Alcohol Consumption in Obese Patients Before and After Gastric Bypass as Assessed with the Alcohol Marker Phosphatidylethanol (PEth)

Introduction: Roux-en-Y gastric bypass (RYGB) causes more rapid and enhanced absorption of alcohol. RYGB patients have also been reported to use more inpatient care for alcohol-related disease than do patients after other bariatric procedures. The present study was designed to evaluate alcohol consumption level before and after gastric bypass using a sensitive and specific alcohol biomarker. Materials and Methods: Two separate consecutive groups of patients and a group of healthy blood donors, as reference group, were included in the study. Alcohol intake was assessed using the alcohol marker phosphatidylethanol (PEth) at preoperative baseline and at 1 and 2 years postoperatively. In the first patient group (n = 133), neither surgeon nor patient was informed about the results of PEth testing. In the second group (n = 214), PEth results above 0.30 μmol/L were considered to indicate excessive alcohol consumption and led to preoperative alcohol counseling. The groups were followed for 2 and 1 year, respectively. Results: PEth results were significantly lower in both patient groups at baseline as well as postoperatively compared with the reference group. In both patient groups, there was a significant increase in PEth values at postoperative follow-up compared to baseline. Conclusions: Several physiological changes postoperatively have to be considered when interpreting PEth results in obese patients with dramatic weight reductions. According to results for PEth, obese patients treated with bariatric surgery would seem to have lower alcohol consumption compared with the reference group. Although slightly increasing their PEth values postoperatively, the RYGB patients did not reach the PEth values of the reference group.