Risk of Metabolic Complications Post Liver Transplant Reduced with Pre-Transplant Weight Loss Surgery

Obese patients who underwent weight-loss surgery prior to receiving a liver transplant had sustained weight loss and a significantly lower risk of metabolic complications post transplant than patients who followed medical weight loss prior to transplant, according to the results of a new study.

Although alcohol-related liver disease, nonalcoholic fatty liver disease (NAFLD), and hepatitis C virus infection are the top 3 indications for liver transplant in the United States, national efforts to diagnose and connect individuals who are infected with hepatitis C virus with treatment are likely to lead to a decrease in the number of people who need a liver transplant because of hepatitis C virus. Those who require a transplant because of nonalcoholic fatty liver disease are likely to increase. As such, efforts to combat obesity, and the potential obesity-related metabolic complications that can arise after liver transplant, are sorely needed.

“The prevalence of obesity among liver transplant candidates is significantly increasing,” study co-author, Suzanne Sharpton, MD, MAS, a transplant hepatology fellow at the University of California—San Francisco (UCSF) remarked in a statement. “While weight-loss surgery is more effective than medical weight loss in improvement in obesity-related comorbidities in the general population, little is known about the efficacy of weight-loss surgery in patients undergoing liver transplantation and how this affects their outcomes.”

To this end, a team of investigators conducted a retrospective cohort study to determine the effects of undergoing pre-liver transplant weight loss surgery compared with medical weight loss on post-liver transplant outcomes. They studied 70 adult patients with a body mass index (BMI) of ≥35 kg/m² who had been waitlisted to receive a liver transplant at UCSF between January 1, 2006, and January 1, 2016, and who were eligible for weight loss surgery prior to liver transplant. The investigators used logistic regression models to evaluate the association of weight loss surgery prior to liver transplant on progressive diabetes and hypertension, which was defined as new-onset disease or escalation of pharmacologic therapy for established disease more than 60 days after liver transplant. The team used Cox regression models to evaluate the association of the pre-transplant weight loss surgery on either recurrent or de novo NAFLD post-liver transplant, which was defined either by a liver biopsy, or elevated liver enzymes and new hepatic steatosis found on imaging. The multivariable models were adjusted for age, sex, BMI, diabetes, and hypertension (which was measured at the time they were wait-listed.)

Of the 70 patients, a total of 14 (20%) had weight-loss surgery (laparoscopic sleeve gastrectomy) while 56 (80%) chose medical weight loss prior to liver transplant. After 4.7 years of follow-up post liver transplant (interquartile range [IQR] 2.4-7.0 years) patients who underwent weight-loss surgery prior to liver transplant were able to achieve a higher percentage of total body weight loss at the time of liver transplant (-22.6% ±14.9% vs -9.7% ±11.8%, P = .001) than those who elected medical weight loss. Furthermore, this group was more likely to sustain this percentage of total body weight loss at 1 year (-28.0% ±15.4% vs. -7.3% ±9.7%, P = .08) and 3 years (-28.9% ±12.8% vs. -5.4% ±10.1%, P <.001) post liver transplant than the group of patients who elected for medical weight loss. In addition, the 3-year-post-liver-transplant BMI for patients who underwent pre-transplant weight loss surgery was lower (30.6 ±5.9 vs. 38.0 ±6.2, P = .01).

Compared with patients who underwent medical weight loss, multivariable analyses revealed that patients who underwent weight loss surgery prior to liver transplant had a significantly lower risk of progressive diabetes (odds ratio [OR] 0.04, 95% CI 0.00-0.41, P = .01), hypertension (OR 0.05, 95% CI 0.01-0.58, P = .02), and recurrent or de novo NAFLD (hazard ratio [HR] 0.19, 95% CI 0.04-0.90, P = .04).

“Our results demonstrate that weight-loss surgery in carefully selected patients, as compared to non-surgical weight loss, leads to marked improvement in obesity-related morbidities after transplant,” Sharpton said. “Our next steps are to better delineate both the most appropriate timing of the pre-liver transplantation weight-loss surgery procedure and refining patient selection criteria in order to identify those patients that would derive the greatest benefit with the least risk of harm. Moreover, we plan to examine whether pre-liver transplantation weight-loss surgery leads to less risk of dropout on the waitlist when compared to medical weight loss strategies.”

The study, “Weight Loss Surgery Pre-Liver Transplant Is Superior to Medical Weight Loss in Reducing Post-Transplant Metabolic Complications,” was presented at the 2018 American Association for the Study of Liver Diseases (AASLD) Liver Meeting, November 9-13, 2018, in San Francisco, California.