medwireNews: Hair ethyl glucuronide (EtG) can be reliably used to detect moderate levels of alcohol consumption in the previous 28 days in patients with liver disease, show study results.
"The measurement of hair EtG would provide a strong supplement to other clinical assessments of drinking in patients with liver disease," say Scott Stewart (University of Buffalo, New York, USA) and colleagues.
"Use of hair EtG would also improve classification of drinking in studies of alcoholic liver disease where inaccurate self-reported drinking represents a threat to study validity."
The study included 191 patients who had previously been treated for liver disease. Of the 57.1% who reported drinking in the prior 3 months, 34.6% had detectable hair EtG (≥2pg/mg) and 27.2% had hair EtG equal or greater to 30 pg/mg.
There was only a modest correlation between average daily alcohol consumption during the previous 90 days and hair EtG concentration in patients with detectable EtG, showing that the technique is unlikely to be useful for determining the specific amount of alcohol an individual has consumed.
However, the results showed that a cutoff value of 8 pg/mg was highly sensitive, at 90%, and highly specific, at 88%, for detection of an average alcohol consumption of at least 28 g per day over the previous 90 days, which equates to two or more standard US drinks per day.
Regression analyses also revealed that there were significant interactions between gender and cirrhosis and positive hair EtG results, such that lighter drinking may be more easily detected in men and the detection of heavier drinking may be enhanced in patients with cirrhosis. Further research to characterize these associations is needed, the authors say in Alcohol and Alcoholism.
While previous studies of EtG levels have shown ability to detect heavy drinking, Stewart and colleagues say that the more modest alcohol consumption detected in their study could exacerbate liver disease in susceptible individuals.