Stressed/Scared over Liver Enzymes

I am a 27 year old male that drinks alcohol more than average, but not at alcoholic levels (probably around 15-18 drinks per week).  I have had 5 blood tests in the past 9 to 10 months for various reasons (insurance applications and follow-up with primary doctor), and in each test my ALT liver enzyme has been slightly elevated near the low-to-middle 60s (72, 54, 62, 64, 68, respectfully).   All other blood tests are normal, including all liver function tests (AST is always around mid-20s and GGT is well within normal range) and others (cholesterol, glucose, thyroid, etc...).  It has not caused me problems when obtaining life insurance or disability insurance and my doctor is not worried at all.  In fact, my doctor specifically said that he is not worried because I display no symptoms of liver disease and my ALT is only slightly elevated.  Also, it should be noted that I did not have any alcohol for three weeks before taking my last blood test, which resulted in an ALT level of 68.  

I am 5'10 and 165 pounds. I run 3 miles four times a week, eat moderately healthy, have a lot of energy, have no symptoms or any past medical problems. I have been tested for Hepatitis B and C twice (6 months apart) and I was non-reactive in all tests.  Also, I take absolutely no medication except the occasional allergy pill.

My questions are

1) should I be more aggressive with my doctor and request an ultrasound/MRI and more follow-up tests or just follow his recommendation and get re-tested in 6 months and see where my ALT is at.   (I plan on completely abstaining from alcohol for 5-6 weeks before my next test.)

2) Is my elevated ALT likely related to Alcohol?  I've read that AST is usually higher than ALT in alcohol related elevations, which is not the case with me.  Also, my GGT is not elevated either.  

2)  How worried should I be about these tests?  

Thank you in advance for your answer

[Thomas D Schiano, MD]

i think that this ALT elevation could be due to alcohol use or fatty liver due to drinking alcohol. i would definitely have an U/S performed. If it remains elevated despite strict sobriety then you should see a hepatologist.

[Thomas D Schiano, MD]

i think that this ALT elevation could be due to alcohol use or fatty liver due to drinking alcohol. i would definitely have an U/S performed. If it remains elevated despite strict sobriety then you should see a hepatologist.

[nd102]

I take it from your comments that you do not subscribe to the AST/ALT ratio theory as it relates to alcohol use.  Is that true?  

Also, is it typcal, in regard to patients with elevated liver enzymes, to see an elevation in ALT when all other liver function tests are normal (Albumin, Alkaline Phosphate, AST, Dir Bilirubin, Total Bilirubin, and Total Protein)?