--and even that is considered high.

Unfortunately, I don't know of any timed released form of lipoic acid on the market as of yet. You could try taking 50mg twice a day--once in the morning, once in the evening--and see how that works. We're all experiments of one in this regard.

I do agree, though with your self-designation as prediabetic--your insulin numbers, even if skewed, are indicative of insulin resistance in your bodily tissues, even if your pancreas can still make enough to keep your glucose levels relatively in check. As Mrs. D says, eating more conservatively and more carb/fat/protein balanced might be enough to keep it controlled; I would also recommend weight-bearing/muscle building exercise to the extent you can tolerate it, as muscle is more sensitive to insulin than most other body tissue and increased muscle mass can help the body reduce its overall insulin needs. Fat is harder to sensitize, so getting rid of some also helps.