Straighter line on CGM during day, better sleep at night?

for those using a cgm, does a flatter line during the day usually predict a more restful night? conversely, do greater peaks and valleys during the day seem to echo at night causing a less restful sleep and night sweats?

If I swing too far up and down, the odds are that overnights will also be problematic. I haven’t had night sweats since I stopped using animal insulins oh-so many years ago.

phoenixbound, why do you think the overnights are like that if you swing too far up and down? also, are those swing days days when you are using more insulin?
and, why do you think animal insulins caused night sweats? thx.

All other things being held equal, I think that is true. If you’re pre-diabetic and just using diet and exercise to control your blood sugar, you are helped a great deal with some native insulin. I know it’s a problem if your pancreas is not consistent in its output. I take insulin via a pump, so my experience may not echo yours with regard to BG variability.

I find that my blood sugar variability tends to be “sticky.” That is, low variability during the day tends to leads to less variable over-nights. Low variability nights, in turn tends to lead to low variability days. The opposite tends to be true, too.

Having said that, any number of things can change that dynamic. Restaurant meals can throw a curve. Extra exercise can change things also.

If I drink more than one glass of wine with dinner, I tend to go low in the midnight to 2 a.m. timeframe.


at night my blood sugar seems to be at a perfection i don’t see in the daytime. i get 78-83 in the middle of the night, but sometimes i am testing in the middle of the night and seeing that beautiful number because i feel so hot i can’t sleep. some hot spells are worse than others. with perimenopausal hot flashes/night sweats, one line of thinking is that the body becomes used to a very narrow range of temperature, and hot conditions can trigger a hot flash. so my feeling is, based on my experience, that my body only can accept a certain range of blood sugar. if i go out of that range during the day, i will get hot at night. so today i tried to be more conscious and tested more. i’ll see how it goes tonight.

Being a single man, I am out of my depth with perimenopausal issues. When sleeping, I do get hot when my blood sugar goes high or low. I do know that the thyroid plays a role in temperature control. Good luck with your search!

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Most CGM users are going to be either Type 1 or perhaps Type 2 on insulin. I suspect that what a Type 1 would call a straignt line might be rather different from a prediabetic.


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the key point i am focusing on is relative bg fluctuation and sleep quality no matter what kind of diabetic you are.

I can’t say I can correlate the two. It seems I will have up and down sugars for days or weeks and then a period of relative calm for days or weeks.

KC, i am focusing on daytime fluctuations possibly leading to night time fluctuations/feeling hot at night.

A more flt line does not necessary make much difference for sleep for me. I can say that I tend to have more sleeplessness with lows than highs but frankly the difference is pretty minor. Very high or low during the day can spell doom at night but not for the obvious reasons. Obviously if I do not have my blood sugar down i am up in the night and if ti is too low i do not sleep as well. Still the same effect can happen if the high or low happens in the night or evening.

rick phillips

i am very glad that you posted this site. and i am very grateful for the variety of responses. i will eat the same exact food every day at exactly the same time and go for weeks with completely “perfect” BGs. then, seemingly out of nowhere, my BGs go high. first i change my pump site, then i change my pump completely and last but not least, i look for trends regarding when i am going high (or low). so i used to panic and call up the endo, thinking that something was definitely wrong with me or that perhaps my pump wasn’t working. now i know how to tweak my basal rates myself, little by little (no major changes at first, just to see how it goes). i can say this about sleep: when i bounce in either direction or back and forth, my sleep is miserable. i have the “alarm” feature on my CGM, and when it goes off during the night, it wakes up not just me, but my husband as well. i test, either recalibrate, give myself a correction bolus, and try and go back to sleep. by the time the morning comes, i would like to stretch my arms in the air and be thankful for a bright new day, but i am so frustrated and so exhausted that i just feel completely depressed. then i get a reaction to the depression and the frustration. UGH, will this ever end???

being tired stinks. i have been like this for so long, it’s sort of normal. when i have a good sleep, i want to note everything i did or ate to see if i can replicate it. i don’t have the heavy worry of going to low since i am not on insulin. daisy, have you tried the 6 gram breakfast, 12 gram lunch dinner carb plan from dr bernstein? i haven’t done it yet because i am controlling bg fairly well with diet/exercise/metformin. but i wonder if it would help my sleep?

Boring and unnecessary. If you low carb you will be able to eat a variety of foods and at varying times without worrying much about bg swings. Anyone eating tons of carbs is going to be walking a tightrope between hypers and hypos from the dosing errors that occur with eating lots of carbs. the fewer carbs you ingest the less insulin you need, so if your basals are correct you can pretty much “flatline”. it’s so much more pleasant that way. Indulge once in a while to have some “fun” eating your favorite foods but don’t do it every day or you’ll suffer from bg swings which are definitely NOT “fun”. Get some good recipes for low carbing to make that type of eating more tasty than you might think.

I’d want to shoot myself if I ate the same thing every day.

my dexcom cgm gives me misreadings during the night, many lows which send the ALARM feature to go off. then i must do a finger stick to make certain that my BG are “normal/safe” (which they usually are) why this happens i have no idea. the same thing happens when my BG is too high…the cgm alarm goes off and i test again to see if i need a correction bolus. all this waking up during the night causes a terrible nights sleep. i am up, i fall back asleep, i am up again and again…question, could you be going through pre-menopause or menopause? that was a very difficult period for me, particularly w/ night sweats. also, the hormonal changes that i went through caused many ups and downs all day/all night. it was hellish. just a thought. also, to lessen the menopause symptoms, my gyno wanted to put me on estrogen replacement therapy, which only made things much worse; i had to stop that med asap. hope this helps. good luck. daisy mae

i am 50 and still have my period, so perimenopause. i think i have finally found a way to sleep better. i have not had any major temperature changes for 5 days and my weight is going down. i’m just using some information about circadian rhythms. i put it all on my blog and i’m not selling anything. i’m keeping my fingers crossed that my new method is going to keep working. my brain has really been fried from chronic lack of sleep and i make mistakes because of memory lapses, not paying attention everyday. so i am still like that cuz i guess 5 days of semi normal sleep will not fix that overnight. but i am so happy i think i have found something that works. hopefully my brain will recover or stabilize. my hearing has also really been going down hill this year. after checking for wax and not finding any, my doctor is sending me for a hearing evaluation. i think being able to hear clearly is going to help my brain recover as well.