Postbariatric hypoglycemia: symptom patterns and associated risk factors in the Longitudinal Assessment of Bariatric Surgery study.

BACKGROUND: Postbariatric hypoglycemia (PBH) can be a devastating complication for which current therapies are often incompletely effective. More information is needed regarding frequency, incidence, and risk factors for PBH. OBJECTIVES: To examine hypoglycemia symptoms following Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) and baseline and in-study risk factors. SETTING: Multicenter, at 10 US hospitals in 6 geographically diverse clinical centers. METHODS: A prospective, longitudinal cohort study of adults undergoing RYGB or LAGB as part of clinical care between 2006 and 2009 were recruited and followed until January 31, 2015, with baseline and annual postoperative research assessments. We analyzed baseline prevalence and post-operative incidence and frequency of self-reported hypoglycemia symptoms as well as potential preoperative risk factors. RESULTS: In all groups, postoperative prevalence of hypoglycemia symptoms was 38.5%. Symptom prevalence increased postoperatively from 2.8%-36.4% after RYGB in patients without preoperative diabetes (T2D), with similar patterns in prediabetes (4.9%-29.1%). Individuals with T2D had higher baseline hypoglycemia symptoms (28.9%), increasing after RYGB (57.9%). Hypoglycemia symptoms were lower after LAGB, with 39.1% reported hypoglycemia symptoms at only 1 postoperative visit with few (4.0%) having persistent symptoms at 6 or more annual visits. Timing of symptoms was not restricted to the postprandial state. Symptoms of severe hypoglycemia were reported in 2.6-3.6% after RYGB. The dominant risk factor for postoperative symptoms was preoperative symptoms; additionally, baseline selective serotonin (SSRI) and serotonin-norepinephrine (SNRI) reuptake inhibitor use was also associated with increased risk in multivariable analysis. Weight loss and regain were not related to hypoglycemia symptom reporting. CONCLUSION: Hypoglycemia symptoms increase over time after RYGB, particularly in patients without diabetes. In a small percentage, symptoms can be persistent or severe and require hospitalization. Preoperative hypoglycemia symptoms and SSRI/SNRI use in RYGB patients without diabetes is associated with increased risk of symptoms.

Diabetes Remission Status During Seven-year Follow-up of the Longitudinal Assessment of Bariatric Surgery Study.

CONTEXT: Few studies have examined the clinical characteristics that predict durable, long-term diabetes remission after bariatric surgery. OBJECTIVE: To compare diabetes prevalence and remission rates during 7-year follow-up after Roux-en-Y gastric bypass (RYGB) and laparoscopic gastric banding (LAGB). DESIGN: An observational cohort of adults with severe obesity recruited between 2006 and 2009 who completed annual research assessments for up to 7 years after RYGB or LAGB. SETTING: Ten US hospitals. PARTICIPANTS: A total sample of 2256 participants, 827 with known diabetes status at both baseline and at least 1 follow-up visit. INTERVENTIONS: Roux-en-Y gastric bypass or LAGB. MAIN OUTCOME MEASURES: Diabetes rates and associations of patient characteristics with remission status. RESULTS: Diabetes remission occurred in 57% (46% complete, 11% partial) after RYGB and 22.5% (16.9% complete, 5.6% partial) after LAGB. Following both procedures, remission was greater in younger participants and those with shorter diabetes duration, higher C-peptide levels, higher homeostatic model assessment of ß-cell function (HOMA %B), and lower insulin usage at baseline, and with greater postsurgical weight loss. After LAGB, reduced HOMA insulin resistance (IR) was associated with a greater likelihood of diabetes remission, whereas increased HOMA-%B predicted remission after RYGB. Controlling for weight lost, diabetes remission remained nearly 4-fold higher compared with LAGB. CONCLUSIONS: Durable, long-term diabetes remission following bariatric surgery is more likely when performed soon after diagnosis when diabetes medication burden is low and beta-cell function is preserved. A greater weight-independent likelihood of diabetes remission after RYGB than LAGB suggests mechanisms beyond weight loss contribute to improved beta-cell function after RYGB.Trial Registration clinicaltrials.gov Identifier: NCT00465829.

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.

Physical and Mental Health-Related Quality of Life Changes Among Insurer Subgroups Following Bariatric Surgery.

OBJECTIVE: This study sought to determine improvements in mental and physical health-related quality of life (HRQOL) following bariatric surgery in Medicaid and commercially insured patients. METHODS: Using data from the Longitudinal Assessment of Bariatric Surgery, an observational cohort study of adults undergoing bariatric surgery (2006-2009), changes in Short Form 36 mental component summary (MCS) and physical component summary (PCS) scores were examined in 1,529 patients who underwent Roux-en-Y gastric bypass, laparoscopic adjustable band, or sleeve gastrectomy and were followed for 5 years. Piecewise linear mixed-effects models estimated MCS and PCS scores as a function of insurance group (Medicaid, N = 177; commercial, N = 1,352) from 0 to 1 year and from 1 to 5 years after surgery, with interactions between insurance group and surgery type. RESULTS: Patients with Medicaid had lower PCS and MCS scores at baseline. At 1 year after surgery, patients with Medicaid and commercial insurance experienced similar improvement in PCS scores (commercial-Medicaid difference in PCS change [95% CI]: Roux-en-Y gastric bypass, 1.5 [-0.2, 3.3]; laparoscopic adjustable band, 1.9 [-2.2, 6.0]; sleeve gastrectomy, 6.4 [0.0, 12.8]). One-year MCS score improvement was minimal and similar between insurance groups. In years 1 to 5, PCS and MCS scores were stable in all groups. CONCLUSIONS: Both insurance groups experienced improvements in physical HRQOL and minimal changes in mental HRQOL.

Bariatric Surgery Among Medicare Subgroups: Short- and Long-Term Outcomes.

OBJECTIVE: This study sought to examine weight change, postoperative adverse events, and related outcomes of interest among age-qualified (AQ) and disability-qualified (DQ) Medicare recipients compared with non-Medicare (NM) patients undergoing an initial bariatric procedure. METHODS: The Longitudinal Assessment of Bariatric Surgery (LABS-2) is an observational cohort study of 2,458 adults who underwent Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB) bariatric surgery. Weight, percentage body fat, functional status, and comorbidities, as well as postoperative adverse events, were assessed at baseline and annually for 5 years. The 1,943 participants who reported insurance type were categorized into the following groups: AQ, DQ, or NM. RESULTS: The median preoperative BMI ranged from 45 to 48 kg/m2 across groups. For RYGB, 5-year BMI loss was approximately 30% for all groups, and for LAGB, BMI loss was 12% to 15%. Diabetes remission after 5 years was also similar across groups within procedure types (RYGB: 33%-40%; LAGB: 13%-19%). The frequency of adverse events after RYGB ranged from 4.1% for NM participants to 6.7% for DQ participants. After LAGB, there were no adverse events for the AQ group, whereas 3% of DQ participants and 1.8% of NM participants had at least one adverse event. CONCLUSIONS: Medicare participants experienced substantial BMI loss and diabetes remission, with a frequency of adverse events similar to that of NM participants.

Reduction in Comorbid Conditions Over 5 Years Following Bariatric Surgery in Medicaid and Commercially Insured Patients.

OBJECTIVE: This study sought to determine changes in the prevalence of comorbid disease following bariatric surgery in Medicaid patients compared with commercially insured patients. METHODS: Data were obtained from the Longitudinal Assessment of Bariatric Surgery, an observational cohort study of adults undergoing bariatric surgery at one of six geographically diverse centers in the United States. A total of 1,201 patients who underwent Roux-en-Y gastric bypass with 5 years of follow-up were identified. Poisson mixed models were used to estimate relative risks (RRs) and compare changes in common comorbidities between insurance groups within 0-1 and 1-5 years post surgery. Propensity scores were used to achieve balance in the baseline comorbidity burden between Medicaid and commercial patients. RESULTS: In the first year, risk of all six comorbidities decreased substantially over time in both groups, ranging from a 32% to a 69% decrease from baseline. After 1 year post surgery, the risk of disease was stable in both groups (RRs ranged from 1.0 to 1.1). After propensity score weighting, the RRs in the first year were more similar in magnitude, while the RRs in the 1- to 5-year period were unchanged. CONCLUSIONS: These results suggest that Medicaid patients experience a medium-term reduction in comorbid disease after bariatric surgery.

Insurance status differences in weight loss and regain over 5 years following bariatric surgery.

BACKGROUND: The effectiveness of bariatric surgery among Medicaid beneficiaries, a population with a disproportionately high burden of obesity, remains unclear. We sought to determine if weight loss and regain following bariatric surgery differed in Medicaid patients compared to commercial insurance. SUBJECTS/METHODS: Data from the Longitudinal Assessment of Bariatric Surgery, a ten-site observational cohort of adults undergoing bariatric surgery (2006-2009) were examined for patients who underwent Roux-en-Y Gastric Bypass (RYGB), Laparoscopic Adjustable Band (LAGB), or Sleeve Gastrectomy (SG). Using piecewise spline linear mixed-effect models, weight change over 5 years was modeled as a function of insurance type (Medicaid, N = 190; commercially insured, N = 1448), time, procedure type, and sociodemographic characteristics; additionally, interactions between all time, insurance, and procedure type indicators allowed time- and procedure-specific associations with insurance type. For each time-spline, mean (kg) difference in weight change in commercially insured versus Medicaid patients was calculated. RESULTS: Medicaid patients had higher mean weight at baseline (138.3 kg vs. 131.2 kg). From 0 to 1 year post-operatively, Medicaid patients lost similar amounts of weight to commercial patients following all procedure types (mean weight Δ difference [95% CI]: RYGB: -0.9 [-3.2, 1.4]; LAGB: -1.5 [-6.7, 3.8]; SG: 5.1 [-4.0, 14.2]). From 1 to 3 years post-operatively Medicaid and commercial patients continued to experience minimal weight loss or began to slowly regain weight (mean weight Δ difference [95% CI]: RYGB: 0.9 [0.0, 2.0]; LAGB: -2.1 [-4.2, 0.1]; SG: 0.7 [-3.0, 4.3]). From 3 to 5 years post-operatively, the rate of regain tended to be faster among commercial patients compared to Medicaid patients (mean weight Δ difference [95% CI]: RYGB: 1.1 [0.1, 2.0]; LAGB: 1.5 [-0.5, 3.5]; SG: 1.0 [-2.5, 4.5]). CONCLUSIONS: Although Medicaid patients had a higher baseline weight, they achieved similar amounts of weight loss and tended to regain weight at a slower rate than commercial patients.

Resting Metabolic Rate, Total Daily Energy Expenditure, and Metabolic Adaptation 6 Months and 24 Months After Bariatric Surgery.

OBJECTIVE: Little is known about long-term metabolic (energy expenditure) adaptation after bariatric surgery. METHODS: Resting metabolic rate under basal conditions (RMR), total daily energy expenditure (TDEE), and body composition were measured in 25 participants in the Longitudinal Assessment of Bariatric Surgery-2. RESULTS: Six months after surgery, BMI (±SD) decreased (47 ± 6 kg/m2 to 37 ± 5 kg/m2 ), body fat went from 48% ± 6% to 40% ± 6% fat, and fat-free mass went from 67 ± 9 kg to 60 ± 9 kg. In absolute terms, RMR and TDEE both decreased significantly (1,730 ± 278 kcal/d vs. 1,430 ± 200 kcal/d and 2,879 ± 544 kcal/d vs. 2,369 ± 304 kcal/d), and the achieved energy balance was -1,293 ± 355 kcal/d. Sixteen of these participants underwent repeated measures at ∼24 months; TDEE decreased 6 months postoperatively (2,957 ± 540 kcal/d to 2,423 ± 324 kcal/d; P = 0.0003), but at ∼24 months, TDEE (2,602 ± 471 kcal/d) was not significantly different compared with month 6. The average negative energy balance from baseline to month 24 was -379 ± 131 kcal/d. CONCLUSIONS: RMR and TDEE fall precipitously in the first 6 months after bariatric surgery, but these adaptive changes were no longer significant after 2 years.

Weighing in on Bariatric Surgery: Effectiveness Among Medicaid Beneficiaries-Limited Evidence and Future Research Needs.

INTRODUCTION: In the general population, bariatric surgery is well documented as the most effective obesity treatment for sustained weight loss and remission of comorbidities. Characterization of the patient populations most likely to benefit from surgical intervention is needed, but the heterogeneity of treatment effects across payer groups has not been reviewed. METHODS: A systematic review of published studies focusing on bariatric surgery outcomes among Medicaid beneficiaries was conducted. By using PubMed and Scopus, this study searched for studies that quantitatively compared clinical or social bariatric surgery outcomes for United States adult Medicaid recipients and commercially insured patients. RESULTS: Of the 568 titles reviewed, 21 met inclusion criteria. Weight loss and the remission of comorbidities at 1 or 2 years postoperatively were similar between groups despite differences in baseline health status. Short-term health care utilization and mortality outcomes were worse in Medicaid recipients; for instance, Medicaid patients had an average length of stay that was 2 days longer and experienced three more deaths in the first postoperative year. CONCLUSIONS: The critical research gaps in the evidence base needed to improve treatment guidelines for Medicaid patients undergoing bariatric surgery include an understanding of the causes of the baseline health differences and how these differences contribute to postoperative outcomes.

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.

Type 2 Diabetes Remission Rates After Laparoscopic Gastric Bypass and Gastric Banding: Results of the Longitudinal Assessment of Bariatric Surgery Study.

OBJECTIVE: The goals of this study were to determine baseline and postbariatric surgical characteristics associated with type 2 diabetes remission and if, after controlling for differences in weight loss, diabetes remission was greater after Roux-en-Y gastric bypass (RYGBP) than laparoscopic gastric banding (LAGB). RESEARCH DESIGN AND METHODS: An observational cohort of obese participants was studied using generalized linear mixed models to examine the associations of bariatric surgery type and diabetes remission rates for up to 3 years. Of 2,458 obese participants enrolled, 1,868 (76%) had complete data to assess diabetes status at both baseline and at least one follow-up visit. Of these, 627 participants (34%) were classified with diabetes: 466 underwent RYGBP and 140 underwent LAGB. RESULTS: After 3 years, 68.7% of RYGBP and 30.2% of LAGB participants were in diabetes remission. Baseline factors associated with diabetes remission included a lower weight for LAGB, greater fasting C-peptide, lower leptin-to-fat mass ratio for RYGBP, and a lower hemoglobin A1c without need for insulin for both procedures. After both procedures, greater postsurgical weight loss was associated with remission. However, even after controlling for differences in amount of weight lost, relative diabetes remission rates remained nearly twofold higher after RYGBP than LAGB. CONCLUSIONS: Diabetes remission up to 3 years after RYGBP and LAGB was proportionally higher with increasing postsurgical weight loss. However, the nearly twofold greater weight loss-adjusted likelihood of diabetes remission in subjects undergoing RYGBP than LAGB suggests unique mechanisms contributing to improved glucose metabolism beyond weight loss after RYGBP.

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.

Longitudinal Assessment of Bariatric Surgery (LABS): retention strategy and results at 24 months.

BACKGROUND: Retaining participants in observational longitudinal studies after bariatric surgery is difficult yet critical because the retention rate affects interpretation and generalizability of results. Strategies for keeping participants involved in such studies are not commonly published. The objective of this study was to review LABS retention strategies and present the 24-month retention data. METHODS: The LABS Consortium monitors an observational cohort study of 2458 adults enrolled before bariatric surgery at 10 centers within the United States (LABS-2). To maximize data completeness, the investigators developed retention strategies, including flexible scheduling, a call protocol, reminder letters, abbreviated visit options, honoraria, travel reimbursement, providing research progress reports, laboratory results, newsletters, study website, and retention surveys. Strategies for locating participants included frequent updates of contact information, sending registered letters, and searching medical and public records. RESULTS: At 12 and 24 months, 2426 and 2405 participants remained active, with vital status known for 98.7% and 97.3% and weight obtained for 95.2% and 92.2%, respectively. There were 148 missed visits (6.2%) at 24 months primarily because of inability to contact the participant. Only 15 (0.6%) active participants at 24 months missed all follow-up visits. Although 42 participants could not be located or contacted at 6 months, data were obtained for 23 (54.7%) of them at 12 months, and of the 52 participants who could not be located or contacted at 12 months, data were obtained for 18 (34.6%) at 24 months. CONCLUSION: Longitudinal studies provide the ability to evaluate long-term effects of bariatric surgical procedures. The retention achieved in LABS is superior to that of many published reports but requires extensive effort and resources. This report identifies useful retention strategies. Further research is needed to identify the efficacy and cost-effectiveness of specific retention strategies.

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).