I’ve been talking with some friends who measure their blood glucose to manage type 1 diabetes and they also know these dawn spikes. Interestingly, though, mine are not necessarily at dawn. With insulin resistance increased by hormones like cortisol and epinephrine, it’s possible that there could be complex triggers of nighttime spikes, ranging from physical stress caused by sleep disturbance to more complex feedback loops in which declining blood glucose levels trigger hormone release which leads to an overcorrection. I don’t have a theory yet, but I’m collecting ideas.
My thought on snoring was not a causal link to blood sugar, but an indicator of body status. People tend to snore when they relax fully, which I think would be related to low blood sugar. Apnea can occur when you relax and block the airway which I think would lead to an adrenalin rush and spike in blood sugar.
Does holding your breath cause your blood sugar to rise?
@Agaricus
Hi Gary,
Your nocturnal sugar spikes seem unusual. Typically we would expect your sugars to run 80-100 through the night. Some will even drop into the 70s. Perhaps the good thing is that, from what I saw, the spikes seem to be staying under 140.
Whereas, there is definitely a dawn phenomena, the cause of spikes in the middle of the night are a bit more mysterious. In medical school, we never really studied continuous glucose monitors in non-diabetics so there really is no clear and common differential diagnosis of which I am aware.
Previous research definitely shows a correlation between sleep apnea and blood sugars and it would make sense that nocturnal hyperglycemia would be the source. It definitely makes physiologic sense that (an) episode(s) of hypoxemia from sleep apnea could spike epinephrine in the blood stream and thus cause a rise in blood sugar.
If it is sleep apnea, yours could the first case of apnea diagnosed by continuous blood sugar monitoring. It could definitely be case reportable. We could search PubMed to see.
I recall seeing that there are iPhone apps that record sound through the night. (Some are used to record sleep talking - like the Sleep Talking Man blog.) It could be interesting to see if you catch anything - and if you do - whether it occurs before you see a spike in your sugars.
I am happy to prescribe any other diagnostics as well to get to the bottom of what might be the cause. I increasingly get the feeling that this continuous glucose monitoring is going to open up a whole new diagnostic world…and to think…given the latest news this week…it sounds like the next Apple Watch might even have a watch band that does it. It will be a new world.
@praxiteles - I’m with you - The suggestion by @OP_Engr to look at snoring, apnea, and body position got me thinking also. I thought: snoring/apnea->stress hormones->blood sugar rise. But he also pointed at a different possibility: low blood sugar at the point of deepest sleep (indicated by snoring/apnea) leading to cyclical overcorrection. Since audio tracking of snoring is fairly simple, I think, it seems smart to start there. Will probably take me a few days to get going. Thank you for making these suggestions!
@jackpark There are a number of steps you have to take with Nightscout. As far as I know the only way to run it is locally. But I haven’t yet gone down this path.
@Agaricus Hi Gary - yes - rebound hyperglycemia after an episode of hypoglycemia could also be a cause. That should be easy to diagnose given you are using a CGM. If you see a steady downward trend followed by a spike upwards - that would be a clue. If nocturnal hypoglycemia does look like the diagnosis, you can help confirm the diagnosis by trying to prevent it by eating something heavy in fat or protein before bed (i.e. peanut butter, greek yogurt, nuts etc.) Slow digestion will keep your blood sugar higher through the night and should prevent the hypoglycemia.
Great series of blood glocose posts by Chris Kresser also. They’re a little old but the figures in them look very similar that 2017 post, for pre and full diabetes: