Bariatric Surgery Reduced Risk of Major Adverse Liver, CV Outcomes in Patients With NASH

Bariatric surgery was associated with a significantly lower risk of incident major adverse liver outcomes and major adverse cardiovascular events (MACE) compared with nonsurgical management for patients with nonalcoholic steatohepatitis (NASH) and obesity, according to a study published in JAMA.

In addition to being a leading cause of cirrhosis and hepatocellular carcinoma, NASH is significantly linked to cardiovascular disease. Diagnosis of NASH is difficult and requires a liver biopsy for accuracy, and management is challenging as there are drugs approved and no therapy has been shown to be effective.

“NASH in patients with obesity is associated with major adverse liver and cardiovascular outcomes,” the authors explained. “Ideal management requires a comprehensive approach to reverse liver injury and minimize the risk of both major adverse liver outcomes and MACE.”

They sought to investigate the relationship between bariatric surgery and major adverse liver outcomes and MACE using a retrospective cohort study evaluating all patients who underwent liver biopsy at the Cleveland Clinic health system between 2004 and 2016.

They analyzed 1158 patients—650 of whom underwent bariatric surgery and 508 who underwent nonsurgical management. The majority were women (63.9%), the median age was 49.8 years, and the median body mass index was 44.1. Most of the patients underwent bariatric surgery had Roux-en-Y gastric bypass (83%) while the remainder had sleeve gastrectomy. The full cohort was followed for a median of 7 years.

Overlap weighting analysis was used. This method assigned weights to each patient “proportional to the probability of that patient belonging to the opposite treatment group, resulting in inclusion of all available patients and exact balance for the mean of all covariates included in the model.”

After overlap weighting, the 2 groups were well balanced. In the overlap weighted analysis, the mean age was 49 years, 62.9% were women, 40.6% had type 2 diabetes, and 8.4% were current smokers.

By the end of the study, in the unweighted data set, 5 patients who had bariatric surgery and 40 patients who had nonsurgical management experienced major adverse liver outcomes and 39 patients who had surgery and 60 patients who did not experienced MACE.

At 10 years follow-up:

• Cumulative incidence of major adverse liver outcomes was 2.3% (95% CI, 0%-4.6%) among patients who underwent bariatric surgery and 9.6% (95% CI, 6.1%-12.9%) in the nonsurgical group
• Cumulative incidence of MACE in the overlap-weighted analysis was 8.5% (95% CI, 5.5%-11.4%) for the patients who underwent bariatric surgery and 15.7% (95% CI, 11.3%-19.8%) in the nonsurgical group
• Patients who had surgery had a mean body weight reduction of 22.4% (95% CI, 21.7%-23.0%) compared with 4.6% (95% CI, 3.9%-5.4%) for patients in the nonsurgical group
• There was a significant reduction in hemoglobin A_1c in patients with diabetes

“Among patients with NASH and obesity, bariatric surgery, compared with nonsurgical management, was associated with a significantly lower risk of incident major adverse liver outcomes and MACE,” the authors concluded.

Reference

Aminian A, Al-Kurd A, Wilson R, et al. Association of bariatric surgery with major adverse liver and cardiovascular outcomes in patients with biopsy-proven nonalcoholic steatohepatitis. JAMA. Published online November 11, 2021. doi:10.1001/jama.2021.19569