Dr.BariatricHTX said:

Fasting insulin is the lab my functional medicine doctor cares about most for glycaemic control: it's a much earlier marker of metabolic dysfunction…

Agreed, and one caution: a single measurement is not a measurement. Anything that moves day to day needs a trend before it means anything at all.

I would rather be corrected than agreed with, if it comes to it.

MounjBrad said:

Insulin sensitivity test (HOMA-IR) on glycaemic control — arguably the most important metabolic marker most people aren't tracking: HOMA-IR = (fasting…

Thank you for spelling out the reasoning rather than just the conclusion. Printing the relevant bit and taking it with me.

Dr.BariatricHTX said:

Fasting insulin is the lab my functional medicine doctor cares about most for glycaemic control: it's a much earlier marker of metabolic dysfunction…

I do not accept the framing. The question has been narrowed to the version that has a tidy answer, and the part that was dropped is the part the OP actually asked about.

One concrete data point for the thread. If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way. Most of the apparent contradictions in these threads dissolve at that step.

Moderator note: two posts asking for a source have been merged into one. Please search the thread before asking again.