research reveals that advanced fibrosis is a significant predictor of
mortality in patients with nonalcoholic fatty liver disease (NAFLD),
largely brought about by cardiovascular causes. NAFLD alone was not
associated with increased mortality according to findings published in
the April issue of Hepatology, a journal of the American Association for the Study of Liver Diseases.
With super-sized portions, sugary soft drinks and
physical inactivity, obesity is on the rise and showing no sign of
slowing. Studies report that the prevalence of obesity has doubled in
the U.S. over the past 25 years. As obesity rates have soared, so has
the incidence of NAFLD, making it the most prevalent liver disease in
NAFLD is a chronic form of liver disease that
includes such conditions as steatosis without fibrosis, nonalcoholic
steatohepatitis (NASH) with fibrosis, and cirrhosis. Fibrosis is the
progressive scarring of the liver with stages ranging from zero to four
(cirrhosis). Medical evidence has found that patients with simple
steatosis have a better prognosis than those with NASH, which could
progress to end-stage liver disease.
Lead investigator Dr. W. Kim Ray from the Mayo Clinic
in Rochester, Minn. explains, “The effect of NAFLD on public health is
not well understood. Large, population-based studies, which can provide
insight into disease activity, present some difficulty given that liver
biopsy is required to confirm NAFLD.”
To investigate the long-term impact of NAFLD on
mortality, the team used data from the National Health and Nutrition
Examination Survey (NHANES)—a survey by the National Center for Health
Statistics in conjunction with the Centers for Disease Control and
Prevention (CDC) that was conducted from 1988 to 1994 with mortality
follow-up through 2006. NAFLD was diagnosed by ultrasound and severity
of fibrosis was measured by non-invasive fibrosis markers such as the
NAFLD fibrosis score (NFS).
Findings indicate that of the 11,154 participants,
34% had NAFLD, with 72% of these patients having a NFS that indicated
lack of significant fibrosis (NFS less than -1.455) and 3% with advanced
fibrosis (NFS greater than 0.676). NAFLD was not associated with
higher mortality risk after a median of 15 years of follow-up.
Further analysis shows that mortality increases as
fibrosis advances. In fact, patients likely to progress to advanced
fibrosis had a 69% increase in mortality compared to those without
fibrosis. Higher mortality in those with advanced fibrosis was largely
due to cardiovascular causes, more than expected from conditions common
in patients with NAFLD such as high blood pressure or high levels of
cholesterol. “Our findings confirm that NAFLD patients without advanced
fibrosis do not have higher mortality risk,” concludes Dr. Kim.
“Careful monitoring of disease progression in patients with NAFLD and
fibrosis, along with interventions that reduce cardiovascular risk
factors are warranted.”
“Association Between Noninvasive
Fibrosis Markers and Mortality Among Adults with Non-alcoholic Fatty
Liver Disease in the United States.” Donghee Kim, W. Ray Kim, Hwa Jung
Kim and Terry M. Therneau. Hepatology
; (DOI: 10.1002/hep.26156) Print Issue Date: April, 2013.
Author Contact: Media wishing to speak with Dr. Kim may contact Brian Kilen with the Mayo Clinic at email@example.com or at +1 507-266-1161.
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