With HbA1c 5.7 you have early prediabetes, which is good news (relatively). I think you can reverse it with simple steps, before more serious disease arises. The provlem with prediabetes that it is almost always associated with insulin resistance, which leads not only to diabetes but also to high blood pressure, fatty liver and lipid disturbances. So it is the root of heart diseases. The best thing you can do for yourself now is to control prediabetes/insulin resistance now, this needs only lifestyle modification as reducing carbs, intermittent fasting and exercise. I have the same problem as my HbA1c was 5.8 and I had high blood pressure and am trying to follow these simple steps and retest after 3 months to see if these steps are sufficient. Good luck for you.