Know Your Numbers #3: Blood Sugar
So far in this series: triglycerides, then HDL. Two of the five numbers in the Borderline Trap.
This week, number three: blood sugar. And this is the one where my own numbers don’t make sense yet.
Two tests, two different pictures
Most lab panels check blood sugar one of two ways, or both.
Fasting glucose is how much sugar is in your blood after 8 or more hours without food. It’s a snapshot of one morning.
A1C measures how much sugar has stuck to your red blood cells. Those cells live about three months, so A1C is a rough three-month average.
One tells you about today. The other tells you about your season.
What’s a good number?
Fasting Glucose | A1C | |
|---|---|---|
Normal | Under 100 | Under 5.7% |
Prediabetes | 100 to 125 | 5.7% to 6.4% |
Diabetes | 126 and up | 6.5% and up |
A fasting glucose of 100 or higher is one of the five Borderline Trap numbers.
Here’s the edgy part: blood sugar is often the late sign
When you eat, your body works to move sugar out of your blood and into your cells. If your cells start resisting, your body doesn’t give up. It pushes harder.
That extra effort keeps your blood sugar looking normal, sometimes for years. On paper, you’re fine. Underneath, your body is working overtime to keep you there.
By the time fasting glucose finally creeps over 100, that’s often not the beginning of the problem. It’s the point where your body can’t hide it anymore.
There’s an earlier warning sign. It’s an inexpensive blood test, and almost nobody gets it. It was never ordered for me until after my heart attack.
My numbers
This is where it gets confusing.
When I had my heart attack in 2021, my fasting glucose was 114. My A1C was 5.6 … another “normal” blind spot. Today, my personal A1C goal is 5.0 or lower.
Since then, I’ve also changed what I eat. I’ve changed how I move. My triglycerides dropped from 111 to 47. My HDL went from 39 to 84.
My blood sugar barely noticed. My latest fasting glucose is 109. My latest A1C is 5.7.
That’s still prediabetes on both tests. Of the Borderline Trap numbers I’ve shared so far, this is the one I haven’t fixed.
But here’s the twist. That earlier warning sign, the test almost nobody gets? Mine has been in the ideal range every time I’ve checked it.
So one number says my body handles sugar well. Two others say I’m prediabetic. They can’t all be the whole story.
And in 2025, one test result made the picture even more confusing. That’s a story for its own letter.
What I think is really going on is something I’ll walk through in my free webinar.
A question I asked my cardiologist
Statins, the cholesterol medication most heart attack survivors take, can raise blood sugar a little in some people.
I asked my cardiologist about it. He agreed the statin may be contributing. He also made it clear why he still wants me on it: after a heart attack, the protection for my heart outweighs a small bump in blood sugar.
I’m still taking mine. That’s what a good conversation looks like: an honest answer about the downside, and a clear reason for the decision. Never stop a heart medication on your own. Ask the question, and decide together.
Your fasting number is one snapshot
A fasting test tells you how your body handles an empty stomach. It doesn’t tell you what happens after you eat.
Wearing a continuous glucose monitor (CGM), a small sensor on my arm, showed me what happens after meals, and some of what I saw surprised me. If you want to try it yourself, my free 14-day CGM food experiment walks you through it (link below).
What to ask at your next appointment
What were my fasting glucose and A1C, and how have they changed over the past few years?
Am I in the prediabetes range? If so, what do you think is driving it?
Could any of my medications be affecting my blood sugar?
Is there a test that could show a blood sugar problem earlier than these two?
As always on Thursdays, the small things that matter:
This week's happiness check
Enjoyment: Still going through the photos and videos from our Holy Land trip three years ago. Every clip brings back a fond memory with my mom and my sisters. I keep stopping to rewatch them instead of editing.
Satisfaction: The video editing has been anything but straightforward. One technical problem after another. But I’m working through each one as it comes. Slowly, but surely. Just like my health journey.
Meaning: Reached out to my last remaining uncle on my dad’s side. He just turned 90, and I shared this newsletter with him. Heart disease runs in our family, and he’s the one who’s managed it best among all the siblings. I’m hoping to learn a thing or two from him.
What’s yours? Hit reply. I read every one.
Dennis
Cardiac Survivor · Your Friend in Recovery
Spokane, Washington
I’m a heart attack survivor, not a doctor. This is my personal experience and is for educational purposes only. Talk with your own care team before changing anything about your treatment.
P.S. Want to see what your meals do to your blood sugar? Try my free 14-day CGM food experiment.
P.P.S. Missed the first two in the series? Triglycerides · HDL