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LSG, alcohol and women

Sleeve gastrectomy lowers tolerance to alcohol in females

Breathalyser values compared to those measured by gas chromatography, the ‘gold-standard’ technique, underestimated blood alcohol by 27 percent

Women who have had sleeve gastrectomy to lose weight may want to consider limiting the number of alcoholic drinks they consume post-surgery, according to a study from a team of researchers at the University of Illinois and Washington University School of Medicine in St Louis, who reported that after undergoing sleeve gastrectomy, women could be legally intoxicated after drinking half the number of drinks than women who did not have this surgery.

The study, ‘Sleeve gastrectomy surgery: When two alcoholic drinks are converted to four’, published in the journal Surgery for Obesity and Related Diseases, found that sleeve gastrectomy, speeds up alcohol absorption to the bloodstream leading to blood alcohol levels increasing much faster and reaching higher levels than what would be expected before surgery.

While it is well established that Roux-en-Y gastric bypass (RYGB) causes a rapid and heightened peak blood alcohol concentration (BAC), results from previous studies on the effects of sleeve gastrectomy on alcohol pharmacokinetics are conflicting. Data from two studies found SG did not affect BAC, whereas another study found SG caused a heightened peak BAC after alcohol ingestion. Moreover, these three studies estimated BAC from breathalysers, which might not reliably estimate peak BAC.

Marta Pepino

"We know that changes in the pharmacokinetics of a drug are important because the faster a drug of abuse reaches your brain, the higher the potential for addiction," said Dr Marta Yanina Pepino, an assistant professor in the Department of Food Science and Human Nutrition at U of I who led the study. "Although it is well known that RYGB affects how the body handles alcohol, findings from earlier studies on the effects of sleeve gastrectomy on alcohol pharmacokinetics are contradictory."

The researchers wanted to learn whether sleeve gastrectomy, currently the most frequently used weight-loss surgical procedure used in the world, would affect how the body handles alcohol, also known as alcohol pharmacokinetics. Women were included in the study because they comprise the majority of patients who undergo bariatric surgery.

"After having a sleeve gastrectomy, if a woman has a couple of drinks, she could be exposing her brain to blood alcohol levels that are achieved in a woman without surgery when she consumes four or five drinks," said first author, M Belen Acevedo, a postdoctorate in Pepino's group at U of I. "Drinking, such that it raises blood alcohol levels above legal drinking limits, is considered a binge drinking episode and has been associated with an increased risk of developing alcohol problems."

Therefore, they evaluated the effect of sleeve gastrectomy, relative to RYGB and a pre-surgery group, on alcohol pharmacokinetics and subjective effects, and whether breathalysers are reliable in this population.

Out of three previously published studies, Pepino says that two found that sleeve surgery did not change blood alcohol levels and one study found that sleeve surgery causes a higher blood alcohol peak. "However, all previous studies on sleeve gastrectomy, estimated blood alcohol levels by using breathalyzers, which might not reliably estimate peak blood alcohol levels in bariatric patients," she adds.

In this single-centre, prospective, non-randomised trial they performed alcohol challenge tests in 11 women who had sleeve gastrectomy 1.9±0.1 years ago (BMI=35.1±6.6), eight women who had RYGB surgery 2.2±0.4 years ago (BMI=30.0±5.2) and nine women who were scheduled for bariatric surgery (BMI=44.1±4.0) in two sessions.

In one session the women consumed the equivalent of two standard alcoholic drinks over a 10-minute period. At another, they consumed non-alcoholic drinks. At each visit, the researchers measured BAC from breath samples (BrAC) and measured by gas chromatography at various times. They also used a questionnaire to determine the women's level of drunkenness.


For the women in the non-surgery group, blood alcohol contents peaked at 0.6g/L about 26 minutes after they finished drinking. In those who had sleeve surgery and RYGB, blood alcohol contents peaked at 1.1 and 1.0g/L about 9 and 5 minutes, respectively, after finishing the drink. The women who had sleeve surgery or RYGB also reported more intense feelings of drunkenness (all p<.001).

Another finding showed that breathalyser values compared to those measured by gas chromatography, the ‘gold-standard’ technique, underestimated blood alcohol by 27 percent. This finding - and the fact that breathalysers must be used 15 minutes after the final drink of alcohol - Pepino points out that breathalysers may not be a reliable way to get accurate alcohol levels from those who have had sleeve or RYGB surgery.

"Bariatric surgeries are the most effective long-term treatment of obesity that we know of today, and findings from this study or others showing associations between RYGB and increased risk to develop alcoholism are not to say we should not perform these procedures," said Pepino. "The therapeutic effects of these surgical procedures are unparalleled. People recover from diseases such as diabetes and are able to leave many of their medications because of these procedures. We hope our finding motivates surgeons and the team of bariatric support professionals interacting with bariatric patients to discuss the potentially serious consequences of moderate alcohol consumption following sleeve gastrectomy and RYGB." 

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