Surgically-Induced Weight Loss Significantly
Improves Nonalcoholic Fatty Liver Disease
and the Metabolic Syndrome
Samer G. Mattar, MD, FACS,* Laura M. Velcu, MD,† Mordechai Rabinovitz, MD,‡
A. J. Demetris, MD,§ A. M. Krasinskas, MD,§ Emma Barinas-Mitchell, PhD,
George M. Eid, MD,*
Ramesh Ramanathan, MD,* Debra S. Taylor, RN,* and Philip R. Schauer, MD†
To evaluate the effects of surgical weight loss on fatty
liver disease in severely obese patients.
Summary Background Data:
Nonalcoholic fatty liver disease
(NAFLD), a spectrum that extends to liver ±brosis and cirrhosis, is
rising at an alarming rate. This increase is occurring in conjunction
with the rise of severe obesity and is probably mediated in part by
metabolic syndrome (MS). Surgical weight loss operations, proba-
bly by reversing MS, have been shown to result in improvement in
Patients who underwent laparoscopic surgical weight loss
operations from March 1999 through August 2004, and who agreed
to have an intraoperative liver biopsy followed by at least one
postoperative liver biopsy, were included.
There were 70 patients who were eligible. All patients
underwent laparoscopic operations, the majority being laparoscopic
Roux-en-Y gastric bypass. The mean excess body weight loss at
time of second biopsy was 59%
22% and the time interval
between biopsies was 15
9 months. There was a reduction in
prevalence of metabolic syndrome, from 70% to 14% (
and a marked improvement in liver steatosis (from 88% to 8%),
in²ammation (from 23% to 2%), and ±brosis (from 31% to 13%; all
0.001). In²ammation and ±brosis resolved in 37% and 20% of
patients, respectively, corresponding to improvement of 82% (
0.001) in grade and 39% (
0.001) in stage of liver disease.
Surgical weight loss results in signi±cant improvement
of liver morphology in severely obese patients. These bene±cial
changes may be associated with a signi±cant reduction in the
prevalence of the metabolic syndrome.
esolutely, the incidence of obesity continues its steady
rise towards most-lethal disease status. If the current trend
continues, 40% of the US population will be obese by the
Other indicators, such as the ±nding that 15% of
children and adolescents are obese (body mass index
95th percentile on the Centers for Disease Control and
Prevention standard charts) and over 20% are “at risk” (BMI
85th percentile) are even more alarming harbingers of an
impending health crisis.
Obesity is associated with numerous
comorbid factors (most of which are life-threatening) and these
disease processes, not unexpectedly, are also on the rise. One of
these complexes, nonalcoholic fatty liver disease (NAFLD),
now occurs in a range of 30% to 100% of obese adults.
Remarkably, it is prevalent in 53% of obese children.