Very low blood sugars at night

gingerblah2023 said:

I have noticed that my blood sugars drop below 3.9 mmol/L at night. Would this explain my fatigue in the mornings?

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Be aware that libre is notorious for reading low at night if you sleep on it - so called compression lows.

Also, non diabetics can easily go down to the high 3s without any medical concerns. The reason insulin users panic about this is that the use of insulin can make them go much lower.

Here's a study of what happened when non diabetics wore a cgm for 10 days


(Note that US mg/dL blood sugar measurements convert to UK mmol/L if you divide by 18)

edited to add
And welcome to the forums

Hi @gingerblah2023 and welcome to the forum.

While many people don't notice their symptoms before being diagnosed as Type 2 Diabetic, in some like you and like one of my moderator colleagues, they get symptoms when barely pre-diabetic. We are all a little different.

It is normal for non-diabetics to have very short periods of low blood glucose overnight. They just don't usually wear a CGM and so don't know about it. This isn't a problem because the BG low is detected by the body and the liver reacts by dumping some glucose into the blood stream - as is shown in your CGM graph by the rapid rise in BG after those 2 lows.

You say you have cut sugary foods and are eating a 'healthy diet'. Are you aware that a healthy diet for a T2 diabetic isn't the same as a 'healthy diet' for a non-diabetic. We need to cut down on all our carbohydrates (starches as well as sugars) and need to add in more Protein and more Fat to compensate - otherwise we will feel tired due to reduced calories (at least for a while until 'Fat adapted').
The transition to eating LCHF is (in my opinion) easier than doing the alternative Ultra Low Calorie Diet, but it is still a transition the body needs time to adjust to - hence some people report 'Keto Flu' for a few days to weeks.

I always caution against reducing calories when starting to eat Low Carb - it is called Low Carb Higher Fat for a reason! Higher Fat (than this 30yr low fat fad) helps the body adjust to being able to utilise its' own body fat for fuel when required, so it can switch seamlessly from running on glucose (cabs) and running on ketones from the 'huge fuel tank' we carry around with us = several weeks energy requirements.

gingerblah2023 said:

Attached photo with blood glucose readings View attachment 64326

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I had a very similar picture to yours. A drift downwards most of the night but a sudden cliff edge drop and then an equally quick rise. For me the low point is marked by extreme sweating and nightmares. It doesn't happen all the time and seems to come and go with no apparent cause. I am sure these aren't "compression lows" as compression lows don't come with sweats and nightmares. It's been suggested to me that this could be caused by a rise in insulin, which is then matched by the liver producing more glucose. Obviously things are usually thought to operate the other way round, a rise in glucose triggering insulin production. Maybe it's just a question of timing.

The research EllieM tagged above does show that a fair proportion of non-diabetic people get exactly the same night time fall to comparatively low (sub-4) levels, somewhat to the bemusement of the research team.