Five-year attrition, active enrollment, and predictors of level of participation in the Longitudinal Assessment of Bariatric Surgery (LABS-2) study.

BACKGROUND: Reporting high-quality bariatric surgery outcomes depends on participant attrition and level of study participation among enrolled participants. OBJECTIVES: Our aims are to report participant attrition, active enrollment, and level of participation, and to evaluate pre-surgery sociodemographic, physical health, and psychosocial factors as predictors of attrition and level of participation through 5 years. SETTING: The Longitudinal Assessment of Bariatric Surgery-2 study which enrolled 2458 adults undergoing a first bariatric surgical procedure at 1 of 6 US cites from 2006 through 2009. METHODS: In-person research assessments were conducted pre-surgery and annually for five years. Extensive retention strategies including offering remote assessments (telephone, email, mail, or a combination) were fully implemented in 2009. Among living participants, including those inactivated, annual follow-up assessments were categorized as in-person, remote or missed through 5 years. RESULTS: By year 5, 1.7% of participants had died and 3.2% had withdrawn or were inactivated by the study staff; thus, attrition was 4.9% (n = 121). Controlling for site and calendar year, missed assessments increased from 14.7%-21.8% between years 1 and 2 and then stayed relatively stable (20.8%-19.6%) for years 3-5. Younger age, male sex, White race, lower body mass index, smoking, illicit drug use, and higher weight loss expectations preoperatively were independently associated with a higher likelihood of a missed versus in-person assessment across follow-up. CONCLUSION: The LABS-2 participant attrition was low. The percentage of missed assessments did not increase after year 2, perhaps due to implementation of a comprehensive retention plan. Predictors of missed assessments highlight subgroups to target for focused retention efforts.

Association between weight loss and serum biomarkers with risk of incident cancer in the Longitudinal Assessment of Bariatric Surgery cohort.

BACKGROUND: Bariatric surgery reduces cancer risk in populations with obesity. It is unclear if weight loss alone or metabolic changes related to bariatric surgery cause this effect. OBJECTIVE: We evaluated the relationship between surgical weight loss and serum biomarker changes with incident cancer in a bariatric surgery cohort. SETTING: Ten U.S. clinical facilities. METHODS: The Longitudinal Assessment of Bariatric Surgery 2 (LABS-2) is a prospective multicenter cohort (n = 2458, 79% female, mean age = 46). We evaluated weight and serum biomarkers, measured preoperatively and 1 year postoperatively, as predictors for incident cancer. Associations were determined using Cox proportional hazards models adjusting for weight loss, age, sex, education, and smoking history. RESULTS: Over 8759 person-years of follow-up, 82 patients reported new cancer diagnosis (936 per 100,000 person-years, 95% confidence interval [CI]: 749-1156). Cancer risk was decreased by approximately 50% in participants with 20% to 34.9% total weight loss (TWL) compared with <20% TWL (hazard ratio [HR] = .49, 95%CI: .29-.83). Reduced cancer risk was observed with percent decrease from baseline for glucose (per 10%, HR = .94, 95%CI: .90-.99), proinsulin (per 20%, HR = .95, 95%CI: .93-.98), insulin (per 30%, HR = .97, 95%CI: .96-.99), and leptin (per 20%, HR = .81, 95%CI: .68-.97), and per 15% percent increase in ghrelin (HR = .94, 95%CI: .29-.83). CONCLUSIONS: After bariatric surgery, cancer risk is reduced >50% when weight loss exceeds 20% TWL compared with patients with <20% TWL. Weight loss alone may not explain the observed risk reduction, as improvements in diabetes, leptin, and ghrelin were associated with decreased cancer risk.

Resting Energy Expenditure and Organ-Tissue Body Composition 5 Years After Bariatric Surgery.

INTRODUCTION: Bariatric surgery-induced weight loss may reduce resting energy expenditure (REE) and fat-free mass (FFM) disproportionately thereby predisposing patients to weight regain and sarcopenia. METHODS: We compared REE and body composition of African-American and Caucasian Roux-en-Y gastric bypass (RYGB) patients after surgery with a group of non-operated controls (CON). REE by indirect calorimetry; skeletal muscle (SM), trunk organs, and brain volumes by MRI; and FFM by DXA were measured at post-surgery visits and compared with CON (N = 84) using linear regression models that adjusted for relevant covariates. Ns in RYGB were 50, 42, and 30 for anthropometry and 39, 27, 17 for MRI body composition at years 1, 2, and 5 after surgery, respectively. RESULTS: Regression models adjusted for age, weight, height, ethnicity, and sex showed REE differences (RYGB minus CON; mean ± s.e.): year 1 (43.2 ± 34 kcal/day, p = 0.20); year 2 (- 27.9 ± 37.3 kcal/day, p = 0.46); year 5 (114.6 ± 42.3 kcal/day, p = 0.008). Analysis of FFM components showed that RYGB had greater trunk organ mass (~ 0.4 kg) and less SM (~ 1.34 kg) than CON at each visit. REE models adjusted for FFM, SM, trunk organs, and brain mass showed no between-group differences in REE (- 15.9 ± 54.8 kcal/day, p = 0.8; - 46.9 ± 64.9 kcal/day, p = 0.47; 47.7 ± 83.0 kcal/day, p = 0.57, at years 1, 2, and 5, respectively). CONCLUSIONS: Post bariatric surgery patients maintain a larger mass of high-metabolic rate trunk organs than non-operated controls of similar anthropometrics. Interpreting REE changes after weight loss requires an accurate understanding of fat-free mass composition at both the organ and tissue levels. CLINICAL TRIAL REGISTRATION: Long-term Effects of Bariatric Surgery (LABS-2) NCT00465829.

Association of Obesity Subtypes in the Longitudinal Assessment of Bariatric Surgery Study and 3-Year Postoperative Weight Change.

OBJECTIVE: The study objective was to empirically identify subgroups of patients with obesity and investigate their association with postoperative weight change. METHODS: A longitudinal analysis of 2,458 adults in the Longitudinal Assessment of Bariatric Surgery (LABS) study was used. Baseline data were used to identify subgroups. The outcome was 3-year weight change after bariatric surgery. RESULTS: We identified four classes (subtypes) of obesity, which could be characterized as diabetes with low rates of high-density lipoprotein (Class 1), disordered eating (Class 2), mixed (Class 3), and extreme obesity with early onset (Class 4). Approximately 98% of participants in Class 1 had diabetes compared with < 40% in the other classes. There were high rates of binge eating in Class 2, and more than 92% of those in this class reported eating when not hungry. Class 4 was characterized by a higher BMI at baseline. Adults in Class 4 lost an average of 25.0% (males) and 30.3% (females) of their baseline weight over 3 years. In contrast with participants in Class 1, those in Classes 2 and 3 had significantly larger 3-year weight losses than their peers in Class 4. CONCLUSIONS: Obesity is a heterogeneous disease. Bariatric surgery may be most beneficial for adults with disordered eating.

Long-term weight change and health outcomes for sleeve gastrectomy (SG) and matched Roux-en-Y gastric bypass (RYGB) participants in the Longitudinal Assessment of Bariatric Surgery (LABS) study.

BACKGROUND: Data from a US multicenter longitudinal study of bariatric surgery were used to compare weight change (primary outcome) and comorbidities (secondary outcome) in patients who underwent sleeve gastrectomy versus Roux-en-Y gastric bypass. METHODS: This study includes participants who underwent sleeve gastrectomy and matched participants who underwent Roux-en-Y gastric bypass from the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) study. Adults undergoing initial bariatric surgical procedures between 2006 and 2009 were enrolled. Participants who underwent sleeve gastrectomy were high-risk or superobese and intended to have a second-stage procedure. Mixed models were used to evaluate percent weight change from baseline through 7 years, and diabetes, dyslipidemia, and hypertension prevalence through 5 years. RESULTS: Fifty-seven of 59 participants who underwent sleeve gastrectomy were matched one to one. Most were female (68%) and white (81%), and had a median age of 49 (37-56) years and median body mass index of 56.4 (35.5-76.8) kg/m2 presurgery. Weight loss was significantly less 1 to 7 years after sleeve gastrectomy versus matched Roux-en-Y gastric bypass (eg, year 7 mean weight loss was 23.6% vs 30.4%, respectively; P = .001). For both surgical groups, prevalence of diabetes, low high-density lipoprotein, and hypertension were significantly (P < .05) lower 5 years postsurgery versus baseline. CONCLUSION: Higher-risk or super-obese participants after sleeve gastrectomy lost less weight than did matched Roux-en-Y gastric bypass counterparts throughout 7 years. Both groups exhibited improvements in comorbidities from presurgery through 5 years.

Seven-Year Weight Trajectories and Health Outcomes in the Longitudinal Assessment of Bariatric Surgery (LABS) Study.

Importance: More information is needed about the durability of weight loss and health improvements after bariatric surgical procedures. Objective: To examine long-term weight change and health status following Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB). Design, Setting, and Participants: The Longitudinal Assessment of Bariatric Surgery (LABS) study is a multicenter observational cohort study at 10 US hospitals in 6 geographically diverse clinical centers. Adults undergoing bariatric surgical procedures as part of clinical care between 2006 and 2009 were recruited and followed up until January 31, 2015. Participants completed presurgery, 6-month, and annual research assessments for up to 7 years. Main Outcome and Measures: Percentage of weight change from baseline, diabetes, dyslipidemia, and hypertension, determined by physical measures, laboratory testing, and medication use. Results: Of 2348 participants, 1738 underwent RYGB (74%) and 610 underwent LAGB (26%). For RYBG, the median age was 45 years (range, 19-75 years), the median body mass index (calculated as weight in kilograms divided by height in meters squared) was 47 (range, 34-81), 1389 participants (80%) were women, and 257 participants (15%) were nonwhite. For LAGB, the median age was 48 years (range, 18-78), the body mass index was 44 (range, 33-87), 465 participants (76%) were women, and 63 participants (10%) were nonwhite. Follow-up weights were obtained in 1300 of 1569 (83%) eligible for a year-7 visit. Seven years following RYGB, mean weight loss was 38.2 kg (95% CI, 36.9-39.5), or 28.4% (95% CI, 27.6-29.2) of baseline weight; between years 3 and 7 mean weight regain was 3.9% (95% CI, 3.4-4.4) of baseline weight. Seven years after LAGB, mean weight loss was 18.8 kg (95% CI, 16.3-21.3) or 14.9% (95% CI, 13.1-16.7), with 1.4% (95% CI, 0.4-2.4) regain. Six distinct weight change trajectory patterns for RYGB and 7 for LAGB were identified. Most participants followed trajectories in which weight regain from 3 to 7 years was small relative to year-3 weight loss, but patterns were variable. Compared with baseline, dyslipidemia prevalence was lower 7 years following both procedures; diabetes and hypertension prevalence were lower following RYGB only. Among those with diabetes at baseline (488 of 1723 with RYGB [28%]; 175 of 604 with LAGB [29%]), the proportion in remission at 1, 3, 5, and 7 years were 71.2% (95% CI, 67.0-75.4), 69.4% (95% CI, 65.0-73.8), 64.6% (95% CI, 60.0-69.2), and 60.2% (95% CI, 54.7-65.6), respectively, for RYGB and 30.7% (95% CI, 22.8-38.7), 29.3% (95% CI, 21.6-37.1), 29.2% (95% CI, 21.0-37.4), and 20.3% (95% CI, 9.7-30.9) for LAGB. The incidence of diabetes at all follow-up assessments was less than 1.5% for RYGB. Bariatric reoperations occurred in 14 RYGB and 160 LAGB participants. Conclusions and Relevance: Following bariatric surgery, different weight loss patterns were observed, but most participants maintained much of their weight loss with variable fluctuations over the long term. There was some decline in diabetes remission over time, but the incidence of new cases is low following RYGB. Trial Registration: clinicaltrials.gov Identifier: NCT00465829.

Objective assessment of changes in physical activity and sedentary behavior: Pre- through 3 years post-bariatric surgery.

OBJECTIVE: To evaluate change in sedentary behavior (SB) and physical activity (PA) over 3 years following bariatric surgery. METHODS: A subset of participants in an observational study (n = 473 of 2,458; 79% female, median body mass index 45 kg m(-2) ) wore an activity monitor presurgery and at 1-3 annual postsurgery assessments. RESULTS: Over the first year, on average, sedentary time decreased from 573 (95% CI: 563-582) to 545 (95% CI: 534-555) min days(-1) and moderate- to vigorous-intensity PA (MVPA) increased from 77 (95% CI: 71-84) to 106 (95% CI: 98-116) min week(-1) , or 7 (95% CI: 5-10) to 24 (95% CI: 18-29) min week(-1) in MVPA bouts ≥10 min. There were no changes in these parameters from years 1 to 3 (P for all > 0.05). The percentage of participants achieving ≥150 min week(-1) of bout-related MVPA was not different at year 3 [6.5% (95% CI: 3.1-12.7)] vs. presurgery [3.4% (95% CI: 1.8-5.0); P = 0.45]. Most participants followed SB and PA trajectories that paralleled mean change and were consistent with their presurgery position in relation to the group. CONCLUSIONS: On average, bariatric surgical patients make small reductions in SB and increases in PA during the first postsurgery year, which are maintained through 3 years. Still, postsurgery PA levels fall short of PA guidelines for general health or weight control.

Preoperative factors and 3-year weight change in the Longitudinal Assessment of Bariatric Surgery (LABS) consortium.

BACKGROUND: Limited data guide the prediction of weight loss success or failure after bariatric surgery according to presurgery factors. There is significant variation in weight change after bariatric surgery and much interest in identifying preoperative factors that may contribute to these differences. This report evaluates the associations of a comprehensive set of baseline factors and 3-year weight change. SETTING: Ten hospitals in 6 geographically diverse clinical centers in the United States. METHODS: Adults undergoing a first bariatric surgical procedure as part of clinical care by participating surgeons were recruited between 2006 and 2009. Participants completed research assessments utilizing standardized and detailed data collection on over 100 preoperative and operative parameters for individuals undergoing Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB). Weight was measured 3 years after surgery. Percent weight change for RYGB or LAGB from baseline to 3 years was analyzed as both a continuous and dichotomous outcome with cut points at 25% for RYGB and 10% for LAGB. Multivariable linear and logistic regression models were used to identify independent baseline predictors of the continuous and categorical outcomes, respectively. RESULTS: The median weight loss 3 years after surgery for RYGB (n = 1513) participants was 31.5% (IQR: 24.6%-38.4%; range, 59.2% loss to .9% gain) of baseline weight and 16.0% (IQR: 8.1%-23.1%; range, 56.1% loss to 12.5% gain) for LAGB (n = 509) participants. The median age was 46 years for RYGB and 48 years for LAGB; 80% of RYGB participants and 75% of LAGB participants were female; and the median baseline body mass index (BMI) was 46 kg/m(2) for RYGB and 44 kg/m(2) for LAGB. For RYGB, black participants lost 2.7% less weight compared with whites and participants with diabetes at baseline had 3.7% less weight loss at year 3 than those without diabetes at baseline. There were small but statistically significant differences in weight change for RYGB in those with abnormal kidney function and current or recent smoking. For LAGB participants, those with a large band circumference had 75% greater odds of experiencing less than 10% weight loss after adjusting for BMI and sex. CONCLUSIONS: Few baseline variables were associated with 3-year weight change and the effects were small. These results indicate that baseline variables have limited predictive value for an individual's chance of a successful weight loss outcome after bariatric surgery. TRIAL REGISTRATION: NCT00465829, ClinicalTrials.gov.

Hepatic pathology among patients without known liver disease undergoing bariatric surgery: observations and a perspective from the longitudinal assessment of bariatric surgery (LABS) study.

Liver biopsy is not routine during bariatric surgery. Alanine aminotransferase (ALT) is widely used to screen for liver disease. We assessed the relationship between ALT and pathology in biopsies from Longitudinal Assessment of Bariatric Surgery (LABS) patients with normal preoperative ALTs. Biopsies from the LABS-1 and LABS-2 studies were scored using the NASH CRN and Ishak systems. Diagnosis and histology were examined in relation to alanine aminotransferase (ALT) values. Six-hundred ninety-three suitable biopsies were evaluated. Biopsied patients had a median age of 45 years; 78.6% were female and 35.1% diabetic; median body mass index was 46 kg/m(2). Six-hundred thirty-five biopsied patients had preoperative ALTs. Median ALT was 25 IU/L (interquartile range [IQR] 19-36 IU/L); 26.6% had an ALT > 35 IU/L and 29.9% exceeded the more restrictive Prati criteria for normal. Using the Prati criteria, 7.9% of participants with normal ALT had steatohepatitis and 5.3% had ≥ stage 2 fibrosis. Logistic regression models were used to predict the probabilities of having bridging fibrosis/cirrhosis or a diagnosis of borderline/definite steatohepatitis in the unbiopsied LABS-2 sample. The proportion of biopsied participants with these findings was very similar to the modeled results from the unbiopsied cohorts. We estimated that 86.0% of participants with advanced fibrosis and 88.1% of participants with borderline/definite steatohepatitis were not biopsied and went undiagnosed. As ALT did not reliably exclude significant obesity-related liver disease in bariatric surgery patients, consideration should be given to routine liver biopsy during bariatric surgery and medical follow-up of significant hepatic pathology.

Metabolic syndrome prevalence and associations in a bariatric surgery cohort from the Longitudinal Assessment of Bariatric Surgery-2 study.

BACKGROUND: Metabolic syndrome is associated with higher risk for cardiovascular disease, sleep apnea, and nonalcoholic steatohepatitis, all common conditions in patients referred for bariatric surgery, and it may predict early postoperative complications. The objective of this study was to determine the prevalence of metabolic syndrome, defined using updated National Cholesterol Education Program criteria, in adults undergoing bariatric surgery and compare the prevalence of baseline co-morbid conditions and select operative and 30-day postoperative outcomes by metabolic syndrome status. METHODS: Complete metabolic syndrome data were available for 2275 of 2458 participants enrolled in the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2), an observational cohort study designed to evaluate long-term safety and efficacy of bariatric surgery in obese adults. RESULTS: The prevalence of metabolic syndrome was 79.9%. Compared to those without metabolic syndrome, those with metabolic syndrome were significantly more likely to be men, to have a higher prevalence of diabetes and prior cardiac events, to have enlarged livers and higher median levels of liver enzymes, a history of sleep apnea, and a longer length of stay after surgery following laparoscopic Roux-en-Y gastric bypass (RYGB) and gastric sleeves but not open RYGB or laparoscopic adjustable gastric banding. Metabolic syndrome status was not significantly related to duration of surgery or rates of composite end points of intraoperative events and 30-day major adverse surgical outcomes. CONCLUSIONS: Nearly four in five participants undergoing bariatric surgery presented with metabolic syndrome. Establishing a diagnosis of metabolic syndrome in bariatric surgery patients may identify a high-risk patient profile, but does not in itself confer a higher risk for short-term adverse postsurgery outcomes.

Assessment of obstructive sleep apnea in adults undergoing bariatric surgery in the longitudinal assessment of bariatric surgery-2 (LABS-2) study.

STUDY OBJECTIVES: Evaluate frequency of diagnostic testing for obstructive sleep apnea (OSA), prevalence of OSA, and factors independently associated with OSA status in adults undergoing bariatric surgery. DESIGN, SETTINGS AND INTERVENTIONS: Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) is an observational cohort of 2,458 adults undergoing bariatric surgery at 10 U.S. hospitals. Within 30 days prior to surgery, researchers determined if participants had a diagnostic polysomnography (PSG) in the previous 12 months. When available, apnea-hypopnea index (AHI) was recorded. Based on medical records and participant report, research clinicians recorded OSA status and positive airway pressure (PAP) use. Participants completed the Berlin Questionnaire (BQ). Multivariable logistic regression was used to determine factors independently associated with AHI-confirmed OSA status. RESULTS: 28.7% (n = 693) of participants had a PSG within 12 months before surgery. Of subjects with AHI available (n = 509), 80.7% (n = 411) had OSA (AHI ≥ 5); 83.0% (n = 341) reported PAP use. In participants without a known AHI (n = 1,949), 45.4% (n = 884) had self-reported OSA; 81.2% (n = 718) reported PAP use. Self-reported history of snoring and pauses in breathing (odds ratio [OR] = 10.0; 95%, confidence interval [CI] = 4.8-20.6), male sex (OR = 5.1; 95% CI = 1.7-15.3), older age (OR = 1.4; 95% CI = 1.2-1.6 per 5 years), and larger sagittal abdominal diameter (OR = 1.8; 95% CI = 1.2-2.5 per 5 cm) were independently associated with a greater odds of confirmed OSA. CONCLUSIONS: Preoperative diagnostic testing for OSA was infrequent. Prevalence estimates of OSA differed greatly between those with and without a past-year AHI (81% vs. 46%, respectively). Most BQ responses did not differentiate OSA status, but endorsement of snoring and pauses in breathing was independently associated with presence of OSA.

Distribution of 10-year and lifetime predicted risk for cardiovascular disease prior to surgery in the longitudinal assessment of bariatric surgery-2 study.

Primary prevention guidelines recommend calculation of lifetime cardiovascular disease (CVD) predicted risk in patients who may not meet criteria for high short-term (10-year) Adult Treatment Panel III risk for coronary heart disease (CHD). Extreme obesity and bariatric surgery are more common in women who often have low short-term predicted CHD risk. The distribution and correlates of lifetime CVD predicted risk, however, have not yet been evaluated in bariatric surgical candidates. Using established 10-year (Adult Treatment Panel III) CHD and lifetime CVD risk prediction algorithms and presurgery risk factors, participants from the Longitudinal Assessment of Bariatric Surgery-2 study without prevalent CVD (n = 2,070) were stratified into 3 groups: low 10-year (<10%)/low lifetime (<39%) predicted risk, low 10-year (<10%)/high lifetime (≥39%) predicted risk, and high 10-year (≥10%) predicted risk or diagnosed diabetes. Participants were predominantly white (86%) and women (80%) with a median age of 45 years and median body mass index of 45.6 kg/m(2). High 10-year CHD predicted risk was common (36.5%) and associated with diabetes, male gender, and older age, but not with higher body mass index or high-sensitivity C-reactive protein. Most participants (76%) with low 10-year predicted risk had high lifetime CVD predicted risk, which was associated with dyslipidemia and hypertension but not with body mass index, waist circumference, high-density lipoprotein cholesterol, or high-sensitivity C-reactive protein. In conclusion, bariatric surgical candidates without diabetes or existing CVD are likely to have low short-term, but high lifetime CVD predicted risk. Current data support the need for long-term monitoring and treatment of increased CVD risk factors in bariatric surgical patients to maximize lifetime CVD risk decrease (clinical trial registration, Long-term Effects of Bariatric Surgery, indentifier NCT00465829, available at: http://www.clinicaltrials.gov/ct2/results?term=NCT00465829).

Pre- to postoperative changes in physical activity: report from the longitudinal assessment of bariatric surgery-2 (LABS-2).

BACKGROUND: Numerous studies have reported that bariatric surgery patients report more physical activity (PA) after surgery than before; however, the quality of the PA assessment has been questionable. METHODS: The longitudinal assessment of bariatric surgery-2 is a 10-center longitudinal study of adults undergoing bariatric surgery. Of 2458 participants, 455 were given an activity monitor, which records the steps per minute, and an exercise diary before and 1 year after surgery. The mean number of steps/d, active min/d, and high-cadence min/wk were calculated for 310 participants who wore the monitor ≥10 hr/d for ≥3 days at both evaluations. Pre- and postoperative PA were compared for differences using the Wilcoxon signed-rank test. Generalized estimating equations were used to identify independent preoperative predictors of postoperative PA. RESULTS: PA increased significantly (P < .0001) from before to after surgery for all PA measures. The median values before and after surgery were 7563 and 8788 steps/d, 309 and 340 active min/d, and 72 and 112 high-cadence min/wk, respectively. However, depending on the PA measure, 24-29% of participants were ≥5% less active postoperatively than preoperatively. Controlling for surgical procedure, gender, age, and body mass index, more PA preoperatively independently predicted for more PA postoperatively (P < .0001, for all PA measures). Less pain, not having asthma, and the self-report of increasing PA as a weight loss strategy preoperatively also independently predicted for more high-cadence min/wk postoperatively (P < .05). CONCLUSIONS: The majority of adults increase their PA level after bariatric surgery. However, most remain insufficiently active, and some become less active. Increasing PA, addressing pain, and treating asthma before surgery might have a positive effect on postoperative PA.

Thirty-day mortality after bariatric surgery: independently adjudicated causes of death in the longitudinal assessment of bariatric surgery.

BACKGROUND: Mortality following bariatric surgery is a rare event in contemporary series, making it difficult for any single center to draw meaningful conclusions as to cause of death. Nevertheless, much of the published mortality data come from single-center case series and reviews of administrative databases. These sources tend to produce lower mortality estimates than those obtained from controlled clinical trials. Furthermore, information about the causes of death and how they were determined is not always available. The aim of the present report is to describe in detail all deaths occurring within 30 days of surgery in the Longitudinal Assessment of Bariatric Surgery (LABS). METHODS: LABS is a ten-center observational cohort study of bariatric surgical outcomes. Data were collected prospectively for bariatric surgeries performed between March 2005 and April 2009. All deaths occurring within 30-days of surgery were identified, and cause of death assigned by an independent Adjudication Subcommittee, blinded to operating surgeon and site. RESULTS: Six thousand one hundred eighteen patients underwent primary bariatric surgery. Eighteen deaths (0.3%) occurred within 30-days of surgery. The most common cause of death was sepsis (33% of deaths), followed by cardiac causes (28%), and pulmonary embolism (17%). For one patient cause of death could not be determined despite examination of all available information. CONCLUSIONS: This study confirms the low 30-day mortality rate following bariatric surgery. The recognized complications of anastomotic leak, cardiac events, and pulmonary emboli accounted for the majority of 30-day deaths.

Nutritional assessment of bariatric surgery patients presenting for plastic surgery: a prospective analysis.

BACKGROUND: Assessment of nutritional status in the growing postbariatric patient population remains controversial. Previous literature suggests that these patients have poor nutrition that may have adverse effects on surgical outcomes. The authors sought to determine the optimal method of nutritional assessment in postbariatric patients. METHODS: One hundred patients presenting for body contouring after bariatric surgery were consecutively enrolled in an institutional review board-approved prospective study. A trained nutritionist assessed protein and calorie intake. All patients underwent baseline laboratory assessment. RESULTS: Eighteen percent of subjects had less than the recommended daily protein intake. Hypoalbuminemia was observed in 13.8 percent of subjects, with hypoprealbuminemia in 6.5 percent. Nearly forty percent of all patients had evidence of iron deficiency, with vitamin B12 deficiency present in 14.5 percent. Ten percent of subjects (all women) were confirmed to have iron deficiency anemia. Impaired fasting glucose was seen in 6.2 percent of subjects, whereas 3.6 percent had hemoglobin A1c levels greater than 6.5. Increasing age (odds ratio, 1.07) and greater change in body mass index (odds ratio, 1.11) were predictors of low protein intake. Dumping syndrome led to 13.3 times increased odds of low albumin levels. CONCLUSIONS: The results suggest that inadequate nutrition is common among postbariatric patients presenting for body contouring. The lack of correlation between methods of nutritional assessment supports the combination of multiple methods in determining overall nutritional status. The presence of dumping syndrome, a large change in body mass index, and advanced age may help to identify patients with an increased risk of nutritional deficiency.

Relationship between surgeon volume and adverse outcomes after RYGB in Longitudinal Assessment of Bariatric Surgery (LABS) study.

BACKGROUND: Bariatric surgery is technically demanding surgery performed on high-risk patients. Previous studies using administrative databases have shown a relationship between surgeon volume and patient outcome after Roux-en-Y gastric bypass (RYGB). We examined the relationship between surgeons' annual RYGB volumes and 30-day patient outcomes at 10 centers within the United States. METHODS: The Longitudinal Assessment of Bariatric Surgery (LABS)-1 is a prospective study examining the 30-day adverse outcomes after bariatric surgery. The outcomes after RYGB were adjusted by procedure type (open versus laparoscopic), functional status, body mass index, history of deep vein thrombosis, pulmonary embolism, and obstructive sleep apnea. The data were examined to determine the nature and strength of the association between surgeon volume and patients' short-term (30-day) adverse outcomes after RYGB. RESULTS: The analysis included 3410 initial RYGB operations performed by 31 surgeons, 15 of whom averaged <50 cases annually. The crude composite adverse outcome (i.e., death, deep vein thrombosis, pulmonary embolism, reintervention or nondischarge at day 30) incidence was 5.2%. After risk adjustment, a greater surgeon RYGB volume was associated with lower composite event rates, with a continuous relationship (i.e., varying cutpoints differentiated the composite event rates), such that for each 10-case/yr increase in volume, the risk of a composite event decreased by 10%. CONCLUSION: In the LABS, the patient's risk of an adverse outcome after RYGB decreased significantly with the increase in surgeon RYGB volume (cases performed annually).

Physical activity levels of patients undergoing bariatric surgery in the Longitudinal Assessment of Bariatric Surgery study.

BACKGROUND: Bariatric surgery candidates' physical activity (PA) level might contribute to the variability of weight loss and body composition changes following bariatric surgery. However, there is little research describing the PA of patients undergoing bariatric surgery to inform PA recommendations in preparation for, and following, surgery. We describe the PA assessment in the Longitudinal Assessment of Bariatric Surgery-2 study at 6 sites in the United States and report preoperative PA level. We also examined the relationships between objectively determined PA level and the patient's body mass index and self-reported purposeful exercise. METHODS: The participants wore an accelerometer and completed a PA diary. Standardized measures of height and weight were obtained. RESULTS: Of the 757 participants, 20% were sedentary (<5000 steps/d), 34% had low activity (5000-7499 steps/d), 27% were somewhat active (7500-9999 steps/d), 14% were active (10,000-12,499 steps/d), and 6% were highly active (>or=12,500 steps/d). Body mass index was inversely related to the mean number of steps daily and the mean number of steps each minute during the most active 30 minutes of each day. The most commonly reported activities were walking (44%), gardening (11%), playing with children (10%), and stretching (7%). The self-reported minutes of exercise accounted for 2% of the variance in the objectively determined steps. CONCLUSION: Patients present for bariatric surgery with a wide range of PA levels, with almost one half categorized as somewhat active or active. Body mass index was inversely related to the total amount and intensity of PA. Few patients reported a regular preoperative exercise regimen, suggesting most PA is accumulated from activities of daily living. Patients' report of daily minutes of walking or exercise might not be a reliable indication of their PA level.

Relationship of body mass index with demographic and clinical characteristics in the Longitudinal Assessment of Bariatric Surgery (LABS).

BACKGROUND: The relationship between body mass index (BMI) and demographic/clinical characteristics of patients undergoing bariatric surgery is poorly characterized. BMI is often used to characterize patient risk in bariatric surgery. However, its relationship with other risk factors has not been well characterized. METHODS: The Longitudinal Assessment of Bariatric Surgery-1 was a study of the 30-day outcomes in patients undergoing bariatric procedures at 10 clinical centers in the United States. The sample for this study included participants with a BMI > or =40 kg/m(2) and no history of undergoing a bariatric procedure from March 1, 2005 to March 26, 2007. This analysis examined the relationships between BMI strata and several demographic/clinical characteristics. RESULTS: Of 2559 patients (23% male, 10% black, 9% age > or =60 yr) with a BMI of > or =40 kg/m(2), 29% had a BMI of 50 to <60 kg/m(2) and 12% a BMI of > or =60 kg/m(2). The percentage of men and blacks increased with greater BMI category and the percentage of older patients (age > or =60 yr) decreased. Patients with a greater BMI were more likely to have a history of several co-morbid conditions (hypertension, diabetes, congestive heart failure, asthma, poor functional status, sleep apnea, pulmonary hypertension, venous thromboembolism, or venous edema with ulcerations) than were patients with a BMI of 40-50 kg/m(2) after adjusting for age, race, sex, and ethnicity. CONCLUSION: A greater BMI was associated with several patient characteristics that have been linked to less weight loss, more adverse outcomes, and increased healthcare use in previous studies. Outcomes analyses should consider the potential for the confounding of BMI with demographic and clinical characteristics.