TUESDAY, April 16, 2013 (HealthDay News) -- Advanced fibrosis -- or progressive scarring of the liver -- is tied to higher death rates from a type of fatty liver disease found in people who drink little or no alcohol, according to a new study.
This increased mortality is primarily due to heart-related causes, not nonalcoholic fatty liver disease alone, the researchers said. The study was published in the April issue of the journal Hepatology.
"Our findings confirm that [nonalcoholic fatty liver disease] patients without advanced fibrosis do not have higher mortality risk," lead study investigator Dr. W. Kim Ray, of the Mayo Clinic in Rochester, Minn., said in a journal news release. "Careful monitoring of disease progression in patients with [nonalcoholic fatty liver disease] and fibrosis, along with interventions that reduce cardiovascular risk factors, are warranted."
The study involved data on more than 11,000 people from a large national survey compiled by the U.S. National Center for Health Statistics and the U.S. Centers for Disease Control and Prevention from 1988 to 1994. Researchers also included follow-up data on deaths through 2006.
Thirty-four percent of the participants had nonalcoholic fatty liver disease. Of these people, 72 percent did not have significant scarring or fibrosis. Meanwhile, 3 percent were affected by advanced fibrosis.
Although nonalcoholic fatty liver disease was not linked to an increase in death rates after 15 years, mortality increased as scarring progressed. The patients with advanced scarring had a 69 percent increase in mortality compared with those without scarring of the liver.
Nonalcoholic fatty liver disease was diagnosed by ultrasound. Fibrosis scores were used to rate the severity of organ scarring.
"The effect of [nonalcoholic fatty liver disease] on public health is not well understood," Ray said. "Large, population-based studies, which can provide insight into disease activity, present some difficulty given that liver biopsy is required to confirm [nonalcoholic fatty liver disease]."
As obesity rates have doubled in the United States during the past 25 years, so has the incidence of nonalcoholic fatty liver disease, making it the most prevalent liver disease in the United States, according to the news release.
The American Liver Foundation has more about nonalcoholic fatty liver disease.