Ethnic and Gender Differences in the Prevalence of Nonalcoholic Steatohepatitis Among Bariatric Surgery Patients

• Fatty liver disease and its more serious form, NASH, is one of the most common health problems found in patients with severe obesity. This study examined how common NASH is among bariatric surgery patients and whether rates differ by ethnicity or gender.
• The study found significant differences in NASH prevalence across ethnic and gender groups, helping surgeons identify which patients need closer liver monitoring.
• Bariatric surgery is one of the most effective treatments for fatty liver disease, often reducing liver inflammation and, in some patients, even improving liver scarring.
• Fatty liver disease often has no symptoms until it has progressed, which is why many patients don't know they have it until surgery reveals it.
• Dr. de la Cruz-Muñoz is the senior author, reflecting his comprehensive approach evaluating liver disease alongside obesity and diabetes in his diverse Miami patient population.
• For patients concerned about fatty liver disease, this study helps identify who may need closer liver evaluation before and after surgery.

Why This Study Was Needed

Nonalcoholic steatohepatitis (NASH), now called metabolic dysfunction-associated steatohepatitis (MASH), is the inflammatory form of fatty liver disease. It can progress silently to scarring, cirrhosis and liver cancer, and it is common in people with severe obesity. Whether its frequency differs by ethnicity and sex in a diverse population like Miami’s was not well understood.

How the Study Was Done

With Dr. de la Cruz-Muñoz as senior author, the team analyzed liver biopsies taken during bariatric surgery in a multiethnic patient group and compared the prevalence of NASH by ethnicity and gender.

What the Study Found

• NASH was common among bariatric surgery patients.
• Its prevalence differed significantly across ethnic groups and between men and women.
• Many patients had no symptoms, and the disease was identified only through biopsy at surgery.

What This Means for Patients

You can have serious fatty liver disease without knowing it. Bariatric surgery is one of the most effective treatments: a five-year French biopsy study (Gastroenterology, 2020) found that NASH resolved in most patients five years after surgery, and liver scarring improved in many. Read about visceral fat and GLP-1 medications and the liver.

Clinical Pearls

• NASH is frequently silent and discovered at the time of bariatric surgery.
• Ethnicity and sex influence NASH risk, which can guide liver evaluation.
• Bariatric surgery can reverse NASH in most patients.

Strengths and Limitations

Biopsy is the most accurate way to diagnose NASH, and the study included a diverse population. It reflects a single program and patients selected for surgery.

Expert Commentary

I see fatty liver in the operating room every week, often in patients who had no idea. This study showed us that some groups in our community are at particularly high risk. The good news is that weight loss surgery is one of the best treatments we have for this disease.

— Dr. Nestor de la Cruz-Muñoz