Bariatric Surgery Reduces Cardiovascular Disease Risk of NAFLD Patients

Bariatric surgery could be a way to reduce the risk of cardiovascular disease for patients with severe obesity and non-alcoholic fatty liver disease (NAFLD).

A team, led by Mohamed I. Elsaid, PhD, MPH, Department of Biomedical Informatics, College of Medicine, The Ohio State University, examined the association between bariatric surgery and cardiovascular disease risk in patients with severe obesity and NAFLD.

While NAFLD is a liver disease, there are some associations with cardiovascular disease.

“Nonalcoholic fatty liver disease is the hepatic manifestation of metabolic syndrome because it is closely linked to obesity-induced insulin resistance, dyslipidemia, and hypertension,” the authors wrote.“The prevalence of NAFLD increases with body mass index (BMI) and is highest among individuals with severe obesity.”

Patients With Obesity and NAFLD

In the large, population-based retrospective cohort study, the investigators identified data from the MarketScan Commercial Claims and Encounters database between 2007-2017 of insured adults aged 18-64 years with NAFLD and severe obesity, defined as a body mass index (BMI) of at least 40.

The baseline characteristics between individuals who underwent surgery and participants who did not were balanced using inverse probability of treatment weighting.

Overall, the study included 86,964 adult patients with a mean age of 44.3 years.

Of this group, 34.8% (n = 30,300) underwent bariatric surgery and 65.2% (n = 56,664) received nonsurgical care.

The investigators sought main outcomes of the incidence of cardiovascular events, either primary or secondary composite cardiovascular disease outcomes.

They also sought primary composite outcomes of myocardial infarction, heart failure, or ischemic stroke and secondary composite outcomes of secondary ischemic heart events, transient ischemic attack, secondary cerebrovascular events, arterial embolism and thrombosis, or atherosclerosis.

A Reduction in Cardiovascular Disease

The team examined the associations between bariatric surgery, modeled as time varying, and all outcomes, using Cox proportional hazards regression models with inverse probability treatment weighting.

The results show the surgical group had 1568 patients with incident cardiovascular events, compared to 7215 participants in the nonsurgical group (incidence rate difference, 4.8 per 100 person-years; 95% CI, 4.5-5.0). At the conclusion, bariatric surgery resulted in a 49% lower risk of cardiovascular disease (aHR, 0.51; 95% CI, 0.48-0.54) compared to nonsurgical care.

In addition, the risk of primary composite cardiovascular outcomes was reduced by 47% (aHR, 0.53; 95% CI, 0.48-0.59), while the risk of secondary cardiovascular disease outcomes was reduced by 50% (aHR, 0.50; 95% CI, 0.46-0.53) in patients with bariatric surgery compared to nonsurgical patients.

“Results of this study suggest that, compared with nonsurgical care, bariatric surgery was associated with significant reduction in CVD risk in individuals with severe obesity and NAFLD,” the authors wrote.

The study, “Association of Bariatric Surgery With Cardiovascular Outcomes in Adults With Severe Obesity and Nonalcoholic Fatty Liver Disease,” was published online in JAMA Network Open.