02? When you wrote 0.02 in your original post that’s what kind of bowled me over.

@Nan Given your evening basal rate is 0.2 (and not 0.02), have you considered adding more protein to your last meal of the day?

Evening blood sugars can be tricky, especially for older long term diabetics. Mine have changed dramatically over the past year or so, and have required constantly adjusting both basal rates and food consumptions to maintain a satisfactory BG level.

Like you I have a Tslim x2 pump but haven’t been happy with the level of control CIQ Sleep Mode gives me.

If / when I’m on a zero carb diet I use a completely different set of basal rates than I do on a low carb diet. The amount and types of protein I consume can change my basal needs dramatically.


Ok, so I have a guess about what’s going on. It’s only a guess. I’m not a doctor and the only diabetes I know a lot about is my own. My guess is you need less basal during the day and maybe more at night (which I realize is weird since the lows are at night). Again, I could be totally wrong.

Here’s my thinking. Your basal during the day is five and a half times higher than your nighttime basal. That seems like a big difference. For me, my daytime and nighttime basals are the same (which obviously doesn’t mean that they should be the same for you or anyone else, but just as a piece of data.)

I think your daytime basal is doing a lot of the work of covering your meals. This is the way we did things back in the day, or, at least, the way I did things. I took a big shot of NPH and then smaller shots of regular at meals. I snacked in the late morning and afternoon and before bed to match the NPH and the long tail of the R. I’m still kind of used to that eating pattern.

I think because you maybe hate hypos (I could be projecting, I REALLY hate hypos), you’re wary of big boluses to cover food so you just have that basal in the background kind of keeping things under control during the day and you’re taking small food boluses. The high basal blunts the rises from food, but feels safe in that if you notice you’re dropping, you can eat to counteract.

There’s nothing wrong with managing your BG this way. Whatever works works. But, one of the downsides might be that any kind of busy-ness or activity or inattention sends you low because you have more insulin hanging around in your body from the relatively high daytime basal compared to your needs.

I’m not sure how this all relates to the nighttime lows. Maybe it doesn’t. But, it’s notable that your nighttime lows are very early in the night when daytime basal may still play a role.

I kind of think you could think about (with your doctor) bringing your daytime and nightime basal rates a little closer to each other. You’ll have to bolus more agressively at mealtime to make up for the lower daytime basal, but I think it could yield benefits.

Anyway, something to think about. I definitely don’t have it figured out. I’ve lowered my basals recently because I kept on having to cover my basal by eating every time I exercised or was active. (As I mentioned, I just hate lows.) But, now, I still haven’t gotten dinner (my largest meal and most inactive time of day) figured out. I try to take big extended boluses but they don’t seem quite enough. It’s hard, every change seems to carry unintended consequences.

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I was able to see your screenshot report. I’ll make comments about your case as if it were me, but you and your medical advisors must make the ultimate decisions.

For a starting point for basal rates, I would consider 1/2 your average total daily insulin amount as a total basal amount. If you take a total of 28 units per day, that would nominally mean 14 units daily for basal. 14/24 hours gives about 0.6 units per hour all day. You could start at 0.6 units per hour during the day and a lower number through the night. You may need to strengthen (or weaken) your meal bolus carb ratio to compensate.

Realize that your basal rate might be subsidizing your meal boluses. As a rule, I would make changes that err on the conservative side for safety. I would carefully watch a well-calibrated CGM, confirm with numerous finger sticks, and use an alarm clock to wake me up for over-night finger-sticks.

If you need help, you could seek the advice of a medical counselor service like Integrated Diabetes Services. Unfortunately, most doctors/endos don’t know insulin dosing very well. I’ve made my best gains by doing my own experiments but my methods are not for everyone.

Your glucose variability, as reflected by your standard deviation (SD) is 47 mg/dL, high. You report concerning lows overnight while your BGs during this time period is 150-250, probably the result of high glucose variability. I think reducing your glucose variability should be your first goal.

If it were me, I would reduce the foods that I eat to just a few different meals. I would eliminate, a least temporarily, all foods that lead to post-meal BGs > 150. In general, fewer carbs are better. I’m not saying you have to do this forever, just until you can make some adjustments that will stabilize your situation.

I realize that my comments are not complete or comprehensive, just some things that have helped me in my 40 years of living with T1D. Good luck.

Sorry, my mistake. Yes 0.2.

Yes, it is better, but I still get lows.

I hear you. I decided to try something different last night. I changed my uhr to 5 hours, from 3. I ate a meal of cottage cheese, fruit, some whole grain, and a slice of cheese. In sleep mode my sugar stayed level all night. No Highs, no lows. This morning I decided to repeat that same meal. I repeated except forgot the slice of cheese. I bloused for the same number of carbs. An hour later; I looked at my sugar. It was 263 and rising. This. Even though my daytime profile should definitely have covered it. No rhyme or reason to thus.

I have the same issue about dropping when I get into bed. My basal amount for the day is 17 units. I just started doing part of it by 2 shots of Lantus at 4 and 3 units. 10 units from my Omnipod pump. I have been having a lot of issues with site failures but I also have DP and FOTF so I kind of still want to use a pump. But I have been having the issue of dropping when I go to bed for a couple of years now while only on the pump for basal. When I use Afrezza a lot the drop gets worse. My A1c is 5.2 and my SD is usually around the low 20’s.

I have the minimum amount set for basal starting at 6pm to 5 am. I usually have no bolus amounts given after 6 pm as at the most I eat a couple of crackers or a tangerine. I might try 1 hour of no basal a couple of hours before I go to bed. I think the Dash will let me. But like you with no Basal at all I usually climb so…

I use 1.1 units total through my pump from 6pm-5am and 3 units between 5 am and 11 am. It’s Crazy. Add on the steady flow of 7 units from Lantus.

I’m not willing to stay higher all evening because of the drop that happens, so I usually end up drinking a small amount of chocolate or vanilla soymilk at bedtime. It seems to give me a slight boost and maintains levels longer. There was a vegan candy bar that was peanuts and caramel and it was 6 carbs that worked well, but it was discontinued.

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