Single cell atlas of human gastric muscle immune cells and macrophage-driven changes in idiopathic gastroparesis

Gastrointestinal immune cells, particularly muscularis macrophages (MM) interact with the enteric nervous system and influence gastrointestinal motility. Here we determine the human gastric muscle immunome and its changes in patients with idiopathic gastroparesis (IG). Single cell sequencing was performed on 26,000 CD45+ cells obtained from the gastric tissue of 20 subjects. We demonstrate 11 immune cell clusters with T cells being most abundant followed by myeloid cells. The proportions of cells belonging to the 11 clusters were similar between IG and controls. However, 9/11 clusters showed 578-11,429 differentially expressed genes. In IG, MM had decreased expression of tissue-protective and microglial genes and increased the expression of monocyte trafficking and stromal activating genes. Furthermore, in IG, IL12 mediated JAK-STAT signaling involved in the activation of tissue-resident macrophages and Eph-ephrin signaling involved in monocyte chemotaxis were upregulated. Patients with IG had a greater abundance of monocyte-like cells. These data further link immune dysregulation to the pathophysiology of gastroparesis.

Type-2 diabetes mellitus remission prediction models after Roux-En-Y gastric bypass and sleeve gastrectomy based on disease severity scores

AIM

Metabolic and bariatric surgery (MBS) is considered one of the most effective interventions for weight loss and associated type-2 diabetes mellitus (T2DM) remission. Multiple scores including the Individualized Metabolic Surgery (IMS), DiaRem, advanced DiaRem, and Robert et al. scores, have been developed predict T2DM remission after MBS. We aim to validate each of these scores in our cohort of patients undergoing MBS with long-term follow-up and assess their efficacy based on procedure type and preoperative BMI.

METHODS

We conducted a multicenter cohort study including patients with T2DM undergoing either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Areas under the receiver operating characteristics (ROC) curve (AUC) were calculated to assess the discriminatory ability of the four models to detect T2DM remission.

RESULTS

A total of 503 patients (67 % females, mean age 53.5 [11] years, BMI 46.2 [8.8] kg/m2) with T2DM were included. The majority (78 %) underwent RYGB, while the rest (28 %) had SG. All four scores predicted T2DM remission in our cohort with an ROC AUC of 0.79 for IMS, 0.78 for both DiaRem and advanced-DiaRem, and 0.75 for Robert et al. score. Specific subgroups for each of these scores demonstrated higher T2DM remission rates after RYGB compared to SG.

CONCLUSION

We demonstrate the ability of the IMS, DiaRem, advanced-DiaRem and Robert et al. scores to predict T2DM remission in patients undergoing MBS. T2DM remission rates was demonstrated to decrease with more severe IMS, DiaRem and advanced-DiaRem scores and lower Robert et al. scores.

Hypoxia-Inducible Factor 1α Stabilization Restores Epigenetic Control of Nitric Oxide Synthase 1 Expression and Reverses Gastroparesis in Female Diabetic Mice

BACKGROUND & AIMS

Although depletion of neuronal nitric oxide synthase (NOS1)-expressing neurons contributes to gastroparesis, stimulating nitrergic signaling is not an effective therapy. We investigated whether hypoxia-inducible factor 1α (HIF1A), which is activated by high O2 consumption in central neurons, is a Nos1 transcription factor in enteric neurons and whether stabilizing HIF1A reverses gastroparesis.

METHODS

Mice with streptozotocin-induced diabetes, human and mouse tissues, NOS1+ mouse neuroblastoma cells, and isolated nitrergic neurons were studied. Gastric emptying of solids and volumes were determined by breath test and single-photon emission computed tomography, respectively. Gene expression was analyzed by RNA-sequencing, microarrays, immunoblotting, and immunofluorescence. Epigenetic assays included chromatin immunoprecipitation sequencing (13 targets), chromosome conformation capture sequencing, and reporter assays. Mechanistic studies used Cre-mediated recombination, RNA interference, and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9)-mediated epigenome editing.

RESULTS

HIF1A signaling from physiological intracellular hypoxia was active in mouse and human NOS1+ myenteric neurons but reduced in diabetes. Deleting Hif1a in Nos1-expressing neurons reduced NOS1 protein by 50% to 92% and delayed gastric emptying of solids in female but not male mice. Stabilizing HIF1A with roxadustat (FG-4592), which is approved for human use, restored NOS1 and reversed gastroparesis in female diabetic mice. In nitrergic neurons, HIF1A up-regulated Nos1 transcription by binding and activating proximal and distal cis-regulatory elements, including newly discovered super-enhancers, facilitating RNA polymerase loading and pause-release, and by recruiting cohesin to loop anchors to alter chromosome topology.

CONCLUSIONS

Pharmacologic HIF1A stabilization is a novel, translatable approach to restoring nitrergic signaling and treating diabetic gastroparesis. The newly recognized effects of HIF1A on chromosome topology may provide insights into physioxia- and ischemia-related organ function.

Type 2 diabetes remission after Roux-en-Y gastric bypass: a multicentered experience with long-term follow-up

BACKGROUND

Roux-en-Y gastric bypass (RYGB) is associated with short- and mid-term type 2 diabetes (T2D) remission. Long-term outcomes and predictive parameters associated with remission following RYGB have not been well elucidated.

OBJECTIVE

Determining the overall long-term T2D remission rates following RYGB and identifying predictive variables associated with remission.

SETTING

Multicentered study including patients who underwent RYGB at 3 tertiary referral centers for bariatric surgery.

METHODS

We performed a retrospective cohort study between 2008-2017 to allow a minimum of 5 years of follow-up. We evaluated long-term T2D remission rates and annual T2D clinical and metabolic parameters up to 14 years after surgery. Predictors of remission were assessed using multivariate logistic regression. Patients were divided into 4 groups based on quartiles of total body weight loss percentage (%TBWL) to compare remission rates between groups.

RESULTS

A total of 815 patients were included (68.9% female, age 52.1 ± 11.5 yr; body mass index 45.1 ± 7.7 kg/m2) with a follow-up of 7.3 ± 3.8 years. Remission was demonstrated in 51% of patients. Predictors of remission included pre-operative duration of diabetes, baseline HbA1C, insulin use prior to surgery, number of antidiabetic medications and %TBWL (all P < .01). Remission rates were proportionally associated with %TBWL quartile (Q1, 40.9%; Q2, 52.7%; Q3, 53.1%; Q4, 56.1%) (P = .02).

CONCLUSIONS

Longer duration and higher severity of T2D were negatively associated with remission while higher %TBWL had a positive association. A significant proportion of patients in all quartiles experienced long-term remission after RYGB with a greater likelihood of remission correlated with greater weight loss.

Bariatric surgery outcomes in patients with bipolar or schizoaffective disorders

BACKGROUND

Obesity is associated with many co-morbidities and can cause harm to physical and mental well-being. While much has been studied in the general population about the outcomes of bariatric surgery, its implications in patients with bipolar/schizoaffective disorder (BSD) are less well understood.

OBJECTIVE

We aimed to describe outcomes of bariatric surgery in patients with BSD.

SETTING

Referral center for bariatric surgery.

METHODS

We conducted a retrospective chart review analysis of bariatric surgical procedures in patients with BSD between 2008 and 2021 at Mayo Clinic. Patients with BSD (cases) were matched via propensity score matching (1:2) with non-BSD controls based on surgical procedure, age, sex, body mass index, and type 2 diabetes. Hierarchical logistic regression model was performed using SAS software.

RESULTS

We matched 71 patients with BSD with 142 controls in a 1:2 ratio. After adjusting for baseline preoperative weight, patients with BSD had a 3.4% greater total weight loss compared with controls over 24 months (P = .02 [95% CI, .65-6.08]). Remission in obesity-related diseases, such as diabetes, hypertension, dyslipidemia, and sleep apnea, was similar in both groups. Perioperative complication rates were similar other than deep venous thrombosis, which showed a higher rate in patients with BSD (P = .04). Patients with long-term BSD were at increased risk of alcohol use compared with controls.

CONCLUSIONS

When compared with the general bariatric population, weight loss was similar to slightly improved, with a comparable risk and complication profile. Patients with BSD have increased alcohol use after bariatric surgery, highlighting the need for psychological care before and after surgery in this population.

Feasibility and Outcomes of Simultaneous Gastric Bypass with Paraesophageal Hernia Repair in Elderly Patients

BACKGROUND

Paraesophageal hernias (PEH) have a higher incidence in patients with obesity. Roux-en-Y gastric bypass (RYGB) with concomitant PEH repair is established as a valid surgical option for PEH management in patients with obesity. The safety and feasibility of this approach in the elderly population are not well elucidated.

METHODS

We performed a multicenter retrospective cohort study of patients aged 65 years and older who underwent simultaneous PEH repair and RYGB from 2008 to 2022. Patient demographics, hernia characteristics, postoperative complications, and weight loss data were collected. Obesity-related medical conditions' resolution rates were evaluated at the last follow-up. A matched paired t-test and Pearson's test were used to assess continuous and categorical parameters, respectively.

RESULTS

A total of 40 patients (82.5% female; age, 69.2 ± 3.6 years; BMI, 39.4 ± 4.7 kg/m2) with a mean follow-up of 32.3 months were included. The average hernia size was 5.8 cm. Most cases did not require mesh use during surgery (92.5%) with only 3 (7.5%) hernial recurrences. Postoperative complications (17.5%) and mortality rates (2.5%), as well as readmission (2.5%), reoperation (2.5%), and reintervention (0%) rates at 30-day follow-up were reported. There was a statistically significant resolution in gastroesophageal reflux disease (p < 0.001), hypertension (p = 0.019), and sleep apnea (p = 0.014).

CONCLUSIONS

The safety and effectiveness of simultaneous PEH repair and RYGB are adequate for the elderly population. Patient selection is crucial to reduce postoperative complications. Further studies with larger cohorts are needed to fully assess the impact of this surgery on elderly patients with obesity.

Positive Predictive Value for Multitarget Stool DNA After Bariatric and Metabolic Surgery

BACKGROUND AND AIMS

Bariatric and metabolic surgery (BMS) may adversely affect noninvasive stool tests for colorectal cancer (CRC) screening through several mechanisms. Multitarget stool DNA (mt-sDNA) is approved for CRC screening; however, performance in post-BMS patients is unknown. As the rates of BMS are anticipated to increase with rising incidence of obesity, it is important to evaluate mt-sDNA test performance among these patients.

METHODS

In a multisite academic and community-based practice, we obtained mt-sDNA results from 10/2014 to 12/2019 through electronic records and an institutional BMS registry. Average CRC risk patients with BMS prior to a positive mt-sDNA underwent a detailed chart review. Follow-up colonoscopy findings were compared to those among BMS patients screened with colonoscopy alone and a historical cohort of patients without BMS, screened by mt-sDNA. The primary study endpoint was the positive predictive value (PPV) for advanced colorectal neoplasia.

RESULTS

Among 336 average-risk patients who had mt-sDNA after BMS, mt-sDNA was positive in 49 (14.6%), 47/49 (96%) underwent follow-up colonoscopy, and the PPV for advanced neoplasia was 12/47 (25.5%). This is similar to the PPV for advanced colorectal neoplasia (425/1542, 28%) in a historical cohort of persons without prior BMS, screened by mt-sDNA at our center (P = .86). Among those who had prior BMS, the rate of advanced neoplasia was higher after mt-sDNA compared to screening colonoscopy alone.

CONCLUSION

Despite anatomic and physiologic mechanisms that could alter blood or DNA content in stool, BMS does not appear to adversely affect the PPV of mt-sDNA.

Insulin-Like Growth Factor1 Preserves Gastric Pacemaker Cells and Motor Function in Aging via ERK1/2 Activation

BACKGROUND & AIMS

Impaired gastric motor function in the elderly causes reduced food intake leading to frailty and sarcopenia. We previously found that aging-related impaired gastric compliance was mainly owing to depletion of interstitial cells of Cajal (ICC), pacemaker cells, and neuromodulator cells. These changes were associated with reduced food intake. Transformation-related protein 53-induced suppression of extracellular signal-regulated protein kinase (ERK)1/2 in ICC stem cell (ICC-SC) cell-cycle arrest is a key process for ICC depletion and gastric dysfunction during aging. Here, we investigated whether insulin-like growth factor 1 (IGF1), which can activate ERK in gastric smooth muscles and invariably is reduced with age, could mitigate ICC-SC/ICC loss and gastric dysfunction in klotho mice, a model of accelerated aging.

METHODS

Klotho mice were treated with the stable IGF1 analog LONG R3 recombinant human (rh) IGF1 (150 μg/kg intraperitoneally twice daily for 3 weeks). Gastric ICC/ICC-SC and signaling pathways were studied by flow cytometry, Western blot, and immunohistochemistry. Gastric compliance was assessed in ex vivo systems. Transformation-related protein 53 was induced with nutlin 3a and ERK1/2 signaling was activated by rhIGF-1 in the ICC-SC line.

RESULTS

LONG R3 rhIGF1 treatment prevented reduced ERK1/2 phosphorylation and gastric ICC/ICC-SC decrease. LONG R3 rhIGF1 also mitigated the reduced food intake and impaired body weight gain. Improved gastric function by LONG R3 rhIGF1 was verified by in vivo systems. In ICC-SC cultures, rhIGF1 mitigated nutlin 3a-induced reduced ERK1/2 phosphorylation and cell growth arrest.

CONCLUSIONS

IGF1 can mitigate age-related ICC/ICC-SC loss by activating ERK1/2 signaling, leading to improved gastric compliance and increased food intake in klotho mice.

Lumen-apposing metal stents for the treatment of benign gastrointestinal tract strictures: a single-center experience and proposed treatment algorithm

BACKGROUND

Lumen-apposing metal stents (LAMS) are an alternative therapeutic option for benign gastrointestinal (GI) tract strictures. Our study aimed to evaluate the safety and efficacy of LAMS for the management of benign GI strictures.

METHODS

Consecutive patients who underwent a LAMS placement for benign luminal GI strictures at a tertiary care center between January 2014 and July 2021 were reviewed. Primary outcomes included technical success, early clinical success, and adverse events (AEs). Other outcomes included rates of stent migration and re-intervention after LAMS removal.

RESULTS

One hundred and nine patients who underwent 128 LAMS placements (67.9% female, mean age of 54.3 ± 14.2 years) were included, and 70.6% of the patients had failed prior endoscopic treatments. The majority of strictures (83.5%) were anastomotic, and the most common stricture site was the gastrojejunal anastomosis (65.9%). Technical success was achieved in 100% of procedures, while early clinical success was achieved in 98.4%. The overall stent-related AE rate was 25%. The migration rate was 27.3% (35/128). Of these, five stents were successfully repositioned endoscopically. The median stent dwell time was 119 days [interquartile range (IQR) 68-189 days], and the median follow-up duration was 668.5 days [IQR: 285.5-1441.5 days]. The re-intervention rate after LAMS removal was 58.3%.

CONCLUSIONS

LAMS is an effective therapeutic option for benign GI strictures, offering high technical and early clinical success. However, the re-intervention rate after LAMS removal was high. In select cases, using LAMS placement as destination therapy with close surveillance is a reasonable option.

Human Obesity Attenuates Cardioprotection Conferred by Adipose Tissue-Derived Mesenchymal Stem/Stromal Cells

To explore the impact of obesity on reparative potency of adipose tissue-derived mesenchymal stromal/stem cells (A-MSC) in hypertensive cardiomyopathy, A-MSC were harvested from subcutaneous fat of obese and age-matched non-obese human subjects during bariatric or kidney donation surgeries, and then injected into mice 2 weeks after inducing renovascular hypertension (RVH) or sham surgery. Two weeks later, left ventricular (LV) function and deformation were estimated in vivo by micro-magnetic resonance imaging and myocardial damage ex vivo. Blood pressure and myocardial wall thickening were elevated in RVH + Vehicle and normalized only by lean-A-MSC. Both A-MSC types reduced LV mass and normalized the reduced LV peak strain radial in RVH, yet obese-A-MSC also impaired LV systolic function. A-MSC alleviated myocardial tissue damage in RVH, but lean-A-MSC decreased oxidative stress more effectively. Obese-A-MSC also showed increased cellular inflammation in vitro. Therefore, obese-A-MSC are less effective than lean-A-MSC in blunting hypertensive cardiomyopathy in mice with RVH.

Impact of Chronic Immunosuppression on Short-, Mid-, and Long-Term Bariatric Surgery Outcomes

INTRODUCTION

Bariatric surgical outcomes depend heavily on proper healing of gastrointestinal anatomy, metabolic alterations, and patient lifestyle modifications which are all negatively impacted by immunosuppression and underlying inflammatory diseases. There is a lack of literature exploring how patients with diseases requiring immunosuppression respond to bariatric surgical intervention in the long term.

METHODS

A retrospective analysis of chronically immunosuppressed patients who underwent primary bariatric surgeries at Mayo Clinic was conducted (2008-2020). Data collected included patient demographics, BMI, underlying disease, and immunosuppression regimen and complications at 3, 6, 12, 24, and 60 months.

RESULTS

We identified a total of 89 (RYGB = 49, SG = 34, BPD/DS = 6) patients on chronic immunosuppression who underwent bariatric surgery at our center. RYGB (N = 49), 38.2% had a SG (N = 34) and 6.7% had a BPD/DS (N = 6). Rheumatoid arthritis and renal transplantation were the most underlying condition at 20.22% each (N = 18). There were a total of 2 (2.25%) intraoperative complications. In the immediate post-operative period, there were 15 (16.5%) minor complications. In follow-up, 6.1% of RYGB patients experienced marginal ulcerations, while no gastrointestinal leaks occurred. The mean pre-surgical BMI was 48.29 kg/m² (SD = 18.41). Percent total weight loss (%TWL) and BMI reduction were 30.89% and 14.83 kg/m² (SD = 9.07) at 12 months and 29.48% and 14.43 kg/m² (SD = 13.46) at 60 months, respectively. The mean follow-up time was 30.49 months.

CONCLUSIONS

Bariatric surgery remains safe and effective therapy for chronically immunosuppressed patients with excellent long-term outcomes for patients with moderate to severe obesity.

Mucosal and hormonal adaptations after Roux-en-Y gastric bypass

The aim of this study was to perform a comprehensive literature review regarding the relevant hormonal and histologic changes observed after Roux-en-Y gastric bypass (RYGB). We aimed to describe the relevant hormonal (glucagon-like peptides 1 and 2 [GLP-1 and GLP-2], peptide YY [PYY], oxyntomodulin [OXM], bile acids [BA], cholecystokinin [CCK], ghrelin, glucagon, gastric inhibitory polypeptide [GIP], and amylin) profiles, as well as the histologic (mucosal cellular) adaptations happening after patients undergo RYGB. Our review compiles the current evidence and furthers the understanding of the rationale behind the food intake regulatory adaptations occurring after RYGB surgery. We identify gaps in the literature where the potential for future investigations and therapeutics may lie. We performed a comprehensive database search without language restrictions looking for RYGB bariatric surgery outcomes in patients with pre- and postoperative blood work hormonal profiling and/or gut mucosal biopsies. We gathered the relevant study results and describe them in this review. Where human findings were lacking, we included animal model studies. The amalgamation of physiologic, metabolic, and cellular adaptations following RYGB is yet to be fully characterized. This constitutes a fundamental aspiration for enhancing and individualizing obesity therapy.

Effects of Heterozygous Variants in the Leptin-Melanocortin Pathway on Roux-en-Y Gastric Bypass Outcomes: a 15-Year Case-Control Study

INTRODUCTION

Heterozygous variants in the leptin-melanocortin pathway are associated with obesity. However, their effect on the long-term outcomes after Roux-en-Y gastric bypass (RYGB) is still unknown.

METHODS

In this matched case-control study, 701 participants from the Mayo Clinic Biobank with a history of RYGB were genotyped. Sixty-three patients had a heterozygous variant in the leptin-melanocortin pathway. After excluding patients with potential confounders, carriers were randomly matched (on sex, age, body mass index [BMI], and years since surgery) with two non-carrier controls. The electronic medical record of carriers and matched non-carriers was reviewed for up to 15 years after RYGB.

RESULTS

A total of 50 carriers and 100 matched non-carriers with a history of RYGB were included in the study. Seven different genes (LEPR, PCSK1, POMC, SH2B1, SRC1, MC4R, and SIM1) in the leptin-melanocortin pathway were identified. At the time of surgery, the mean age was 50.8 ± 10.6 years, BMI 45.6 ± 7.3 kg/m², and 79% women. There were no differences in postoperative years of follow-up, Roux limb length, or gastric pouch size between groups. Fifteen years after RYGB, the percentage of total body weight loss (%TBWL) in carriers was - 16.6 ± 10.7 compared with - 28.7 ± 12.9 in non-carriers (diff = 12.1%; 95% CI, 4.8 to 19.3) and the percentage of weight regain after maximum weight loss was 52.7 ± 29.7 in carriers compared with 29.8 ± 20.7 in non-carriers (diff = 22.9%; 95% CI, 5.3 to 40.5). The nadir %TBWL was lower - 32.1 ± 8.1 in carriers compared with - 36.8 ± 10.4 in non-carriers (diff = 4.8%; 95% CI 1.8 to 7.8).

CONCLUSIONS

Carriers of a heterozygous variant in the leptin-melanocortin pathway have a progressive and significant weight regain in the mid- and long-term after RYGB. Genotyping patients experiencing significant weight regain after RYGB could help implement multidisciplinary and individualized weight loss interventions to improve weight maintenance after surgery.

Telemedicine Video Follow-Up for Bariatric Surgery Patients: What Do Patients Prefer? A Prepandemic Pilot Randomized Clinical Trial

While the safety of video follow-up in bariatric surgery is established, patients' perception of telemedicine visits remained unknown. A randomized clinical trial evaluating patients' perception of video postoperative follow-up (F/U) visits was conducted in the pre COVID-19 era. 24 patients were randomized in the preoperative clinic to receive either in-person or video F/U, and then surveyed about their experience and preference. The majority reported that if they had to do it over, they would prefer a video visit. Among those who received video visits, 11/12 reported that the lack of physical contact was acceptable. 82% of the video group expressed that their visit was better or as good as an in-person visit, while 9% were not sure, and 9% reported that video was worse. This finding suggests that postoperative video follow-up visits are acceptable among bariatric surgery patients and should be offered as an alternative to traditional visits.

Diabetic Kidney Disease Alters the Transcriptome and Function of Human Adipose-Derived Mesenchymal Stromal Cells but Maintains Immunomodulatory and Paracrine Activities Important for Renal Repair

Mesenchymal stem/stromal cells (MSCs) facilitate repair in experimental diabetic kidney disease (DKD). However, the hyperglycemic and uremic milieu may diminish regenerative capacity of patient-derived therapy. We hypothesized that DKD reduces human MSC paracrine function. Adipose-derived MSC from 38 participants with DKD and 16 control subjects were assessed for cell surface markers, trilineage differentiation, RNA sequencing (RNA-seq), in vitro function (coculture or conditioned medium experiments with T cells and human kidney cells [HK-2]), secretome profile, and cellular senescence abundance. The direction of association between MSC function and patient characteristics were also tested. RNA-seq analysis identified 353 differentially expressed genes and downregulation of several immunomodulatory genes/pathways in DKD-MSC versus Control-MSC. DKD-MSC phenotype, differentiation, and tube formation capacity were preserved, but migration was reduced. DKD-MSC with and without interferon-γ priming inhibited T-cell proliferation greater than Control-MSC. DKD-MSC medium contained higher levels of anti-inflammatory cytokines (indoleamine 2,3-deoxygenase 1 and prostaglandin-E2) and prorepair factors (hepatocyte growth factor and stromal cell-derived factor 1) but lower IL-6 versus control-MSC medium. DKD-MSC medium protected high glucose plus transforming growth factor-β-exposed HK-2 cells by reducing apoptotic, fibrotic, and inflammatory marker expression. Few DKD-MSC functions were affected by patient characteristics, including age, sex, BMI, hemoglobin A_1c, kidney function, and urine albumin excretion. However, senescence-associated β-galactosidase activity was lower in DKD-MSC from participants on metformin therapy. Therefore, while DKD altered the transcriptome and migratory function of culture-expanded MSCs, DKD-MSC functionality, trophic factor secretion, and immunomodulatory activities contributing to repair remained intact. These observations support testing of patient-derived MSC therapy and may inform preconditioning regimens in DKD clinical trials.

Adipocyte Proteins and Storage of Endogenous Fatty Acids in Visceral and Subcutaneous Adipose Tissue in Severe Obesity

OBJECTIVE

This study tested whether substrate concentrations or fatty acid storage proteins predict storage of endogenous lipids in visceral adipose tissue (VAT) and upper body subcutaneous adipose tissue (UBSQ) fat.

METHODS

The day prior to surgery, 25 patients undergoing bariatric procedures received an infusion of autologous [1-¹⁴ C]triolein-labeled very low-density lipoprotein (VLDL) particles, and during surgery, they received a continuous [U-¹³ C]palmitate infusion/bolus [9,10-³ H]palmitate tracer. VAT and UBSQ fat were collected to measure VLDL-triglyceride (TG) storage, direct free fatty acid (FFA) storage rates, CD36 content, lipoprotein lipase (LPL), acyl-CoA synthetase, diacylglycerol acetyl-transferase, and glycerol-3-phosphate acyltransferase activities.

RESULTS

Storage of VLDL-TG and FFA-palmitate in UBSQ and VAT was not different. Plasma palmitate concentrations correlated with palmitate storage rates in UBSQ and VAT (r = 0.46, P = 0.02 and r = 0.46, P = 0.02, respectively). In VAT, VLDL-TG storage was correlated with VLDL concentrations (r = 0.53, P < 0.009) and LPL (r = 0.42, P < 0.05). In UBSQ, VLDL-TG storage was correlated with LPL (r = 0.42, P < 0.05). CD36, acyl-CoA synthetase, glycerol-3-phosphate acyltransferase, and diacylglycerol acetyl-transferase were not correlated with VLDL-TG or palmitate storage.

CONCLUSIONS

Adipose storage of VLDL-TG is predicted by VLDL-TG concentrations and LPL; FFA concentrations predict direct adipose tissue FFA storage rates.

Are In-Person Post-operative Clinic Visits Necessary to Detect Complications Among Bariatric Surgery Patients?

Patients undergoing bariatric surgery are expected to have frequent post-surgical follow-up. With the increased utilization of telemedicine across different surgical specialties, we are considering replacing the in-person post-surgery visits with telemedicine video visits in our bariatric practice. However, the safety and efficacy of conducting these visits through telemedicine is still unknown. Due to the concern of missing complications by eliminating in-person assessments, we reviewed 30-day complications, their severity, and the context of their detection experienced by bariatric surgical patients at our institution. Our results suggest that the majority of complications are detected when patients seek medical care rather than during clinic visits. Therefore, telemedicine is likely safe for 30-day follow-up in bariatric patients. Further studies are needed to assess its effect on patient compliance and outcomes.

Symptoms of bipolar disorder are associated with lower bariatric surgery completion rates and higher food addiction

BACKGROUND

Bipolar disorder (BP) is highly comorbid with obesity, however, little is known about how BP might be associated with bariatric surgery outcomes.

METHODS

In this retrospective clinical cohort study, 1034 patients completed a psychological evaluation, and screening positive for possible BP was defined as a score ≥7 and moderate disability on the Mood Disorders Questionnaire. Food addiction (FA), subthreshold binge eating disorder (BED), and illegal drug use were also assessed using standardized questionnaires.

RESULTS

The 54 (5.2%) patients screening positive for BP were less likely to have bariatric surgery compared to 980 (94.8%) patients who screened negative for BP (5 patients or 9.3% vs 273 patients, or 27.9%). Patients with possible BP also had significantly higher prevalence of FA (37% vs 13.2%), subthreshold BED (29.6% vs 8.3%) and illegal drug use (7.4% vs 2.1%).

CONCLUSIONS

In this retrospective clinical cohort study, patients who screened positive for BP had a higher prevalence of food addiction, subthreshold binge eating disorder and recent illegal drug use. They also demonstrated lower completion rates for having bariatric surgery. Clearly, more needs to be learned about how to help patients with symptoms of bipolar disorder manage their obesity and behavioral challenges.

Wnt-induced, TRP53-mediated Cell Cycle Arrest of Precursors Underlies Interstitial Cell of Cajal Depletion During Aging

BACKGROUND & AIMS

Gastric dysfunction in the elderly may cause reduced food intake, frailty, and increased mortality. The pacemaker and neuromodulator cells interstitial cells of Cajal (ICC) decline with age in humans, and their loss contributes to gastric dysfunction in progeric klotho mice hypomorphic for the anti-aging Klotho protein. The mechanisms of ICC depletion remain unclear. Klotho attenuates Wnt (wingless-type MMTV integration site) signaling. Here, we examined whether unopposed Wnt signaling could underlie aging-associated ICC loss by up-regulating transformation related protein TRP53 in ICC stem cells (ICC-SC).

METHODS

Mice aged 1-107 weeks, klotho mice, APC^Δ468 mice with overactive Wnt signaling, mouse ICC-SC, and human gastric smooth muscles were studied by RNA sequencing, reverse transcription-polymerase chain reaction, immunoblots, immunofluorescence, histochemistry, flow cytometry, and methyltetrazolium, ethynyl/bromodeoxyuridine incorporation, and ex-vivo gastric compliance assays. Cells were manipulated pharmacologically and by gene overexpression and RNA interference.

RESULTS

The klotho and aged mice showed similar ICC loss and impaired gastric compliance. ICC-SC decline preceded ICC depletion. Canonical Wnt signaling and TRP53 increased in gastric muscles of klotho and aged mice and middle-aged humans. Overstimulated canonical Wnt signaling increased DNA damage response and TRP53 and reduced ICC-SC self-renewal and gastric ICC. TRP53 induction persistently inhibited G₁/S and G₂/M cell cycle phase transitions without activating apoptosis, autophagy, cellular quiescence, or canonical markers/mediators of senescence. G₁/S block reflected increased cyclin-dependent kinase inhibitor 1B and reduced cyclin D1 from reduced extracellular signal-regulated kinase activity.

CONCLUSIONS

Increased Wnt signaling causes age-related ICC loss by up-regulating TRP53, which induces persistent ICC-SC cell cycle arrest without up-regulating canonical senescence markers.

Chronic Intermittent Hypoxia Triggers a Senescence-like Phenotype in Human White Preadipocytes

Obstructive sleep apnea (OSA) is a common sleep disorder associated with obesity. Emerging evidence suggest that OSA increases the risk of cardiovascular morbidity and mortality partly via accelerating the process of cellular aging. Thus, we sought to examine the effects of intermittent hypoxia (IH), a hallmark of OSA, on senescence in human white preadipocytes. We demonstrate that chronic IH is associated with an increased generation of mitochondrial reactive oxygen species along with increased prevalence of cells with nuclear localization of γH2AX & p16. A higher prevalence of cells positive for senescence-associated β-galactosidase activity was also evident with chronic IH exposure. Intervention with aspirin, atorvastatin or renin-angiotensin system (RAS) inhibitors effectively attenuated IH-mediated senescence-like phenotype. Importantly, the validity of in vitro findings was confirmed by examination of the subcutaneous abdominal adipose tissue which showed that OSA patients had a significantly higher percentage of cells with nuclear localization of γH2AX & p16 than non-OSA individuals (20.1 ± 10.8% vs. 10.3 ± 2.7%, Padjusted < 0.001). Furthermore, the frequency of dual positive γH2AX & p16 nuclei in adipose tissue of OSA patients receiving statin, aspirin, and/or RAS inhibitors was comparable to non-OSA individuals. This study identifies chronic IH as a trigger of senescence-like phenotype in preadipocytes. Together, our data suggest that OSA may be considered as a senescence-related disorder.

Human Obesity Induces Dysfunction and Early Senescence in Adipose Tissue-Derived Mesenchymal Stromal/Stem Cells

BACKGROUND

Chronic inflammatory conditions like obesity may adversely impact the biological functions underlying the regenerative potential of mesenchymal stromal/stem cells (MSC). Obesity can impair MSC function by inducing cellular senescence, a growth-arrest program that transitions cells to a pro-inflammatory state. However, the effect of obesity on adipose tissue-derived MSC in human subjects remains unclear. We tested the hypothesis that obesity induces senescence and dysfunction in human MSC.

METHODS

MSC were harvested from abdominal subcutaneous fat collected from obese and age-matched non-obese subjects (n = 40) during bariatric or kidney donation surgeries, respectively. MSC were characterized, their migration and proliferation assessed, and cellular senescence evaluated by gene expression of cell-cycle arrest and senescence-associated secretory phenotype markers. In vitro studies tested MSC effect on injured human umbilical vein endothelial cells (HUVEC) function.

RESULTS

Mean age was 59 ± 8 years, 66% were females. Obese subjects had higher body-mass index (BMI) than non-obese. MSC from obese subjects exhibited lower proliferative capacities than non-obese-MSC, suggesting decreased function, whereas their migration remained unchanged. Senescent cell burden and phenotype, manifested as p16, p53, IL-6, and MCP-1 gene expression, were significantly upregulated in obese subjects' MSC. BMI correlated directly with expression of p16, p21, and IL-6. Furthermore, co-incubation with non-obese, but not with obese-MSC, restored VEGF expression and tube formation that were blunted in injured HUVEC.

CONCLUSION

Human obesity triggers an early senescence program in adipose tissue-derived MSC. Thus, obesity-induced cellular injury may alter efficacy of this endogenous repair system and hamper the feasibility of autologous transplantation in obese individuals.

Postoperative nausea and vomiting after bariatric surgery and dexmedetomidine anesthetic: a propensity-weighted analysis

BACKGROUND

Patients undergoing laparoscopic bariatric surgery have high rates of postoperative nausea and vomiting (PONV). Dexmedetomidine based anesthetic could reduce PONV rates.

OBJECTIVES

To determine if PONV rates differ in patients undergoing laparoscopic bariatric surgery with anesthesia primarily based on dexmedetomidine or standard anesthetic management with inhalational agents and opioids.

SETTING

University hospital.

METHODS

From January 2014 to April 2018, 487 patients underwent laparoscopic bariatric surgery and met inclusion criteria (dexmedetomidine, n = 174 and standard anesthetic, n = 313 patients). In both groups, patients received preoperative PONV prophylaxis. We analyzed rates of PONV and moderate-to-deep sedation. A propensity score was calculated and outcomes were assessed using generalized estimating equations with inverse probability of treatment weighting.

RESULTS

Perioperative opioids and volatile anesthetics were reduced in dexmedetomidine patients. During anesthesia recovery the incidence of PONV was similar between dexmedetomidine and standard anesthetic patients (n = 37 [21.3%] versus n = 61 [19.5%], respectively; inverse probability of treatment weighting odds ratio = 1.35; 95% confidence interval .78-2.32, P = .281), and the incidence of sedation higher in dexmedetomidine patients (n = 86 [49.4%] versus n = 75 [24.0%]; inverse probability of treatment weighting odds ratio = 2.43; 95% confidence interval 1.47-4.03, P < 0.001). Rates of PONV and sedation were similar during the remainder of the hospital stay. A secondary sensitivity analysis was performed limited to dexmedetomidine patients who did not receive volatile and results were similar.

CONCLUSIONS

While dexmedetomidine-based anesthesia was associated with reduced opioid and volatile agents use, it was not associated with a reduction of PONV. The higher rates of moderate-to-deep sedation during anesthesia recovery observed with dexmedetomidine may be undesirable in morbidly obese patients.

Evolution of NAFLD and Its Management

The global prevalence of nonalcoholic fatty liver disease (NAFLD) is estimated to be 25% and continues to rise worldwide in the setting of the obesity epidemic. This increase is especially concerning because NAFLD is often a progressive disease that can be associated with significant complications such as liver cirrhosis, hepatocellular carcinoma, and an increase in liver-related and overall mortality. Because of the devastating complications and comorbidities, NAFLD is a very costly disease for the healthcare system, with estimated annual direct medical costs exceeding $100 billion in the United States alone. Given this progressive course, it is imperative to make the diagnosis in patients with risk factors (metabolic syndrome, weight gain, and insulin resistance/diabetes). Once the diagnosis is made, the focus should shift to treatment and monitoring for the development of associated complications. Given that currently no pharmaceutical intervention is approved for the treatment of NAFLD, focus shifts instead to mitigation of risk factors through avoidance of foods that are rich in red meat, trans fats, refined carbohydrates, and high-fructose corn syrup; are low fiber; and have high energy density. The landmark of treatment, however, continues to be weight loss and improvement of insulin resistance, often through a multimodality approach. The current manuscript reviews the clinical phenotypes of NAFLD, its risk factors, and pathogenesis, as well as treatment options including lifestyle modifications and dietary interventions, medical therapies, endoscopic bariatric interventions, and bariatric surgery.

Hepatic Fatty Acid Balance and Hepatic Fat Content in Humans With Severe Obesity

OBJECTIVE

Nonalcoholic fatty liver disease can lead to hepatic inflammation/damage. Understanding the physiological mechanisms that contribute to excess hepatic lipid accumulation may help identify effective treatments.

DESIGN

We recruited 25 nondiabetic patients with severe obesity scheduled for bariatric surgery. To evaluate liver export of triglyceride fatty acids, we measured very-low-density lipoprotein (VLDL)-triglyceride secretion rates the day prior to surgery using an infusion of autologous [1-14C]triolein-labeled VLDL particles. Ketone body response to fasting and intrahepatic long-chain acylcarnitine concentrations were used as indices of hepatic fatty acid oxidation. We measured intraoperative hepatic uptake rates of plasma free fatty acids using a continuous infusion of [U-13C]palmitate, combined with a bolus dose of [9,10-3H]palmitate and carefully timed liver biopsies. Total intrahepatic lipids were measured in liver biopsy samples to determine fatty liver status. The hepatic concentrations and enrichment from [U-13C]palmitate in diacylglycerols, sphingolipids, and acyl-carnitines were measured using liquid chromatography/tandem mass spectrometry.

RESULTS

Among study participants with fatty liver disease, intrahepatic lipid was negatively correlated with VLDL-triglyceride secretion rates (r = -0.92, P = 0.01) but unrelated to hepatic free fatty acid uptake or indices of hepatic fatty acid oxidation. VLDL-triglyceride secretion rates were positively correlated with hepatic concentrations of saturated diacylglycerol (r = 0.46, P = 0.02) and sphingosine-1-phosphate (r = 0.44, P = 0.03).

CONCLUSION

We conclude that in nondiabetic humans with severe obesity, excess intrahepatic lipid is associated with limited export of triglyceride in VLDL particles rather than increased uptake of systemic free fatty acids.

Multiparametric Magnetic Resonance Elastography Improves the Detection of NASH Regression Following Bariatric Surgery

Disease monitoring in nonalcoholic steatohepatitis (NASH) is limited by absence of noninvasive biomarkers of disease regression or progression. We aimed to examine the role of multiparametric three-dimensional magnetic resonance elastography (3D-MRE) and magnetic resonance imaging proton density fat fraction (MRI-PDFF) in the detection of NASH regression after interventions. This is a single-center prospective clinical trial of 40 patients who underwent bariatric surgery. Imaging and liver biopsies were obtained at baseline and 1 year after surgery. The imaging protocol consisted of multifrequency 3D-MRE to determine the shear stiffness at 60 Hz and damping ratio at 40 Hz, and MRI-PDFF to measure the fat fraction. A logistic regression model including these three parameters was previously found to correlate with NASH. We assessed the model performance in the detection of NASH resolution after surgery by comparing the image-predicted change in NAFLD activity score (delta NAS) to the histologic changes. A total of 38 patients (median age 43, 87% female, 30 of 38 with NAS ≥ 1, and 13 of 38 with NASH) had complete data at 1 year. The NAS decreased in all subjects with NAS ≥ 1 at index biopsy, and NASH resolved in all 13. There was a strong correlation between the predicted delta NAS by imaging and the delta NAS by histology (r = 0.73, P < 0.001). The strength of correlation between histology and the predicted delta NAS using single conventional parameters, such as the fat fraction by MRI-PDFF or shear stiffness at 60 Hz by MRE, was r = 0.69 (P < 0.001) and r = 0.43 (P = 0.009), respectively. Conclusion: Multiparametric 3D-MRE and MRI-PDFF can detect histologic changes of NASH resolution after bariatric surgery. Studies in a nonbariatric setting are needed to confirm the performance as a composite noninvasive biomarker for longitudinal NASH monitoring.

Proteomics in gastroparesis: unique and overlapping protein signatures in diabetic and idiopathic gastroparesis

Macrophage-based immune dysregulation plays a critical role in development of delayed gastric emptying in diabetic mice. Loss of anti-inflammatory macrophages and increased expression of genes associated with pro-inflammatory macrophages has been reported in full-thickness gastric biopsies from gastroparesis patients. We aimed to determine broader protein expression (proteomics) and protein-based signaling pathways in gastric biopsies of diabetic (DG) and idiopathic gastroparesis (IG) patients. Additionally, we determined correlations between protein expressions, gastric emptying, and symptoms. Full-thickness gastric antrum biopsies were obtained from nine DG patients, seven IG patients, and five nondiabetic controls. Aptamer-based SomaLogic tissue scan that quantitatively identifies 1,305 human proteins was used. Protein fold changes were computed, and differential expressions were calculated using Limma. Ingenuity pathway analysis and correlations were carried out. Multiple-testing corrected P < 0.05 was considered statistically significant. Seventy-three proteins were differentially expressed in DG, 132 proteins were differentially expressed in IG, and 40 proteins were common to DG and IG. In both DG and IG, "Role of Macrophages, Fibroblasts and Endothelial Cells" was the most statistically significant altered pathway [DG false discovery rate (FDR) = 7.9 × 10^-9; IG FDR = 6.3 × 10^-12]. In DG, properdin expression correlated with GCSI bloating (r = -0.99, FDR = 0.02) and expressions of prostaglandin G/H synthase 2, protein kinase C-ζ type, and complement C2 correlated with 4 h gastric retention (r = -0.97, FDR = 0.03 for all). No correlations were found between proteins and symptoms or gastric emptying in IG. Protein expression changes suggest a central role of macrophage-driven immune dysregulation in gastroparesis, specifically, complement activation in diabetic gastroparesis.NEW & NOTEWORTHY This study uses SOMAscan, a novel proteomics assay for determination of altered proteins and associated molecular pathways in human gastroparesis. Seventy-three proteins were changed in diabetic gastroparesis, 132 in idiopathic gastroparesis compared with controls. Forty proteins were common in both. Macrophage-based immune dysregulation pathway was most significantly affected in both diabetic and idiopathic gastroparesis. Proteins involved in the complement and prostaglandin synthesis pathway were associated with symptoms and gastric emptying delay in diabetic gastroparesis.

Senolytics decrease senescent cells in humans: Preliminary report from a clinical trial of Dasatinib plus Quercetin in individuals with diabetic kidney disease

Background

Senescent cells, which can release factors that cause inflammation and dysfunction, the senescence-associated secretory phenotype (SASP), accumulate with ageing and at etiological sites in multiple chronic diseases. Senolytics, including the combination of Dasatinib and Quercetin (D + Q), selectively eliminate senescent cells by transiently disabling pro-survival networks that defend them against their own apoptotic environment. In the first clinical trial of senolytics, D + Q improved physical function in patients with idiopathic pulmonary fibrosis (IPF), a fatal senescence-associated disease, but to date, no peer-reviewed study has directly demonstrated that senolytics decrease senescent cells in humans.

Methods

In an open label Phase 1 pilot study, we administered 3 days of oral D 100 mg and Q 1000 mg to subjects with diabetic kidney disease (N = 9; 68·7 ± 3·1 years old; 2 female; BMI:33·9 ± 2·3 kg/m²; eGFR:27·0 ± 2·1 mL/min/1·73m²). Adipose tissue, skin biopsies, and blood were collected before and 11 days after completing senolytic treatment. Senescent cell and macrophage/Langerhans cell markers and circulating SASP factors were assayed.

Findings

D + Q reduced adipose tissue senescent cell burden within 11 days, with decreases in p16^INK4A-and p21^CIP1-expressing cells, cells with senescence-associated β-galactosidase activity, and adipocyte progenitors with limited replicative potential. Adipose tissue macrophages, which are attracted, anchored, and activated by senescent cells, and crown-like structures were decreased. Skin epidermal p16^INK4A+ and p21^CIP1+ cells were reduced, as were circulating SASP factors, including IL-1α, IL-6, and MMPs-9 and −12.

Interpretation

“Hit-and-run” treatment with senolytics, which in the case of D + Q have elimination half-lives <11 h, significantly decreases senescent cell burden in humans.

Fund

NIH and Foundations.

ClinicalTrials.gov Identifier: NCT02848131. Senescence, Frailty, and Mesenchymal Stem Cell Functionality in Chronic Kidney Disease: Effect of Senolytic Agents.

The Role of Three-Dimensional Magnetic Resonance Elastography in the Diagnosis of Nonalcoholic Steatohepatitis in Obese Patients Undergoing Bariatric Surgery

The lack of reliable, noninvasive methods to diagnose early nonalcoholic steatohepatitis (NASH) is a major unmet need. We aimed to determine the diagnostic accuracy of three-dimensional magnetic resonance elastography (3D-MRE), with shear stiffness measured at 60 Hz, damping ratio at 40 Hz, and magnetic resonance imaging proton density fat fraction (MRI-PDFF) in the detection of NASH in individuals undergoing bariatric surgery. Obese adults at risk for NASH were enrolled between 2015 and 2017 (prospective cohort, n = 88) and 2010 and 2013 (retrospective cohort, n = 87). The imaging protocol consisted of multifrequency 3D-MRE (mf3D-MRE) with shear waves delivered at different frequencies to explore parameters that best correlated with histologic NASH, and MRI-PDFF to estimate steatosis. The prospective cohort was used to establish the optimal mf3D-MRE technical parameters for NASH detection. The two cohorts were then combined to derive predictive models of NASH and disease activity by nonalcoholic fatty liver disease activity score (NAS) using the three imaging parameters that correlated with NASH. A total of 175 patients (median age 45, 81% women, and 81 [46%] with histologic NASH) were used for model derivation. From the complex shear modulus output generated by mf3D-MRE, the damping ratio at 40 Hz and shear stiffness at 60 Hz best correlated with NASH. The fat fraction obtained from MRI-PDFF correlated with steatosis (P < 0.05 for all). These three parameters were fit into a logistic regression model that predicted NASH with cross-validated area under the receiver operating characteristic curve (AUROC) = 0.73, sensitivity = 0.67, specificity = 0.80, positive predictive value = 0.73 and negative predictive value = 0.74, and disease activity by NAS with cross-validated AUROC = 0.82. Conclusion: The mf3D-MRE allows identification of imaging parameters that predict early NASH and disease activity. This imaging biomarker represents a promising alternative to liver biopsy for NASH diagnosis and monitoring. The results provide motivation for further studies in nonbariatric cohorts.

Comparative Expression of Renin-Angiotensin Pathway Proteins in Visceral Versus Subcutaneous Fat

Body fat distribution contributes to obesity-related metabolic and cardiovascular disorders. Visceral fat is more detrimental than subcutaneous fat. However, the mechanisms underlying visceral fat-mediated cardiometabolic dysregulation are not completely understood. Localized increases in expression of the renin angiotensin system (RAS) in adipose tissue (AT) may be implicated. We therefore investigated mRNA and protein expression of RAS components in visceral versus subcutaneous AT using paired samples from individuals undergoing surgery (N = 20, body mass index: 45.6 ± 6.2 kg/m², and age: 44.6 ± 9.1 years). We also examined RAS-related proteins in AT obtained from individuals on renin angiotensin aldosterone system (RAAS) targeted drugs (N = 10, body mass index: 47.2 ± 9.3 kg/m², and age: 53.3 ± 10.1 years). Comparison of protein expression between subcutaneous and visceral AT samples showed an increase in renin (p = 0.004) and no change in angiotensinogen (p = 0.987) expression in visceral AT. Among proteins involved in angiotensin peptide generation, angiotensin converting enzyme (p = 0.02) was increased in subcutaneous AT while chymase (p = 0.001) and angiotensin converting enzyme-2 (p = 0.001) were elevated in visceral fat. Furthermore, visceral fat expression of angiotensin II type-2 receptor (p = 0.007) and angiotensin II type-1 receptor (p = 0.031) was higher, and MAS receptor (p < 0.001) was lower. Phosphorylated-p53 (p = 0.147), AT fibrosis (p = 0.138) and average adipocyte size (p = 0.846) were similar in the two depots. Nonetheless, visceral AT showed increased mRNA expression of inflammatory (TNFα, p < 0.001; IL-6, p = 0.001) and oxidative stress markers (NOX2, p = 0.038; NOX4, p < 0.001). Of note, mRNA and protein expression of RAS components did not differ between subjects taking or not taking RAAS related drugs. In summary, several RAS related proteins are differentially expressed in subcutaneous versus visceral AT. This differential expression may not alter AngII but likely increases Ang1-7 generation in visceral fat. These potential differences in active angiotensin peptides and receptor expression in the two depots suggest that localized RAS may not be involved in differences in visceral vs subcutaneous AT function in obese individuals. Our findings do not support a role for localized RAS differences in visceral fat-mediated development of cardiovascular and metabolic pathology.

Transcriptomic signatures reveal immune dysregulation in human diabetic and idiopathic gastroparesis

BACKGROUND

Cellular changes described in human gastroparesis have revealed a role for immune dysregulation, however, a mechanistic understanding of human gastroparesis and the signaling pathways involved are still unclear.

METHODS

Diabetic gastroparetics, diabetic non-gastroparetic controls, idiopathic gastroparetics and non-diabetic non-gastroparetic controls underwent full-thickness gastric body biopsies. Deep RNA sequencing was performed and pathway analysis of differentially expressed transcripts was done using Ingenuity®. A subset of differentially expressed genes in diabetic gastroparesis was validated in a separate cohort using QT-PCR.

RESULTS

111 genes were differentially expressed in diabetic gastroparesis and 181 in idiopathic gastroparesis with a log₂fold difference of | ≥ 2| and false detection rate (FDR) < 5%. Top canonical pathways in diabetic gastroparesis included genes involved with macrophages, fibroblasts and endothelial cells in rheumatoid arthritis, osteoarthritis pathway and differential regulation of cytokine production in macrophages and T helper cells by IL-17A and IL-17F. Top canonical pathways in idiopathic gastroparesis included genes involved in granulocyte adhesion and diapedesis, agranulocyte adhesion and diapedesis, and role of macrophages, fibroblasts and endothelial cells in rheumatoid arthritis. Sixty-five differentially expressed genes (log₂fold difference | ≥ 2|, FDR < 5%) were common in both diabetic and idiopathic gastroparesis with genes in the top 5 canonical pathways associated with immune signaling. 4/5 highly differentially expressed genes (SGK1, APOLD1, CXCR4, CXCL2, and FOS) in diabetic gastroparesis were validated in a separate cohort of patients using RT-PCR. Immune profile analysis revealed that genes associated with M1 (pro inflammatory) macrophages were enriched in tissues from idiopathic gastroparesis tissues compared to controls (p < 0.05).

CONCLUSIONS

Diabetic and idiopathic gastroparesis have both unique and overlapping transcriptomic signatures. Innate immune signaling likely plays a central role in pathogenesis of human gastroparesis.

Long-term outcomes of patients undergoing simultaneous liver transplantation and sleeve gastrectomy

Obesity is increasingly common before and after liver transplantation (LT), yet optimal management remains unclear. The aim of this study was to analyze the long-term outcomes for obese patients undergoing LT, including a noninvasive weight loss program and combined LT and sleeve gastrectomy (SG). Since 2006, all patients referred for LT with a body mass index (BMI) ≥35 kg/m² were enrolled. Patients who achieved weight loss (BMI <35) underwent LT alone, and those who did not underwent simultaneous LT + SG. Analysis of long-term outcomes for patients ≥3 years posttransplant was performed. Since 2006, there were 36 in the weight loss intervention (LT cohort) and 13 in the LT + SG cohort with >3 years of follow-up, whereas overall, a total of 29 patients underwent LT + SG. Patients in the LT cohort had less severe obesity at enrollment (40.0 ± 2.7 vs. LT + SG cohort 46.0 ± 4.5; P < 0.001). In the LT cohort, 83.3% (30 of 36) achieved >10% loss in total body weight (TBW) pre-LT. Three years posttransplant, 29.4% of patients in the LT cohort maintained >10% loss in TBW, whereas 100% of the LT + SG patients did (P < 0.001). Patients who underwent LT + SG maintained a significantly higher percentage of total body weight loss after 3 years of follow-up (LT cohort 3.9 ± 13.3% vs. LT + S G cohort 34.8 ± 17.3%; P < 0.001). Patients in the LT + SG also had a lower prevalence of hypertension, insulin resistance, and hepatic steatosis and required fewer antihypertensive medications and lipid agents at last follow-up.

CONCLUSION

Whereas weight loss before transplantation was achieved by obese patients, weight regain was common in the LT cohort. Combined LT + SG resulted in more effective and more durable weight loss, as well as fewer metabolic complications at last follow-up. (Hepatology 2018).

Guiding Patients Toward the Appropriate Surgical Treatment for Obesity: Should Presurgery Psychological Correlates Influence Choice Between Roux-en-Y Gastric Bypass and Vertical Sleeve Gastrectomy?

BACKGROUND

Helping patients determine which type of bariatric surgery, Roux-en-Y gastric bypass (RYGB) or vertical sleeve gastrectomy (VSG), may be the best treatment can be challenging. This study investigated psychological correlates and their influence on weight loss for patients who underwent RYGB or VSG.

METHODS

Four hundred twenty-two patients (RYGB = 305; VSG = 117) completed screening questionnaires presurgery and underwent surgery between August 2012 and April 2015. Associations between demographics and questionnaires with percentage weight change were evaluated using multivariable linear regression models.

RESULTS

Median age was 48 years and median BMI 45.3 kg/m2 presurgery. Median percentage changes in weight from baseline to years 1 and 2 follow-up were - 31.5% (range - 52.2 to - 9.2%) and - 31.2% (range - 50.0 to - 1.2%) for RYGB and 25.3% (range - 49.8 to - 4.7%) and - 23.3% (range - 58.9 to - 1.6%) for VSG, respectively. Linear regression models revealed that younger patients lost more weight than older patients at years 1 (RYGB p < 0.0001; VSG p = 0.0001) and 2 (RYGB p = 0.005; VSG p = 0.002). No psychological correlates were significantly associated with weight loss outcomes. Post hoc analyses comparing patients who had surgery to those in the same cohort who did not have surgery revealed significantly higher rates of depression (p < 0.001), anxiety (p < 0.001), binge eating (p = 0.003), night eating (p < 0.001), food addiction (p = 0.042), and lower self-efficacy (p < 0.001) among patients who did not have surgery.

DISCUSSION

Patients who are psychologically higher functioning are more likely to complete the evaluation process and undergo bariatric surgery. For patients who had surgery, psychological correlates were not associated with weight loss outcome for either RYGB or VSG. Implications for surgical choice are discussed.

Transoral outlet reduction with full thickness endoscopic suturing for weight regain after gastric bypass: a large multicenter international experience and meta-analysis

BACKGROUND AND AIMS

Many patients who undergo bariatric surgery will experience weight regain and effective strategies are needed to help these patients. A dilated gastrojejunal anastomosis (GJA) has been associated with weight recidivism after Roux-en-Y gastric bypass surgery (RYGB). Endoscopic transoral outlet reduction (TORe) with a full thickness endoscopic suturing device (Overstitch, Apollo Endosurgery, Austin, TX) is a minimally invasive therapeutic option. The primary aim of this project was to examine the safety and long-term efficacy data from three bariatric surgery centers and to conduct a systematic review and meta-analysis of the existing literature.

METHODS

Patients who underwent TORe with the Overstitch device from Jan 2013 to Nov 2016 at 3 participating bariatric surgery centers were included in the multicenter analysis. For the systematic review and meta-analysis, a comprehensive search of multiple English databases was conducted. Random effects model was used.

RESULTS

130 consecutive patients across three centers underwent TORe with an endolumenal suturing device. These patients (mean age 47; mean BMI 36.8) had experienced 24.6% weight regain from nadir weight after RYGB. Average weight lost at 6, 12, and 18 months after TORe was 9.31 ± 6.7 kg (N = 84), 7.75 ± 8.4  kg (N = 70), 8 ± 8.8 kg (N = 46) (p < 0.01 for all three time points), respectively. The meta-analysis included 330 patients. The pooled weight lost at 12 months was 8.4 kg (95% CI 6.5-10.3) with no significant heterogeneity across included studies (p = 0.07). Overall, 14% of patients experienced nausea, 18% had pain and 8% required a repeat EGD. No serious adverse events reported.

CONCLUSION

When implemented as part of a multidisciplinary intervention, TORe using endolumenal suturing is safe, reproducible, and effective approach to manage weight recidivism after RYGB and should be utilized early in the management algorithm of these patients.

Diabetic and idiopathic gastroparesis is associated with loss of CD206-positive macrophages in the gastric antrum

BACKGROUND

Animal studies have increasingly highlighted the role of macrophages in the development of delayed gastric emptying. However, their role in the pathophysiology of human gastroparesis is unclear. Our aim was to determine changes in macrophages and other cell types in the gastric antrum muscularis propria of patients with diabetic and idiopathic gastroparesis.

METHODS

Full thickness gastric antrum biopsies were obtained from patients enrolled in the Gastroparesis Clinical Research Consortium (11 diabetic, 6 idiopathic) and 5 controls. Immunolabeling and quantitative assessment was done for interstitial cells of Cajal (ICC) (Kit), enteric nerves protein gene product 9.5, neuronal nitric oxide synthase, vasoactive intestinal peptide, substance P, tyrosine hydroxylase), overall immune cells (CD45) and anti-inflammatory macrophages (CD206). Gastric emptying was assessed using nuclear medicine scintigraphy and symptom severity using the Gastroparesis Cardinal Symptom Index.

RESULTS

Both diabetic and idiopathic gastroparesis patients showed loss of ICC as compared to controls (Mean [standard error of mean]/hpf: diabetic, 2.28 [0.16]; idiopathic, 2.53 [0.47]; controls, 6.05 [0.62]; P=.004). Overall immune cell population (CD45) was unchanged but there was a loss of anti-inflammatory macrophages (CD206) in circular muscle (diabetic, 3.87 [0.32]; idiopathic, 4.16 [0.52]; controls, 6.59 [1.09]; P=.04) and myenteric plexus (diabetic, 3.83 [0.27]; idiopathic, 3.59 [0.68]; controls, 7.46 [0.51]; P=.004). There was correlation between the number of ICC and CD206-positive cells (r=.55, P=.008). Enteric nerves (PGP9.5) were unchanged: diabetic, 33.64 (3.45); idiopathic, 41.26 (6.40); controls, 46.80 (6.04).

CONCLUSION

Loss of antral CD206-positive anti-inflammatory macrophages is a key feature in human gastroparesis and it is associates with ICC loss.

Predicting Energy Expenditure in Extremely Obese Women

BACKGROUND

The most common clinical method for resting energy expenditure (REE) assessment is prediction equations. The purpose of this study was to elucidate which prediction equation is most accurate for REE assessment in extremely obese women.

METHODS

Fourteen extremely obese women (mean +/- SD body mass index: 49.8 +/- 6.2 kg/m(2); age: 49 +/- 10 years) were measured for height and weight and REE via indirect calorimetry (IC) by a metabolic cart system. Predicted REE was evaluated by several equations, including Harris-Benedict with actual body weight, Harris-Benedict with several adjustments to body weight, Cunningham, Mifflin-St Jeor, Owen, World Health Organization (WHO), and Bernstein equations. Accuracy was determined by mean difference data (IC REE - equation REE; Student's paired t-test), correlation coefficients, and agreement between methods by Bland-Altman plots. Accuracy was also evaluated on an individual basis, defined by the percentage of individuals within +/-10% of IC REE.

RESULTS

The Mifflin-St Jeor, Harris-Benedict with actual body weight, and the WHO equations were the most accurate in terms of mean predicted REE. The mean predicted REE values by all other equations were different from the IC REE values (p < .1). According to the individual data, the Mifflin-St Jeor was most accurate (14% outside +/-10% IC REE). The Harris-Benedict with actual body weight and WHO equations were less accurate on individual terms, with 29% and 42% of the predicted REE values, respectively, falling outside +/-10% of IC REE.

CONCLUSIONS

The Mifflin-St Jeor equation was most accurate method for REE assessment in extremely obese women.

Feasibility of Smartphone-Based Education Modules and Ecological Momentary Assessment/Intervention in Pre-bariatric Surgery Patients

BACKGROUND

Bariatric surgery is the most effective means of long-term weight loss. Knowledge gaps and lack of engagement in pre-operative patients can result in suboptimal outcome after surgery. Mobile technology, utilizing ecological momentary assessment (EMA)/intervention (EMI), has shown tremendous promise in changing behaviors. The primary objective of the study is to assess feasibility of using smartphone app with EMA/EMI functionality to prepare patients for bariatric surgery.

METHODS

Subjects seeking primary bariatric surgery were provided a smartphone app containing video-based education modules with linked assessments to evaluate mastery of topic. Subjects received algorithmic EMA text messages soliciting a response regarding lifestyle behavior. Upon answering, subjects received tailored EMI text messaging supporting healthy lifestyle.

RESULTS

Thirty subjects (27 female and 3 male), with age of 41.3 ± 11.4 years and BMI of 46.3 ± 7.4 kg/m(2) were enrolled. Twenty subjects completed the study. Ten subjects withdrew. On average, seven out of nine education modules were completed (70.9 ± 27.3%), and 37.8/123 EMA were answered (30.7 ± 21.7%), with response time of 17.4 ± 4.4 min. Subjects reported high satisfaction with the app. Many felt that the app fit into their routine "somewhat easily" or "very easily" (n = 12), had "perfect" amount of EMA messages (n = 8), and was very helpful in preparing for surgery (n = 7).

CONCLUSIONS

This study is the first to reveal the feasibility of using a smartphone app in the education and engagement of patients prior to bariatric surgery. The app was well-received based on subject satisfaction scores and revealed trends toward positive behavior change and increased weight loss. Randomized trials are necessary to delineate true efficacy.

Bariatric Surgery Patients' Response to a Chronic Pain Rehabilitation Program

BACKGROUND

Chronic pain (CP) is a prevalent and disabling diagnosis in obese individuals, but how bariatric surgery patients respond to chronic pain rehabilitation treatment programs has not previously been described.

OBJECTIVES

The aim of this study was to compare treatment outcomes of a chronic pain rehabilitation program (psychological and pain variables, medication use, treatment completion rates) for post-bariatric surgery patients to those of a non-bariatric surgery control group.

SETTING

Three week outpatient multidisciplinary chronic pain program in an academic medical center.

METHODS

This was a retrospective case-control study. Medical records of patients admitted to the Pain Rehabilitation Center at Mayo Clinic from 2008 to 2012 were reviewed. One hundred six patients with a history of bariatric surgery (cases) were identified and matched to 106 patients without a history of bariatric surgery (controls) on age, gender, and smoking status (n = 202). Matched t tests and McNemar's tests were used for analyses.

RESULTS

Mean age was 46 years; 91% were female and 58% were non-smokers. The majority of cases (71%) had undergone Roux-en-Y gastric bypass. Bariatric patients had higher rates of benzodiazepine use at discharge (33 vs. 19%, p = 0.0433) and were less likely to complete treatment (87 vs. 97%, p = 0.007) compared to controls. Morphine equivalent use for cases was 127.3 mg ± 135.4 (n = 62) compared to 88.3 mg ± 95.3 (n = 62), p = 0.12, for controls at admission.

CONCLUSIONS

These results suggest that bariatric patients may be at risk for treatment non-adherence and have difficulty reducing medication use in the treatment of chronic pain.

Factors associated with prolonged anesthesia recovery following laparoscopic bariatric surgery: a retrospective analysis

BACKGROUND

Phase I postanesthesia recovery is often prolonged after laparoscopic bariatric surgery. We hypothesized that postoperative respiratory depression is a major contributor to this delayed recovery.

METHODS

Medical records of all patients who had a laparoscopic bariatric surgical operation from January 1, 2009, to December 31, 2012, were reviewed for clinical, anesthetic, and postanesthesia variables. Recoveries were defined as discharge from the recovery room in ≤90 min and in >90 min (prolonged postanesthesia recovery). We compared characteristics of patients without prolonged recovery to those with prolonged recovery.

RESULTS

Of 781 bariatric patients, 304 (38.9 %) had prolonged recovery. These patients had more respiratory depression (29 vs 6 patients), more postoperative nausea and vomiting (106 vs 92 patients), more treatments of hypertension in the recovery room (49 vs 33 patients), and more opioid treatment (median intravenous morphine equivalents [interquartile range], 10.0 [3.0-15.0] vs 5.0 [0.0-10.5]) (P < 0.001 for all). On multivariable analysis, preoperative history of hypertension (P = 0.03), fewer prophylactic antiemetics received (P = 0.02), and longer surgical duration (P = 0.03) were associated with prolonged postanesthesia recovery.

CONCLUSIONS

Inadequate antiemetic prophylaxis and the treatment of postoperative hypertension were associated with prolonged postanesthesia recovery. Surprisingly, diagnosis of obstructive sleep apnea was not associated with prolonged recovery, which may be attributable to use of continuous positive airway pressure devices following emergence from anesthesia. Prolonged recovery in patients treated for hypertension may be related to institutional guidelines that require additional monitoring time after these medications are administered.

Bariatric surgery and diabetes: Implications of type 1 versus insulin-requiring type 2

OBJECTIVE

To report the impact of bariatric surgery on metabolic outcomes in patients with type 1 diabetes (DM1) versus insulin-requiring type 2 diabetes mellitus (IRDM2).

METHODS

Ten subjects with DM1 were compared with 118 subjects with IRDM2 at baseline and at 1 and 2 years post-bariatric surgery for: anthropometric measures, HbA1c, and number of medications (anti-hyperglycemic, anti-hypertensive, lipid-lowering).

RESULTS

DM1 and IRDM2 groups lost similar amounts of weight 2 years post-bariatric surgery (39.5 ± 14.7 kg vs. 40.3 ± 24.4 kg). IRDM2 subjects had significant improvements in HbA1c (7.8% ± 1.4% vs. 6.8% ± 1.4%, P value <0.0001) and decreases in number of anti-hyperglycemic (2.4 ± 0.8 vs. 0.7 ± 0.8, P value <0.0001), anti-hypertensive (2.2 ± 1.3 vs. 1.3 ± 1.2, P value <0.0001), and lipid-lowering (1.1 ± 0.8 vs. 0.6 ± 0.6, P value <0.0001) medications. DM1 subjects had no improvement in HbA1c (8.2% ± 1.6% vs. 7.8% ± 0.9%) or use of anti-hypertensive medications (2.1 ± 1.4 vs. 2.3 ± 1.5). Their use of lipid-lowering medications improved (1.0 ± 0.5 vs. 0.5 ± 0.8, P value 0.04).

CONCLUSIONS

Our study suggests that improved glycemic control may not be an expected outcome when considering bariatric surgery in patients with DM1; however, additional investigation is warranted.

Serum 25(OH) vitamin D concentration changes after Roux-en-Y gastric bypass surgery

OBJECTIVE

To describe serum 25(OH)D changes after Roux-en-Y gastric bypass (RYGB) and to determine if fat mass (FM) loss and vitamin D intake are associated with changes in serum levels.

DESIGN AND METHODS

The relationship between serum 25(OH)D and 1) FM, 2) weight, 3) % excess weight loss (EWL), and 4) BMI was investigated after controlling for potential confounders using a mixed effects linear model in 20 women before and up to 1-year post-RYGB. Subcutaneous (SAT) and visceral adipose tissue (VAT) vitamin D concentrations at time of RYGB were also evaluated.

RESULTS

Weight and FM decreased 1-year after surgery by 45 ± 1 kg and 37 ± 1 kg, respectively while 25(OH)D increased by 10 ± 2 ng mL(-1) . Weight, FM, BMI, and %EWL changes were associated with 25(OH)D change. VAT had an average 21% more vitamin D per gram than SAT and concentrations were highly correlated.

CONCLUSIONS

Although weight loss may lead to increased serum 25(OH)D after RYGB, low levels remain a concern in some patients 1-year postsurgery. Additional research is needed to clarify the relationship between adipose storage of vitamin D and serum 25(OH)D in obesity, and how that relationship might change after surgery. This could lead to improved clinical management of vitamin D in this ever-growing clinical population.

Routine upper gastrointestinal imaging is superior to clinical signs for detecting gastrojejunal leak after laparoscopic Roux-en-Y gastric bypass

BACKGROUND

There are myriad symptoms and signs of gastrojejunal leak; prompt recognition is essential. Many surgeons use clinical predictors to guide selective use of upper gastrointestinal imaging (UGI). The appropriate practice remains undefined.

STUDY DESIGN

A review of patients who underwent primary laparoscopic Roux-en-Y gastric bypass between January 2002 and December 2008 was conducted. All underwent routine UGI studies on postoperative day 1. Actual gastrojejunal leak within 7 days of surgery (actual leak [AL], radiologic leaks), operative reports, patient charts, and postoperative vital signs were retrospectively reviewed.

RESULTS

There were 2,099 operations. Eight ALs (0.43%) occurred without associated mortality. UGI was positive in 7 AL patients and falsely positive in 6 patients. The AL patients underwent laparoscopy on postoperative days 1 and 3 (n = 5 and n = 1, respectively), laparotomy on postoperative day 3 (n = 1), and peritoneal drainage (n = 1). False-positive UGIs prompted laparoscopy (n = 3) and close observation (n = 3). Pulse was 100 to 120 beats per minute in 2 patients and fever (>38.5°C) was present in 0 AL patients. AL patients had osteogenesis imperfecta (n = 1), macronodular cirrhosis (n = 1), positive bubble test (n = 3), and concomitant splenectomy (n = 1). No jejunojejunostomy leaks were identified.

CONCLUSIONS

Routine UGI after laparoscopic Roux-en-Y gastric bypass has greater sensitivity than clinical signs for detecting gastrojejunal leak. Delay in the diagnosis of leakage can impact mortality, and this suggests that indications for routine UGI might still exist. Tachycardia is not a reliable early marker of leak. There might be risk factors for leak in addition to vital signs, including patient medical history or intraoperative events, which should prompt routine UGI on postoperative day 1.

Changes in gastrointestinal hormones and leptin after Roux-en-Y gastric bypass surgery

BACKGROUND

Roux-en-Y gastric bypass (RYGB) imparts long-term weight loss, the mechanisms for which are not well understood. Changes in leptin and gastrointestinal (GI) hormones, including glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and ghrelin, may contribute to the relative success of RYGB compared with conventional weight loss methods. This study evaluated changes in GI hormones and leptin post-RYGB. The study also evaluated whether GI hormones differed after a short-term dose of protein or fat.

METHODS

GLP-1, PYY, ghrelin, and leptin were assessed in 16 women before RYGB and up to 1 year after RYGB. Plasma was collected before and at several times after a short-term equicaloric dose of protein or fat.

RESULTS

GLP-1 area under the curve (AUC) increased at week 6 and 1 year in the fat beverage (FAT-BEV) group compared with baseline. PYY AUC remained elevated at 1 year in the FAT-BEV group. Ghrelin AUC decreased at week 2, week 6, and 1 year in the protein beverage (PRO-BEV) group compared with baseline. Ghrelin AUC was lower in the PRO-BEV group compared with the FAT-BEV group at week 6. Fasted leptin decreased at all visits in both groups and was lower in the FAT-BEV group compared with the PRO-BEV group at 1 year.

CONCLUSIONS

Changes from baseline were evident for all GI hormones and leptin; some differences were evident soon after surgery (ghrelin, leptin), whereas others were maintained long term (GLP-1, PYY, ghrelin, leptin). In response to a short-term stimulus, protein suppressed ghrelin and fat potently stimulated GLP-1 and PYY. Future work in this area is warranted.