Outcomes after metabolic and bariatric surgery in preteens versus teens using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database and center-specific data.

OBJECTIVE: The American Academy of Pediatrics (AAP) recently released clinical guidelines for the treatment of childhood obesity, including surgery being appropriate for children 13 years of age and older. The use of this age cut-off was due to a lack of data for children younger than 13. To address this knowledge gap, the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database was queried to compare outcomes in preteens to teens after bariatric surgery hypothesizing that there would be no difference in outcomes between the two groups. METHODS: Patients from the MSAQIP database (2016-2021) were identified and divided into groups <13 years and 13-18 years and were matched using propensity scores based on race, sex, and preoperative BMI. Outcomes were compared including change in BMI, complication rates, 30-day readmission or reoperation, and mortality. Additionally, the centers responsible for the bulk of the preteen patient entries queried their center-specific databases to evaluate weight loss over time. RESULTS: A total of 4755 patients were identified, 47 of whom were <13 years of age. Preteens had similar sex distribution (66% vs. 75% female), were more likely to be Black (27.7% vs. 18.3%) or Hispanic (21.3% vs. 7.6%) race, and weighed less (274 ± 58 vs. 293 ± 85 lb, p = 0.01), but they had similar BMI (46.9 ± 7 vs. 47 ± 13 kg/m2 ) as their teen counterparts. Preteens were more likely to suffer from sleep apnea (34% vs. 19%, p < 0.01) and insulin-dependent type 2 diabetes (10.6% vs. 1.8%, p < 0.01). There were no complications in the preteens compared to teens (0% vs. 0.5%), and they did not undergo any unplanned readmissions (0% vs. 2.9%) or reoperations (0% vs. 0.8%) within 30 days of surgery. There were also no mortalities reported in preteens (0% vs. 0.1%). The risk-adjusted decrease in BMI between preteens and teens was also comparable at 30 days (4.2 [95% CI: 3.0-5.4] vs. 4.6 [95% CI: 4.4-4.7], p = 0.6). Decrease in BMI in preteens was 7 ± 3 kg/m2 at 3 months and 9 ± 4 kg/m2 at 12 months after surgery, which represented a percentage BMI change of 16 ± 7 and 20 ± 8, respectively. CONCLUSIONS: This study demonstrates that bariatric surgery in preteens is safe and efficacious when performed at specialized centers, and that age criteria may not be required. The AAP and others are encouraged to include age cut-offs in their guidelines for children with obesity and bariatric surgery only when data are available to support their inclusion.

Immune profile of adipose tissue from youth with obesity and asthma.

BACKGROUND: Obesity is a risk factor for paediatric asthma. Obesity-mediated systemic inflammation correlates with metabolic dysregulation; both are associated with asthma burden. However, adipose tissue inflammation is not defined in obesity-related asthma. OBJECTIVE: Define adipose tissue inflammation and its association with metabolic measures in paediatric obesity-related asthma. METHODS: Cellular profile of stromal vascular fraction from visceral adipose tissue (VAT) from youth with obesity-related asthma (n = 14) and obesity without asthma (n = 23) was analyzed using flow cytometry and correlated with metabolic measures. RESULTS: Compared to youth without asthma, VAT from youth with obesity-related asthma was enriched for leukocytes and macrophages, including M1 and dual M1M2 cells, but did not differ for CD4+ lymphocytes, and endothelial cells, their progenitors, and preadipocytes. M1 macrophage counts positively correlated with glucose, while M1M2 cells, CD4+ lymphocytes, and their subsets negatively correlated with high-density lipoprotein, in youth with obesity without asthma, but not among those with obesity-related asthma. CONCLUSIONS: Enrichment of macrophage-mediated inflammation in VAT from youth with obesity-related asthma supports its role in systemic inflammation linked with asthma morbidity. Lack of correlation of VAT cells with metabolic dysregulation in youth with obesity-related asthma identifies a need to define distinguishing factors associated with VAT inflammation in obesity-related asthma.

Child and Adolescent Bariatric Surgery in an Urban Tertiary Center: Special Anesthetic Considerations for Obesity.

Children and adolescents with obesity who present for weight loss surgery are a unique subset of patients. A thorough understanding of the perioperative needs of these individuals is essential to avoid deleterious complications. This review illustrates the necessity for specialized care, including the continued need of specified drug dosing and a systematic approach in the management of the pediatric bariatric patient.

The Role of Devices in the Management of Pediatric Obesity.

PURPOSE OF REVIEW: Approximately 20% of children and adolescents in the USA suffer from obesity with significant long-term effects well into adulthood. Metabolic and bariatric surgery, although well adopted in the adult population, has been underutilized in children. RECENT FINDINGS: There are four categories of weight loss devices regulated by the Food and Drug Administration for use in adults - gastric bands, gastric balloon systems, electrical stimulation systems, and gastric emptying systems. In this commentary we discuss the role these devices may play in increasing the adoption of procedural intervention for severe obesity in children and adolescents.

The impact of parental bariatric surgery and patient age on laparoscopic sleeve gastrectomy outcomes in adolescents.

BACKGROUND: Adolescent obesity is multifactorial, but parental history is the most significant risk factor. Laparoscopic sleeve gastrectomy (LSG) is part of the multidisciplinary approach to adolescent weight loss. OBJECTIVE: We aimed to evaluate the effects of parental history of bariatric surgery, as well as age at time of operation, on adolescents who underwent LSG at our institution. METHODS: We performed a retrospective review of patients, aged 10 to 19 years, who underwent LSG from January 2010 to December 2019. The adolescent bariatric surgical dataset maintained by our group was used to obtain patient demographics, weight, body mass index (BMI), and parental history of bariatric surgery. RESULTS: Among 328 patients, 76 (23.2%) had parents who had previously undergone bariatric surgery. These patients were significantly heavier by weight (p = 0.012) at the time of operation but had no difference in postoperative weight loss. When all patients were compared by age at operation (< 16 years, n = 102, ≥ 16 years, n = 226), there were few differences in outcomes. CONCLUSIONS: LSG is an effective approach to surgical weight loss in adolescents. Patient age should not be a barrier to weight loss surgery, especially among patients with a parental history of obesity. By intervening at a younger age, the metabolic sequelae of obesity may be reduced.

All in the Family: Child and Adolescent Weight Loss Surgery in the Context of Parental Weight Loss Surgery.

BACKGROUND: Bariatric surgery is the most effective current treatment option for patients with severe obesity. More children and adolescents are having surgery, many whose parents have also had surgery. The current study examines whether parental surgery status moderates the association between perceived social support, emotional eating, food addiction and weight loss following surgery, with those whose parents have had surgery evidencing a stronger relationship between the psychosocial factors and weight loss as compared to their peers. METHODS: Participants were 228 children and adolescents undergoing sleeve gastrectomy between 2014 and 2019 at one institution. Children and adolescents completed self-report measures of perceived family social support, emotional eating, and food addiction at their pre-surgical psychological evaluation. Change in body mass index (BMI) from pre-surgery to 3, 6, and 12 months post-surgery was assessed at follow-up clinic visits. Parents reported their surgical status as having had surgery or not. RESULTS: There were no differences in perceived family support, emotional eating, or food addiction symptoms between those whose parents had bariatric surgery and those whose parents did not. There were some moderating effects of parent surgery status on the relationship between social support, emotional eating/food addiction, and weight loss following surgery. Specifically, at 3 months post-surgery, higher change in BMI was associated with lower perceived family support only in those whose parents had not had surgery. More pre-surgical food addiction symptoms were associated with greater weight loss at 3 months for those whose parents had not had surgery, whereas this finding was true only for those whose parents had surgery at 12 months post-surgery. CONCLUSIONS: Children and adolescents whose parents have had bariatric surgery may have unique associations of psychosocial factors and weight loss. More research is needed to determine mechanisms of these relationships.

Type 2 Diabetes Modifies Skeletal Muscle Gene Expression Response to Gastric Bypass Surgery.

Introduction: Roux-en-Y gastric bypass (RYGB) is an effective treatment for type 2 diabetes mellitus (T2DM) that can result in remission of clinical symptoms, yet mechanisms for improved skeletal muscle health are poorly understood. We sought to define the impact of existing T2DM on RYGB-induced muscle transcriptome changes. Methods: Vastus lateralis biopsy transcriptomes were generated pre- and 1-year post-RYGB in black adult females with (T2D; n = 5, age = 51 ± 6 years, BMI = 53.0 ± 5.8 kg/m2) and without (CON; n = 7, 43 ± 6 years, 51.0 ± 9.2 kg/m2) T2DM. Insulin, glucose, and HOMA-IR were measured in blood at the same time points. ANCOVA detected differentially expressed genes (p < 0.01, fold change < |1.2|), which were used to identify enriched biological pathways. Results: Pre-RYGB, 95 probes were downregulated with T2D including subunits of mitochondrial complex I. Post-RYGB, the T2D group had normalized gene expression when compared to their non-diabetic counterparts with only three probes remaining significantly different. In the T2D, we identified 52 probes upregulated from pre- to post-RYGB, including NDFUB7 and NDFUA1. Conclusion: Black females with T2DM show extensive downregulation of genes across aerobic metabolism pathways prior to RYGB, which resolves 1 year post-RYGB and is related to improvements in clinical markers. These data support efficacy of RYGB for improving skeletal muscle health, especially in patients with T2DM.

30-Day morbidity and mortality of bariatric metabolic surgery in adolescence during the COVID-19 pandemic - The GENEVA study.

BACKGROUND: Metabolic and bariatric surgery (MBS) is an effective treatment for adolescents with severe obesity. OBJECTIVES: This study examined the safety of MBS in adolescents during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This was a global, multicentre and observational cohort study of MBS performed between May 01, 2020, and October 10,2020, in 68 centres from 24 countries. Data collection included in-hospital and 30-day COVID-19 and surgery-specific morbidity/mortality. RESULTS: One hundred and seventy adolescent patients (mean age: 17.75 ± 1.30 years), mostly females (n = 122, 71.8%), underwent MBS during the study period. The mean pre-operative weight and body mass index were 122.16 ± 15.92 kg and 43.7 ± 7.11 kg/m2 , respectively. Although majority of patients had pre-operative testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 146; 85.9%), only 42.4% (n = 72) of the patients were asked to self-isolate pre-operatively. Two patients developed symptomatic SARS-CoV-2 infection post-operatively (1.2%). The overall complication rate was 5.3% (n = 9). There was no mortality in this cohort. CONCLUSIONS: MBS in adolescents with obesity is safe during the COVID-19 pandemic when performed within the context of local precautionary procedures (such as pre-operative testing). The 30-day morbidity rates were similar to those reported pre-pandemic. These data will help facilitate the safe re-introduction of MBS services for this group of patients.

Effects of severe obesity and sleeve gastrectomy on cortical thickness in adolescents.

OBJECTIVE: Neurocognitive differences in pediatric obesity may be underpinned by cortical structural alterations. Differences in cortical thickness associated with severe obesity were examined, and preliminary evidence was sought for changes following vertical sleeve gastrectomy (VSG). METHODS: A total of 18 adolescents with severe obesity (OB) and 17 without obesity (nOB), aged 14 to 21, underwent T1-weighted structural magnetic resonance imaging. A subset was scanned twice 5 months apart to compare cortical thickness following VSG (n = 6) with two control groups: wait-listed (n = 9) and nOB (n = 12). RESULTS: At baseline, OB had a thinner cortex than nOB in motor and superior parietal cortices. At follow-up, VSG adolescents lost weight, the wait-listed group gained weight, and nOB did not change. Group × Time interactions indicated that VSG had cortical thinning in orbitofrontal, primary sensorimotor, superior, and middle temporal cortices and thickening in lingual, fusiform, and lateral occipital cortices. Wait-listed and nOB groups largely did not change. CONCLUSIONS: Severe obesity is associated with a thinner cortex in motor and attentional function-associated regions. VSG resulted in cortical thinning in reward valuation, sensory, and perceptual regions and thickening in visual regions. Surgery-related changes in regions distinct from those associated with obesity suggest compensation, rather than normalization. These results provide preliminary evidence supporting structural neural alterations following sleeve gastrectomy.

Surgical Treatment of Type 2 Diabetes Mellitus in Youth.

Bariatric surgery is currently the most effective weight loss treatment of severe obesity and its associated comorbidities and is being increasingly used to treat children and adolescents with severe obesity, including those with Type 2 Diabetes (T2D). This review focuses on the conventional management of T2D in children and adolescents, comparison of various types of bariatric surgeries, effect of bariatric surgery on gastrointestinal physiology and metabolism, current literature on the use of bariatric surgery to treat youth with severe obesity and T2D, and the potential complications of bariatric surgery in this population.

Weight and Glycemic Control Outcomes of Bariatric Surgery and Pharmacotherapy in Patients With Melanocortin-4 Receptor Deficiency.

Background: Melanocortin-4 receptor (MC4R) mutations are the most common of the rare monogenic forms of obesity. However, the efficacy of bariatric surgery (BS) and pharmacotherapy on weight and glycemic control in individuals with MC4R deficiency (MC4R-d) is not well-established. We investigated and compared the outcomes of BS and pharmacotherapy in patients with and without MC4R-d. Methods: Pertinent details were derived from the electronic database among identified patients who had BS with MC4R-d (study group, SG) and wild-type controls (age- and sex-matched control group, CG). Short- and long-term outcomes were reported for the SG. Short-term outcomes were compared between the two groups. Results: Seventy patients were screened for MC4R-d. The SG [six individuals (four females, two males); 18 (10-27) years old at BS; 50.3 (41.8-61.9) kg/m2 at BS, three patients with homozygous T162I mutations, two patients with heterozygous T162I mutations, and one patient with heterozygous I170V mutation] had a follow-up duration of up to 10 years. Weight loss, which varied depending on mutation type [17.99 (6.10-22.54) %] was stable for 6 months; heterogeneity of results was observed thereafter. BS was found superior to liraglutide on weight and glycemic control outcomes. At a median follow-up of 6 months, no significant difference was observed on weight loss (20.8% vs. 23.0%, p = 0.65) between the SG and the CG [eight individuals (four females, four males); 19.0 (17.8-36.8) years old at BS, 46.2 (42.0-48.3) kg/m2 at BS or phamacotherapeutic intervention]. Glycemic control in patients with MC4R-d and Type 2 diabetes improved post-BS. Conclusion: Our data indicate efficacious short-term but varied long-term weight loss and glycemic control outcomes of BS on patients with MC4R-d, suggesting the importance of ongoing monitoring and complementary therapeutic interventions.

Implications of Perioperative Polypharmacy in Adolescents Undergoing Bariatric Surgery: a Single-Center Experience.

Adolescents seeking bariatric surgery may present with pre-existing psychiatric diagnoses for which they use chronic medications. To heighten awareness concerning perioperative polypharmacy in adolescents with extreme obesity, we conducted a retrospective review of patients undergoing laparoscopic sleeve gastrectomy between February 2010 and May 2017 at Children's National Health System (CNHS). A total of 167 adolescent patients had pre-existing psychiatric diagnoses which included depression (50%), anxiety (23%), ADHD (23%), and binge eating disorder (11%). Medications prescribed to treat these diagnoses included selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). Additionally, all patients were given fentanyl, ondansetron, morphine, and acetaminophen perioperatively. Although no life threatening symptoms of drug-drug interactions (DDIs) were appreciated, the combined use of many different potent drugs in these patients warrants attention.

Prophylactic Use of Enoxaparin in Adolescents During Bariatric Surgery-a Prospective Clinical Study.

INTRODUCTION: Severe obesity predisposes youth to a higher risk of venous thromboembolism (VTE). This study evaluates a BMI-stratified prophylactic dosing regimen of enoxaparin in adolescents with severe obesity undergoing surgery. METHODS: Adolescents aged 12-20 years received prophylactic enoxaparin at 40 mg SC (for a BMI < 50 kg/m2) and 60 mg SC (for a BMI ≥ 50 kg/m2) every 12 h until discharge. Blood samples were drawn at pre-dose, 1, 2, 4, 6, and 12 h. Plasma Anti-Factor Xa (Anti-FXa) activity was used as a surrogate marker for enoxaparin pharmacokinetics. RESULTS: Ten female and two male obese adolescents (age range 14-19 years) had a mean BMI of 49.9 kg/m2 (38.4-58 kg/m2). Four patients had a BMI of less than 50 kg/m2 and received 40 mg enoxaparin, resulting in a mean dosage of 0.352 ± 0.070 mg/kg body weight. Eight patients were dosed with 60 mg enoxaparin every 12 h, resulting in a mean dosage of 0.395 ± 0.028 mg/kg. Peak plasma anti-FXa activity (Cmax) ranged from 0.14 to 0.30 IU/mL, median Cmax was 0.205 IU/mL. Median Tmax was 5.67 h (range 3.78-7.52 h). Median AUCi was 1.00 h IU/mL (range 0.42-1.67 h IU/mL). Ten out of 12 patients (83%) reached the primary endpoint with anti-FXa activity in the range for VTE prevention (0.1-0.3 IU/mL). CONCLUSIONS: Our dosing scheme of 40 mg vs. 60 mg enoxaparin stratified according to BMI proved to be effective in reaching prophylactic anti-FXa activity in 83% of adolescent patients.

Altered neural correlates of episodic memory in adolescents with severe obesity.

Negative effects of obesity on memory and associated medial temporal circuitry have been noted in animal models, but the status in humans, particularly children, is not well established. Our study is the first to examine neural correlates of successful memory encoding of visual scenes and their associated context in adolescents with severe obesity (age 14-18 years, 43% male). Despite similar subsequent memory as adolescents without obesity (BMI for age and sex <95th percentile), those with severe obesity (BMI for age and sex 120% above the 95th percentile) showed reduced hippocampal, parahippocampal, frontal, and parietal engagement during encoding of remembered visual scenes and greater lateral temporal engagement during encoding of their associated context. Standardized testing revealed a trend level group difference in memory performance, with a larger magnitude of obesity-related difference in recollection-related memory that was mediated by individual differences in lateral temporal activation during contextual encoding. The observed widespread functional alterations are concerning in light of the importance of mnemonic processing for academic achievement and feeding behavior and underscore the need for prevention and intervention initiatives for pediatric obesity.

Comparison of visceral adipose tissue DNA methylation and gene expression profiles in female adolescents with obesity.

BACKGROUND: Epigenetic changes in visceral adipose tissue (VAT) with obesity and their effects on gene expression are poorly understood, especially during emergent obesity in youth. The current study tested the hypothesis that methylation and gene expression profiles of key growth factor and inflammatory pathways are altered in VAT from obese compared to non-obese youth. METHODS: VAT samples from adolescent females grouped as Lean (L; n = 15; age = 15 ± 3 years, BMI = 21.9 ± 3.0 kg/m2) or Obese (Ob; n = 15, age = 16 ± 2 years, BMI = 45.8 ± 9.8 kg/m2) were collected. Global methylation (n = 20) and gene expression (N = 30) patterns were profiled via microarray and interrogated for differences between groups by ANCOVA (p < 0.05), followed by biological pathway analyses. RESULTS: Overlapping differences in methylation and gene expression in 317 genes were found in VAT from obese compared to lean groups. PI3K/AKT Signaling (p = 1.83 × 10-6; 11/121 molecules in dataset/pathway) was significantly overrepresented in Ob VAT according to pathway analysis. Upregulations in the PI3K/AKT signaling pathway mRNAs TFAM (p = 0.03; fold change = 1.8) and PPP2R5C (p = 0.03, FC = 2.6) were confirmed via qRT-PCR. CONCLUSION: Our analyses show obesity-related differences in DNA methylation and gene expression in visceral adipose tissue of adolescent females. Specifically, we identified methylation site/gene expression pairs differentially regulated and mapped these differences to pathways including PI3K/AKT signaling, suggesting that PI3K/AKT signaling pathway dysfunction in obesity may be driven in part by changes in DNA methylation.

Pattern of Biliary Disease Following Laparoscopic Sleeve Gastrectomy in Adolescents.

OBJECTIVE: The use of laparoscopic sleeve gastrectomy (LSG) has risen steadily as a treatment for adolescents with obesity. This study determined whether obstructive biliary complications after rapid, LSG-related weight loss occur similarly in adolescents compared with adults. METHODS: Between 2010 and 2019, 309 patients underwent LSG. Demographics and clinical factors, including pre- and perioperative BMI and weight changes, were included. RESULTS: Overall, 21 patients (7%) had post-LSG biliary disease (BD), of whom 13 presented with acute pancreatitis (AP) and 8 with biliary colic. No differences existed between those with BD (n = 21) and the remaining cohort (n = 288). Patients with BD were 16.3 (SD 2.4) years of age at LSG, with a preoperative BMI of 49.3 (SD 6.7) kg/m2 . Preoperative excess BMI loss was 7.1% (SD 11.3%). An ultrasound revealed gallstones (71%) and sludge or crystals (12%). Eighteen patients underwent cholecystectomy between 4 weeks and 29 months after LSG. CONCLUSIONS: Pediatric patients present with BD at a similar rate after LSG compared with adults. The majority of adolescents, however, manifest with AP. Thus, pancreatitis should be high on the differential diagnosis list when evaluating post-LSG abdominal symptoms. Additional studies are warranted to elucidate the pathophysiology of post-LSG AP for prevention in the future because its etiology may or may not be solely related to BD.

Cholesterol efflux alterations in adolescent obesity: role of adipose-derived extracellular vesical microRNAs.

BACKGROUND: Macrophage cholesterol efflux capacity has been identified as a predictor for cardiovascular disease. We assessed the relationship between adipocyte-derived extracellular vesicle microRNAs and macrophage cholesterol efflux capacity. METHODS: We assessed an adolescent cohort (n = 93, Age, median (IQR) = 17 (3) year, Female = 71, Male = 22) throughout the BMI continuum (BMI = 45.2 (13.2) kg/m2) for: (1) cholesterol efflux capacity and lipoprotein profiles; (2) adipocyte-derived extracellular vesicle microRNAs in serum; (3) the role of visceral adipose tissue extracellular vesicle in regulation of cholesterol efflux and cholesterol efflux gene expression in THP-1 macrophages in vitro. RESULTS: Efflux capacity was significantly associated with HDL (r = 0.30, p = 0.01) and LDL (r = 0.33, p = 0.005) particle size. Multivariate-analysis identified six microRNAs associated (p < 0.05) with cholesterol efflux capacity: miR-3129-5p (Beta = 0.695), miR-20b (0.430), miR9-5p (0.111), miR-320d (- 0.190), miR301a-5p (0.042), miR-155-5p (0.004). In response to increasing concentrations (1 µg/mL vs. 3 µg/mL) of VAT extracellular vesicle, cholesterol efflux (66% ± 10% vs. 49% ± 2%; p < 0.01) and expression of ABCA1 (FC = 1.9 ± 0.8 vs 0.5 ± 0.2; p < 0.001), CD36 (0.7 ± 0.4 vs. 2.1 ± 0.8, p = 0.02), CYP27A1 (1.4 ± 0.4 vs. 0.9 ± 0.5; p < 0.05), and LXRA (1.8 ± 1.1 vs. 0.5 ± 0.2; p < 0.05) was altered in THP-1 cells in vitro. CONCLUSION: Adipocyte-derived extracellular vesicle microRNAs may, in part, be involved macrophage cholesterol efflux regulation.

Preoperative exercise as a predictor of weight loss in adolescents and young adults following sleeve gastrectomy: a cohort study.

BACKGROUND: Preoperative exercise is associated with weight loss following bariatric surgery in adults, but this relationship in adolescents and young adults (AYA) is not well studied. OBJECTIVES: The present study examined AYA-reported preoperative exercise and demographic factors and their prediction of percent excess body mass index (BMI) loss at 6 and 12 months following sleeve gastrectomy. SETTING: The setting for recruitment and surgeries was in a children's hospital in the United States. METHODS: Participants were 173 AYA aged 12-21 years (mean age, 16.5 [SD, 2.0] yr; mean preoperative BMI, 50 [SD, 8.5] kg/m2). Demographic characteristics including age, sex, ethnicity, and preoperative BMI were extracted from the medical record. Preoperatively, adolescents self-reported on exercise using 5 items from the Center for Disease Control's Youth Risk Behavior Surveillance Survey. The study evaluated the association of self-reported preoperative exercise in total and obtained a threshold of higher exercise to weight loss at 6 and 12 months after surgery. RESULTS: More preoperative exercise was associated with greater weight loss at 12 months. Grouping participants by those who reported exercising at high levels (≥5 hr/wk) compared with those who reported <5 hr/wk, high levels of exercise predicted greater weight loss at 6 and marginally at 12 months postoperatively. Lower preoperative BMI was a significant predictor of weight loss in all analyses. CONCLUSIONS: Preoperative exercise may predict and contribute to weight loss in AYA and could be a target for pre- and postoperative intervention to improve outcomes. The importance of lower preoperative BMI for maximizing postoperative weight loss was also supported.