Checking fasting insulin (as well as glucose) is often very
revealing of insulin resistance.

When people have insulin resistance often the fasting is glucose is normal or even a bit low, until it gets bad enough for
pre-diabetes to appear.

So checking the fasting insulin level is useful. (do not engage in any exercise before this is taken, as it will skew the result).

If elevated then you can start with supplements that help insulin work. And there are many of those that do work.