Self-reported remission of obstructive sleep apnea following bariatric surgery: cohort study.

BACKGROUND: Evidence on remission of obstructive sleep apnea (OSA) after bariatric surgery and its relation to weight loss is conflicting. We sought to identify factors associated with successful self-reported OSA remission in a large cohort of bariatric surgery patients. METHODS: We analyzed data from the statewide, prospective clinical registry of the Michigan Bariatric Surgery Collaborative and identified 3,550 patients with OSA who underwent a primary bariatric procedure between June 2006 and October 2011 and had at least 1 year of follow-up data. We used multivariate logistic regression to identify preoperative factors associated with successful self-reported OSA remission, defined as discontinuation of continuous positive airway pressure or bilevel positive airway pressure at 1 year. Our regression model also included procedure type and weight loss at 1 year, divided into equal quintiles, as covariates. RESULTS: The overall 1-year self-reported OSA remission rate was 60%. Significant predictors of remission included age category (per 10 yr) (OR .73, CI .69-.78), body mass index category (per 10 units) (OR .57, CI .54-.62), male gender (OR .58, CI .52-.69), hypertension (OR .83, CI .74-.99), depression (OR .78, CI .69-.88), pulmonary disease (OR .88, CI .78-.98), and baseline Health and Activities Limitations Index score (OR 1.70, CI 1.32-2.23). Relative to gastric banding, the adjusted odds of OSA remission were greater with gastric bypass (OR 2.38, CI 1.89-3.08), sleeve gastrectomy (OR 2.01, CI 1.44-2.55), and duodenal switch (OR 2.57, CI 1.02-7.26). The odds ratio of OSA remission increased stepwise through quintiles of 1-year weight loss. Relative to the lowest quintile, the odds ratios of remission in the 2(nd) through 5(th) quintiles were 1.44 (CI 1.11-1.84), 2.03 (CI 1.48-2.57), 2.47 (1.85-3.40), and 3.53 (CI 2.56-4.85). CONCLUSIONS: Weight loss is an important predictor of self-reported OSA remission after bariatric surgery. However, independent of weight loss, there remain significant differences in the likelihood of remission between gastric banding and other bariatric procedures. This suggests that there may be metabolic, weight-independent effects of procedure type on self-reported OSA remission.

Variation in utilization of acid-reducing medication at 1 year following bariatric surgery: results from the Michigan Bariatric Surgery Collaborative.

BACKGROUND: Morbidly obese patients undergoing bariatric surgery have high rates of gastroesophageal reflux and are often treated with acid-reducing medications (ARM) such as proton pump inhibitors or H2-blockers. The objective of this study was to evaluate the effect of bariatric procedures on the utilization of ARM. We analyzed data from the clinical registry of the Michigan Bariatric Surgery Collaborative on 35,477 patients undergoing bariatric surgery between January 2006 and October 2012 who completed both baseline and 1-year follow-up surveys. Procedures included laparoscopic adjustable gastric banding (LAGB, n=2,627), Roux-en-Y gastric bypass (RYGB, n=6,410), sleeve gastrectomy (SG, n=1,567), and biliopancreatic diversion with duodenal switch (BPD/DS, n=162). METHODS: Rates of ARM at 1 year by procedure type were compared using logistic regression analysis. Models were adjusted for patient characteristics, baseline co-morbidities, weight loss, and hiatal hernia repair. RESULTS: Overall ARM use at baseline was 37.7% and declined to 29.6% at 1 year after bariatric surgery. The proportion of patients starting an ARM at 1 year when they were not using one at baseline by procedure was LAGB (13.9%), RYGB (19.2%), SG (21.6%), and BPD/DS (26.7%). The proportion of patients discontinuing an ARM at 1 year when they were using one at baseline by procedure was LAGB (55.6%), RYGB (56.2%), SG (37.3%), and BPD/DS (42.1%). Compared with LAGB on multivariable analysis, the likelihood of ARM use at 1 year was higher for SG (OR 1.70, 95% CI 1.45-1.99) and BDP/DS (OR 1.53, CI .97-2.40) but not different for RYGB (OR 1.02, CI .90-1.16). CONCLUSION: Overall ARM use decreases after bariatric surgery; however, it is not uniform and depends on procedure type. SG is a significant predictor for ARM use at 1 year.

The comparative effectiveness of sleeve gastrectomy, gastric bypass, and adjustable gastric banding procedures for the treatment of morbid obesity.

OBJECTIVE: To evaluate the comparative effectiveness of sleeve gastrectomy (SG), laparoscopic gastric bypass (RYGB), and laparoscopic adjustable gastric banding (LAGB) procedures. BACKGROUND: Citing limitations of published studies, payers have been reluctant to provide routine coverage for SG for the treatment of morbid obesity. METHODS: Using data from an externally audited, statewide clinical registry, we matched 2949 SG patients with equal numbers of RYGB and LAGB patients on 23 baseline characteristics. Outcomes assessed included complications occurring within 30 days, and weight loss, quality of life, and comorbidity remission at 1, 2, and 3 years after bariatric surgery. RESULTS: Matching resulted in cohorts of SG, RYGB, and LAGB patients that were well balanced on baseline characteristics. Overall complication rates among patients undergoing SG (6.3%) were significantly lower than for RYGB (10.0%, P < 0.0001) but higher than for LAGB (2.4%, P < 0.0001). Serious complication rates were similar for SG (2.4%) and RYGB (2.5%, P = 0.736) but higher than for LAGB (1.0%, P < 0.0001). Excess body weight loss at 1 year was 13% lower for SG (60%) than for RYGB (69%, P < 0.0001), but was 77% higher for SG than for LAGB (34%, P < 0.0001). SG was similarly closer to RYGB than LAGB with regard to remission of obesity-related comorbidities. CONCLUSIONS: With better weight loss than LAGB and lower complication rates than RYGB, SG is a reasonable choice for the treatment of morbid obesity and should be covered by both public and private payers.

Risks and benefits of prophylactic inferior vena cava filters in patients undergoing bariatric surgery.

BACKGROUND: The United States Food and Drug Administration recently issued a warning about adverse events in patients receiving inferior vena cava (IVC) filters. OBJECTIVE: To assess relationships between IVC filter insertion and complications while controlling for differences in baseline patient characteristics and medical venous thromboembolism prophylaxis. DESIGN: Propensity-matched cohort study. SETTING: The prospective, statewide, clinical registry of the Michigan Bariatric Surgery Collaborative. PATIENTS: Bariatric surgery patients (n=35,477) from 32 hospitals during the years 2006 through 2012. INTERVENTION: Prophylactic IVC filter insertion. MEASUREMENTS: Outcomes included the occurrence of complications (pulmonary embolism, deep vein thrombosis, and overall combined rates of complications by severity) within 30 days of bariatric surgery. RESULTS: There were no significant differences in baseline characteristics among the 1,077 patients with IVC filters and in 1,077 matched control patients. Patients receiving IVC filters had higher rates of pulmonary embolism (0.84% vs 0.46%; odds ratio [OR], 2.0; 95% confidence interval [CI], 0.6-6.5; P=0.232), deep vein thrombosis (1.2% vs 0.37%; OR, 3.3; 95% CI, 1.1-10.1; P=0.039), venous thromboembolism (1.9% vs 0.74%; OR, 2.7; 95% CI, 1.1-6.3, P=0.027), serious complications (5.8% vs 3.8%; OR, 1.6; 95% CI, 1.0-2.4; P=0.031), permanently disabling complications (1.2% vs 0.37%; OR, 4.3; 95% CI, 1.2-15.6; P=0.028), and death (0.7% vs 0.09%; OR, 7.0; 95% CI, 0.9-57.3; P=0.068). Of the 7 deaths among patients with IVC filters, 4 were attributable to pulmonary embolism and 2 to IVC thrombosis/occlusion. CONCLUSIONS: We have identified no benefits and significant risks to the use of prophylactic IVC filters among bariatric surgery patients and believe that their use should be discouraged.

Comparative effectiveness of unfractionated and low-molecular-weight heparin for prevention of venous thromboembolism following bariatric surgery.

OBJECTIVE: To evaluate the effectiveness and safety of 3 predominant venous thromboembolism (VTE) prophylaxis strategies among patients undergoing bariatric surgery. DESIGN: Cohort study. SETTING: The Michigan Bariatric Surgery Collaborative, a statewide clinical registry and quality improvement program. PATIENTS: Twenty-four thousand seven hundred seventy-seven patients undergoing bariatric surgery between 2007 and 2012. INTERVENTIONS: Unfractionated heparin preoperatively and postoperatively (UF/UF), UF heparin preoperatively and low-molecular-weight heparin postoperatively (UF/LMW), and LMW heparin preoperatively and postoperatively (LMW/LMW). MAIN OUTCOME MEASURES: Rates of VTE, hemorrhage, and serious hemorrhage (requiring >4 U of blood products or reoperation) occurring within 30 days of surgery. RESULTS: Overall, adjusted rates of VTE were significantly lower for the LMW/LMW (0.25%; P < .001) and UF/LMW (0.29%; P = .03) treatment groups compared with the UF/UF group (0.68%). While UF/LMW (0.22%; P = .006) and LMW/LMW (0.21%; P < .001) were similarly effective in patients at low risk of VTE (predicted risk <1%), LMW/LMW (1.46%; P = .10) seemed more effective than UF/LMW (2.36%; P = .90) for high-risk (predicted risk ≥1%) patients. There were no significant differences in rates of hemorrhage or serious hemorrhage among the treatment strategies. CONCLUSION: Low-molecular-weight heparin is more effective than UF heparin for the prevention of postoperative VTE among patients undergoing bariatric surgery and does not increase rates of bleeding.