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HOUSTON -- Patients with nonalcoholic fatty liver disease (NAFLD) who underwent bariatric surgery saw significant decreases in both their liver volume and fat density at 6 months, a researcher said here.
Results from a multi-institutional prospective study of 49 patients with NAFLD found that liver volume changes plateaued 1 month after bariatric surgery, but liver fat percentage continued to decrease at 6 months post-operatively, reported Ran B. Luo, MD, of University of California in San Diego.
Action Points
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
Additionally, patients with NAFLD experienced significant improvement of their liver fat composition, with 83.7% of patients having radiologic resolution of hepatosteatitis on MRI imaging within 6 months, he said during a presentation at the 2017 Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) meeting.
SAGES panel moderator Daniel J. Scott, MD, of UT Southwestern in Dallas commented that "the study clearly supports the efficacy of bariatric surgery for individuals with nonalcoholic fatty liver disease."
"I am a strong proponent of bariatric surgery for severely obese individuals because the data is very clear that it helps those individuals, and this study helps us point in the direction that bariatric surgery is highly effective for liver disease caused by severe obesity," he told ľֱ.
Luo's group recruited 124 patients who met NIH criteria for bariatric surgery from October 2010 to June 2015.
Patients underwent MRIs at five separate time points: baseline, after pre-operative liquid diet (PLD), and post-operative 1, 3, and 6 months. They also underwent liver biopsies at the time of bariatric surgery and received the three post-operative MRI scans only if they were biopsy positive for NAFLD.
The researchers used OsiriX (Pixmeo SARL, Bernex, Switzerland) imaging software to calculate liver volumes and proton-density fat fraction (PDFF), an objective measure of mobile proton density of the liver.
Patients' NAFLD status was reevaluated based on a previously published PDFF cut off of 6.4% for diagnosing grade 1 or higher hepatic steatosis, noted Luo.
The authors reported that of the 124 patients, 102 completed the liquid diet and 49 patients (39.5%) completed all MRI scans with 6-month follow-up. Of these patients (85.7% female), 26 received laproscopic Roux-en-Y gastric bypass, 20 received laproscopic sleeve gastrectomy, and three received laproscopic adjustable gastric band.
The researchers found that mean BMI decreased from 45.3 to 34.4.
Mean liver volume decreased from 2464.6 cm3 to 1874.3 cm3 with a mean volumetric change of 22.2%.
The researchers also found that PDFF decreased from 16.6% to 4.4%, with a mean change of 71.0%. At 6-month follow-up, 83.7% patients fell below the 6.4% PDFF cutoff for MRI diagnosed NAFLD.
"Liver volume plateaued at post-operative one month, but PDFF and BMI continued to decrease," Luo concluded.
When Scott asked if the study findings should steer future patient trends toward bariatric bypass, Luo gave a firm "yes."
Disclosures
The study was funded by the NIH.
Luo and co-authors disclosed no relevant relationships with industry.
Primary Source
Society of American Gastrointestinal and Endoscopic Surgeons
Luo R, et al "How bariatric surgery affects liver volume and fat density in NAFLD patients" SAGES 2017; S144.