Retrospective Cohort Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Nov 27, 2020; 12(11): 1004-1019
Published online Nov 27, 2020. doi: 10.4254/wjh.v12.i11.1004
Phase angle and non-alcoholic fatty liver disease before and after bariatric surgery
Joise Teixeira, Cláudio Augusto Marroni, Paula Rosales Zubiaurre, Ana Henz, Lais Faina, Lilian Kethelyn Pinheiro, Claudio Cora Mottin, Sabrina Alves Fernandes
Joise Teixeira, Department of Postgraduate Program in Medicine: Hepatology, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre 90050170, RS, Brazil
Cláudio Augusto Marroni, Department of Gastroenterology and Hepatology, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre 91760470, RS, Brazil
Paula Rosales Zubiaurre, Department of Center of Morbid Obesity, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre 90610000, RS, Brazil
Ana Henz, Lilian Kethelyn Pinheiro, Sabrina Alves Fernandes, Department of Nutrition, Centro Universitário Metodista (IPA), Porto Alegre 90420060, RS, Brazil
Lais Faina, Department of Vascular Surgery, Hospital Federal dos Servidores do Estado do Rio de Janeiro, Rio de Janeiro 20221161, RJ, Brazil
Claudio Cora Mottin, Department of Obesity and Metabolic Syndrome Center, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre 90619-900, RS, Brazil
Author contributions: Teixeira J and Fernandes SA performed the data collection; all the authors wrote the paper and approved the final version.
Institutional review board statement: This project was approved by the Research Ethics Committee of the Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS). No. 2.423.466.
Informed consent statement: Patients who accepted to participate in the study signed the Informed Consent Form.
Conflict-of-interest statement: The authors declare no conflicts of interest for this article.
STROBE statement: The authors have read the STROBE Statement checklist of items, and the manuscript was prepared and revised according to the STROBE Statement checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Sabrina Alves Fernandes, RN, Research Scientist, Department of Nutrition, Centro Universitário Metodista (IPA), Coronel Joaquim Pedro Salgado, Porto Alegre 90420060, RS, Brazil. sabrina@drasabrinafernandes.com
Received: June 30, 2020
Peer-review started: June 30, 2020
First decision: August 8, 2020
Revised: August 24, 2020
Accepted: October 12, 2020
Article in press: October 12, 2020
Published online: November 27, 2020
Abstract
BACKGROUND

Obesity is a global health problem that is continuing to increase in the young population. In Brazil, the frequency of obesity in 2018 was 19.8%. Several comorbidities are directly associated with obesity, such as non-alcoholic fatty liver disease (NAFLD), which is considered the most common liver disorder in Western countries and affects up to 46% of adults. Bariatric surgery is effective in treating obesity and can improve NAFLD; however, the effect of bariatric surgery on body composition, phase angle (PA), and improving NAFLD needs to be further studied.

AIM

To analyze the PA in the postoperative period of bariatric surgery and to correlate it with changes in body composition and liver disease.

METHODS

This study is a retrospective cohort study of the analysis of the medical records of patients undergoing bariatric surgery in a reference center of a teaching hospital in Porto Alegre over a 2-year period. Patients older than 18 years whose record contained all information relevant to the study were included. The data analyzed were body composition and PA through electrical bioimpedance and NAFLD through liver biopsy in the pre- and postoperative period. The level of significance adopted for the statistical analyses was 5%.

RESULTS

We evaluated 379 patients with preoperative data. Regarding PA, 169 patients were analyzed, and 33 patients had liver biopsy pre- and postoperatively with NAFLD information. In total, 79.4% were female, with a mean age of 39.1 ± 10.6 years. The average body mass index (BMI) was 45.9 ± 7.5 kg/m². The PA showed a mean of 5.8 ± 0.62° in the preoperative period and a significant reduction in the postoperative period. A postoperative reduction in body composition data (skeletal muscle mass, fat percentage, fat mass, body cell mass, BMI and visceral fat area) was shown as well. Regarding liver disease, all patients presented a reduction in the degrees and stages of liver disease in the postoperative period, and some had no degree of liver disease at all.

CONCLUSION

PA decreased after bariatric surgery, with a direct correlation with weight loss and changes in body composition. The decrease in PA was not correlated with the improvement in NAFLD.

Keywords: Obesity, Body composition, Bariatric surgery, Phase angle, Non-alcoholic fatty liver disease, Liver disease

Core Tip: We retrospectively evaluated 379 patients who underwent bariatric surgery, with non-alcoholic fatty liver disease in the preoperative period; we compared body composition, phase angle (PA) behavior and change in non-alcoholic fatty liver disease (NAFLD) in the pre- and postoperative period. There was an important improvement in body composition/body fat percentage and an improvement in NAFLD after bariatric surgery. Worsening PA was directly correlated with weight loss and skeletal muscle mass.