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©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
Role of nutritional ketosis in the improvement of metabolic parameters following bariatric surgery
Fioralba Pindozzi, Carlo Socci, Massimiliano Bissolati, Monica Marchi, Elisabetta Devecchi, Alessandro Saibene, Caterina Conte
Fioralba Pindozzi, Unità di Chirurgia Generale Provinciale, Ospedale del Delta, Lagosanto (FE) 44023, Italy
Carlo Socci, Massimiliano Bissolati, Transplant and Metabolic/Bariatric Surgery Unit, IRCCS Ospedale San Raffaele, Milan 20132, Italy
Monica Marchi, Elisabetta Devecchi, Alessandro Saibene, Department of General Medicine, Diabetes and Endocrinology, IRCCS Ospedale San Raffaele, Milan 20132, Italy
Caterina Conte, Department of Human Sciences and Promotion of the Quality of Life, San Raffaele Open University, Rome 00166, Italy
Caterina Conte, Department of Endocrinology, Nutrition and Metabolic Diseases, IRCCS MultiMedica, Milan 20099, Italy
Author contributions: Pindozzi F and Socci C contributed equally to this work; Pindozzi F and Socci C contributed to data acquisition, interpretation of data and drafting the work; Bissolati M contributed to data acquisition, Marchi M contributed to data acquisition, Devecchi E contributed to data acquisition; Saibene A contributed to data acquisition and interpretation of data; Conte C designed the work, analyzed and interpreted data; all authors have revised the work critically for important intellectual content and approve the final version of the manuscript.
Institutional review board statement: The protocol was approved by the Institutional Ethics Committee (Keto-BMS study).
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: The authors have none to declare.
Data sharing statement: No additional data are available.
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:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Caterina Conte, MD, PhD, Associate Professor, Department of Human Sciences and Promotion of the Quality of Life, San Raffaele Open University, Via di val Cannuta, 247, Rome 00166, Italy. caterina.conte@uniroma5.it
Received: May 8, 2021
Peer-review started: May 8, 2021
First decision: June 16, 2021
Revised: June 29, 2021
Accepted: January 5, 2022
Article in press: January 5, 2022
Published online: January 15, 2022
BACKGROUND
Ketone bodies (KB) might act as potential metabolic modulators besides serving as energy substrates. Bariatric metabolic surgery (BMS) offers a unique opportunity to study nutritional ketosis, as acute postoperative caloric restriction leads to increased lipolysis and circulating free fatty acids.
AIM
To characterize the relationship between KB production, weight loss (WL) and metabolic changes following BMS.
METHODS
For this retrospective study we enrolled male and female subjects aged 18-65 years who underwent BMS at a single Institution. Data on demographics, anthropometrics, body composition, laboratory values and urinary KB were collected.
RESULTS
Thirty-nine patients had data available for analyses [74.4% women, mean age 46.5 ± 9.0 years, median body mass index 41.0 (38.5; 45.4) kg/m2, fat mass 45.2% ± 6.2%, 23.1% had diabetes, 43.6% arterial hypertension and 74.4% liver steatosis]. At 46.0 ± 13.6 d post-surgery, subjects had lost 12.0% ± 3.6% of pre-operative weight. Sixty-nine percent developed ketonuria. Those with nutritional ketosis were significantly younger [42.9 (37.6; 50.7) years vs 51.9 (48.3; 59.9) years, P = 0.018], and had significantly lower fasting glucose [89.5 (82.5; 96.3) mg/dL vs 96.0 (91.0; 105.3) mg/dL, P = 0.025] and triglyceride levels [108.0 (84.5; 152.5) mg/dL vs 152.0 (124.0; 186.0) mg/dL, P = 0.045] vs those with ketosis. At 6 mo, percent WL was greater in those with postoperative ketosis (-27.5% ± 5.1% vs 23.8% ± 4.3%, P = 0.035). Urinary KBs correlated with percent WL at 6 and 12 mo. Other metabolic changes were similar.
CONCLUSION
Our data support the hypothesis that subjects with worse metabolic status have reduced ketogenic capacity and, thereby, exhibit a lower WL following BMS.
Core Tip: Ketone bodies might act as potential metabolic modulators besides serving as energy substrates. Acute postoperative caloric and carbohydrate restriction after bariatric metabolic surgery (BMS) leads to increased lipolysis, inducing ketogenesis. We report that the majority, but not all patients undergoing BMS, develop nutritional ketosis. Patients with nutritional ketosis had significantly lower baseline fasting glucose and triglyceride levels vs those without ketonuria. Weight loss was greater in those with postoperative ketonuria, and urinary ketones positively correlated with percent weight loss. These observations suggest that subjects with worse glucometabolic status have reduced ketogenic capacity, which might blunt the metabolic response to BMS.
