Bariatric Surgery Reduces Metabolic Comorbidities in Patients With Obesity

Bariatric surgery significantly decreased the likelihood of 5 obesity-related comorbidities compared with a weight loss management (WMP) program, a new study published in JAMA Network Open reported.¹

Prior research shows that bariatric surgery can result in sustainable weight loss and remission of key metabolic comorbidities like hypertension, diabetes, hyperlipidemia, and metabolic dysfunction–associated steatotic liver disease (MASLD). Yet it is underutilized, as only 0.5% to 1.0% of eligible patients receive bariatric surgery. Underuse of the surgery has been associatedwith a lack of education about safety and efficacy and limited access due to socioeconomic factors and lack of insurance coverage. Additionally, FDA-approved weight loss and management medications have further decreased the demand for bariatric surgery. However, questions remain about how these therapies interact with surgical outcomes. Recent research highlights the need for more studies on glucagon-like peptide 1 (GLP-1) receptor agonist use following bariatric surgery to better understand its role in long-term patient care and real-world practice.^1,2

As a result, this new study aimed to quantify obesity-related comorbidities among patients eligible for bariatric surgery and the incidence of said comorbidities post surgery, a potential modifier of underutilization.¹

“The ability to provide prognostic counseling regarding future risk of metabolic comorbidities with and without bariatric surgery is crucial given the substantial health, psychological, and economic burdens associated with obesity-related comorbidities,” the study authors wrote.

This retrospective, multicenter cohort study used data from the Veterans Health Administration (VHA) corporate data warehouse. Patients who met the eligibility criteria were 18 years or older and had a body mass index (BMI) of 35 or higher, or 30 or higher with at least 1 of 5 major metabolic comorbidities (hypertension, hyperlipidemia, type 2 diabetes [T2D], obstructive sleep apnea [OSA], and MASLD); all of whomeither were referred to the VHA’s medical WMP—called MOVE!—or received bariatric surgery (sleeve gastrectomy [SG] or Roux-en-Y gastric bypass [RYGB]) between January 1, 2008, and December 31, 2023.

The WMP promoted engagement inhealthier lifestyle behaviors like increased physical activity and healthy eating habits, provided through group counseling as well as telephone care. Additionally, treatments like weight loss medication were also offered as adjuncts to the core WMP program.

Of the 269,470 patients in the study, 87.1% were male, with a median (IQR) age of 57 (47-64) years. The race and ethnicity of patients with available data were as follows: 0.5% identified as Asian, 20.1% as Black, 14.3% as Hispanic, 3.9% as Hispanic Black, 1.0% as Native Hawaiian or Other Pacific Islander, 53.3% as White, and 1.1% as other race or ethnicity. Furthermore, 263,657 were enrolled in the WMP but never underwent surgery. Of the 5813 patients who underwent bariatric surgery, 1803 (0.7%) received RYGB and 4010 (1.5%) received SG; 3417 of the patients who received bariatric surgery were also previously enrolled in the WMP. The median (IQR) amount of time in the WMP group for patients who eventually underwent surgery was 36.6 (16.4-69.8) months.

Incidence of Metabolic Comorbidities

Overall, the bariatric surgery groups had significantly lower incidence of all 5 comorbidities assessed compared with the WMP group. The bariatric surgery group was also younger than the WMP group (median[IQR] age, 49 [41-57] vs 57 [47-64] years, respectively), had higher baseline median (IQR) BMI (44.2 [40.0-49.4] vs 36.7 [33.9-40.4]), and had higher baseline prevalence of all 5 comorbidities (eg, T2D: 37.5% vs 32.0%). The overall median (IQR) follow-up time was112.9 (79.5-145.4) months overall, with 113.2 (80.0-145.5) months in the WMP group and 96.9 (58.1-135.6) months in the bariatric surgery group.

The crude, unadjusted cumulative incidence rates of each comorbidity in the WMP vs the bariatric surgery groups were as follows: at 5 years, the incidence rate per 1000 person-years was 8.9 vs 3.3 for hypertension, 9.7 vs 4.9 for hyperlipidemia, 4.3 vs 1.1 for T2D, 4.0 vs 3.4 for OSA, and 2.4 vs 2.0 for MASLD. In the adjusted Cox proportional hazards regression models after propensity score matching, patients in the bariatric surgery group were more than 50% less likely to develop T2D, hypertension, hyperlipidemia, and OSA, and 40.4% less likely to develop MASLD. 

These findings were also consistent in the subcohort of female veterans who underwent bariatric surgery vs those enrolled in the WMP, who also demonstrated a significant decrease in the hazard of comorbidity development.

“Compared with medical or lifestyle interventions, bariatric surgery offers patients both a higher rate of comorbidity remission and a higher likelihood of de-escalating daily medications,” the study authors wrote.“Mental health also improves after bariatric surgery, as studies have shown a greater health-related quality-of-life score in the years following surgery.”

This study may be affected by misclassification of exposures and outcomes, incomplete capture of surgeries outside the VHA, and residual confounding despite propensity score matching. Other limitations include variability in engagement with weight management programs, lack of adjustment for anti-obesity medications or baseline BMI, and limited generalizability given the older, male-predominant veteran cohort. The growing use of GLP-1 therapies adds another layer of complexity, as recent studies emphasize that more research is needed to clarify their role in post–bariatric surgery care.² These factors may restrict external validity, although subgroup analyses suggest the findings are still informative for female veterans.¹

“These findings suggest that risk mitigation of metabolic comorbidities may contribute to the long-term advantages of bariatric surgery that have been demonstrated previously, including reduction in cardiovascular and oncologic risk, which strengthens the mechanistic understanding of the benefits of bariatric surgery,” the study authors concluded.

References

1. Bader A, Hsu JY, Altieri MS, et al. Bariatric surgery and incident development of obesity-related comorbidities. JAMA Netw Open. 2025;8(9):e2530787. doi:10.1001/jamanetworkopen.2025.30787

2. McCrear S. GLP-1 usage post bariatric surgery requires more research. AJMC^®. August 28, 2025. Accessed September 8, 2025. https://www.ajmc.com/view/glp-1-usage-post-bariatric-surgery-requires-more-research