Reduction in Long-term Mortality After Sleeve Gastrectomy and Gastric Bypass Compared to Nonsurgical Patients With Severe Obesity.

OBJECTIVE: To separately compare the long-term risk of mortality among bariatric surgical patients undergoing either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) to large, matched, population-based cohorts of patients with severe obesity who did not undergo surgery. BACKGROUND: Bariatric surgery has been associated with reduced long-term mortality compared to usual care for severe obesity which is particularly relevant in the COVID-19 era. Most prior studies involved the RYGB operation and there is less long-term data on the SG. METHODS: In this retrospective, matched cohort study, patients with a body mass index ≥35 kg/m 2 who underwent bariatric surgery from January 2005 to September 2015 in three integrated health systems in the United States were matched to nonsurgical patients on site, age, sex, body mass index, diabetes status, insulin use, race/ethnicity, combined Charlson/Elixhauser comorbidity score, and prior health care utilization, with follow-up through September 2015. Each procedure (RYGB, SG) was compared to its own control group and the two surgical procedures were not directly compared to each other. Multivariable-adjusted Cox regression analysis investigated time to all-cause mortality (primary outcome) comparing each of the bariatric procedures to usual care. Secondary outcomes separately examined the incidence of cardiovascular-related death, cancer related-death, and diabetes related-death. RESULTS: Among 13,900 SG, 17,258 RYGB, and 87,965 nonsurgical patients, the 5-year follow-up rate was 70.9%, 72.0%, and 64.5%, respectively. RYGB and SG were each associated with a significantly lower risk of all-cause mortality compared to nonsurgical patients at 5-years of follow-up (RYGB: HR = 0.43; 95% CI: 0.35,0.54; SG: HR = 0.28; 95% CI: 0.13,0.57) Similarly, RYGB was associated with a significantly lower 5-year risk of cardiovascular-(HR = 0.27; 95% CI: 0.20, 0.37), cancer- (HR = 0.54; 95% CI: 0.39, 0.76), and diabetes-related mortality (HR = 0.23; 95% CI:0.15, 0.36). There was not enough follow-up time to assess 5-year cause-specific mortality in SG patients, but at 3-years follow-up, there was significantly lower risk of cardiovascular- (HR = 0.33; 95% CI:0.19, 0.58), cancer- (HR = 0.26; 95% CI:0.11, 0.59), and diabetes-related (HR = 0.15; 95% CI:0.04, 0.53) mortality for SG patients. CONCLUSION: This study confirms and extends prior findings of an association with better survival following bariatric surgery in RYGB patients compared to controls and separately demonstrates that the SG operation also appears to be associated with lower mortality compared to matched control patients with severe obesity that received usual care. These results help to inform the tradeoffs between long-term benefits and risks of bariatric surgery.

Remission and Relapse of Hypertension After Bariatric Surgery: A Retrospective Study on Long-Term Outcomes.

To compare hypertension remission and relapse after bariatric surgery compared with usual care. Background: The effect of Roux-en-Y gastric bypass and sleeve gastrectomy on hypertension remission and relapse has not been studied in large, multicenter studies over long periods and using clinical blood pressure (BP) measurements. Methods: This retrospective cohort study was set in Kaiser Permanente Washington, Northern California, and Southern California. Participants included 9432 patients with hypertension 21-65 years old who underwent bariatric surgery during 2005-2015 and 66,651 nonsurgical controls matched on an index date on study site, age, sex, race/ethnicity, body mass index, comorbidity burden, diabetes status, diastolic and systolic BP, and number of antihypertensive medications. Results: At 5 years, the unadjusted cumulative incidence of hypertension remission was 60% (95% confidence interval [CI], 58-61%) among surgery patients and 14% (95% CI, 13-14%) among controls. At 1 year, the adjusted hazard ratio for the association of bariatric surgery with hypertension remission was 10.24 (95% CI, 9.61-10.90). At 5 years, the adjusted hazard ratio was 2.10 (95% CI, 1.57-2.80). Among those who remitted, the unadjusted cumulative incidence of relapse at 5 years after remission was 54% (95% CI, 51-56%) among surgery patients and 78% (95% CI 76-79%) among controls, although the adjusted hazard ratio was not significant (hazard ratio, 0.71; 95% CI, 0.46-1.08). Conclusions: Bariatric surgery was associated with greater hypertension remission than usual care suggesting that bariatric surgery should be discussed with patients with severe obesity and hypertension. Surgical patients who experience remission should be monitored carefully for hypertension relapse.

Investigating Bias from Missing Data in an Electronic Health Records-Based Study of Weight Loss After Bariatric Surgery.

PURPOSE: Missing data is common in electronic health records (EHR)-based obesity research. To avoid bias, it is critical to understand mechanisms that underpin missingness. We conducted a survey among bariatric surgery patients in three integrated health systems to (i) investigate predictors of disenrollment and (ii) examine differences in weight between disenrollees and enrollees at 5 years. MATERIALS AND METHODS: We identified 2883 patients who had bariatric surgery between 11/2013 and 08/2014. Patients who disenrolled before their 5-year anniversary were invited to participate in a survey to ascertain reasons for disenrollment and current weight. Logistic regression was used to investigate predictors of disenrollment. Five-year percent weight change distributions were estimated using inverse-probability weighting to adjust for (un)availability of EHR weight data at 5 years among enrollees and survey (non-)response among disenrollees. RESULTS: Among 536 disenrolled patients, 104 (19%) completed the survey. Among 2347 patients who maintained enrollment, 384 (16%) had no weight measurement in the EHR near 5 years. Insurance, age, Hispanic ethnicity, and site predicted disenrollment. Disenrollees had slightly greater weight loss than enrollees. CONCLUSION: We found little evidence of weight loss differences by enrollment status. Collecting information through surveys can be an effective tool to investigate and adjust for missingness in EHR-based studies.

Validity of Privacy-Protecting Analytical Methods That Use Only Aggregate-Level Information to Conduct Multivariable-Adjusted Analysis in Distributed Data Networks.

Distributed data networks enable large-scale epidemiologic studies, but protecting privacy while adequately adjusting for a large number of covariates continues to pose methodological challenges. Using 2 empirical examples within a 3-site distributed data network, we tested combinations of 3 aggregate-level data-sharing approaches (risk-set, summary-table, and effect-estimate), 4 confounding adjustment methods (matching, stratification, inverse probability weighting, and matching weighting), and 2 summary scores (propensity score and disease risk score) for binary and time-to-event outcomes. We assessed the performance of combinations of these data-sharing and adjustment methods by comparing their results with results from the corresponding pooled individual-level data analysis (reference analysis). For both types of outcomes, the method combinations examined yielded results identical or comparable to the reference results in most scenarios. Within each data-sharing approach, comparability between aggregate- and individual-level data analysis depended on adjustment method; for example, risk-set data-sharing with matched or stratified analysis of summary scores produced identical results, while weighted analysis showed some discrepancies. Across the adjustment methods examined, risk-set data-sharing generally performed better, while summary-table and effect-estimate data-sharing more often produced discrepancies in settings with rare outcomes and small sample sizes. Valid multivariable-adjusted analysis can be performed in distributed data networks without sharing of individual-level data.

Association Between Bariatric Surgery and Macrovascular Disease Outcomes in Patients With Type 2 Diabetes and Severe Obesity.

Importance: Macrovascular disease is a leading cause of morbidity and mortality for patients with type 2 diabetes, and medical management, including lifestyle changes, may not be successful at lowering risk. Objective: To investigate the relationship between bariatric surgery and incident macrovascular (coronary artery disease and cerebrovascular diseases) events in patients with severe obesity and type 2 diabetes. Design, Setting, and Participants: In this retrospective, matched cohort study, patients with severe obesity (body mass index ≥35) aged 19 to 79 years with diabetes who underwent bariatric surgery from 2005 to 2011 in 4 integrated health systems in the United States (n = 5301) were matched to 14 934 control patients on site, age, sex, body mass index, hemoglobin A1c, insulin use, observed diabetes duration, and prior health care utilization, with follow-up through September 2015. Exposures: Bariatric procedures (76% Roux-en-Y gastric bypass, 17% sleeve gastrectomy, and 7% adjustable gastric banding) were compared with usual care for diabetes. Main Outcomes and Measures: Multivariable-adjusted Cox regression analysis investigated time to incident macrovascular disease (defined as first occurrence of coronary artery disease [acute myocardial infarction, unstable angina, percutaneous coronary intervention, or coronary artery bypass grafting] or cerebrovascular events [ischemic stroke, hemorrhagic stroke, carotid stenting, or carotid endarterectomy]). Secondary outcomes included coronary artery disease and cerebrovascular outcomes separately. Results: Among a combined 20 235 surgical and nonsurgical patients, the mean (SD) age was 50 (10) years; 76% of the surgical and 75% of the nonsurgical patients were female; and the baseline mean (SD) body mass index was 44.7 (6.9) and 43.8 (6.7) in the surgical and nonsurgical groups, respectively. At the end of the study period, there were 106 macrovascular events in surgical patients (including 37 cerebrovascular and 78 coronary artery events over a median of 4.7 years; interquartile range, 3.2-6.2 years) and 596 events in the matched control patients (including 227 cerebrovascular and 398 coronary artery events over a median of 4.6 years; interquartile range, 3.1-6.1 years). Bariatric surgery was associated with a lower composite incidence of macrovascular events at 5 years (2.1% in the surgical group vs 4.3% in the nonsurgical group; hazard ratio, 0.60 [95% CI, 0.42-0.86]), as well as a lower incidence of coronary artery disease (1.6% in the surgical group vs 2.8% in the nonsurgical group; hazard ratio, 0.64 [95% CI, 0.42-0.99]). The incidence of cerebrovascular disease was not significantly different between groups at 5 years (0.7% in the surgical group vs 1.7% in the nonsurgical group; hazard ratio, 0.69 [95% CI, 0.38-1.25]). Conclusions and Relevance: In this observational study of patients with type 2 diabetes and severe obesity who underwent surgery, compared with those who did not undergo surgery, bariatric surgery was associated with a lower risk of macrovascular outcomes. The findings require confirmation in randomized clinical trials. Health care professionals should engage patients with severe obesity and type 2 diabetes in a shared decision making conversation about the potential role of bariatric surgery in the prevention of macrovascular events.

Microvascular Outcomes in Patients With Diabetes After Bariatric Surgery Versus Usual Care: A Matched Cohort Study.

Background: Bariatric surgery improves glycemic control in patients with type 2 diabetes mellitus (T2DM), but less is known about microvascular outcomes. Objective: To investigate the relationship between bariatric surgery and incident microvascular complications of T2DM. Design: Retrospective matched cohort study from 2005 to 2011 with follow-up through September 2015. Setting: 4 integrated health systems in the United States. Participants: Patients aged 19 to 79 years with T2DM who had bariatric surgery (n = 4024) were matched on age, sex, body mass index, hemoglobin A1c level, insulin use, diabetes duration, and intensity of health care use up to 3 nonsurgical participants (n = 11 059). Intervention: Bariatric procedures (76% gastric bypass, 17% sleeve gastrectomy, and 7% adjustable gastric banding) compared with usual care. Measurements: Adjusted Cox regression analysis investigated time to incident microvascular disease, defined as first occurrence of diabetic retinopathy, neuropathy, or nephropathy. Results: Median follow-up was 4.3 years for both surgical and nonsurgical patients. Bariatric surgery was associated with significantly lower risk for incident microvascular disease at 5 years (16.9% for surgical vs. 34.7% for nonsurgical patients; adjusted hazard ratio [HR], 0.41 [95% CI, 0.34 to 0.48]). Bariatric surgery was associated with lower cumulative incidence at 5 years of diabetic neuropathy (7.2% for surgical vs. 21.4% for nonsurgical patients; HR, 0.37 [CI, 0.30 to 0.47]), nephropathy (4.9% for surgical vs. 10.0% for nonsurgical patients; HR, 0.41 [CI, 0.29 to 0.58]), and retinopathy (7.2% for surgical vs. 11.2% for nonsurgical patients; HR, 0.55 [CI, 0.42 to 0.73]). Limitation: Electronic health record databases could misclassify microvascular disease status for some patients. Conclusion: In this large, multicenter study of adults with T2DM, bariatric surgery was associated with lower overall incidence of microvascular disease (including lower risk for neuropathy, nephropathy, and retinopathy) than usual care. Primary Funding Source: National Institute of Diabetes and Digestive and Kidney Diseases.

Bariatric surgery results: reporting clinical characteristics and adverse outcomes from an integrated healthcare delivery system.

BACKGROUND: Limited data have been reported on bariatric surgery within a large, high-volume regional multicenter integrated healthcare delivery system. OBJECTIVES: Review clinical characteristics and short- and intermediate-term outcomes and adverse events from a bariatric surgery program within an integrated healthcare delivery system. SETTING: Single high-volume, multicenter regional integrated healthcare delivery system. METHODS: Adult patients who underwent primary bariatric surgery during 2010-2011 were reviewed. Clinical characteristics, outcomes, and weight loss results were extracted from the electronic medical record. RESULTS: A total of 2399 patients were identified within the study period. The 30-day rates of clinical outcomes for Roux-en-Y gastric bypass (RYGB; n = 1313) and sleeve gastrectomy (SG; n = 1018) were 2.9% for readmission, 3.0% for major complications, .8% for reoperation, and 0% for mortality. One-year and 2-year weight loss results were as follows: percent weight loss (%WL) was 31.4 (±SD 8.5) and 34.2±12.0% for SG and 34.1±9.3 and 39.1±11.9 for RYGB; percent excess weight loss (%EBWL) was 64.2±18.0 and 69.8±23.7 for SG and 68.0±19.3 and 77.8±23.7 for RYGB; percent excess body mass index loss (%EBMIL) was 72.9±21.0 and 77.7±22.4 for SG and 76.6±22.1% and 85.6±21.6 for RYGB. Follow-up for each procedure at 1 year was 76% for SG (n = 778) and 80% for RYGB (n = 1052) and at 2 years was 65% for SG (n = 659) and 67% for RYGB (n = 875). CONCLUSIONS: A large regional high-volume multicenter bariatric program within an integrated healthcare delivery system can produce excellent short-term results with low rates of short- and intermediate-term adverse outcomes.