Postprandial metabolomics analysis reveals disordered serotonin metabolism in post-bariatric hypoglycemia.

BACKGROUNDBariatric surgery is a potent therapeutic approach for obesity and type 2 diabetes but can be complicated by post-bariatric hypoglycemia (PBH). PBH typically occurs 1-3 hours after meals, in association with exaggerated postprandial levels of incretins and insulin.METHODSTo identify mediators of disordered metabolism in PBH, we analyzed the plasma metabolome in the fasting state and 30 and 120 minutes after mixed meal in 3 groups: PBH (n = 13), asymptomatic post-Roux-en-Y gastric bypass (post-RYGB) (n = 10), and nonsurgical controls (n = 8).RESULTSIn the fasting state, multiple tricarboxylic acid cycle intermediates and the ketone ß-hydroxybutyrate were increased by 30%-80% in PBH versus asymptomatic. Conversely, multiple amino acids (branched-chain amino acids, tryptophan) and polyunsaturated lipids were reduced by 20%-50% in PBH versus asymptomatic. Tryptophan-related metabolites, including kynurenate, xanthurenate, and serotonin, were reduced 2- to 10-fold in PBH in the fasting state. Postprandially, plasma serotonin was uniquely increased 1.9-fold in PBH versus asymptomatic post-RYGB. In mice, serotonin administration lowered glucose and increased plasma insulin and GLP-1. Moreover, serotonin-induced hypoglycemia in mice was blocked by the nonspecific serotonin receptor antagonist cyproheptadine and the specific serotonin receptor 2 antagonist ketanserin.CONCLUSIONTogether these data suggest that increased postprandial serotonin may contribute to the pathophysiology of PBH and provide a potential therapeutic target.FUNDINGNational Institutes of Health (NIH) grant R01-DK121995, NIH grant P30-DK036836 (Diabetes Research Center grant, Joslin Diabetes Center), and Fundação de Amparo à Pesquisa do Estado de São Paulo grant 2018/22111-2.

Association between geospatial disparities in food security with weight loss and nutritional outcomes of metabolic surgery.

BACKGROUND: Food insecurity has been linked to higher rates of obesity. It has also been shown to diminish the effectiveness of weight loss strategies, including intensive lifestyle interventions. One essential component of food insecurity is having a geospatial disadvantage in access to healthy, affordable food, such as living within a food desert. This study aims to determine if food insecurity also impacts weight loss and nutritional outcomes in patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). METHODS: Clinical outcomes of patients who underwent RYGB or SG at Cleveland Clinic or affiliate regional hospitals in the United States from 2010 to 2018 were collected. Modified Retail Food Environmental Index (mRFEI) data was collected from the Center for Disease Control and merged with patient census tract data, allowing the patient cohort to be divided into those living in areas identified as food secure (mRFEI > 10%), food swamps (mRFEI = 1-10%), or food deserts (mRFEI = 0). Postoperative weight change was evaluated with quadratic growth mixture models and stratified by surgery type. RESULTS: A total of 5097 patients were included in this study cohort, including 3424 patients who underwent RYGB and 1673 who underwent SG. The median duration of follow-up was 2.3 years (IQR 0.89-3.6 years). Food security status was not associated with postoperative weight change (RYGB p = 0.73, SG p = 0.60), weight loss nadir (RYGB p = 0.60, SG p = 0.79), or weight regain (RYGB p = 0.93, SG p = 0.85). Deficiencies in nutritional markers at 1-2 years after surgery were also not significantly different between food security groups. CONCLUSION: Despite the established relationship between food insecurity and obesity, food insecurity does not negatively impact weight loss or nutritional outcomes following RYGB or SG, demonstrating metabolic surgery as a powerful and equitable tool for treating obesity. LEVEL OF EVIDENCE: IV.

EndoBridge 2023: highlights and pearls.

EndoBridge 2023 took place on October 20-22, 2023, in Antalya, Turkey. Accredited by the European Council, the 3-day scientific program of the 11th Annual Meeting of EndoBridge included state-of-the-art lectures and interactive small group discussion sessions incorporating interesting and challenging clinical cases led by globally recognized leaders in the field and was well attended by a highly diverse audience. Following its established format over the years, the program provided a comprehensive update across all aspects of endocrinology and metabolism, including topics in pituitary, thyroid, bone, and adrenal disorders, neuroendocrine tumors, diabetes mellitus, obesity, nutrition, and lipid disorders. As usual, the meeting was held in English with simultaneous translation into Russian, Arabic, and Turkish. The abstracts of clinical cases presented by the delegates during oral and poster sessions have been published in JCEM Case Reports. Herein, we provide a paper on highlights and pearls of the meeting sessions covering a wide range of subjects, from thyroid nodule stratification to secondary osteoporosis and from glycemic challenges in post-bariatric surgery to male hypogonadism. This report emphasizes the latest developments in the field, along with clinical approaches to common endocrine issues. The 12th annual meeting of EndoBridge will be held on October 17-20, 2024 in Antalya, Turkey.

Growth Hormone Mediators and Glycemic Control in Youths With Type 2 Diabetes: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Youth-onset type 2 diabetes (T2D) has a more aggressive phenotype than adult-onset T2D, including rapid loss of glycemic control and increased complication risk. Objective: To identify associations of growth hormone mediators with glycemic failure, beta cell function, and insulin sensitivity in youth-onset T2D. Design, Setting, and Participants: This post hoc secondary analysis of the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) randomized clinical trial, which enrolled participants from July 2004 to February 2009, included 398 participants from 15 university-affiliated medical centers with available plasma samples from baseline and 36 months. Participants were youths aged 10 to 17 years with a duration of T2D of less than 2 years who were randomized to metformin, metformin plus lifestyle intervention, or metformin plus rosiglitazone. Participants were followed up for a mean (SD) of 3.9 (1.5) years during the trial, ending in 2011. Statistical analysis was performed from August 2022 to November 2023. Exposure: Plasma insulin-like growth factor-1 (IGF-1), growth hormone receptor (GHR), and insulin-like growth factor binding protein 1 (IGFBP-1). Main Outcomes and Measures: Main outcomes were (1) loss of glycemic control during the TODAY study, defined as hemoglobin A1c (HbA1c) level of 8% or more for 6 months or inability to wean from insulin therapy, and (2) baseline and 36-month measures of glycemia (fasting glucose, HbA1c), insulin sensitivity (1/fasting C-peptide), high-molecular-weight adiponectin, and beta cell function (C-peptide index, C-peptide oral disposition index). Results: This analysis included 398 participants (mean [SD] age, 13.9 [2.0] years; 248 girls [62%]; 166 Hispanic participants [42%]; 134 non-Hispanic Black participants [34%], and 84 non-Hispanic White participants [21%]). A greater increase in IGF-1 level between baseline and 36 months was associated with lower odds of glycemic failure (odds ratio [OR], 0.995 [95% CI, 0.991-0.997]; P < .001) and higher C-peptide index per 100-ng/mL increase in IGF-1 (ß [SE], 0.015 [0.003]; P < .001). A greater increase in log2 GHR level between baseline and 36 months was associated with higher odds of glycemic failure (OR, 1.75 [95% CI, 1.05-2.99]; P = .04) and lower C-peptide index (ß [SE], -0.02 [0.006]; P < .001). A greater increase in log2 IGFBP-1 level between baseline and 36 months was associated with higher odds of glycemic failure (OR, 1.37 [95% CI, 1.09-1.74]; P = .007) and higher high-molecular-weight adiponectin (ß [SE], 431 [156]; P = .007). Conclusions and Relevance: This study suggests that changes in plasma growth hormone mediators are associated with loss of glycemic control in youth-onset T2D, with IGF-1 associated with lower risk and GHR and IGFBP-1 associated with increased risk. Trial Registration: ClinicalTrials.gov Identifier: NCT00081328.

Long-Term Outcomes of Medical Management vs Bariatric Surgery in Type 2 Diabetes.

Importance: Randomized clinical trials of bariatric surgery have been limited in size, type of surgical procedure, and follow-up duration. Objective: To determine long-term glycemic control and safety of bariatric surgery compared with medical/lifestyle management of type 2 diabetes. Design, Setting, and Participants: ARMMS-T2D (Alliance of Randomized Trials of Medicine vs Metabolic Surgery in Type 2 Diabetes) is a pooled analysis from 4 US single-center randomized trials conducted between May 2007 and August 2013, with observational follow-up through July 2022. Intervention: Participants were originally randomized to undergo either medical/lifestyle management or 1 of the following 3 bariatric surgical procedures: Roux-en-Y gastric bypass, sleeve gastrectomy, or adjustable gastric banding. Main Outcome and Measures: The primary outcome was change in hemoglobin A1c (HbA1c) from baseline to 7 years for all participants. Data are reported for up to 12 years. Results: A total of 262 of 305 eligible participants (86%) enrolled in long-term follow-up for this pooled analysis. The mean (SD) age of participants was 49.9 (8.3) years, mean (SD) body mass index was 36.4 (3.5), 68.3% were women, 31% were Black, and 67.2% were White. During follow-up, 25% of participants randomized to undergo medical/lifestyle management underwent bariatric surgery. The median follow-up was 11 years. At 7 years, HbA1c decreased by 0.2% (95% CI, -0.5% to 0.2%), from a baseline of 8.2%, in the medical/lifestyle group and by 1.6% (95% CI, -1.8% to -1.3%), from a baseline of 8.7%, in the bariatric surgery group. The between-group difference was -1.4% (95% CI, -1.8% to -1.0%; P < .001) at 7 years and -1.1% (95% CI, -1.7% to -0.5%; P = .002) at 12 years. Fewer antidiabetes medications were used in the bariatric surgery group. Diabetes remission was greater after bariatric surgery (6.2% in the medical/lifestyle group vs 18.2% in the bariatric surgery group; P = .02) at 7 years and at 12 years (0.0% in the medical/lifestyle group vs 12.7% in the bariatric surgery group; P < .001). There were 4 deaths (2.2%), 2 in each group, and no differences in major cardiovascular adverse events. Anemia, fractures, and gastrointestinal adverse events were more common after bariatric surgery. Conclusion and Relevance: After 7 to 12 years of follow-up, individuals originally randomized to undergo bariatric surgery compared with medical/lifestyle intervention had superior glycemic control with less diabetes medication use and higher rates of diabetes remission. Trial Registration: ClinicalTrials.gov Identifier: NCT02328599.

Cognition in patients with post-bariatric hypoglycemia.

OBJECTIVE: Bariatric surgery, a highly effective treatment for obesity and associated comorbidities, may improve cognition and brain volume in parallel with cardiometabolic function. However, some post-bariatric individuals develop post-bariatric hypoglycemia (PBH), which can be frequent and severe. The impact of recurrent hypoglycemia on cognition in PBH is unknown. The objective of this study was to determine whether individuals with PBH display reduced cognitive function compared with postsurgical counterparts without hypoglycemia. METHODS: Fourteen adults with a history of Roux-en-Y gastric bypass with hypoglycemia (PBH+, n = 7) or without PBH (PBH-, n = 7) completed assessments of memory, executive function, attention, and psychomotor speed. RESULTS: PBH+ individuals displayed significantly decreased performance in category fluency (p < 0.01), category switching (p < 0.01), and category switching accuracy (p < 0.01), compared with PBH- individuals. Performance in the first (p = 0.03) and third intervals (p = 0.045) of verbal fluency was significantly lower in PBH+ individuals versus PBH- individuals. All other assessments did not differ. CONCLUSIONS: PBH+ individuals may be at greater risk for cognitive impairment compared with PBH- individuals, as suggested by impaired semantic processing and cognitive flexibility, as well as greater difficulty initiating and sustaining word retrieval.

Ketone-Based Alert System for Insulin Pump Failures.

BACKGROUND: An increasing number of individuals with type 1 diabetes (T1D) manage glycemia with insulin pumps containing short-acting insulin. If insulin delivery is interrupted for even a few hours due to pump or infusion site malfunction, the resulting insulin deficiency can rapidly initiate ketogenesis and diabetic ketoacidosis (DKA). METHODS: To detect an event of accidental cessation of insulin delivery, we propose the design of ketone-based alert system (K-AS). This system relies on an extended Kalman filter based on plasma 3-beta-hydroxybutyrate (BOHB) measurements to estimate the disturbance acting on the insulin infusion/injection input. The alert system is based on a novel physiological model capable of simulating the ketone body turnover in response to a change in plasma insulin levels. Simulated plasma BOHB levels were compared with plasma BOHB levels available in the literature. We evaluated the performance of the K-AS on 10 in silico subjects using the S2014 UVA/Padova simulator for two different scenarios. RESULTS: The K-AS achieves an average detection time of 84 and 55.5 minutes in fasting and postprandial conditions, respectively, which compares favorably and improves against a detection time of 193 and 120 minutes, respectively, based on the current guidelines. CONCLUSIONS: The K-AS leverages the rapid rate of increase of plasma BOHB to achieve short detection time in order to prevent BOHB levels from rising to dangerous levels, without any false-positive alarms. Moreover, the proposed novel insulin-BOHB model will allow us to understand the efficacy of treatment without compromising patient safety.

Mapping the transcriptional landscape of human white and brown adipogenesis using single-nuclei RNA-seq.

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 Identified several novel transcription factors as potential targets for adipogenic/thermogenic drivers in humans. Among these novel candidates, we explored the role of TRPS1 in adipocyte differentiation and showed that its knockdown impairs white adipogenesis in vitro. 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.

Continuous glucose monitoring in patients with post-bariatric hypoglycaemia reduces hypoglycaemia and glycaemic variability.

AIM: To determine whether continuous glucose monitoring (CGM) can reduce hypoglycaemia in patients with post-bariatric hypoglycaemia (PBH). MATERIALS AND METHODS: In an open-label, nonrandomized, pre-post design with sequential assignment, CGM data were collected in 22 individuals with PBH in two sequential phases: (i) masked (no access to sensor glucose or alarms); and (ii) unmasked (access to sensor glucose and alarms for low or rapidly declining sensor glucose). Twelve participants wore the Dexcom G4 device for a total of 28 days, while 10 wore the Dexcom G6 device for a total of 20 days. RESULTS: Participants with PBH spent a lower percentage of time in hypoglycaemia over 24 hours with unmasked versus masked CGM (<3.3 mM/L, or <60 mg/dL: median [median absolute deviation {MAD}] 0.7 [0.8]% vs. 1.4 [1.7]%, P = 0.03; <3.9 mM/L, or <70 mg/dL: median [MAD] 2.9 [2.5]% vs. 4.7 [4.8]%; P = 0.04), with similar trends overnight. Sensor glucose data from the unmasked phase showed a greater percentage of time spent between 3.9 and 10 mM/L (70-180 mg/dL) (median [MAD] 94.8 [3.9]% vs. 90.8 [5.2]%; P = 0.004) and lower glycaemic variability over 24 hours (median [MAD] mean amplitude of glycaemic excursion 4.1 [0.98] vs. 4.4 [0.99] mM/L; P = 0.04). During the day, participants also spent a greater percentage of time in normoglycaemia with unmasked CGM (median [MAD] 94.2 [4.8]% vs. 90.9 [6.2]%; P = 0.005), largely due to a reduction in hyperglycaemia (>10 mM/L, or 180 mg/dL: median [MAD] 1.9 [2.2]% vs. 3.9 [3.6]%; P = 0.02). CONCLUSIONS: Real-time CGM data and alarms are associated with reductions in low sensor glucose, elevated sensor glucose, and glycaemic variability. This suggests CGM allows patients to detect hyperglycaemic peaks and imminent hypoglycaemia, allowing dietary modification and self-treatment to reduce hypoglycaemia. The use of CGM devices may improve safety in PBH, particularly for patients with hypoglycaemia unawareness.