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This manuscript provides a review of post-bariatric hypoglycemia (PBH) with a special focus on the role of the registered dietitian-nutritionist (RDN) and medical nutrition therapy (MNT) recommendations as foundational for management.As the number of bariatric surgeries rises yearly, with 256,000 performed in 2019, PBH is an increasingly encountered late complication. Following Roux-en-Y (RYGB) or vertical sleeve gastrectomy (VSG), about 1/3 of patients report symptoms suggestive of at least mild postprandial hypoglycemia, with severe and/or medically confirmed hypoglycemia in 1-10%. Anatomical alterations, changes in GLP1 and other intestinally derived hormones, excessive insulin response, reduced insulin clearance, impaired counterregulatory hormone response to hypoglycemia, and other factors contribute to PBH. MNT is the cornerstone of multidisciplinary treatment, with utilization of personal continuous glucose monitoring to improve safety when possible. While many individuals require pharmacotherapy, there are no currently approved medications for PBH. Increasing awareness and identification of individuals at risk for or with PBH is critical given the potential impact on safety, nutrition, and quality of life. A team-based approach involving the individual, the RDN, and other clinicians is essential in providing ongoing assessment and individualization of MNT in the long-term management of PBH.

Canonical growth hormone (GH)-dependent signaling is essential for growth and counterregulatory responses to hypoglycemia, but also may contribute to glucose homeostasis (even in the absence of hypoglycemia) via its impact on metabolism of carbohydrates, lipids and proteins, body composition, and cardiovascular risk profile. The aim of this review is to summarize recent data implicating GH action in metabolic control, including both IGF-1-dependent and -independent pathways, and its potential role as target for T2D therapy.Experimental blockade of the GHR can modulate glucose metabolism. Moreover, the soluble form of the GH receptor (GHR, or GHBP) was recently identified as a mediator of improvement in glycemic control in patients with T2D randomized to bariatric surgery vs. medical therapy. Reductions in GHR were accompanied by increases in plasma GH, but unchanged levels of both total and free IGF-1. Likewise, hepatic GHR expression is reduced following both RYGB and VSG in rodents. Emerging data indicate that GH signaling is important for regulation of long-term glucose metabolism in T2D. Future studies will be required to dissect tissue-specific GH signaling and sensitivity and their contributions to systemic glucose metabolism.

Decentralized sensing of analytes in remote locations is today a reality. However, the number of measurable analytes remains limited, mainly due to the requirement for time-consuming successive standard additions calibration used to address matrix effects and resulting in greatly delayed results, along with more complex and costly operation. This is particularly challenging in commonly used immunoassays of key biomarkers that typically require from 60 to 90 min for quantitation based on two standard additions, hence hindering their implementation for rapid and routine diagnostic applications, such as decentralized point-of-care (POC) insulin testing. In this work we have developed and demonstrated the theoretical framework for establishing a universal slope for direct calibration-free POC insulin immunoassays in serum samples using an electrochemical biosensor (developed originally for extended calibration by standard additions). The universal slope is presented as an averaged slope constant, relying on 68 standard additions-based insulin determinations in human sera. This new quantitative analysis approach offers reliable sample measurement without successive standard additions, leading to a dramatically simplified and faster assay (30 min vs 90 min when using 2 standard additions) and greatly reduced costs, without compromising the analytical performance while significantly reducing the analyses costs. The substantial improvements associated with the new universal slope concept have been demonstrated successfully for calibration-free measurements of serum insulin in 30 samples from individuals with type 1 diabetes using meticulous statistical analysis, supporting the prospects of applying this immunoassay protocol to routine decentralized POC insulin testing.

The ability to continuously monitor the concentration of specific molecules in the body is a long-sought goal of biomedical research. For this purpose, interstitial fluid (ISF) was proposed as the ideal target biofluid because its composition can rapidly equilibrate with that of systemic blood, allowing the assessment of molecular concentrations that reflect full-body physiology. In the past, continuous monitoring in ISF was enabled by microneedle sensor arrays. Yet, benchmark microneedle sensors can only detect molecules that undergo redox reactions, which limits the ability to sense metabolites, biomarkers, and therapeutics that are not redox-active. To overcome this barrier, here, we expand the scope of these devices by demonstrating the first use of microneedle-supported electrochemical, aptamer-based (E-AB) sensors. This platform achieves molecular recognition based on affinity interactions, vastly expanding the scope of molecules that can be sensed. We report the fabrication of microneedle E-AB sensor arrays and a method to regenerate them for multiple uses. In addition, we demonstrate continuous molecular measurements using these sensors in flow systems in vitro using single and multiplexed microneedle array configurations. Translation of the platform to in vivo measurements is possible as we demonstrate with a first E-AB measurement in the ISF of a rodent. The encouraging results reported in this work should serve as the basis for future translation of microneedle E-AB sensor arrays to biomedical research in preclinical animal models.

AIMS. Post-bariatric hypoglycemia (PBH) is an increasingly-recognized complication of bariatric surgery, but current therapies are limited. We hypothesized pramlintide would reduce hypoglycemia by slowing gastric emptying and reducing postprandial glucagon secretion, thus limiting postprandial glycemic excursions and insulin secretion. We thus determined the efficacy of pramlintide on frequency and severity of hypoglycemia in PBH. MATERIALS AND METHODS. Participants with PBH following gastric bypass were recruited from outpatient clinics at Joslin Diabetes Center, Boston, MA for an open-label study of pramlintide efficacy over 8 weeks. 23 participants were assessed for eligibility, 20 participants had at least 1 pramlintide dose, and 14 completed the study. Mixed meal tolerance test (MMTT) was performed at baseline and following 8 weeks of subcutaneous pramlintide with sequential dose increase to maximum of 120 micrograms (mean 69±32 mcg) 3 times daily. The primary endpoint was change in glucose excursions during MMTT. Secondary measures included MMTT insulin response, satiety and dumping score, percentage time with sensor glucose

BACKGROUND/PURPOSE: Litter size is a biological variable that strongly influences adult physiology in rodents. Despite evidence from previous decades and recent studies highlighting its major impact on metabolism, information about litter size is currently underreported in the scientific literature. Here, we urge that this important biological variable should be explicitly stated in research articles. RESULTS/CONCLUSION: Below, we briefly describe the scientific evidence supporting the impact of litter size on adult physiology and outline a series of recommendations and guidelines to be implemented by investigators, funding agencies, editors in scientific journals, and animal suppliers to fill this important gap.

Single-cell RNA sequencing (scRNA-seq) enables molecular characterization of complex biological tissues at high resolution. The requirement of single-cell extraction, however, makes it challenging for profiling tissues such as adipose tissue, for which collection of intact single adipocytes is complicated by their fragile nature. For such tissues, single-nucleus extraction is often much more efficient and therefore single-nucleus RNA sequencing (snRNA-seq) presents an alternative to scRNA-seq. However, nuclear transcripts represent only a fraction of the transcriptome in a single cell, with snRNA-seq marked with inherent transcript enrichment and detection biases. Therefore, snRNA-seq may be inadequate for mapping important transcriptional signatures in adipose tissue. In this study, we compare the transcriptomic landscape of single nuclei isolated from preadipocytes and mature adipocytes across human white and brown adipocyte lineages, with whole-cell transcriptome. We show that snRNA-seq is capable of identifying the broad cell types present in scRNA-seq at all states of adipogenesis. However, we also explore how and why the nuclear transcriptome is biased and limited, as well as how it can be advantageous. We robustly characterize the enrichment of nuclear-localized transcripts and adipogenic regulatory lncRNAs in snRNA-seq, while also providing a detailed understanding for the preferential detection of long genes upon using this technique. To remove such technical detection biases, we propose a normalization strategy for a more accurate comparison of nuclear and cellular data. Finally, we show successful integration of scRNA-seq and snRNA-seq data sets with existing bioinformatic tools. Overall, our results illustrate the applicability of snRNA-seq for the characterization of cellular diversity in the adipose tissue.

Context Severe hypoglycemia with neuroglycopenia, termed post-bariatric hypoglycemia (PBH). typically occurs postprandially, but it is also reported after activity or mid-nocturnally. Objective To quantify glycemia, glycemic variability, and magnitude/duration of low sensor glucose (SG) values in patients with PBH after Roux-en-Y gastric bypass (PBH-RYGB). Methods This retrospective analysis of data from an academic medical center included individuals with PBH-RYGB (n = 40), reactive hypoglycemia without gastrointestinal surgery (Non-Surg Hypo, n = 20), prediabetes (Pre-DM, n = 14), newly diagnosed T2D (n = 5), and healthy controls (HC, n = 38). Masked continuous glucose monitoring (Dexcom G4) was used to assess patterns over 24 hours, daytime (6 am–midnight) and nighttime (midnight–6 am). Prespecified measures included mean and median SG, variability, and percent time at thresholds of sensor glucose. Results Mean and median SG were similar for PBH-RYGB and HC (mean: 99.8 ± 18.6 vs 96.9 ± 10.2 mg/dL; median: 93.0 ± 14.8 vs 94.5 ± 7.4 mg/dL). PBH-RYGB had a higher coefficient of variation (27.3 ± 6.8 vs 17.9 ± 2.4%, P 2-fold greater time with SG Conclusion Patients with PBH-RYGB experience higher glycemic variability and frequency of SG

White adipose tissue is characterized by substantial functional heterogeneity based on anatomic location and developmental lineages. Such differences may contribute to depot-dependent differences in adipose regulation of systemic metabolism and the relative impact of adipose distribution (e.g. subcutaneous, SQ, vs. intraabdominal, IA) on risk for type 2 diabetes. While mouse adipose depot heterogeneity at the single-cell level has recently been explored, comparative analysis of human white fat depots is still in its infancy.Hereby, we establish a single-nucleus RNA sequencing (snRNA Seq) method for isolating and sequencing intact single nuclei from frozen human WAT biopsies. Using this approach, we analyzed the transcriptome of individual nuclei from 22 WAT SQ or IA biopsies (SQ, 12 IA, 3 paired) acquired from subjects (16 females, 3 males) with or without type 2 diabetes (T2D) across a wide BMI range (Mean+/-SD = 45.4+/-10.3 kg/m2. Range: 23.6 - 60.9 kg/m2) . We show that both SQ and IA human fat depots demonstrate substantial cell-to-cell heterogeneity, and identify multiple adipose and non-adipose-related cell types resident in both tissues. Our analysis identifies several novel subclusters, including two distinct mature adipocyte subclusters, characterized by low vs. high adiponectin expression and thus potentially contributing to adipose-mediated effects on systemic metabolism. Moreover, we identify a novel cluster present in both SQ and IA depots, with a unique transcriptomic signature marked by DAPK1 and enrichment for hedgehog signaling and endocytosis KEGG terms. Comprehensive cross-sample integrative bioinformatics analysis using the software tools scVI and VISION reveals distinct molecular markers and transcriptomic signatures between depots, between clusters, and across a range of BMI, that may serve as promising targets for understanding the mechanism by which specific adipose-resident cell populations mediate metabolic risk associated with adiposity. Disclosure V.Efthymiou: None. S.Kodani: None. A.Gupta: None. F.Shamsi: None. A.Streets: None. Y.Tseng: Consultant; Cellarity. M.Patti: Consultant; AstraZeneca, Eiger BioPharmaceuticals, Hanmi Pharm. Co., Ltd., MBX Biosciences, Poxel SA, Other Relationship; Fractyl Health, Inc., Xeris Pharmaceuticals, Inc., Research Support; Dexcom, Inc. Funding Chan Zuckerberg Initiative (CZI)

Adipogenesis is key to maintaining organism-wide energy balance and healthy metabolic phenotype, making it critical to thoroughly comprehend its molecular regulation in humans. By single-nuclei RNA-sequencing (snRNA-seq) of over 20,000 differentiating white and brown preadipocytes, we constructed a high-resolution temporal transcriptional landscape of human white and brown adipogenesis. White and brown preadipocytes were isolated from a single individual’s neck region, thereby eliminating inter-subject variability across two distinct lineages. These preadipocytes were also immortalized to allow for controlled, in vitro differentiation, allowing sampling of distinct cellular states across the spectrum of adipogenic progression. Pseudotemporal cellular ordering revealed the dynamics of ECM remodeling during early adipogenesis, and lipogenic/thermogenic response during late white/brown adipogenesis. Comparison with adipogenic regulation in murine models revealed several targets for potential adipogenic/thermogenic drivers in humans. Key adipogenic and lipogenic markers revealed in our analysis were applied to analyze publicly available scRNA-seq datasets; these confirmed unique cell maturation features in recently discovered murine preadipocytes, and revealed inhibition of adipogenic expansion in humans with obesity. Overall, our study presents a comprehensive molecular description of both white and brown adipogenesis in humans and provides an important resource for future studies of adipose tissue development and function in both health and metabolic disease state.

The gut-derived peptide hormones glucagon-like peptide-1 (GLP-1), oxyntomodulin (OXM), and peptide YY (PYY) are regulators of energy intake and glucose homeostasis and are thought to contribute to the glucose-lowering effects of bariatric surgery.To establish the metabolomic effects of a combined infusion of GLP-1, OXM, and PYY (tripeptide GOP) in comparison to a placebo infusion, Roux-en-Y gastric bypass (RYGB) surgery, and a very low-calorie diet (VLCD).Subanalysis of a single-blind, randomized, placebo-controlled study of GOP infusion (ClinicalTrials.gov NCT01945840), including VLCD and RYGB comparator groups.Twenty-five obese patients with type 2 diabetes or prediabetes were randomly allocated to receive a 4-week subcutaneous infusion of GOP (n = 14) or 0.9% saline control (n = 11). An additional 22 patients followed a VLCD, and 21 underwent RYGB surgery.Plasma and urine samples collected at baseline and 4 weeks into each intervention were subjected to cross-platform metabolomic analysis, followed by unsupervised and supervised modeling approaches to identify similarities and differences between the effects of each intervention.Aside from glucose, very few metabolites were affected by GOP, contrasting with major metabolomic changes seen with VLCD and RYGB.Treatment with GOP provides a powerful glucose-lowering effect but does not replicate the broader metabolomic changes seen with VLCD and RYGB. The contribution of these metabolomic changes to the clinical benefits of RYGB remains to be elucidated.

Context Post-bariatric hypoglycemia (PBH) is an increasingly encountered complication of upper gastrointestinal surgery; the prevalence of this condition is anticipated to rise given yearly increases in bariatric surgical procedures. While PBH is incompletely understood, there is a growing body of research describing the associated factors, mechanisms, and treatment approaches for this condition. Evidence acquisition Data are integrated and summarized from studies of individuals affected by PBH and hypoglycemia following upper gastrointestinal surgery obtained from PubMed searches (1990-2020). Evidence synthesis Information addressing etiology, incidence/prevalence, clinical characteristics, assessment, and treatment were reviewed and synthesized for the practicing physician. Literature reports were supplemented by clinical experience as indicated, when published data were not available. Conclusion PBH can be life-altering and severe for a subset of individuals. Given the chronic nature of this condition, and sequelae of both acute and recurrent episodes, increasing provider awareness of both the condition and associated risk factors is critical for assessment, prompt diagnosis, treatment, and preoperative identification of individuals at risk.

OBJECTIVE The overall aim of the Alliance of Randomized Trials of Medicine versus Metabolic Surgery in Type 2 Diabetes (ARMMS-T2D) consortium is to assess the durability and longer-term effectiveness of metabolic surgery compared with medical/lifestyle management in patients with type 2 diabetes (NCT02328599). RESEARCH DESIGN AND METHODS A total of 316 patients with type 2 diabetes previously randomly assigned to surgery (N = 195) or medical/lifestyle therapy (N = 121) in the STAMPEDE, TRIABETES, SLIMM-T2D, and CROSSROADS trials were enrolled into this prospective observational cohort. The primary outcome was the rate of diabetes remission (hemoglobin A1c [HbA1c] ≤6.5% for 3 months without usual glucose-lowering therapy) at 3 years. Secondary outcomes included glycemic control, body weight, biomarkers, and comorbidity reduction. RESULTS Three-year data were available for 256 patients with mean 50 ± 8.3 years of age, BMI 36.5 ± 3.6 kg/m2, and duration of diabetes 8.8 ± 5.7 years. Diabetes remission was achieved in more participants following surgery than medical/lifestyle intervention (60 of 160 [37.5%] vs. 2 of 76 [2.6%], respectively; P < 0.001). Reductions in HbA1c (Δ = −1.9 ± 2.0 vs. −0.1 ± 2.0%; P < 0.001), fasting plasma glucose (Δ = −52 [−105, −5] vs. −12 [−48, 26] mg/dL; P < 0.001), and BMI (Δ = −8.0 ± 3.6 vs. −1.8 ± 2.9 kg/m2; P < 0.001) were also greater after surgery. The percentages of patients using medications to control diabetes, hypertension, and dyslipidemia were all lower after surgery (P < 0.001). CONCLUSIONS Three-year follow-up of the largest cohort of randomized patients followed to date demonstrates that metabolic/bariatric surgery is more effective and durable than medical/lifestyle intervention in remission of type 2 diabetes, including among individuals with class I obesity, for whom surgery is not widely used.

AIMS: Long-term data from randomized clinical trials comparing metabolic (bariatric) surgery vs. a medical/lifestyle intervention for treatment of patients with obesity/overweight and type 2 diabetes (T2D) are lacking. The Alliance of Randomized Trials of Medicine vs. Metabolic Surgery in Type 2 Diabetes (ARMMS-T2D) is a consortium of four randomized trials designed to compare long-term efficacy and safety of surgery vs. medical/lifestyle therapy on diabetes control and clinical outcomes. MATERIALS AND METHODS: Patients with T2D and BMI of 27–45 kg/m(2) who were previously randomized to metabolic surgery (Roux-en-Y gastric bypass, adjustable gastric band, or sleeve gastrectomy) vs. medical/lifestyle intervention in the STAMPEDE, SLIMM-T2D, TRIABETES, or CROSSROADS trials have been enrolled in ARMMS-T2D for observational follow-up. The primary outcome is change in HbA(1c) after a minimum 7 years of follow-up, with additional analyses to determine rates of diabetes remission and relapse, as well as cardiovascular and renal endpoints. RESULTS: A total of 302 patients (192 surgical, 110 medical/lifestyle) previously randomized in the four parent studies were eligible for participation in the ARMMS-T2D observational study. Participant demographics were 71% Caucasian, 27% African-American, and 68% female. At baseline, age=50±8 yrs, BMI=36.5±3.5 kg/m(2), duration of diabetes=8.8±5.6 yrs, HbA(1c)=8.6±1.6 %, and fasting glucose=168±64 mg/dl. More than 35% of patients had a BMI

Background: The estimation of available active insulin remains a limitation of automated insulin delivery systems. Currently, insulin pumps calculate active insulin using mathematical decay curves, while quantitative measurements of insulin would explicitly provide person-specific PK insulin dynamics to assess remaining active insulin more accurately, permitting more effective glucose control. Methods: We performed the first clinical evaluation of an insulin immunosensor chip, providing near real-time measurements of insulin levels. In this study, we sought to determine the accuracy of the novel insulin sensor and assess its therapeutic risk and benefit by presenting a new tool developed to indicate the potential therapeutic consequences arising from inaccurate insulin measurements. Results: Nine adult participants with type-1 diabetes completed the study. The change from baseline in immunosensor-measured insulin levels was compared with values obtained by standard enzyme-linked immunosorbant assay (ELISA) after preprandial injection of insulin. The point-of-care quantification of insulin levels revealed similar temporal trends as those from the laboratory insulin ELISA. The results showed that 70% of the paired immunosensor-reference values were concordant, which suggests that the patient could take action safely based on insulin concentration obtained by the novel sensor. Conclusions: This proposed technology and preliminary feasibility evaluation show encouraging results for near real-time evaluation of insulin levels, with the potential to improve diabetes management. Real-time measurements of insulin provide person-specific insulin dynamics that could be used to make more informed decisions regarding insulin dosing, thus helping to prevent hypoglycemia and improve diabetes outcomes.

Epigenetic regulation is an important factor in glucose metabolism, but underlying mechanisms remain largely unknown. Here we investigated epigenetic control of systemic metabolism by bromodomain-containing proteins (Brds), which are transcriptional regulators binding to acetylated histone, in both intestinal cells and mice treated with the bromodomain inhibitor JQ-1. In vivo treatment with JQ-1 resulted in hyperglycemia and severe glucose intolerance. Whole-body or tissue-specific insulin sensitivity was not altered by JQ-1; however, JQ-1 treatment reduced insulin secretion during both in vivo glucose tolerance testing and ex vivo incubation of isolated islets. JQ-1 also inhibited expression of fibroblast growth factor (FGF)15 in the ileum and decreased FGF receptor 4-related signaling in the liver. These adverse metabolic effects of Brd4 inhibition were fully reversed by in vivo overexpression of FGF19, with normalization of hyperglycemia. At a cellular level, we demonstrate Brd4 binds to the promoter region of FGF19 in human intestinal cells; Brd inhibition by JQ-1 reduces FGF19 promoter binding and downregulates FGF19 expression. Thus, we identify Brd4 as a novel transcriptional regulator of intestinal FGF15/19 in ileum and FGF signaling in the liver, and a contributor to the gut-liver axis and systemic glucose metabolism.

The purpose of the current review is to summarize findings from the most recent and impactful studies which investigated human and mouse adipose tissue transcriptomes at a single-cell level. We provide perspective about the potential importance of data derived from these single-cell technologies in improving our understanding of the adipose organ and metabolic disease and likely future directions of this approach.The majority of single-cell or single-nuclei studies of the adipose organ so far have focused on investigating the stromal-vascular fraction (SVF) of mouse subcutaneous and intraabdominal white and interscapular brown fat depots. Few studies have also evaluated the impact of additional factors as drivers of adipose phenotypes, such as high-fat diet-induced obesity, adolescence, aging, and cold exposure. Recent studies have also investigated human cell lines and human fat biopsies across a range of body mass index (BMI) and in response to insulin resistance or T2D. These studies have identified numerous previously unexplored subpopulations of adipocyte progenitors, immune cells, and mature adipocytes in both mice and men. Single-cell and single-nuclei technologies have brought an explosion of data that have advanced our understanding of the adipose organ in health and disease. However, we are still at the dawn of achieving a complete and comprehensive map of the mouse and human adipose organ. Multi-modal single-cell approaches to identify both anatomic localization of specific cellular populations and epigenetic mechanisms responsible for observed transcriptomic patterns are underway and will likely provide an even deeper understanding of the adipose organ in response to health and disease.

With the increasing performance of bariatric surgery, rare complications are becoming prevalent. We review the diagnosis and treatment of dysautonomia after bariatric surgery and the limited treatment options available. We summarize the suggested mechanisms and explain why a complete understanding of the etiology has yet to be determined.In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review was performed.Of 448 studies identified in the literature search, 4 studies were reviewed, describing 87 patients diagnosed with dysautonomia. We present a patient who developed severe dysautonomia following conversion of sleeve gastrectomy to gastric bypass.Treatment needs to focus on optimizing nutrition, avoiding hypoglycemia, and optimizing volume status.

Few randomized trials have compared surgical versus lifestyle and pharmacologic approaches for type 2 diabetes (T2D) patients with mild to moderate obesity.This study examined resolution of hyperglycemia (A1C6.5% and fasting glucose126 mg/dL) 3 years after randomization to either a laparoscopic adjustable gastric band (LAGB) or 1-year diabetes and weight management (DWM) program.University medical center, United States.Forty T2D patients (mean ± SD: age, 51.3 ±10.0 yr; weight 109.5 ± 15.0 kg; body mass index [BMI] 36.5 ± 3.7 kg/mAt 3 years, 13% of 16 patients in LAGB and 5% of 17 patients in DWM achieved resolution of hyperglycemia (P = .601), with a modestly greater reduction in antidiabetic medications in the surgical group (P = .054). Reductions from baseline in A1C were sustained at 3 years in LAGB (-.82% [95% CI: -1.62 to -.01], P = .046) compared with DWM (+.23% [95% CI: -.57 to 1.03], P = .567). The surgical group had greater weight loss (-12.0 kg [95% CI: -15.9 to -8.1] versus -4.8 [95% CI: -8.6 to -.9], P = .010). HDL-cholesterol increased more after surgery (P = .003), but changes in triglycerides, LDL-cholesterol, and blood pressure did not differ between treatments. Diabetes- and obesity-specific quality of life improved comparably with both therapies.Achievement of American Diabetes Association targets for glucose, lipids, and blood pressure was similar with both treatment strategies. LAGB leads to greater sustained weight loss and higher HDL cholesterol compared with a DWM program. These findings may help guide patients with T2D and obesity when exploring options for diabetes and weight management.

Physiologic adaptations to fasting ensure health when food intake is limited; engaging these regulatory mechanisms is a potential tool for T2D and obesity. One approach utilizes SGLT2 inhibitors (SGLT2i), which reduce glucose, weight and cardiovascular/renal complications. In preclinical studies, we demonstrated SGLT2i induce a fasting-like transcriptional program in liver, and identified Ctcfl (CCTC-binding factor (CTCF)-like, also known as Boris, or Brother Of Regulator of Imprinting sites), as a top-ranking upregulated transcript in SGLT2i-treated C57BL/6J mice (↑1.5-fold, p=0.017). Ctcfl was also upregulated 2.5-fold with fasting as compared to ad lib-fed littermates. Thus, we hypothesize Ctcfl mediates fasting-related transcription via dynamic epigenetic regulation of chromatin accessibility.To identify drivers of increased Ctcfl expression in the fasting state, we performed in vitro studies in cultured AML12 hepatocytes revealing a key role for AMPK activation and mTOR inhibition as upstream regulators of Ctcfl. Transcriptomic analysis in siRNA-mediated Ctcfl knockdown (KD) vs. wild type (WT) cells indicates Ctcfl regulates critical pathways of lipid/carbohydrate metabolism, mitochondrial biogenesis, and transcriptional mediators of fasting (e.g., Hnf4, Srebf, Chrebp, Pgc1α). Single-cell RNAseq revealed distinct populations in Ctcfl-KD vs. WT cells, with the two largest sub-clusters of Ctcfl-KD cells enriched in genes associated with mTOR and insulin signaling and Tfeb target genes. Conversely, gain-of-function studies via overexpression of human CTCFL resulted in significant repression of key transcription factors and enzymes regulating lipid/cholesterol metabolism and gluconeogenesis (Pgc1α). In conclusion, we demonstrate that AMPK and mTor-mediated pathways regulate Ctcfl, a mediator of fasting-associated lipid and glucose transcriptional programs in the liver, potentially via alterations in chromatin accessibility. Disclosure V. Efthymiou: None. J. I. Chimene-weiss: None. L. Zhou: None. S. Osataphan: None. L. Su: None. M. Patti: Consultant; Self; Cello Health, Fractyl Laboratories, Inc., MBX, Poxel SA, WGBH, Other Relationship; Self; Xeris Pharmaceuticals, Inc., Research Support; Self; Dexcom, Inc.

There is limited Level-1 evidence from well-powered randomized controlled trials (RCTs) examining improved glycemic control after metabolic surgery in patients with type 2 diabetes (T2D) and obesity. ARMMS-T2D is a multi-center consortium conducting a follow-up study of 4 merged RCTs in 256 patients with baseline Class 1-3 obesity and T2D, randomly assigned to metabolic surgery (MS;Roux-en-Y gastric bypass, sleeve gastrectomy, or gastric banding) or intensive Medical/Lifestyle Intervention (MLI). Three years after randomization, T2D remission rates were higher after MS than MLI (37.5%, 60/160 vs. 2.6%, 2/76, respectively, P

Paternal obesity and diabetes are associated with cardiometabolic risk in offspring. To test the hypothesis that paternal metabolism could exert these effects via modulation of the sperm epigenome, we collected motile sperm at two study visits 3 months apart in men with and without T2D (NCT03860558). Sperm DNA methylation was quantified in 32 samples using the Infinium MethylationEPIC array. HbA1c was higher in men with T2D vs. controls (7.6±1.1% vs. 5.2±0.2%, n=9 vs. 7, p0.2), including sites annotated to SLFN5, MMAA, and LOC101927829. All 7 sites were hypermethylated in T2D, with mean difference in beta of 26.4%. Paired analysis between study visits for individual participants revealed no significant CpG, indicating stability of sperm methylation over time. Genes annotated to differentially methylated CpG at both study visits (n=89, nominal p In summary, DNA methylation is altered in motile sperm from men with T2D, with hypermethylation at significant CpG sites. These alterations may reflect differential transcriptional regulation at developmentally important loci, and should be investigated as potential contributors to the impact of paternal metabolism on offspring. Disclosure L. Su: None. D. Wolfs: None. M. Hivert: None. J. Patel: None. L. Richardson: None. C. O. Charmant: None. E. M. Isganaitis: None. M. Patti: Consultant; Self; Cello Health, Fractyl Laboratories, Inc., MBX, Poxel SA, WGBH, Other Relationship; Self; Xeris Pharmaceuticals, Inc., Research Support; Self; Dexcom, Inc. Funding National Institutes of Health (R21HD091974)

As wearable healthcare monitoring systems advance, there is immense potential for biological sensing to enhance the management of type 1 diabetes (T1D). The aim of this work is to describe the ongoing development of biomarker analytes in the context of T1D. Technological advances in transdermal biosensing offer remarkable opportunities to move from research laboratories to clinical point‐of‐care applications. In this review, a range of analytes, including glucose, insulin, glucagon, cortisol, lactate, epinephrine, and alcohol, as well as ketones such as beta‐hydroxybutyrate, will be evaluated to determine the current status and research direction of those analytes specifically relevant to T1D management, using both in‐vitro and on‐body detection. Understanding state‐of‐the‐art developments in biosensing technologies will aid in bridging the gap from bench‐to‐clinic T1D analyte measurement advancement.

Single-cell RNA-sequencing (scRNA-seq) enables molecular characterization of complex biological tissues at high resolution. The requirement of single-cell extraction, however, makes it challenging for profiling tissues such as adipose tissue where collection of intact single adipocytes is complicated by their fragile nature. For such tissues, single-nuclei extraction is often much more efficient and therefore single-nuclei RNA-sequencing (snRNA-seq) presents an alternative to scRNA-seq. However, nuclear transcripts represent only a fraction of the transcriptome in a single cell, with snRNA-seq marked with inherent transcript enrichment and detection biases. Therefore, snRNA-seq may be inadequate for mapping important transcriptional signatures in adipose tissue. In this study, we compare the transcriptomic landscape of single nuclei isolated from preadipocytes and mature adipocytes across human white and brown adipocyte lineages, with whole-cell transcriptome. We demonstrate that snRNA-seq is capable of identifying the broad cell types present in scRNA-seq at all states of adipogenesis. However, we also explore how and why the nuclear transcriptome is biased and limited, and how it can be advantageous. We robustly characterize the enrichment of nuclear-localized transcripts and adipogenic regulatory lncRNAs in snRNA-seq, while also providing a detailed understanding for the preferential detection of long genes upon using this technique. To remove such technical detection biases, we propose a normalization strategy for a more accurate comparison of nuclear and cellular data. Finally, we demonstrate successful integration of scRNA-seq and snRNA-seq datasets with existing bioinformatic tools. Overall, our results illustrate the applicability of snRNA-seq for characterization of cellular diversity in the adipose tissue.

e21104 Background: Immune checkpoint inhibitors (ICI) are standard of care in the treatment of non-small cell lung cancer (NSCLC). Predictive markers of response to ICI are being studied extensively. Obesity has been correlated with a better response to ICI in NSCLC and other types of cancer. This may in-part be related to high circulating leptin or impaired T-cell fatty acid oxidation within the tumor microenvironment. We aim to further explore the effects of obesity, dyslipidemia and other components of the metabolic syndrome such as diabetes on treatment outcomes on NSCLC patients receiving ICI. Methods: We conducted a retrospective cohort study in patients with NSCLC treated with pembrolizumab, nivolumab, durvalumab, cemiplimab or atezolizumab as monotherapy or combined with chemotherapy at Mount Auburn and Lahey Hospital between January 2016 to June 2021. Obesity was defined as body mass index (BMI) > 30 kg/m2, dyslipidemia and type 2 diabetes were defined by ICD-10 diagnosis codes. Overall survival was evaluated. Kaplan-Meier survival analysis and cox proportional hazards regression were used to assess correlation between overall survival and obesity, dyslipidemia, type 2 diabetes, metformin use and statin use. These were adjusted for age, biological sex, cancer stage, ECOG and smoking status. Patients with BMI < 18.5 were excluded. Results: We identified 408 patients with NSCLC who were treated with ICIs. Of these, 66.7% had adenocarcinoma, 29.1% had squamous and 4.2% had either adenosquamous, large cell or poorly differentiated carcinoma. Among these patients 23.3% were classified as obese, 55.6% had dyslipidemia and 23% had type 2 diabetes. Of these, 66% of patients received ICIs as monotherapy. Median survival was 840 days in obese patients compared to 483 days in non-obese patients (HR 0.66, CI 0.42-0.92, p = 0.014). Conversely, within this cohort, median survival in patients with dyslipidemia was 483 days when compared to 762 days in controls (HR 1.37, CI 1.07-1.81, p = 0.013). Overall survival was not significantly different between type 2 diabetes, metformin use or statin use. Conclusions: Our study shows a trend towards a better survival in obesity and poor survival associated with dyslipidemia. Obesity and dyslipidemia may be important markers of ICI response in patients with NSCLC regardless of treatment strategies. Further studies are needed to explore the molecular mediators within the metabolic syndrome that may provide a synergistic effect with immune checkpoint inhibitors.

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

Flow-limiting atherosclerotic lesions of arteries supplying the limbs are a cause of symptoms in patients with peripheral artery disease (PAD). Musculoskeletal metabolic factors also contribute to the pathophysiology of claudication, which is manifest as leg discomfort that impairs walking capacity. Accordingly, we conducted a case-control study to determine whether skeletal muscle metabolic gene expression is altered in PAD. Calf skeletal muscle gene expression of patients with PAD and healthy subjects was analyzed using microarrays. The top-ranking gene differentially expressed between PAD and controls (FDR < 0.001) wasPLA2G16, which encodes adipose-specific phospholipase A2 (AdPLA) and is implicated in the maintenance of insulin sensitivity and regulation of lipid metabolism. Differential expression was confirmed by qRT-PCR;PLA2G16was downregulated by 68% in patients with PAD (p< 0.001). Expression ofPla2g16was then measured in control (db/+) and diabetic (db/db) mice that underwent unilateral femoral artery ligation. There was significantly reduced expression ofPla2g16in the ischemic leg of both control and diabetic mice (by 51%), with significantly greater magnitude of reduction in the diabetic mice (by 79%). We conclude that AdPLA is downregulated in humans with PAD and in mice with hindlimb ischemia. Reduced AdPLA may contribute to impaired walking capacity in patients with PAD via its effects on skeletal muscle metabolism. Further studies are needed to fully characterize the role of AdPLA in PAD and to investigate its potential as a therapeutic target for alleviating symptoms of claudication. American Diabetes AssociationAmerican Diabetes Association [K12HL083786] National Heart, Lung, and Blood InstituteUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Heart Lung & Blood Institute (NHLBI) [K12HL083786] American Heart AssociationAmerican Heart Association [10SDG4200060, 18SFRN33900085] Joslin Diabetes Research Center [P30 DK036836] info:eu-repo/semantics/publishedVersion

Poor maternal diet increases the risk of obesity and type 2 diabetes in offspring, adding to the ever-increasing prevalence of these diseases. In contrast, we find that maternal exercise improves the metabolic health of offspring, and here, we demonstrate that this occurs through a vitamin D receptor-mediated increase in placental superoxide dismutase 3 (SOD3) expression and secretion. SOD3 activates an AMPK/TET signaling axis in fetal offspring liver, resulting in DNA demethylation at the promoters of glucose metabolic genes, enhancing liver function, and improving glucose tolerance. In humans, SOD3 is upregulated in serum and placenta from physically active pregnant women. The discovery of maternal exercise-induced cross talk between placenta-derived SOD3 and offspring liver provides a central mechanism for improved offspring metabolic health. These findings may lead to novel therapeutic approaches to limit the transmission of metabolic disease to the next generation.

While bariatric surgery can promote remission of type 2 diabetes (T2D), it can also result in severe hypoglycemia, termed post-bariatric hypoglycemia (PBH). Hypoglycemia is most often recognized after meals, but also can occur after activity or during mid-nocturnal hours and can yield unawareness and disabling neuroglycopenia. We used blinded CGM (Dexcom G4) to characterize glycemia, glycemic variability (GV), and severity and length of hypoglycemia in patients with PBH with prior roux-en-Y gastric bypass (PBH, n=40). We compared results to those of individuals with reactive hypoglycemia with no prior GI surgery (Hypo, no-GS, n=20) and to publicly available Dexcom G4 data from 3 additional groups: healthy controls (HC, n=38), prediabetes (Pre-DM, n=14), and T2D (n=5). Metrics were assessed over 24 hours as well as during daytime (6 AM to midnight) and nighttime (midnight to 6 AM) independently. Mean and median sensor glucose (SG) were similar for PBH and HC (mean: 99.8±18.6 vs. 96.9±10.2 mg/dL; median: 93.0±14.8 vs. 94.5±7.4 mg/dL, p>0.05 for both). By contrast, PBH had higher coefficient of variation (27.3±6.8 vs. 17.9±2.4%, p In summary, patients with PBH experience higher GV and greater severity and frequency of hypoglycemia compared to HC, especially at night. Future studies should explore the potential of CGM technology in assisting PBH patients to recognize early hypoglycemia and prevent severe hypoglycemia. Disclosure D. Lee: None. J. Dreyfuss: None. C.M. Mulla: None. M. Patti: Consultant; Self; Fractyl Laboratories, Inc. Research Support; Self; Dexcom, Inc., Xeris Pharmaceuticals, Inc. Other Relationship; Self; Academy of Nutrition and Dietetics, American Diabetes Association, American Society of Metabolic and Bariatric Surgery, Endocrine Society, Insulet Corporation, King Abdullah International Medical Research Center, SUNY Downstate. Funding National Institutes of Health (R01DK121995); National Institute of Diabetes and Digestive and Kidney Diseases (T32DK007260)

Insulin monitoring is clinically relevant for diabetes management. We present a first evaluation of an insulin immunosensor as a step towards point-of-care devices to enhance automated insulin delivery for T1D. The sensor is a novel, wearable, minimally invasive microneedle/microfluidic device for real-time insulin monitoring. To validate the sensor, a mid-study analysis was performed on 4 adults with T1D (43±12 years, 75% male) using insulin pumps. Insulin lispro or aspart was injected via syringe just prior to breakfast. Insulin levels were collected prior to injection and over the next 4h. Insulin quantification was performed using the participants’ serum samples extracted from venous blood. The change in real-time immunosensor-measured insulin levels was compared with values obtained by ELISA in a central lab. At each time point, a median insulin level was derived from replicate immunosensor samples. Concordance of immunosensor and ELISA insulin levels was assessed as a comparison of their changes from baseline (Figure). The mean absolute relative difference between immunosensor and venous insulin levels was 16%, 8%, and 18% at 1, 2, and 4h after the baseline measurement, respectively. The results of the 1st phase real-time insulin immunosensor evaluation are promising and may provide data to improve current insulin decay curve assumptions used in insulin-on-board approximations. Disclosure K.L. Wolkowicz: None. E. Vargas: None. H. Teymourian: None. F. Tehrani: None. J.E. Pinsker: Advisory Panel; Self; Medtronic. Consultant; Self; Eli Lilly and Company, Tandem Diabetes Care. Research Support; Self; Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Tandem Diabetes Care. Speaker’s Bureau; Self; Tandem Diabetes Care. M. Church: None. M. Piper: None. F.J. Doyle: Research Support; Self; DreaMed Diabetes, Tandem Diabetes Care, Xeris Pharmaceuticals, Inc. Stock/Shareholder; Self; Mode AGC. Other Relationship; Self; Dexcom, Inc., Insulet Corporation, Roche Diabetes Care. M. Patti: Consultant; Self; Fractyl Laboratories, Inc. Research Support; Self; Dexcom, Inc., Xeris Pharmaceuticals, Inc. Other Relationship; Self; Academy of Nutrition and Dietetics, American Diabetes Association, American Society of Metabolic and Bariatric Surgery, Endocrine Society, Insulet Corporation, King Abdullah International Medical Research Center, SUNY Downstate. L.M. Laffel: Advisory Panel; Self; Roche Diabetes Care. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc., ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Insulogic LLC, Janssen Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk Inc., Sanofi US. J. Wang: None. E. Dassau: Consultant; Self; Eli Lilly and Company. Research Support; Self; Dexcom, Inc., DreaMed Diabetes, Tandem Diabetes Care, Xeris Pharmaceuticals, Inc. Speaker’s Bureau; Self; Roche Diabetes Care. Other Relationship; Self; Dexcom, Inc., Insulet Corporation, Roche Diabetes Care. Funding The Leona M. and Harry B. Helmsley Charitable Trust (2018PG-TID061); Dexcom, Inc. (IIS-2019-052)

Paternal obesity has a detrimental impact on metabolic health of his offspring, suggesting an opportunity for preventive strategies prior to conception. Indeed, treatment of male mice with the SGLT2 inhibitor canagliflozin (CANA, 25mg/kg/d) for 4 weeks prior to breeding reduces obesity, hepatic steatosis, and glycemia in offspring. To identify molecular mediators, we analyzed mRNA-seq in fetal and adult liver from male offspring of fathers treated with chow (pCHOW), 60% high-fat diet (pHFD), or HFD+CANA (pCANA). Differentially expressed genes were identified using Limma (R). In adult offspring, paternal SGLT2 inhibition altered the expression of 213 genes (FDR In summary, paternal CANA modulates liver mitochondrial gene expression in his offspring during both embryonic and adult life, suggesting that improvements in oxidative capacity may mediate the protective effects of paternal SGLT2 inhibition. Disclosure L. Su: None. S. Osataphan: None. C. Macchi: None. J.I. Chimene-Weiss: None. J. Dreyfuss: None. H. Pan: None. M. Patti: Consultant; Self; Fractyl Laboratories, Inc. Research Support; Self; Dexcom, Inc., Xeris Pharmaceuticals, Inc. Other Relationship; Self; Academy of Nutrition and Dietetics, American Diabetes Association, American Society of Metabolic and Bariatric Surgery, Endocrine Society, Insulet Corporation, King Abdullah International Medical Research Center, SUNY Downstate. Funding National Institutes of Health (R01DK106193, P30DK046200)

One severe complication of gastrointestinal and bariatric surgery is post-bariatric hypoglycemia (PBH). Affected patients may develop severe hypoglycemia, typically 1-3 hours after meals. While exaggerated postprandial incretin hormone and insulin secretion has been implicated, additional contributors to hypoglycemia remain uncertain. We performed untargeted semiquantitative metabolomic analysis of plasma samples collected in the fasting state and at 30 and 120 minutes after a liquid mixed meal (Ensure) in 13 individuals with PBH post-RYGB, 10 asymptomatic post-RYGB, and 8 overweight/obese individuals without history of gastrointestinal surgery. Multiple analytes were reduced in the fasting state in PBH, including 10 amino acids (Leu, Ile, Val, Ala, Phe, Tyr, Met, Trp, Thr, Asn, nominal p Disclosure R. Ferraz-Bannitz: None. C.M. Mulla: None. J. Dreyfuss: None. H. Pan: None. M. Patti: Consultant; Self; Fractyl Laboratories, Inc. Research Support; Self; Dexcom, Inc., Xeris Pharmaceuticals, Inc. Other Relationship; Self; Academy of Nutrition and Dietetics, American Diabetes Association, American Society of Metabolic and Bariatric Surgery, Endocrine Society, Insulet Corporation, King Abdullah International Medical Research Center, SUNY Downstate. Funding National Institutes of Health (R01DK121995, P30DK046200)

To improve the power of mediation in high-throughput studies, here we introduce High-throughput mediation analysis (Hitman), which accounts for direction of mediation and applies empirical Bayesian linear modeling. We apply Hitman in a retrospective, exploratory analysis of the SLIMM-T2D clinical trial in which participants with type 2 diabetes were randomized to Roux-en-Y gastric bypass (RYGB) or nonsurgical diabetes/weight management, and fasting plasma proteome and metabolome were assayed up to 3 years. RYGB caused greater improvement in HbA1c, which was mediated by growth hormone receptor (GHR). GHR’s mediation is more significant than clinical mediators, including BMI. GHR decreases at 3 months postoperatively alongside increased insulin-like growth factor binding proteins IGFBP1/BP2; plasma GH increased at 1 year. Experimental validation indicates (1) hepatic GHR expression decreases in post-bariatric rats; (2) GHR knockdown in primary hepatocytes decreases gluconeogenic gene expression and glucose production. Thus, RYGB may induce resistance to diabetogenic effects of GH signaling. Trial Registration: Clinicaltrials.gov NCT01073020., Factors underlying the effects of gastric bypass surgery on glucose homeostasis are incompletely understood. Here the authors developed and applied high-throughput mediation analysis to identify proteome/metabolome mediators of improved glucose homeostasis after to gastric bypass surgery, and report that improved glycemia was mediated by the growth hormone receptor.

Poor paternal diet has emerged as a risk factor for metabolic disease in offspring, and alterations in sperm may be a major mechanism mediating these detrimental effects of diet. Although exercise in the general population is known to improve health, the effects of paternal exercise on sperm and offspring metabolic health are largely unknown. Here, we studied 7-week-old C57BL/6 male mice fed a chow or high-fat diet and housed either in static cages (sedentary) or cages with attached running wheels (exercise trained). After 3 weeks, one cohort of males was sacrificed and cauda sperm obtained, while the other cohort was bred with chow-fed sedentary C57BL/6 females. Offspring were chow fed, sedentary, and studied during the first year of life. We found that high-fat feeding of sires impairs glucose tolerance and increases the percentage of fat mass in both male and female offspring at 52 weeks of age. Strikingly, paternal exercise suppresses the effects of paternal high-fat diet on offspring, reversing the observed impairment in glucose tolerance, percentage of fat mass, and glucose uptake in skeletal muscles of the offspring. These changes in offspring phenotype are accompanied by changes in sperm physiology, as, for example, high-fat feeding results in decreased sperm motility, an effect normalized in males subject to exercise training. Deep sequencing of sperm reveals pronounced effects of exercise training on multiple classes of small RNAs, as multiple changes to the sperm RNA payload observed in animals consuming a high-fat diet are suppressed by exercise training. Thus, voluntary exercise training of male mice results in pronounced improvements in the metabolic health of adult male and female offspring. We provide the first in-depth analysis of small RNAs in sperm from exercise-trained males, revealing a marked change in the levels of multiple small RNAs with the potential to alter phenotypes in the next generation.

ContextPlasma betaine correlates with insulin sensitivity in humans. Betaine supplementation improves metabolic effects in mice fed a high-fat diet.ObjectiveTo assess metabolic effects of oral betaine in obese participants with prediabetes.DesignA 12-week, parallel arm, randomized, double-masked, placebo-controlled trial.SettingUniversity-affiliated hospital.Participants and InterventionsPersons with obesity and prediabetes (N = 27) were randomly assigned to receive betaine 3300 mg orally twice daily for 10 days, then 4950 mg twice daily for 12 weeks, or placebo.Main Outcome MeasuresChanges from baseline in insulin sensitivity, glycemia, hepatic fat, and endothelial function.ResultsThere was a 16.5-fold increase in plasma dimethylglycine [dimethylglycine (DMG); P < 0.0001] levels, but modest 1.3- and 1.5-fold increases in downstream serine and methionine levels, respectively, in the betaine vs placebo arm. Betaine tended to reduce fasting glucose levels (P = 0.08 vs placebo) but had no other effect on glycemia. Insulin area under curve after oral glucose was reduced for betaine treatment compared with placebo (P = 0.038). Insulin sensitivity, assessed by euglycemic hyperinsulinemic clamp, was not improved. Serum total cholesterol levels increased after betaine treatment compared with placebo (P = 0.032). There were no differences in change in intrahepatic triglyceride or endothelial function between groups.ConclusionDMG accumulation supports DMG dehydrogenase as rate limiting for betaine metabolism in persons with prediabetes. Betaine had little metabolic effect. Additional studies may elucidate mechanisms contributing to differences between preclinical and human responses to betaine, and whether supplementation of metabolites downstream of DMG improves metabolism.

ContextHypoglycemia, occurring after bariatric and other forms of upper gastrointestinal surgery, is increasingly encountered by clinical endocrinologists. The true frequency of this condition remains uncertain, due, in part, to differences in the diagnostic criteria and in the affected populations, as well as relative lack of patient and physician awareness and understanding of this condition. Postbariatric hypoglycemia can be severe and disabling for some patients, with neuroglycopenia (altered cognition, seizures, and loss of consciousness) leading to falls, motor vehicle accidents, and job and income loss. Moreover, repeated episodes of hypoglycemia can result in hypoglycemia unawareness, further impairing safety and requiring the assistance of others to treat hypoglycemia.ObjectiveIn this review, we summarize and integrate data from studies of patients affected by hypoglycemia after Roux-en-Y gastric bypass (RYGB) surgery, obtained from PubMed searches (1990 to 2017) and reference searches of relevant retrieved articles. Whereas hypoglycemia can also be observed after sleeve gastrectomy and fundoplication, this review is focused on post-RYGB, given the greater body of published clinical studies at present.Outcome MeasuresData addressing specific aspects of diagnosis, pathophysiology, and treatment were reviewed by the authors; when not available, the authors have provided opinions based on clinical experience with this challenging condition.ConclusionsHypoglycemia, occurring after gastric bypass surgery, is challenging for patients and physicians alike. This review provides a systematic approach to diagnosis and treatment based on the underlying pathophysiology.

We previously demonstrated that paternal obesity is associated with offspring metabolic risk during later life, and that paternal SGLT2i treatment improves offspring metabolic phenotypes. Since the placenta is a key determinant of prenatal growth and development, we hypothesized the placenta could mediate the impact of paternal obesity and paternal SGLT2i treatment. Male C57BL/6J mice were fed standard chow (Purina 9F) or 60% high-fat diet (HFD, D12492, Research Diet), or 60% HFD plus the SGLT2 inhibitor canagliflozin (CANA, 25 mg/kg/d) for 4 weeks before mating with chow-fed females. Placenta were collected on E16.5, and RNA-seq was performed on placenta from male offspring (paternal chow, pChow, n=4, pHFD, n=5, and pHFD+CANA, n=4), and differentially expressed genes were identified using Limma. Placenta weight was significantly lower in pHFD (0.089±0.004 g, 7 litters from 6 fathers) vs. both pChow (0.108±0.011 g, 4 litters, 4 fathers) and pHFD+CANA (0.107±0.013 g, 5 litters, 5 fathers)(p1.8) for gene sets in steroid metabolic, drug catabolic, and protein-containing complex remodeling processes. Genes responsible for enrichment included cholesterol biosynthesis (Hmgcs1), transport (Apob, Apoa1/2/4, Apom, Apoc1, Vldlr, Pcsk9) and steroid hormone biosynthesis genes (Hsd3b1, Cyp11b1), all upregulated in pHFD by 1.5-3-fold. These results suggest pHFD could potentially affect maternal and fetal cholesterol homeostasis. pHFD+CANA altered expression of 154 genes vs. pHFD (7 up-, 147 down, FDR |1.5|); 18 gene sets were downregulated by pHFD+CANA (GSEA NES

Bariatric surgery is increasingly recognized as one of the most effective interventions to help patients achieve significant and sustained weight loss, as well as improved metabolic and overall health. Unfortunately, the cellular and physiological mechanisms by which bariatric surgery achieves weight loss have not been fully elucidated, yet are critical to understanding the central role of the intestinal tract in whole-body metabolism and to developing novel strategies for the treatment of obesity. In this review, we provide an overview of potential mechanisms contributing to weight loss, including effects on regulation of energy balance and both central and peripheral nervous system regulation of appetite and metabolism. Moreover, we highlight the importance of the gastrointestinal tract, including alterations in bile acid physiology, secretion of intestinally derived hormones, and the microbiome, as a potent mediator of improved metabolism in postbariatric patients.

Hypoglycemia is increasingly recognized as a complication of bariatric surgery. Although medications are often required, medical nutrition therapy remains the key cornerstone for successful prevention of hypoglycemia in patients with post-bariatric hypoglycemia (PBH). We provide suggested approaches to the dietary management of PBH, incorporating data from both the medical literature and extensive clinical experience in an academic referral center for PBH. The overall goal of medical nutrition therapy for PBH is to reduce postprandial surges in glucose, which often trigger surges in insulin secretion and promote subsequent hypoglycemia. Thus, strategies focus on controlled portions of low glycemic index carbohydrates, avoidance of rapidly-absorbed carbohydrates, adjustment of timing of meals and snacks, and attention to personal and cultural barriers to implementation.

Objective Postprandial hypoglycemia is an infrequent but disabling complication of Roux-en-Y gastric bypass (RYGB) surgery. Controversy still exists as to whether the postprandial hyperinsulinemia observed is due to inherent changes in pancreatic β-cell mass or function or to reversible alterations caused by RYGB anatomy. We aimed to determine if gastric feeding or reversal of RYGB would normalize postprandial glucose and hormone excursions in patients with symptomatic hypoglycemia. Methods We completed a prospective study of six patients with severe symptomatic RYGB hypoglycemia who underwent RYGB reversal. An additional subject without hypoglycemia who underwent RYGB reversal was also studied prospectively. Mixed meal tolerance testing (MTT) was done orally (RYGB anatomy), via gastrostomy tube in the excluded stomach in the setting of RYGB, and several months after RYGB reversal. Results All subjects reported symptomatic improvement of hypoglycemia after reversal of RYGB. Weight gain after reversal was moderate and variable. Postprandial glucose, insulin, and GLP-1 excursions were significantly diminished with gastric feeding and after reversal. Insulin secretion changed proportional to glucose levels and insulin clearance increased after reversal. Glucagon/insulin ratios were similar throughout study. We further compared the impact of modified sleeve gastrectomy reversal surgery to those with restoration of complete stomach and found no significant differences in weight regain or in postprandial glucose or hormone levels. Conclusions Reversal of RYGB is an effective treatment option for severe postprandial hypoglycemia. The pathophysiology of this disorder is primarily due to RYGB anatomy resulting in altered glucose, gut, and pancreatic hormone levels and decreased insulin clearance, rather than inherent β-cell hyperplasia or hyperfunction., Graphical abstract, Highlights • Prospective study of gastric feeding and bypass reversal in hypoglycemic subjects. • Altered gut anatomy is the main driver of postmeal glucose and hormone excursions. • Beta-cell function is not inherently altered in gastric-bypass related hypoglycemia. • Bypass reversal is effective therapy for gastric-bypass related hypoglycemia.