Bariatric surgery reduces long-term mortality in patients with metabolic dysfunction-associated steatotic liver disease and cirrhosis
Article information
Abstract
Background/Aims
With the obesity pandemic, metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common liver disease and a leading cause of end-stage liver disease and liver-related deaths in the USA. Therefore, we aimed to compare the long-term outcomes of patients with MASLD and cirrhosis with and without bariatric surgery.
Methods
Patients were retrospectively identified from the California Department of Healthcare Access and Information database, 2005 to 2019, for a population-based cohort study. Propensity score matching (PSM) was used to balance background risks between patients with cirrhosis who underwent bariatric surgery and those who did not. Overall, liver-related and non-liver-related mortality were analyzed.
Results
Of 91,708 eligible patients with MASLD and cirrhosis, PSM yielded 2,107 patients who underwent bariatric surgery and 8,428 non-bariatric controls. Compared to matched controls, patients who underwent bariatric surgery had lower 5-year overall (24.9% vs. 37.1%; P<0.0001), liver-related (3.3% vs. 14%; P<0.0001), and non-liver-related mortality (22.3% vs. 26.9%; P=0.046). In multivariable analysis, bariatric surgery was associated with decreased overall mortality (adjusted hazard ratio [aHR]=0.63; P<0.0001), liver-related (aHR=0.24; P<0.0001), and non-liver-related (aHR=0.81; P=0.0026) mortality. However, only laparoscopic surgeries were associated with lower overall mortality (aHR=0.39; P<0.0001) whereas open surgeries were associated with higher overall mortality (aHR=1.24; P=0.022).
Conclusions
Patients with MASLD and cirrhosis who underwent bariatric surgery, specifically laparoscopic approaches, had significantly lower mortality risk than non-surgical counterparts.
Graphical Abstract
INTRODUCTION
Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease, affects over one in three American adults and is now a major cause of end-stage liver disease and liver-related deaths in the USA [1]. The trajectory of MASLD parallels the obesity epidemic as approximately 75% of patients with obesity have MASLD [2].
While lifestyle modifications for weight loss are indicated for obese patients with MASLD, such recommendations are limited by low adherence and sustainability. Also, resmetirom is the only pharmacological therapy approved for MASLD and is only approved for patients without cirrhosis. Bariatric surgery as a treatment for morbid obesity offers effective, durable weight loss as well as alterations in the hepatic transcriptome that can improve steatosis, inflammation, fibrosis, and liver function [3-11]. Additionally, in a large, matched cohort of patients with MASLD and obesity, bariatric surgery was associated with a significant reduction in mortality risk across 7 years of study follow-up [12].
Studies comparing bariatric surgery in patients with cir-rhosis versus no cirrhosis have identified significant weightloss and improvements in metabolic comorbidities among patients with cirrhosis after surgery [13-17]. Systematic reviews and meta-analyses identify an elevated risk of post-operative complications and peri-operative mortality among patients with cirrhosis compared to no cirrhosis [14,15,18-20]. However, these studies are either limited in sample size or follow-up time, and they only compare surgery between cirrhosis and no cirrhosis patients [13-16,18-21]. As a result, long-term outcome data of patients with MASLD-associated cirrhosis who undergo bariatric surgery compared to non-surgical controls of similar health are sparse.
Therefore, we aimed to evaluate the long-term mortality of patients undergoing bariatric surgery among a large population-based, matched cohort of patients with MASLD and cirrhosis.
MATERIALS AND METHODS
Study design and population
We conducted a retrospective cohort study of patients diagnosed with MASLD in California, USA from 2005 to 2019. The study was approved by the California Health and Human Services Agency Institutional Review Board in Sacramento, California (project number: 14-10-1748).
Data were collected from the California Department of Health Care Access and Information (HCAI), which is a longitudinal database of 45 million inpatient hospital records (>98% of all civilian inpatients) from approximately 450 healthcare facilities throughout California, USA. Patient records were at the event-level with unique identification numbers to link patients across visits. Mortality data were obtained from the California State Death Statistical Master file records, containing death certificates for all Californians. Hospital characteristics data were gathered from HCAI and American Hospital Association databases. Mortality and hospital characteristics data were linked to inpatient records via patient and facility identification numbers, respectively.
Patients eligible for inclusion were adults (≥18 and ≤75 years) with one or more Internal Classification of Diseases, Ninth Revision and Tenth Revision, Clinical Modification (ICD-9-CM and ICD-10-CM) MASLD and cirrhosis codes (Supplementary Appendix) at baseline. We excluded patients with HIV, bariatric surgery prior to index MASLD diagnosis, liver transplant prior to bariatric surgery, or inconsistent death records from manual review.
For treated patients, the index date was defined as the first date of bariatric surgery. For non-bariatric controls, the index date was defined as the first date of MASLD diagnosis, formerly known as non-alcoholic fatty liver disease. Baseline characteristics were obtained for 1 year prior to index date.
Demographic information collected included age, sex, race and ethnicity, and insurance types (Medicare, MediCal, private health maintenance organization [HMO], private traditional, and other). Self-reported race and ethnicity data were presented according to current reporting guidelines [22]. Baseline Charlson Comorbidity index (CCI) was calculated as a composite of various baseline comorbidities (myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, rheumatic disease, peptic ulcer disease, mild liver disease, diabetes with or without chronic complication, hemiplegia or paraplegia, renal disease, any malignancy, moderate or severe liver disease, and metastatic solid tumor) via ICD-9-CM and ICD-10-CM codes shown in the supplement. A weighted index was calculated with a maximum possible score of 24 [23,24]. Compensated cirrhosis was defined by the diagnosis of cirrhosis and/or portal hypertension manifestations, including thrombocytopenia, splenomegaly, and varices. Hepatic decompensation was defined by diagnosis of jaundice, ascites, hepatic encephalopathy, or variceal bleeding. Hospital characteristics, including academic center, setting (urban or rural), and size (<100, 100 to 399, ≥400 beds) were identified for each patient’s baseline visit.
Study end points
Primary study end points included (1) all-cause, (2) liver-related, and (3) non-liver-related mortality. Liver-related mortality was indicated by an ICD-10-CM cause of death code for chronic hepatitis, liver fibrosis and cirrhosis, malignant neoplasm of the liver, hepatic failure, and other inflammatory liver diseases and was further stratified into mortality without liver transplant and mortality with and without hepatocellular carcinoma (HCC) at any point over study follow-up. Non-liver-related mortality was classified as any other cause of death not identified above and was further stratified into mortality from cardiovascular disease (CVD), chronic kidney disease (CKD), and non-liver cancer. Secondary study end points were the incidence of specific liver events (decompensation, HCC, and transplantation). The ICD-9-CM and ICD-10-CM codes used for end point identification are in the supplement (Supplementary Appendix).
Statistical analysis
To reduce the effects of confounding variables, each patient in the bariatric surgery group was matched to 4 nonsurgical controls using propensity score matching (PSM) on age, sex, race and ethnicity, health insurance type, CCI, presence of liver decompensation, and hospital characteristics at baseline. 1:4 PSM was performed via optimal matching in SAS® version 9.4, in which controls were matched to each treated patient by minimizing the total absolute difference in propensity score across all matches, with a caliper of 0.1 of the standard deviation of the logit propensity scores. As P-values are sensitive to sample size, standardized mean difference (SMD) values were used to evaluate the balancing of potential confounding variables between the two study groups. As per the PSM algorithm, patients with missing data for any of the matched variables were not considered eligible for matching and were excluded. Of the 91,708 patients evaluated for matching, only 1,530 (1.67%) were excluded for missing values.
Survival curves were plotted via the Kaplan-Meier method and the log-rank test was used to compare the differences between the bariatric and non-bariatric groups. Curves for cumulative incidence of specific liver events were plotted via the Fine-Gray method with overall mortality as a competing risk; the Gray’s test was used to compare the differences between bariatric and non-bariatric groups.
The Cox proportional hazards regression model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of mortality, and Fine-Gray model was used to estimate subdistribution HRs for the risk of liver complication events with overall mortality as competing risk. The multivariable models were adjusted for age, sex, and baseline CCI. Surgical subgroup analyses also adjusted for year of visit to account for changes in post-operative care over time.
Subgroup analysis explored whether the association between bariatric surgery and mortality differed by surgical approach and across demographic and clinical characteristics. P-values for interaction were calculated to compare the effect of surgery across demographic subgroups.
To confirm the robustness of our findings, we also performed two separate sensitivity analyses by estimating mortality risk after excluding (1) patients with viral hepatitis or alcohol use disorder and (2) patients without cardiometabolic comorbidities (obesity, diabetes, prediabetes, hypertension, hyperlipidemia, hypercholesterolemia, hypertriglyceridemia, or metabolic syndrome).
Statistical significance was defined as a 2-tailed P<0.05 and the SMD threshold was set as 0.10. Continuous variables were reported as mean and standard deviation; categorical variables were reported as percentages. A student’s t-test was used to compare mean age, while a nonparametric Wilcoxon test was used to compare baseline CCI. Chi-square tests were used for descriptive analyses of baseline categorical variables. All statistical analyses were performed using SAS® version 9.4 (SAS Institute) and R version 4.3.2 (The R Foundation) from July to December 2023. Further details regarding the diagnostic and procedural codes for patient selection, cohort classification, and outcome identification are in the supplement (Supplementary Appendix).
RESULTS
A total of 322,151 patients with MASLD were identified, of which 91,708 had cirrhosis at baseline and met our study inclusion criteria (Fig. 1). Among these patients, we identified 2,146 patients who underwent bariatric surgery and 89,562 non-bariatric controls. With PSM, 2,107 patients who underwent bariatric surgery were matched to 8,428 controls. In the bariatric cohort, 1,753 underwent laparoscopic surgery, 284 underwent open surgery, and 70 cases had undefined (open vs. laparoscopic) surgical approach.

Flow chart of study patient selection from the California Department of Healthcare Access and Information (2005 to 2019). MASLD, Metabolic dysfunction-associated steatotic liver disease. aExclusion criteria were not mutually exclusive as some excluded met more than one exclusion criteria. bPropensity score matching by age, sex, race and ethnicity, health insurance type, Charlson-comorbidity index, liver decompensation, and hospital characteristics (academic center, setting, and size).
Patient characteristics
Table 1 describes patient demographics and clinical characteristics at baseline before and after PSM. Before PSM, the patients who underwent bariatric surgery were nearly 5 years younger on average than those who did not (49.93 vs. 54.37 years; P<0.001). Compared to non-bariatric controls, patients who underwent bariatric surgery were more likely to be female (69.90% vs. 48.77%; P<0.0001) and Non-Hispanic (NH) White (55.90% vs. 50.88%; P<0.0001). Treated patients were also more likely to use private or HMO insurance (46.85% vs. 28.11%; P<0.0001) and receive care at a large, academic center in an urban setting (all P<0.05). Clinically, patients who underwent bariatric surgery had a lower CCI (2.18 vs. 3.11; P<0.0001) and were less likely to have liver decompensation at baseline (67.94% vs. 87.33%; P<0.0001). After PSM, the two study groups were similar across demographic and clinical characteristics (all SMD<0.10).
Mortality outcomes
In the PSM cohort, overall mortality was significantly lower for the bariatric group compared to controls at 5 years (24.9% vs. 37.1%; P<0.0001) and 10 years (49.1% vs. 56.1%; P<0.0001; Fig. 2A). Notably, this difference was even more pronounced for liver-related mortality at 5 years (3.3% vs. 14%; P<0.0001) and 10 years (8.3% vs. 22.4%; P<0.0001; Fig. 2B). Consistent findings for liver-related mortality were observed among patients who did not undergo liver transplantation as well as patients with or without HCC at any point during follow-up (all P<0.05; Fig. 2D–F). Overall, non-liver-related mortality risk varied over the course of study follow-up with treated patients at lower risk at 5 years (22.3% vs. 26.9%; P=0.046) and similar risk at 10 years (44.4% vs. 43.5%; P=0.055; Fig. 2C). Such trends were consistent for CVD-related and CKD-related mortality (Fig. 2G, H). Patients who underwent bariatric surgery were observed to have a higher risk of non-liver cancer-related mortality than non-bariatric controls over the study follow-up (10 years: 14.2% vs. 10.8%; P=0.003; Fig. 2I).

Cumulative incidence of mortality in PSM cohort of MASLD patients with baseline cirrhosis, by mortality cause (n=10,535). MASLD, metabolic dysfunction-associated steatotic liver disease; PSM, propensity score matching. aPatients in this analysis did not undergo liver transplantation at any point of study follow-up. bPatients in this analysis were diagnosed with HCC at any point of study follow-up.
Liver outcomes
With all-cause mortality as a competing risk, the incidence of liver decompensation among treated patients was significantly lower than non-bariatric controls throughout study follow-up (10 years: 45.2% vs. 65.0%; P<0.001; Supplementary Fig. 1A). Although rare, incidence of HCC and liver transplantation were both lower relative to non-bariatric controls over study follow-up (HCC: P<0.001; liver transplant: P=0.006; Supplementary Fig. 1B, C).
Association of bariatric surgery with study outcomes
In multivariable analysis, bariatric surgery was independently associated with decreased risk of all-cause and cause-specific mortality (Table 2). After adjusting for age, sex, and baseline CCI, bariatric surgery was associated with a 37% reduction in all-cause (adjusted HR [aHR] 0.63, 95% CI 0.56–0.72; P<0.0001) and 76% reduction in liver-related (aHR 0.24, 95% CI 0.17–0.34; P<0.0001) mortality. Reduced liver-related mortality risk was consistently observed among patients who did not undergo liver transplantation and those with or without HCC at any time during follow-up (all P<0.05). Bariatric surgery was also associated with a 19% reduction in non-liver-related mortality (aHR 0.81, 95% CI 0.70–0.93; P=0.0026). Specifically, bariatric surgery was independently associated with a 30% reduction in CVD-related mortality (aHR 0.70, 95% CI 0.53–0.94; P=0.019), 30% reduction in CKD-related mortality (aHR 0.70, 95% CI 0.37–1.32; P=0.269), and 18% elevation in non-liver cancer-related mortality (aHR 1.18, 95% CI 0.92–1.51; P=0.189).

Factors associated with mortality in PSM cohort of MASLD patients with baseline cirrhosis (n=10,535)
Bariatric surgery was also independently associated with decreased risk of adverse liver outcomes with overall mortality as a competing risk (Supplementary Table 1). After adjusting for age, sex, and baseline CCI, bariatric surgery was associated with a 47% reduction in liver decompensation risk (aHR 0.53, 95% CI 0.43–0.66; P<0.0001), 47% reduction in HCC risk (aHR 0.53, 95% CI 0.27–1.05; P=0.071), and 60% reduction in liver transplantation risk (aHR 0.40, 95% CI 0.21–0.77; P=0.006).
Subgroup analysis
On multivariable analysis adjusting for age, sex, CCI, and year of visit, laparoscopic bariatric surgeries were associated with a 61% reduction in overall mortality (aHR 0.39, 95% CI 0.32–0.47; P<0.0001), but open surgeries were associated with a 24% elevation in overall mortality (aHR 1.24, 95% CI 1.03–1.49; P=0.022; Fig. 3A). Specifically, laparoscopic gastric banding was associated with the largest reduction in all-cause mortality (aHR 0.23, 95% CI 0.12–0.43; P<0.0001; Supplementary Fig. 2A). Both laparoscopic and open surgeries were associated with reduced liver-related mortality, but laparoscopic approaches (aHR 0.16, 95% CI 0.10–0.26; P<0.0001) were associated with greater risk reduction than open approaches (aHR 0.54, 95% CI 0.32–0.90; P=0.019; Fig. 3B).

Factors associated with mortality in PSM cohort of MASLD patients with baseline cirrhosis, by bariatric surgery approach (n=10,535).a PSM, Propensity score matching; MASLD, Metabolic dysfunction-associated steatotic liver disease; HR, hazard ratio; Cl, confidence interval. aPatients without detailed surgical approach excluded from subgroup analyses. bAdjusted for age, sex, baseline Charlson-comorbidity index, and year of visit (before or after 2012).
Additionally, the association between bariatric surgery and reduced overall mortality was consistent across subgroups by age, sex, and race and ethnicity except for groups with small sample sizes (Non-Hispanic Asian and Native American patients; younger age (≤51 years), female, and NH White patients experienced the greatest risk reduction (all P for interaction <0.05; Supplementary Fig. 3A). Patients with a CCI above the average of 2.17 were also at an elevated risk of mortality (aHR 1.26, 95% CI 1.07–1.49) compared to those with CCIs below average (aHR 0.41, 95% CI 0.34–0.49; P for interaction <0.0001). The association between bariatric surgery and reduced liver-related mortality was also consistent across subgroups, but the association only differed significantly across race and ethnicity (P for interaction=0.005) and across CCI (P for interaction=0.031; Supplementary Fig. 3B).
Sensitivity analysis
Results of the sensitivity analyses excluding patients with viral hepatitis or alcohol use disorder and without cardiometabolic comorbidities were consistent with the results from the primary analysis showing reduced overall, liver-related, and non-liver-related mortality among the bariatric group compared to non-bariatric controls (Supplementary Tables 2–3). Specifically, among the 8,046 patients analyzed after exclusion for viral hepatitis or alcohol use disorder, bariatric surgery was associated with reduced risk of overall mortality (aHR 0.66, 95% CI 0.57–0.77; P<0.0001). Among the 9,356 patients with a diagnosis of cardiometabolic co-morbidities, bariatric surgery was also associated with reduced risk of overall mortality (aHR 0.64, 95% CI 0.56–0.73; P<0.0001).
DISCUSSION
To our knowledge, this is the first study to explore the long-term outcomes of bariatric surgery in a large population-based sample of patients with MASLD and cirrhosis compared to matched non-bariatric controls of similar demographic and clinical characteristics. In the current study, bariatric surgery was associated with a large and significant reduction in overall (37%) and liver-related (76%) mortality among patients with MASLD and cirrhosis, especially when approached laparoscopically. Open surgical approach was associated with 56% reduced liver-related mortality but 24% increased overall mortality. Treatment was not found to have a protective association with overall mortality risk in patients with several comorbidities (above average CCI). Bariatric surgery was also associated with reduced risk of liver-related events such as liver decompensation, HCC, and liver transplantation as well as nonliver-related mortality (including CVD and CKD-related mortality). Overall, these results suggest that bariatric surgery should be considered for eligible obese patients with MASLD, cirrhosis, and minimal comorbidities, but open surgical approaches should be avoided.
Although bariatric surgery was associated with an increased risk of non-liver cancer-related mortality, this association was not statistically significant after adjusting for potential confounders on multivariable analyses. This may be explained by the fact that non-liver cancer-related mortality is a heterogenous outcome encompassing several cancers that have been found to not decrease in incidence following bariatric surgery [25], while the association with CVD and CKD as metabolic conditions were significant.
Our findings strengthen and expand upon previously reported outcomes, contributing novel data to the literature. Specifically, observed associations between bariatric surgery and reduced mortality risk in patients with advanced liver disease are consistent with similar findings from studies exploring bariatric surgery in patients with earlier stages of MASLD. Prospective cohort studies from Drai et al. in 2024 and from Lassailly et al. in 2020 found that greater than 83% of bariatric surgery recipients with steatohepatitis experienced biopsy-proven reductions in fibrosis after 1 and 5 years of follow-up, respectively [8,26]. Furthermore, a randomized trial from Verrastro et al. in 2023 found that bariatric surgery induced steatohepatitis resolution more effectively than lifestyle modifications after 1 year of follow-up [9].
Results from our study suggest that bariatric surgery may induce improvements in overall metabolic health, even in the setting of liver cirrhosis. These findings are consistent with a meta-analysis of 8 studies in 2022 that observed that bariatric surgery induced durable weight loss in patients with cirrhosis at 3, 6, and 12 months of follow-up [14]. Another systematic review of 32 patients from 2024 found that patients with cirrhosis-related portal hypertension experienced resolution of diabetes and hypertension after bariatric surgery [27]. Younus et al. followed 26 patients with biopsy-proven cirrhosis for a median of 4.5 years, observing a significant improvement in model end-stage liver disease scores from 7 to 6 (P<0.01) [17]. Additionally, Hanipah et al. performed a retrospective study of 13 patients with cirrhosis and portal hypertension from 2007 to 2017 that identified significant improvements in diabetes, dyslipidemia, and hypertension 2 years after laparoscopic bariatric surgery [13]. A longer-term retrospective analysis of 10 patients with cirrhosis from Izzy et al. in 2021 also observed a mean weight loss of 24 kg over a mean 8.7 years of post-surgical follow-up [16]. While both Hanipah et al. and Izzy et al. analyzed a relatively small sample of patients from one tertiary care center, the present study examined a large sample of patients across many hospital sites.
A retrospective analysis of the National Inpatient Sample from 1998 to 2007 by Mosko and Nguyen compared inhospital mortality following bariatric surgery in patients with cirrhosis (n=3,950) and without cirrhosis (n=670,950) [21]. Although patients with compensated cirrhosis experienced a higher risk of in-hospital mortality relative to those without cirrhosis (aHR 2.2, 95% CI 1.0–4.6; P=0.041), inpatient mortality rates were low at 0.9% and 0.3% among patients with and without compensated cirrhosis, respectively. While this study’s sample is large and nationally representative, it is limited to identifying in-hospital mortality events. Our findings expand upon this analysis by linking inpatient records to state-wide death records, enabling analysis of long-term outcome risk.
Furthermore, the results from previous explorations of bariatric surgery in the current literature compare surgery outcomes between patients with cirrhosis versus those without cirrhosis, which may not adequately inform decision making for patients with cirrhosis as they consider bariatric surgery [13-16,18-21]. By contrast, the present study examined a cohort of patients with cirrhosis, comparing outcomes among patients who underwent bariatric surgery matched to those who did not.
The observed differences in mortality risk, even within laparoscopic and open surgery types, are likely driven by the varying degrees of invasiveness of each approach. Less invasive surgeries, such as laparoscopic gastric banding, are associated with reduced risk of intraoperative bleeding, infection, and long-term malnutrition. Additionally, more extensive surgeries may induce more substantial disruptions to the gut-liver axis via alterations to the gut microbiota, and such changes may elevate inflammation and increase the risk of post-operative progression of cirrhosis to acute liver failure and related complications [28]. The discrepancies in mortality risk between laparoscopic and open approaches observed in the present study are also in line with the existing literature. Prior systematic reviews and meta-analyses have found that laparoscopic bariatric surgeries are associated with reduced post-operative mortality, infection risk, and complication rate [29-31]. The present study expanded our existing knowledge by providing robust and comprehensive long-term data for patients with MASLD-related cirrhosis and obesity who underwent weight-reduction surgeries.
Strengths and limitations
There are several strengths of this study. First, this study utilized data from a longitudinal, population-based patient sample that includes nearly all inpatients from the State of California, which offers an ethnically and socioeconomically diverse sample of about 40 million people. Such large-scale data obtained from inpatient records without selection bias of tertiary care center are more generalizable, better informing clinical decision-making. Second, linkage of individual inpatient records to death certificates enabled evaluation of long-term mortality risk. Third, this study utilized PSM to balance the background risks of treated patients and non-bariatric controls, enabling more robust outcome comparison between the two study cohorts. Additionally, we performed extensive subgroup analysis and several sensitivity analyses to confirm that our results are robust.
There are also some limitations to our study. First, administrative records containing ICD codes are prone to miscoding and misclassification, but the HCAI database is validated and maintained by the State of California to minimize reporting errors. Second, because cirrhosis may elevate risk factors that contraindicate bariatric surgery, selection bias may exist. A lack of anthropometric and laboratory data in the HCAI inpatient records also limited the scope of variable adjustment, so residual confounding may exist. However, our study utilized PSM to successfully match patients across all available and relevant demographic and clinical characteristics, including CCI and liver decompensation, in order to reduce selection bias between the two study groups. Additionally, the index dates differed between bariatric recipients and non-bariatric controls, which may have biased the results. However, because patients who underwent bariatric surgery prior to their first MASLD diagnosis were excluded from the study, we would anticipate that the current methodology may bias towards an underestimated benefit of bariatric surgery as index dates for bariatric surgery recipients would be further along in time and thus a potentially shorter survival. There may also be some loss of follow-up if patients died outside of California but there is probably no reason to expect one group to be more likely to die outside of California versus the other. The loss of follow-up is likely minimal given that our study database includes hospitalizations for greater than 98% of all civilian inpatients from all hospitals in California (except for military and federal hospitals) and is linked to the California State Death Statistical Master file, providing mortality data for nearly all individuals residing in California as the vast majority of people will have died in the hospital. Also, it is possible that, compared to non-surgical controls, patients experiencing substantial weight loss from bariatric surgery were more likely to engage in behavioral and lifestyle modifications to sustain this weight loss, which may have biased the results. However, this potential confounder can also be considered an indirect benefit of bariatric surgery. Lastly, the present study concluded in 2019, prior to the adoption of novel and minimally invasive bariatric surgery mechanisms, such as endoscopic sleeve gastroplasties. Additionally, a recent uptick in the consumption of pharmacotherapies, such as GLP-1 agonists, warrants further investigation as such therapies have demonstrated the ability to induce significant weight loss both independently and following bariatric surgery [32,33]. As sufficient time passes, further research including patient-reported outcomes, such as quality of life assessment, is needed for the long-term evaluation of such novel surgical approaches and pharmacotherapies.
Our population-based study with long-term follow-up showed that patients with MASLD and cirrhosis who underwent bariatric surgery through laparoscopic approaches had significantly lower overall, liver-related, and non-liver-related mortality than their non-surgical counterparts. Open approaches to bariatric surgery were associated with reduced risk of liver-related mortality, yet elevated risk of overall mortality. The present study suggests that bariatric surgery should be considered for eligible patients with MASLD and cirrhosis, favoring the use of laparoscopic surgical approaches. Future prospective studies with patient laboratory data are needed to validate our findings.
Notes
Authors’ contribution
Study design: NAR, MHN. Data analysis: NAR, SB, LK, XZ, MHN. Data collection: NAR, MHN. Drafting of manuscript: NAR, MHN. Data interpretation, review, and revision of manuscript: All authors.
Conflicts of Interest
MHN: Research grant: Pfizer, Enanta, Astra Zeneca, GSK, Delfi, Innogen, Exact Science, CurveBio, Gilead, Vir Biotech, Helio Health, National Cancer Institute, Glycotest. Consulting/Advisory Board: Intercept, Exact Science, Gilead, GSK. Other authors: nothing to disclose.
Abbreviations
aHR
adjusted hazard ratio
CCI
Charlson Comorbidity index
CI
confidence interval
CKD
chronic kidney disease
CM
Clinical Modification
CVD
cardiovascular disease
HCAI
Health Care Access and Information
HCC
hepatocellular carcinoma
HMO
health maintenance organization
HR
hazard ratio
ICD-9 and ICD-10
Internal Classification of Diseases
MASLD
metabolic dysfunction-associated steatotic liver disease
NH
non-Hispanic
PCS
Procedural Coding System
PSM
propensity score matching
SMD
standardized mean difference
SUPPLEMENTAL MATERIAL
Supplementary material is available at Clinical and Molecular Hepatology website (http://www.e-cmh.org).
Estimated cumulative incidence of liver-related events in PSM cohort of MASLD patients with baseline cirrhosis with overall mortality as a competing risk (n=10,535). PSM, Propensity score matching; MASLD, Metabolic dysfunction-associated steatotic liver disease.
Factors associated with mortality in PSM cohort of MASLD patients with baseline cirrhosis, by each bariatric surgery approach (n=10,535).a PSM, Propensity score matching; MASLD, Metabolic dysfunction-associated steatotic liver disease; HR, hazard ratio; CI, confidence interval; VBG, Vertical-banded gastroplasty. Results for one patient with “high gastric bypass, open or laparoscopic” excluded from subgroup analyses. bAdjusted for age, sex, baseline Charlson-comorbidity index, and year of visit (before or after 2012). Illustrations obtained from DeMaria, NEJM 2007.
Subgroup analysis for bariatric surgery status as a predictor of overall and liver-related mortality in PSM cohort of MASLD patients with baseline cirrhosis (n=10,535). PSM, Propensity score matching; MASLD, Metabolic dysfunction-associated steatotic liver disease; HR, hazard ratio; CI, confidence interval; NH, Non-Hispanic; CCI, Charlson-comorbidity index. aAdjusted for age (≤ or >51 years), sex, and baseline Charlson-comorbidity index. bP-value refers to comparison for effects of surgery versus non-surgery across subgroups.
Factors associated with liver-related events in PSM cohort of MASLD patients with baseline cirrhosis with overall mortality as a competing risk (n=10,535)
Sensitivity analysis excluding patients with viral hepatitis or alcohol use disorder for factors associated with mortality in PSM cohort of MASLD patients with baseline cirrhosis (n=8,046)
Sensitivity analysis excluding patients without cardiometabolic comorbidities for factors associated with mortality in PSM cohort of MASLD patients with baseline cirrhosis (n=9,356)
References
Article information Continued
Notes
Study Highlights
• Long-term outcome data of patients with MASLD-associated cirrhosis who undergo bariatric surgery compared to non-surgical controls of similar health remain sparse. Our population-based study with long-term follow-up found that patients with MASLD and cirrhosis who underwent bariatric surgery had significantly lower mortality risk than non-surgical counterparts of similar health. Laparoscopic approaches were associated with more favorable outcomes than open surgery. Results from our study suggest that bariatric surgery should be considered for eligible patients with MASLD and cirrhosis, potentially curbing the progression of advanced MASLD.