An AST / SGOT of 48 is not considered as high as these enzymes need to raise to double of the normal when they are considered as clinically significant. This slight increase can occur just because of no cause or due to some medications like Tylenol or due to alcohol consumption. But as I mentioned, this value does not alarm the doctor.
Hope the following points will clear the raise in your liver enzymes;
1) The liver function tests may be abnormal even in patients with a healthy liver.
2) Studies evaluating the clinical significance of these abnormalities have demonstrated that serious underlying liver disease is uncommon in many individuals.
3) Just this level of enzyme elevation is found in almost 10% of cases without any disease.
4) Only a persistent increase of two fold for three months (tests repeated at monthly interval) will need further studies or invasive investigations like liver biopsy.
5) The other causes should be observed if there is no history of any medications, alcohol abuse and investigation for hepatitis B and C are normal and there are no medical evidence of the following diseases (which can elevate these enzymes); muscle disorders, thyroid disorders, celiac disease, adrenal insufficiency and anorexia nervosa.
Anion gap is to measure the unmeasured anions in blood like protein, phosphate, sulfate, and organic acids. A low anion gap occurs in conditions like low blood albumin, intravenous fluid administration or some medications toxicity. Again this does not show anything serious. Please read the resource for the anion gap;
Please feel free for your follow up questions.