Dr. Bill I am seeking help! I was given an ETG test and it came back positive, however I have abstained form alcohol. I had a bilio-pancreatic diversion and duodenal switch (ie gastric bypass) in 2003 and feel that this change in my digestive system may have a hand in the skewed result. I am seeking any guidance as to how my surgery could effect how the ethanol that I come into contact with on a daily basis.

TY
~SweetP

TY

You are probably on target. Gastrointestinal malformation or alterations (including surgery) often lead to an increase in endogenous ethanol (EE) synthesis and/or deficiency in ethanol metabolism. It could be related to Alcohol Dehydrogenase (ADH) an enzyme present in the stomach and GI tract and/or yeast overgrowth. Even the small amount of environmental alcohol that you are exposed to daily wouldn't be metabolized in the stomach by ADH and pass directly to the liver where it is metabolized and EtG results.

Gastric bypass (or intestinal surgery) has been associated with EE synthesis for at least 40 years and should have been considered in interpreting your test results.

What was the EtG reading?

EtG was 1970 ng/mL
EtS was 332 ng/mL
Creatine was 131.4 mg/dL

Normalized to creatinine your U100-EtG is 1499.17 and U100-EtS 252.65. It is particularly important to make this adjustment. (I'm assuming this wasn't done by the laboratory... it should state on form). [see New Advisory]

This is a little higher than I would expect for incidental exposure under normal conditions, but even that can't be stated with certainty. It is quite possible however that the combination of your surgery, diminished ADH, and incidental exposure to ethanol could easily explain the reading. You simply don't have the enzymes to metabolize the alcohol. The reading is low compared to ingested alcohol. There is also the possibility of EE as noted above.

Did you advise the laboratory of your surgery? And was this your first EtG test.

Are you male or female?

There are a couple of confirmatory tests that could clear it up. 1) Mean Corpuscular Volume (MCV) or 2) Phosphatidylethanol (PEth). These are both blood tests with longer windows of detection that EtG.

It would seem to me that any laboratory or testing agency would negate the test upon learning of the surgery. Even hormonal imbalances or intestinal infections are known to create problems with the test. As noted previously, EE synthesis in relation to intestinal surgery is well known.

I am a 29yr old female. The lab was not aware of my surgery and it was my first ETG.