The Liver is the Cock's Comb

Cutting NASH Harms by 88% with Bariatric Surgery

NASH (non-alcoholic steatohepatitis) is one of the most serious complications of untreated obesity. It’s very hard to treat. It can lead to liver failure, liver cancer, and death. So when a careful study of bariatric surgery shows an an 88 percent reduction in the risk of NASH progressing, this is big news.

JAMA published this study by Ali Aminian and colleagues yesterday.

Senior author Steven Nissen describes these results as very impressive:

“I have been doing clinical trials for three or four decades. This is perhaps the most incredibly effective treatment I’ve ever seen for any disease.”

A Very Careful Observational Study

Known as the SPLENDOR study, this observational research followed 1,158 patients with NASH and liver fibrosis. It used a statistical technique called propensity score overlap weighting to balance covariates and minimize the risk of confounding. Even so, residual confounding is still a possibility.

With that said, it’s really hard to dismiss an 88 percent reduction in the risk of NASH progressing to cause great harm. Furthermore, the risk of major cardiovascular events (MACE), including death, went down by 70 percent.

Of course, this is a serious treatment for a serious disease. Any surgery has risks and though bariatric surgery is a rather safe procedure, complications do occur. In fact, the mortality related to surgery was 0.6 percent. That’s a bit higher than is typical for bariatric surgery these days. It might reflect the patient population.

Unfortunately, we do not have a comparison of all-cause mortality. But the reduction in MACE is a clue that makes a net benefit seem likely.

Diagnosis and Treatment Wanting

Awareness and treatment of NASH is low. Roughly one in four Americans has fatty liver disease due to obesity. NASH is the progressive form of this. Aminian explains:

“Obesity is the main driver of the fatty liver – it all starts with obesity. When we have excess fat that accumulates in the liver, it causes fatty liver. Then inflammation comes and gets worse and then scar tissue forms and leads to cirrhosis.

“When a patient loses weight, fat goes away from everywhere, including the liver. Inflammation subsides, and some of the scar tissue can reverse and get better. Weight loss is the main factor here.”

Bariatric surgery is the most effective treatment for obesity. It’s also one of the most effective tools for putting type 2 diabetes into remission. But it’s vastly under-utilized. Match that with a diagnosis – NASH – that doctors often don’t make until the disease advances to be severe, and we have a real problem.

Why? We would humbly suggest that the bias attached to obesity makes everyone avoid the subject. So health deteriorates. Opportunities to avoid the complications of obesity disappear.

Bariatric surgery can clearly do a lot to reduce the impact of NASH. But only if we make use of it.

Click here for the study in JAMA, here for an editorial, and here for further perspective.

The Liver Is the Cock’s Comb, segment of painting by Arshile Gorky, photograph by Hrag Vartanian / flickr. For more on this painting, click here.

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November 12, 2021