Liver Transplant Surgery

Obesity and Diabetes Bringing More Liver Disease

The nature of liver disease is shifting in the U.S. Over the last three decades, hepatitis C has dropped by nearly half. But over that same time, we’ve seen more liver disease due to obesity and diabetes. In fact, NAFLD (non-alcoholic fatty liver disease) has grown in almost perfect synchrony with obesity and type 2 diabetes.

A new paper in Gut tells us that NAFLD diagnoses have grown by more than half in the last three decades.

Steady Increases in Parallel

Zobair Younossi and colleagues analyzed trends in liver disease and related factors from 1988 through 2016. Their conclusions are stark:

Over the past 30 years in the USA, NAFLD is the only liver disease with growing prevalence, synchronous with the increasing rates of obesity and T2DM.

Alcoholic liver disease is stable, So, too, is hepatitis B. The availability of a cure for hepatitis C has led to more testing and referrals for care. And thus, the halving in prevalence over three decades.

But the opposite is true for diabetes and obesity, two of the key risk factors for NAFLD. The prevalence has grown for both. And based on multivariate regression analysis, Younossi concluded that these two conditions have been the key factors explaining the growth of NAFLD.

Diseases of Visceral Fat

The public is so stuck on obesity as a disease of size that most people lose sight of what it’s really about. It’s not really size or weight that matters. The problem is the unhealthy accumulation of visceral fat. This is adipose tissue stored around and in visceral organs – including the liver.

In the liver, this abnormal adipose tissue promotes inflammation that causes long-term harm. Most people with NAFLD have no symptoms for years. It’s part of the metabolic syndrome characterized by obesity and type 2 diabetes. It doesn’t always progress to the more serious form – NASH. But when it does, liver disease can progress to cirrhosis, liver failure, and death.

New therapies for NASH are coming, but we already have options for treating obesity and reducing the risk of liver disease. In particular, bariatric surgery can be beneficial for individuals with obesity, metabolic syndrome, and NAFLD.

Treating obesity is neither easy, nor cheap. But the complications of untreated obesity are far more problematic.

Click here for the Younossi study and here for further reporting.

Liver Transplant Surgery, photograph © Tareq Salahuddin/ flickr

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August 19, 2019