Your Pre-Sleep Blood Sugar Check Is a Sleep Decision, Not Just a Safety Check
You already do this. You check your blood sugar before bed, glance at your CGM, maybe set a temp basal. You've been doing it for as long as you've had T1D. Here's the reframe: you've been doing it as a safety check. "Am I okay to go to...
The episode, word for word
I want to be upfront about something before we get into today's episode.
I am going to tell you something that sounds like the kind of wellness content that would be delivered by someone standing in a field in linen pants. It is going to sound like that. I cannot control how it sounds. What I can tell you is that there's actual research behind it, it specifically applies to T1D glucose management, and I looked it up at midnight on my phone while lying in bed with the screen at full brightness.
You're allowed to laugh at that. I certainly did.
My name is Neil Greathouse, and this is Your Best T1D Year.
All right. Your bedroom.
Your bedroom has opinions about your blood sugar. I know how that sentence sounds. Stay with me.
Here's what we're actually talking about. Your sleep environment, specifically temperature, light, and screens, directly affects the hormones that regulate both sleep and glucose. And for T1D people, the stakes on those hormones are higher than they are for everyone else because we don't have a backup system to compensate when they go sideways.
Let's start with light. Specifically blue light. Specifically the blue light that is currently coming out of every screen in your life at all times.
Your body has a hormone called melatonin. Melatonin is how your brain knows it's time to sleep. As it gets darker, melatonin rises. As it gets lighter, melatonin drops. Simple, elegant, worked great for about two hundred thousand years.
And then we invented screens.
Your phone, your tablet, your TV, the overhead lights in most rooms, they all emit blue light, which is the specific wavelength that your brain uses to decide whether it's daytime. Your body sees that blue light at 10pm and goes: oh, it's daytime. Let's crank up cortisol. Let's suppress melatonin. Let's be alert. It cannot tell the difference between actual sun and Netflix's menu screen. It just sees light in the blue spectrum and starts its morning protocols.
So. You're lying in bed at 11pm, doomscrolling through TikTok, you know the one, you just went on to check something and then there was a video about a dog learning to skateboard and then somehow forty-five minutes later you're watching somebody restore a vintage cast iron pan at 2am and you have no idea how you got there, and your brain thinks it's noon.
And then you wonder why you can't fall asleep.
And then you check your blood sugar in the morning and it's higher than it should be.
And the screen was doing work the whole time.
I'm not going to tell you to throw your phone in the river. That's dramatic and also phones are expensive and you use yours to check your CGM at 3am so you need it. What I am going to say is: your screen brightness and your screen distance from your face matter more than you probably thought.
OK. Temperature. This one is easier and also slightly more immediately applicable.
Your body drops its core temperature as part of the process of falling into deep sleep. A cooler room supports that drop. The research is consistent: somewhere in the range of 65 to 68 degrees Fahrenheit tends to produce better sleep outcomes for most people. Obviously that varies. Obviously "cooler room" means something different depending on where you live and what your partner thinks about the thermostat. I'm not here to cause relationship problems. I'm just saying: the temperature has an opinion.
A cooler room also means your body can drop into deeper sleep stages more effectively, which for us means more slow-wave sleep, which means more of the repair work that T1D sleep architecture tends to interrupt.
One thing on the irony of all this: I researched most of this episode on my phone in bed at midnight. I checked my CGM on my phone three times while doing it. I have absolutely no self-awareness about any of this. I'm working on it.
What temperature is your bedroom right now?
That's the whole challenge today. Know the number. Just know it.
And tonight, one hour before bed, put your phone face down. Not in a drawer, not in another room if that's not realistic. Just face down. Take the blue light out of your direct line of sight.
One hour. See what happens.
I know this episode sounds like I'm asking you to redesign your room for better sleep and also lecture you about your phone. That is genuinely not the goal. The goal is one small shift in your environment that removes a thing your body was fighting against.
You've been managing T1D in an environment that wasn't designed for it. Slightly adjusting that environment is a reasonable and available tool.
You're not doing a bad job. You're doing a difficult job. And your bedroom is about to be slightly more on your team. I'm proud of you.
Type 1 diabetes is relentless, but managing it doesn't have to be. New episodes every Monday, Wednesday, and Friday. You're not doing a bad job, you're doing a difficult job. Nobody remembers easy.
This is the script as read on the mic, lightly tidied for reading. Education, not medical advice. Talk to your care team before you change anything about your insulin.