Abstract
Goals:
To determine if bariatric surgeries are associated with de novo alcohol-related complications.
Background:
Bariatric surgery is associated with increased risk of alcohol use disorders. The effect of bariatric surgeries on other alcohol-related outcomes, including liver disease, is understudied.
Study:
Using the IMS PharMetrics database, we performed a cohort study of adults undergoing bariatric surgery or cholecystectomy, excluding patients with an alcohol-related diagnosis within one year prior to surgery. The primary outcome was any alcohol-related diagnosis after surgery. We fit a multivariable Cox proportional hazards model to determine independent associations between bariatric surgeries (Roux-en-Y gastric bypass, RYGB; adjustable gastric band, AGB; sleeve gastrectomy, SG) vs. cholecystectomy and the development of de novo alcohol-related outcomes. We further fit complication-specific models for each alcohol-related diagnosis.
Results:
RYGB was significantly associated with an increased hazard of any de novo alcohol-related diagnosis (adjusted hazard ratio (AHR)=1.51, 95% CI 1.40–1.62), while AGB (AHR 0.55, 95% CI 0.48–0.63) and SG (AHR 0.77, 95% CI 0.64–0.91) had decreased hazards. RYGB was associated with a 2–3 fold higher hazard for alcoholic hepatitis (AHR 1.98, 95% CI 1.17–3.33), abuse (AHR 2.05, 95% CI 1.88–2.24), and poisoning (3.14, CI 1.80–5.49).
Conclusions:
RYGB was associated with higher hazards of developing de novo alcohol-related hepatitis, abuse, and poisoning compared to a control group. Patients without a history of alcohol use disorder should still be counseled on the increased risk of alcohol use and alcohol-related complications, including alcohol-related liver disease, following RYGB, and should be monitored long-term for the development of alcohol-related complications.
Keywords: bariatric surgery, alcohol use, alcoholic hepatitis, alcoholic cirrhosis
Introduction
The rising prevalence of obesity has led to a growing population of patients undergoing bariatric surgery worldwide.1 Bariatric surgery is a more effective and durable treatment option for obesity compared to medical therapy and has been shown to reduce complications of obesity such as cardiovascular disease, hypertension, and type 2 diabetes mellitus.2–4 In light of such effectiveness, bariatric surgery continues to become an increasingly popular intervention for patients with obesity. As such, it is important to understand the adverse effects of bariatric surgery. Furthermore, as the options for types of bariatric procedures continue to grow, it is important to understand the complications or adverse effects specific to each type of bariatric surgery, as this will help inform the choice of which bariatric surgery to perform and alert providers of specific post-operative complications.
Bariatric surgery has been associated with increased risk of problematic alcohol use and alcohol use disorders (AUDs) during the postoperative period. Predictors of alcohol and substance use after bariatric surgery include younger age, male sex, and pre-operative substance use.5–7 As a result, the American Society for Metabolic and Bariatric Surgery guidelines suggest that patients with known or suspected substance abuse undergo a formal mental health evaluation before surgery, and many bariatric programs consider a history of substance use to be a contraindication to bariatric surgery.8 The effect of bariatric surgery on the development of AUDs appears to be dependent on the type of bariatric surgery performed. Studies to date suggest that Roux-en-Y gastric bypass (RYGB) increases the risk of AUDs, while this same association has not been clearly demonstrated for pylorus-sparing operations like adjustable gastric band (AGB) and sleeve gastrectomy (SG) procedures.9–11 This difference in risk dependent on type of bariatric surgery might be explained by different alterations in alcohol metabolism and absorption as a result of surgery.
While there has been robust literature evaluating the relationship of bariatric surgery and AUDs, few studies have evaluated de-novo AUDs and other alcohol-related complications or assessed for these associations compared to a control group, and even fewer studies have focused on evaluating how the various types of bariatric surgery affect these relationships. Therefore, we aimed to determine if bariatric surgery is independently associated with de novo alcohol-related outcomes in patients with no pre-existing alcohol-related disease when compared to a non-bariatric abdominal surgery control group, and to determine whether or not the types of bariatric surgery differ in their associations with these outcomes. We hypothesized that patients with a history of RYGB are at highest risk of the development of de novo AUDs and other alcohol-related complications, followed by patients with a history of SG and AGB.
Materials and Methods
Data Source
Our study was conducted using the Legacy IMS PharMetrics database from 1/1/2007 to 9/30/2015. This US database is representative of the privately insured US population and includes more than 27 million people covered by over 100 commercial health plans. Data are de-identified and consists of all paid inpatient and outpatient medical and pharmacy claims, diagnoses based on International Classification of Diseases (ICD) codes, and procedures based on Current Procedural Terminology (CPT) codes. This study is considered to be Not Human Subjects Research and was exempt for approval by the University of North Carolina Institutional Review Board.
Study Population
We identified all patients aged 18–64 years with a history of bariatric surgery (RYGB, AGB, or SG) or cholecystectomy (control group), defined by the presence of CPT codes outlined in Supplemental Table 1. The control group excluded patients who also had a history of bariatric surgery. The surgery index date was based on the first CPT code identified in the database. Patients were required to have at least 12 months of follow-up time before the surgery index date. We excluded patients with an alcohol-related diagnosis identified during the 12 months prior to surgery.
Outcomes
The primary outcome was a composite outcome of time to any alcohol-related diagnosis as defined by at least one of the following ICD-9/10 diagnoses: alcohol abuse, alcohol dependence, alcoholic gastritis, alcoholic fatty liver, acute alcoholic hepatitis, alcoholic fibrosis, alcoholic cirrhosis, alcoholic liver failure, alcoholic liver damage, alcohol poisoning, or elevated blood alcohol level (Supplemental Table 1).
Statistical Analysis
Summary statistics were used to describe baseline patient characteristics. Continuous variables were reported as medians and interquartile ranges (IQR), and categorical variables were reported as frequencies and proportions. We fitted multivariable Cox proportional hazards models to determine independent associations between bariatric surgeries and the development of any de novo alcohol-related disorders, adjusting for age, sex, region, depression, anxiety, and the Deyo-modified Charlson comorbidity index.12 Complication-specific models were fitted for each of the alcohol-related diagnoses, stratified by type of bariatric surgery, adjusting for the same covariates.
Results
Baseline Characteristics
The RYGB cohort consisted of 24,550 patients, SG 7,783 patients, and AGB 16,664 patients (Table 1). Median age at time of surgery and sex distribution were similar among all three bariatric surgery groups. Overall, the median age at time of bariatric surgery was 45 years (IQR 37–53) and 21% of patients were male. Median post-operative follow-up time for patients with bariatric surgery was 2.8 years (IQR 1.8–4.2). The control group consisted of 238,429 patients with a history of cholecystectomy. The median age at time of cholecystectomy was 46 years (IQR 35–55) and 25% were male. Median post-operative follow-up time for patients with cholecystectomy was 2.7 years (IQR 1.8–4.1). A greater proportion of patients in the bariatric surgery cohorts had a prior diagnosis of depression, anxiety, and obesity prior to surgery, as well as higher Charlson comorbidity index scores compared to the cholecystectomy cohort.
Table 1.
Baseline characteristics by surgical group
| Cholecystectomy (N=238,429) | Roux-en-Y Gastric bypass (N=24,550) | Sleeve gastrectomy (N=7,783) | Adjustable gastric band (N=16,664) | |
|---|---|---|---|---|
|
| ||||
| Age, median (IQR) | 46 (35–55) | 45 (37–53) | 44 (36–52) | 45 (37–53) |
|
| ||||
| Male, n (%) | 58,597 (24.6) | 5,188 (21.1) | 1,517 (19.5) | 3,376 (20.3) |
|
| ||||
| Depression, n (%) | 27,585 (11.6) | 6,738 (27.4) | 2,488 (32.0) | 3,600 (21.6) |
|
| ||||
| Region | ||||
| East | 39,367 (16.5) | 7,421 (30.2) | 2,318 (29.8) | 4,736 (28.4) |
| Midwest | 64,321 (27.0) | 7,067 (28.8) | 3,186 (40.9) | 3,025 (18.2) |
| South | 103,743 (43.5) | 7,264 (29.6) | 1,744 (22.4) | 7,256 (43.5) |
| West | 30,998 (13.0) | 2,798 (11.4) | 535 (6.9) | 1,647 (9.9) |
|
| ||||
| Anxiety, n (%) | 25,779 (10.8) | 3,588 (14.6) | 1,707 (21.9) | 1,975 (11.9) |
|
| ||||
| Obesity, n (%) | 33,392 (14.0) | 24,001 (97.8) | 7,755 (99.6) | 16,625 (99.8) |
|
| ||||
| Charlson comorbidity index score | ||||
| 0 | 161,759 (67.8) | 9,794 (39.9) | 3,489 (44.8) | 8,099 (48.6) |
| 1 | 54,641 (22.9) | 9,182 (37.4) | 2,775 (35.7) | 5,864 (35.2) |
| 2 | 11,906 (5.0) | 2,974 (12.1) | 841 (10.8) | 1,581 (9.5) |
| >2 | 10,123 (4.2) | 2,600 (10.6) | 678 (8.7) | 1,120 (6.7) |
Development of Any De Novo Alcohol-Related Diagnosis
During the study period, a total of 1,346 (2.7%) patients with a history of bariatric surgery developed at least one alcohol-related diagnosis compared to 4,448 (1.9%) of patients who underwent a cholecystectomy. The cumulative incidence of developing an alcohol-related diagnosis was greatest in those who had undergone RYGB (4.0%) compared to those who had SG (1.8%) or AGB (1.3%) (Figure 1). After adjusting for covariates, patients with a history of RYGB were at an increased risk of developing any alcohol-related diagnosis with an adjusted HR of 1.51 (95% CI 1.40–1.62, p<0.001) when compared to cholecystectomy patients (Table 2). Contrastingly, SG (AHR 0.77, 95% CI 0.64–0.91, p=0.002) and AGB (AHR 0.55, 95% CI 0.48–0.63, p<0.001) were associated with decreased hazards of any alcohol-related diagnosis.
Figure 1.
Cumulative incidence of alcohol-related outcomes by surgery. Alcohol-related outcome was defined by the presence of ≥1 ICD-9/10 code for at least one of the following: alcohol abuse, alcohol dependence, alcoholic gastritis, alcoholic fatty liver, acute alcoholic hepatitis, alcoholic fibrosis, alcoholic cirrhosis, alcoholic liver failure, alcoholic liver damage, alcohol poisoning, or elevated blood alcohol level.
Table 2.
| Roux-en-Y Gastric bypass (N=24,550) |
Sleeve gastrectomy (N=7,783) | Adjustable gastric band (N=16,664) |
|
|---|---|---|---|
| Any outcome3 |
1.51
(1.40–1.62) |
0.77
(0.64–0.91) |
0.55
(0.48–0.63) |
| Abuse |
2.05
(1.88–2.24) |
0.88 (0.71–1.09) |
0.56
(0.46–0.67) |
| Dependence |
1.39
(1.22–1.57) |
0.82 (0.62–1.08) |
0.58
(0.46–0.73) |
| Gastritis | 1.47 (0.95–2.26) |
NA | 0.51 (0.22–1.17) |
| Alcoholic hepatitis |
1.88
(1.35–2.63) |
0.70 (0.26–1.89) |
0.32
(0.13–0.77) |
| Alcoholic cirrhosis | 0.74 (0.53–1.05) |
0.48 (0.18–1.29) |
0.41
(0.23–0.74) |
| Poisoning |
3.14
(1.80–5.49) |
0.60 (0.08–4.39) |
1.29 (0.51–3.26) |
| Elevated blood alcohol level | 2.07 (0.98–4.39) |
NA | 0.77 (0.18–3.25) |
NA, could not be calculated
Cholecystectomy surgery group serves as the reference group for all hazard ratios.
Models adjusted for age, sex, region, depression, anxiety, and the Charlson comorbidity index.
Defined as the presence of ≥1 ICD-9/10 code for the following diagnoses: alcohol abuse, alcohol dependence, alcoholic gastritis, alcoholic fatty liver, acute alcoholic hepatitis, alcoholic fibrosis, alcoholic cirrhosis, alcoholic liver failure, alcoholic liver damage, alcohol poisoning, elevated blood alcohol level.
Individual Alcohol-Related Outcomes
Among patients with a history of bariatric surgery, a total of 928 (1.9%) patients developed de novo alcohol abuse and 459 (0.9%) patients developed de novo alcohol dependence. In comparison, 2,511 (1.1%) and 1,499 (0.6%) patients in the control group developed alcohol abuse and alcohol dependence, respectively.
RYGB was associated with increased hazards of alcohol abuse (AHR 2.05, 95% 1.88–2.24, p<0.001), alcohol dependence (AHR 1.39, 95% CI 1.22–1.57, p<0.001), alcoholic hepatitis (AHR 1.88, 95% CI 1.35–2.63, p<0.001), and alcohol poisoning (AHR 3.14, 95% CI 1.80–5.49, p<0.001) compared to patients who underwent cholecystectomy (Table 2). Contrastingly, AGB was associated with decreased hazards of alcohol abuse (AHR 0.56, 95% CI 0.46–0.67, p<0.001), alcohol dependence (AHR 0.58, 95% CI 0.46–0.73, p<0.001), alcoholic hepatitis (AHR 0.32, 95% CI 0.13–0.77, p=0.01), and alcoholic cirrhosis (AHR 0.41, 95% CI 0.23–0.74, p=0.003). There were no statistically significant differences when comparing individual alcohol-related outcomes for SG and cholecystectomy.
Discussion
In this nationwide cohort of privately-insured patients, RYGB was independently associated with higher hazards of developing de novo alcohol-related diagnoses, specifically alcoholic hepatitis, abuse, dependence, and poisoning, as compared to a cholecystectomy control group. SG and AGB were associated with decreased hazards for any alcohol-related diagnosis, and AGB was associated with a decreased hazard for alcoholic hepatitis and alcoholic cirrhosis. Our findings are consistent with prior studies demonstrating an association between bariatric surgery and AUDs, particularly after RYGB,9–11,13,14 and are strengthened by the use of a surgical control group, the evaluation of de novo alcohol-related outcomes, and a nationwide larger sample size. Additionally, we are amongst the first to report on an association between RYGB and the development of alcohol-related liver complications. These findings underscore the need to counsel patients without an AUD on the risk of developing one after RYGB and may help influence the choice of bariatric surgery among patients with, or at risk for, an AUD.
The differences in observed associations between type of bariatric surgery and alcohol-related outcomes is likely related to different degrees of altered alcohol absorption or metabolism specific to the anatomical changes.15 RYGB and AGB are both restrictive type bariatric procedures that may decrease volume of alcohol consumption at one time. However, RYGB results in rapid alcohol absorption through direct dumping of alcohol into the jejunum. Furthermore, a degree of alcohol metabolism is lost in the setting of RYGB surgery due to loss of gastric alcohol dehydrogenase. Cumulatively, this results in more rapid absorption with a faster and higher peak serum alcohol level.16 In contrast, AGB results in early satiety, preserves alcohol dehydrogenase, and provides two areas that decrease alcohol flow rate into the duodenum, the band itself and the pylorus, that will prolong absorption time and decrease the peak serum alcohol level. Similarly, SG preserves some gastric alcohol dehydrogenase production and is also pylorus-sparing. All three bariatric surgeries may carry psychosocial risks for AUD (e.g., transfer of addictions or coping mechanisms, disappointment with surgical outcome, or regain of weight),17–19 but RYGB is unique in its rapid alcohol ‘dumping’ into the jejunum. It is telling that amongst those with a history of RYGB, the highest AHR were for alcohol poisoning and alcoholic hepatitis; both attributable to rapid absorption and high blood alcohol levels.
As the demand for bariatric surgery increases, a better understanding of the complications and risks associated with each type of bariatric surgery is required to identify the most appropriate procedure for each patient. Currently, the American Society for Metabolic and Bariatric Surgery recommends screening patients for substance use or mental health disorders as part of pre-operative evaluation prior to bariatric surgery. Patients with regular alcohol consumption or addictive behavior or tendencies should undergo counseling prior to surgery.19 The literature to date has identified certain risk factors associated with AUD, including younger males with a history of AUD, substance use, or tobacco dependence.6,7 However, our findings suggest that even those without a history of AUD should be counseled on the increased risk of developing alcohol-related problems after RYGB. Primary care providers who may see these patients long-term should also be made aware of this post-RYGB risk. For those with AUD risk factors and perhaps those with regular borderline high levels of alcohol intake, SG or AGB may be better choices unless there are compelling reasons to pursue RYGB (e.g. gastroesophageal reflux disease, poorly-controlled type 2 diabetes mellitus).
Bariatric surgery has been increasingly utilized in patients with NAFLD, with up to 80% of adults undergoing bariatric surgery having comorbid NAFLD.20–22 While NAFLD is not a primary indication to pursue bariatric surgery, studies have shown that bariatric surgery has been associated with decreased hepatic steatosis, inflammation, and fibrosis.23–25 What is concerning is our finding that bariatric surgery, particularly RYGB, was associated with an increased hazard of developing alcoholic hepatitis, a finding that is consistent with prior studies suggesting bariatric surgery as a risk factor for alcoholic hepatitis.26,27 This association is of heightened importance, as alcoholic hepatitis would increase the risk for the development of chronic alcohol-related liver disease and liver failure due to alcoholic hepatitis, and we have seen an increase in the burden of alcohol-related liver disease over the past two decades.28,29 If RYGB increases the risk for AUDs, alcoholic hepatitis, and alcohol-related cirrhosis, then patients who undergo RYGB for the management of obesity with concomitant NAFLD must be counseled regarding the importance of alcohol avoidance to prevent further liver injury and progressive chronic liver disease. These patients should arguably undergo pre-operative alcohol screening and counseling and should be monitored for alcohol use during the post-op period.
This study has several strengths. It is the largest study of the US population to date and assesses the varying relationships between the different types of bariatric surgery and several alcohol-related outcomes. We limited our cohort to those without prevalent alcohol-related outcomes by eliminating patients with an alcohol-related diagnosis code during a 12-month lookback period prior to the surgical index date. This enabled us to specifically evaluate for de novo alcohol-related outcomes in patients who might not normally be considered high risk, and allowed us to expand on the existing literature that has documented the association between bariatric surgery and AUDs, but typically among patients with a pre-surgical history of these conditions.6,11,30 This study is also one of few to use a control group, allowing for a more robust association between bariatric surgery and alcohol-related outcomes. Patients who underwent a cholecystectomy were used as a control group because obesity is a known risk factor for gallbladder disease, we felt this patient population would be demographically similar to those undergoing bariatric surgery, and there is no known association between cholecystectomy and alterations in alcohol metabolism, absorption, or use. Differences observed between bariatric surgery and cholecystectomy groups, including a higher prevalence of comorbid depression, anxiety, and obesity, as well as higher Charlson comorbidity index scores, were expected and these variables were included in our multivariable models due to anticipated effects on our outcomes.
Our findings must be interpreted in the context of potential limitations. First, much of the existing literature utilizes AUDIT scores or similar validated assessment instruments to define AUDs. Our outcome definitions relied on ICD codes, leading to possible misclassification of alcohol-related diagnoses. However, this misclassification is likely non-differential leaving the hazards ratios unaffected and biasing toward the null. The cumulative incidence of alcohol-related outcomes in our study was 2.7%, lower than the prevalence of AUD that has been previously reported, and is likely related to misclassification and the lack of validated measures used to identify alcohol use.11,31 However, we also expected to see a lower incidence in our study as we excluded patients with baseline or pre-operative alcohol-related diagnoses. Furthermore, the assessment of long-term consequences of bariatric surgery on alcohol-related outcomes might be limited in our study given the median follow-up of 2.8 years. Studies have shown more pronounced differences in AUDs post-operatively 2–3 years or more after surgery, suggesting that we may be underestimating the hazards of de novo alcohol-related outcomes after bariatric surgery.6,9,11 Taken together, our estimations of AUDs and alcohol-related outcomes post-bariatric surgery are likely conservative estimates.
In this large nationwide study of privately insured patients, RYGB was independently associated with an increased hazard of de novo alcohol-related outcomes. SG and AGB were associated with decreased hazards of de novo alcohol-related outcomes, and AGB in particular was associated with decreased hazard of developing alcoholic hepatitis. These differences in outcome by type of bariatric surgery can be explained by differing anatomical changes resulting in altered alcohol metabolism and absorption. As pre-operative evaluation for alcohol use, addictive tendencies, and pre-existing liver disease (e.g., NAFLD) is already standard of care, the results of these evaluations could be used to discuss the risks and benefits of each procedure and decide which surgery to perform. Additionally, an emphasis must be placed on long-term follow-up and continued engagement in AUD risk reduction.
Supplementary Material
Acknowledgments
Disclosure Statement: This research was supported, in part, by a grant from the National Institutes of Health (T32 DK007634).
Footnotes
All authors declare that they have no conflicts of interest to disclose.
References
- 1.Angrisani L, Santonicola A, Iovino P, et al. Bariatric surgery worldwide 2013. Obes Surg. 2015;25(10):1822–1832. [DOI] [PubMed] [Google Scholar]
- 2.Shariq OA, Mckenzie TJ. Obesity-related hypertension: A review of pathophysiology, management, and the role of metabolic surgery. Gland Surg. 2020;9(1):80–93. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Benotti PN, Wood GC, Carey DJ, et al. Gastric bypass surgery produces a durable reduction in cardiovascular disease risk factors and reduces the long-term risks of congestive heart failure. J Am Heart Assoc. 2017;6(5):e005126. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Cummings DE, Rubino F. Metabolic surgery for the treatment of type 2 diabetes in obese individuals. Diabetologia. 2018;61(2):257–264. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Reslan S, Saules KK, Greenwald MK, et al. Substance misuse following roux-en-y gastric bypass surgery. Subst Use Misuse. 2014;49(4):405–417. [DOI] [PubMed] [Google Scholar]
- 6.King WC, Chen JY, Mitchell JE, et al. Prevalence of alcohol use disorders before and after bariatric surgery. JAMA - J Am Med Assoc. 2012;207:2516–2525. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Ivezaj V, Benoit SC, Davis J, et al. Changes in alcohol use after metabolic and bariatric surgery: Predictors and mechanisms. Curr Psychiatry Rep. 2019;21(9):85. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Ali M, El Chaar M, Ghiassi S, et al. American Society for Metabolic and Bariatric Surgery updated position statement on sleeve gastrectomy as a bariatric procedure. Surg Obes Relat Dis. 2017;13(1):652–657. [DOI] [PubMed] [Google Scholar]
- 9.Conason A, Teixeira J, Hsu CH, et al. Substance use following bariatric weight loss surgery. JAMA Surg. 2013;148:145–150. [DOI] [PubMed] [Google Scholar]
- 10.Östlund MP, Backman O, Marsk R, et al. Increased admission for alcohol dependence after gastric bypass surgery compared With restrictive bariatric surgery. JAMA Surg. 2013;148:374–377. [DOI] [PubMed] [Google Scholar]
- 11.King WC, Chen JY, Courcoulas AP, et al. Alcohol and other substance use after bariatric surgery: prospective evidence from a U.S. multicenter cohort study. Surg Obes Relat Dis. 2017;13:1392–1404. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Deyo RA, Cherkin DC, Ciol MA. Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases. J Clin Epidemiol. 1992;45:613–619. [DOI] [PubMed] [Google Scholar]
- 13.Kanji S, Wong E, Aikioyamen L, et al. Exploring pre-surgery and post-surgery substance use disorder and alcohol use disorder in bariatric surgery: a qualitative scoping review. Int J Obes. 2019;43(9):1659–1674. [DOI] [PubMed] [Google Scholar]
- 14.Svensson PA, Anveden Å, Romeo S, et al. Alcohol consumption and alcohol problems after bariatric surgery in the swedish obese subjects study. Obesity. 2013;21(12):2444–2451. [DOI] [PubMed] [Google Scholar]
- 15.Cederbaum AI. Alcohol Metabolism. Clin Liver Dis. 2012;16(4):667–685. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Steffen KJ, Engel SG, Pollert GA, et al. Blood alcohol concentrations rise rapidly and dramatically after Roux-en-Y gastric bypass. Surg Obes Relat Dis. 2013;9(3):470–473. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Yoder R, MacNeela P, Conway R, et al. How Do Individuals Develop Alcohol Use Disorder After Bariatric Surgery? A Grounded Theory Exploration. Obes Surg. 2018;28:717–724. [DOI] [PubMed] [Google Scholar]
- 18.Müller A, Leukefeld C, Hase C, et al. Food addiction and other addictive behaviours in bariatric surgery candidates. Eur Eat Disord Rev. 2018;26(6):585–596. [DOI] [PubMed] [Google Scholar]
- 19.Steffen KJ, Engel SG, Wonderlich JA, et al. Alcohol and other addictive disorders following bariatric surgery: Prevalence, risk factors and possible etiologies. Eur Eat Disord Rev. 2015;23:442–450. [DOI] [PubMed] [Google Scholar]
- 20.Seki Y, Kakizaki S, Horiguchi N, et al. Prevalence of nonalcoholic steatohepatitis in Japanese patients with morbid obesity undergoing bariatric surgery. J Gastroenterol. 2016;51(3):281–289. [DOI] [PubMed] [Google Scholar]
- 21.Praveenraj P, Gomes RM, Kumar S, et al. Prevalence and predictors of non-alcoholic fatty liver disease in morbidly obese South Indian patients undergoing bariatric surgery. Obes Surg. 2015;25(11):2078–2087. [DOI] [PubMed] [Google Scholar]
- 22.Gupta K, Khan A, Goyal H, et al. Trends in utilization of bariatric surgery in NAFLD patients: A NIS study. Hepatology. 2019;70(S1):732A–733A. [Google Scholar]
- 23.Bower G, Toma T, Harling L, et al. Bariatric surgery and non-alcoholic fatty liver disease: A systematic review of liver biochemistry and histology. Obes Surg. 2015;25(12):2280–2289. [DOI] [PubMed] [Google Scholar]
- 24.Ooi GJ, Burton PR, Doyle L, et al. Effects of bariatric surgery on liver function tests in patients with nonalcoholic fatty liver disease. Obes Surg. 2017;27(6):1533–1542. [DOI] [PubMed] [Google Scholar]
- 25.von Schönfels W, Beckmann JH, Ahrens M, et al. Histologic improvement of NAFLD in patients with obesity after bariatric surgery based on standardized NAS (NAFLD activity score). Surg Obes Relat Dis. 2018;14(10):1607–1616. [DOI] [PubMed] [Google Scholar]
- 26.Bhardwaj MP, Nahas J, Im GY. Prevalence of bariatric surgery inpatients with severe alcoholic hepatitis undergoing evaluation for early liver transplantation. Gastroenterology. 2017;152(5 Suppl 1):S1112. [Google Scholar]
- 27.Garg SK, Sarvepalli S, Bazerbachi F, et al. Bariatric surgery is associated with increased risk of alcoholic hepatitis: Analysis from national inpatient database. Hepatology. 2018;68(S1):808A–809A. [Google Scholar]
- 28.Barritt AS, Jiang Y, Schmidt M, et al. Charges for alcoholic cirrhosis exceed all other etiologies of cirrhosis combined: A national and state inpatient survey analysis. Dig Dis Sci. 2019;64(6):1460–1469. [DOI] [PubMed] [Google Scholar]
- 29.Moon AM, Yang JY, Barritt AS, et al. Rising mortality from alcohol-associated liver disease in the United States in the 21st century. Am J Gastroenterol. 2020;115(1):79–87. [DOI] [PubMed] [Google Scholar]
- 30.Spadola CE, Wagner EF, Dillon FR, et al. Alcohol and drug use among postoperative bariatric patients: A systematic review of the emerging research and its implications. Alcohol Clin Exp Res. 2015;39(9):1582–1601. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.Mitchell JE, Steffen K, Engel S, et al. Addictive disorders after Roux-en-Y gastric bypass. Surg Obes Relat Dis. 2015;11(4):897–905. [DOI] [PMC free article] [PubMed] [Google Scholar]
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