Obesity surgery, also known as bariatric surgery, not only helps obese individuals shed a significant amount of weight, it also significantly improves or completely resolves a common obesity-related liver problem known as non-alcoholic fatty liver disease, a review of published studies shows.

So-called “non-alcoholic fatty liver disease” is an emerging problem related to the obesity epidemic. The prevalence of the condition is estimated to be around 70 percent in obese individuals and 85 percent to 95 percent in those who are morbidly obese.

Studies have shown that weight loss achieved through bariatric surgery improves diabetes and lowers high blood pressure in obese individuals. However, the overall effect of weight loss on fatty liver disease remains unclear.

To investigate, Dr. Gagan K. Sood from the University of Texas Medical Branch in Galveston and colleagues pooled data from 15 studies that looked at the impact of bariatric surgery on the liver.

“Overall results are encouraging for improvement in liver disease associated with obesity,” Sood told Reuters Health.

As expected, liver biopsies showed that the vast majority of obese individuals had clear signs of fatty liver disease. Obesity surgery-induced weight loss improved or completely resolved fatty liver disease in most of the study subjects, Sood and colleagues report.

For example, one severe, progressive form of non-alcoholic fatty liver disease that can lead to cirrhosis and even liver cancer called “steatohepatitis” was present in 299 of 555 liver biopsies (53.8 percent) initially and the pooled proportion of patients with improvement or resolution of this problem was 81.3 percent, the team reports.

“The most encouraging finding,” the team concludes, “is that a majority of patients experience complete resolution of non-alcoholic fatty liver disease after bariatric surgery, and the risk of progression…seems to be minimal.”

SOURCE: Clinical Gastroenterology and Hepatology, December 2008.