Usually the liver levels take a long time to return to normal. Thats why doctors usually order a retest several weeks or months after the first initial test.
45 is normally the high end of the reference range in labs. The thing about it is they get this reference range from a small subset of the population for statistics. My ALT
is normally around +-90. I've been tested for everything and they have never found any structural or functional problems with my liver. I think it is not uncommon for people to outside of the normal reference range on liver enzymes.
But I'm not a doctor, this is just what I've learned from all my research and I have doctors in the family