Abstract
Background
Obesity is the major trigger of nonalcoholic fatty liver disease (NAFLD). NAFLD is
further favored by the patatin-like phospholipase domain-containing 3 (PNPLA3) p.I148M,
transmembrane 6 superfamily member 2 (TM6SF2) p.E167K, and membrane-bound O-acyltransferase
domain containing 7 (MBOAT7) rs641738 variants.
Objectives
To investigate the relationship between the PNPLA3, TM6SF2, and MBOAT7 genotypes and
the outcomes of bariatric surgery.
Setting
University hospital.
Methods
Prospectively we monitored 84 obese individuals (body mass index 35–64 kg/m2) scheduled for bariatric surgery. The PNPLA3 p.I148M, TM6SF2 p.E167K, and MBOAT7
rs641738 variants were genotyped using restriction fragment length polymorphism analysis
and TaqMan assays. Hepatic steatosis was determined before surgery using analysis
of liver biopsy samples and a novel magnetic resonance imaging–based equation. One
year later, steatosis was reevaluated by magnetic resonance imaging.
Results
The presence of the PNPLA3 allle [M] was associated with increased hepatic triglyceride
content (P = .03), steatosis detected by magnetic resonance imaging (P = 0.04), and decreased serum glucose concentrations (P = .04). Neither variant TM6SF2 nor MBOAT7 increased hepatic steatosis (all P>.05); however, the MBOAT7 polymorphism was associated with increased triglyceride,
total cholesterol, low density lipoprotein, and serum glucose levels (all P<.05). Patients carrying the prosteatotic PNPLA3 allele [M] lost more weight (P<.01) and liver fat (P = .04) one year after surgery, as compared to individuals having the common genotype.
The PNPLA3 genotype and initial grade of steatosis, but not the TM6SF2 or MBOAT7 variants,
were independent predictors of NAFLD improvement (P = .03 and P<.01, respectively).
Conclusion
In obese patients, the presence of the PNPLA3 p.I148M allele might be associated with
greater improvement of hepatic steatosis after bariatric surgery in comparison to
carriers of PNPLA3 wild-type alleles.
Keywords
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Article info
Publication history
Published online: July 01, 2016
Accepted:
June 29,
2016
Received:
January 11,
2016
Footnotes
☆This study was presented, in part, at the 50th Annual Meeting of the European Association for the Study of the Liver, April 22–26, 2015, and published in abstract form in Journal of Hepatology 2015;62(Suppl. 2):S753–S54.
Identification
Copyright
© 2016 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.
