Elevated levels of SGPT are due to some liver injury.
The most common causes for non alcoholic reasons are various types of hepatitis
,obesity,diabetes,use of certain medicines like anti seizures and anti biotics etc.
If these causes are ruled out then you should be investigated for other causes like wilson's disease,hemochromatosis
,Coeliac disease,crohn's disease etc.
It will be best for you if you consult a Gastroenterologist
and get all the possible investigations done to find the exact cause.
The treatment will be decided on finding the cause.