The chart that changed how I read A1c

Hey Reader, Dr Karl here.

A1c tracks glucose beautifully, in only one group of people.
​A1c tracks glucose tightly in insulin resistant people.
In everyone else it barely tracks at all.

Two groups. One line is steep. The other is almost flat.
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That is one sentence and it undoes most of what A1c gets used for.

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​Red line is the insulin resistant group. Steep. ​
As glucose rises, A1c rises with it, more or less the way the textbook promises.
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​Green line is everyone else. Nearly flat. ​
Glucose moves across the whole range and A1c hardly notices.

These scatter plots come from my own anonymized client cohort, not from a peer-reviewed journal. From twelve years of pairing labs that almost nobody pairs, on people who actually tracked their food and wore monitors.
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​Here is what the chart means for you. ​
If you are insulin resistant, your A1c is doing roughly the job it claims to do.
It is a reasonable proxy for your average glucose and you should pay attention to it.
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If you are not insulin resistant, your A1c is a weak proxy at best, and the number that moves it most may have nothing to do with your blood sugar at all.
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Same test. Same reference range.
Two completely different meanings depending on which line you are standing on. And here is the problem. Nobody tells you which line you are on.
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The annual physical does not run fasting insulin.
It does not calculate HOMA-IR. It runs glucose and A1c, reads them against a range, and stops. Which line are you on, red or green?
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You cannot answer that from an A1c.
You need a fasting insulin number, and almost nobody has one. —

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Dr. Karl Goldkamp
Keto Naturopath

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