Unfortunately, I'm going to remain a bit autistic on this topic. While I do agree on the practicality aspect, I can't agree on the validity of it's measured outcomes, which then makes it a moot point altogether. It seems like you all are trying to superimpose data taken from huge epidemiological studies on a very specific, mechanistic/pharmacodynamic query. Which honestly doesn't make a lot of sense, as this are two completely different discourses. You can't apply intra-discourse logic from there to here.
Sure, seeing an improvement in homa-ir in a general population cohort study is a huge plus and the nuances of how and why aren't that important as bg management and all it's relevant outcomes have improved. But that can't be your answer to a narrow mechanistic query. Same goes for the fasting bg argument ... Deriving to a conclusion about improved insulin resistance from a lowered fasting bg makes sense only in a very specific controlled environment.
For illustration purposes; if my fasting glucose is 5.6 and I take metformin, which lowers hepatic glucose release, and the next day my fasting bg is 5.2, are you going to surmise improved insulin resistance? Same with glp agonists, they lower glucagon levels which in turn also decreases hepatic glucose release. Is my insulin resistance improved in a 24h timeframe?
An improvement in homa-ir is a broad signifier. Primarily it signifies an improvement in glucose management, period. But the improvement in glucose management can then be a result of a myriad of factors, only one of which can be an improvement of insulin sensitivity. And tissues being insulin sensitive is something very different then just having lowered hepatic glucose release or more insulin.
But why, why care about this if an improvement in homa-ir is really good enough and that's all that matters? Again, since when has this place not cared about exact mechanisms of action? Isn't this basically all that we do here, bicker about the very specific micro nuances of said drugs moa's? We are biohacking and exact mechanisms of action matter to us. Well, at least they do to me ...