Citations 21

Leptin‐Melanocortin pathway variants and gastric emptying in patients with obesity

Neurogastroenterology & Motility | February 16, 2024 | Volume: 36 | Issue: 5 | Pages: No page available

10.1111/nmo.14764 | PMID 38361111

AbstractBackgroundAccelerated gastric emptying (GE) is a trait seen in obesity. Mutations in the hypothalamic leptin‐melanocortin 4 receptor (Leptin‐MC4R) pathway have been associated with obesity. We sought to investigate the association of leptin‐MC4R pathway variants and GE in patients with obesity.MethodsThis is a cross‐sectional study of patients with a history of severe obesity that were genotyped and completed a GE test by scintigraphy. We evaluated the percentage of GE (GE %) at 2 and 4 h between both groups using ANCOVA with weight and sex as covariates. We subdivide patients into carriers based on the location of the identified variants (i.e., upstream or downstream of the Leptin‐MC4R pathway) and compared them with noncarriers using ANOVA. Results are presented as mean and standard deviation (± SD).Key ResultsA total of 95 patients; nine carriers (67% females; 39.78 ± 12.33 years; BMI: 49.14 ± 12.96 kg/m2) and 86 noncarriers (87% female; 49.98 ± 13.74 years; BMI: 40.75 ± 6.29 kg/m2) were included. At 2 and 4 h, carriers had a delayed GE when compared noncarriers (p = 0.03 and p = 0.005, respectively). In carriers, when compared upstream carriers vs. downstream carriers vs. noncarriers by location there was a significant difference in GE among groups at 2 h and at 4 h (p = 0.02 and p = 0.01, respectively).Conclusions & InferencesCarriers of heterozygous variants in the Leptin‐MC4R pathway had a delayed GE compared to noncarriers. These findings point the important relationship between the Leptin‐MC4R pathway and gastric motility.
Neurohormonal response patterns to hunger, satiation, and postprandial fullness in normal weight, anorexia nervosa, and obesity

Neurogastroenterology & Motility | November 6, 2023 | Volume: 36 | Issue: 1 | Pages: No page available

10.1111/nmo.14695 | PMID 37926943

AbstractBackgroundFood intake is regulated by homeostatic and hedonic systems that interact in a complex neuro‐hormonal network. Dysregulation in energy intake can lead to obesity (OB) or anorexia nervosa (AN). However, little is known about the neurohormonal response patterns to food intake in normal weight (NW), OB, and AN.Material & MethodsDuring an ad libitum nutrient drink (Ensure®) test (NDT), participants underwent three pseudo‐continuous arterial spin labeling (pCASL) MRI scans. The first scan was performed before starting the NDT after a > 12 h overnight fast (Hunger), the second after reaching maximal fullness (Satiation), and the third 30‐min after satiation (postprandial fullness). We measured blood levels of ghrelin, cholecystokinin (CCK), glucagon‐like peptide (GLP‐1), and peptide YY (PYY) with every pCASL‐MRI scan. Semiquantitative cerebral blood flow (CBF) maps in mL/100 gr brain/min were calculated and normalized (nCBF) with the CBF in the frontoparietal white matter. The hypothalamus (HT), nucleus accumbens [NAc] and dorsal striatum [DS] were selected as regions of interest (ROIs).ResultsA total of 53 participants, 7 with AN, 17 with NW (body‐mass index [BMI] 18.5–24.9 kg/m2), and 29 with OB (BMI ≥30 kg/m2) completed the study. The NW group had a progressive decrease in all five ROIs during the three stages of food intake (hunger, satiation, and post‐prandial fullness). In contrast, participants with OB showed a minimal change from hunger to postprandial fullness in all five ROIs. The AN group had a sustained nCBF in the HT and DS, from hunger to satiation, with a subsequent decrease in nCBF from satiation to postprandial fullness. All three groups had similar hormonal response patterns with a decrease in ghrelin, an increase in GLP‐1 and PYY, and no change in CCK.ConclusionConditions of regulated (NW) and dysregulated (OB and AN) energy intake are associated with distinctive neurohormonal activity patterns in response to hunger, satiation, and postprandial fullness.
Effectiveness and Safety of Antiobesity Medications in Patients With Obesity and Inflammatory Bowel Disease

American Journal of Gastroenterology | October 9, 2023 | Volume: 119 | Issue: 6 | Pages: 1197-1200

10.14309/ajg.0000000000002490 | PMID 37811776

INTRODUCTION: Limited data exist evaluating antiobesity medications (AOM) in patients with inflammatory bowel disease (IBD). METHODS: We performed a case-control study evaluating the effectiveness and safety of AOM in patients with IBD with obesity, matched to non-IBD controls. RESULTS: After 12 months, the case (n = 36) and control (n = 36) groups achieved similar percent total body weight loss of −6.9 ± 8.3 and −8.1 ± 7.0 ( P = 0.30), respectively. Side effect profiles were similar between groups. Seven patients experienced an IBD flare, all managed medically. DISCUSSION: AOM use in patients with IBD demonstrated similar effectiveness and safety when compared with that observed in the non-IBD population.
Effect of endoscopic sleeve gastroplasty on gastric emptying, motility and hormones: a comparative prospective study

Gut | October 14, 2022 | Volume: 72 | Issue: 6 | Pages: 1073-1080

10.1136/gutjnl-2022-327816 | PMID 36241388

Objective Endoscopic sleeve gastroplasty (ESG) has gained global adoption but our understanding of its mechanism(s) of action and durability of efficacy is limited. We sought to determine changes in gastric emptying (GE), gastric motility (GM), hormones and eating behaviours after ESG. Design A priori-designed single-centre substudy of a large US randomised clinical trial, adults with obesity were randomised to ESG or lifestyle interventions (LS) alone. We measured GE, hormones and weight loss and assessed eating behaviours. In a subset of ESG patients, we assessed GM. The primary outcome was the change in T1/2 (min) at 3 months, and secondary outcomes were changes in weight, GE, GM, hormones and eating behaviours. We used t-test analyses and regression to determine the association between GE and weight loss. Results 36 (ESG=18; LS=18) participated in this substudy. Baseline characteristics were similar between the two groups. At 3 months, T1/2 was delayed in the ESG group (n=17) compared with the LS group (n=17) (152.3±47.3 vs 89.1±27.9; p<0.001). At 12 months, T1/2 remained delayed in the ESG group (n=16) vs control group (n=14) (137±37.4 vs 90.1±23.4; p<0.001). Greater delays in GE at 3 months were associated with greater weight loss. GM was preserved and fasting ghrelin, glucagon-like peptide 1 and polypeptide YY significantly increased 18 months after ESG. Conclusion ESG promotes weight loss through several key mechanistic pathways involving GE and hormones while preserving GM. These findings further support clinical adoption of this technique for the management of obesity. Trial registration number NCT03406975.
Effects of liraglutide on gastrointestinal functions and weight in obesity: A randomized clinical and pharmacogenomic trial

Obesity | July 27, 2022 | Volume: 30 | Issue: 8 | Pages: 1608-1620

10.1002/oby.23481 | PMID 35894080

Abstract Objective This study aimed to determine the effects of a long‐acting glucagon‐like peptide‐1 (GLP‐1) receptor agonist, liraglutide, and placebo subcutaneously over 16 weeks on weight and gastric functions and to evaluate associations of single‐nucleotide polymorphisms in GLP1R (rs6923761) and TCF7L2 (rs7903146) with effects of liraglutide. Methods The study conducted a randomized, parallel‐group, placebo‐controlled, 16‐week trial of liraglutide, escalated to 3 mg subcutaneously daily in 136 otherwise healthy adults with obesity. Weight, gastric emptying of solids (GES), gastric volumes, satiation, and body composition measured at baseline and after treatment were compared in two treatment groups using analysis of covariance. Results Liraglutide ( n = 59) and placebo ( n = 65) groups completed treatment. Relative to placebo, liraglutide increased weight loss at 5 and 16 weeks (both p < 0.05), slowed time to half GES (T 1/2 ) at 5 and 16 weeks (both p < 0.001), and increased fasting gastric volume ( p = 0.01) and satiation ( p < 0.01) at 16 weeks. GES T 1/2 was positively correlated with weight loss on liraglutide (both p < 0.001). After 16 weeks of liraglutide, GLP1R rs6923761 (AG/AA vs. GG) was associated with reduced percent body fat ( p = 0.062), and TCF7L2 rs7903146 (CC vs. CT/TT) was associated with lower body weight ( p = 0.015). Conclusions Liraglutide, 3 mg, induces weight loss with delay in GES T 1/2 and reduces calorie intake. Slowing GES and variations in GLP1R and TCF7L2 are associated with liraglutide effects in obesity.
Effect of caloric intake and macronutrient composition on intestinal cholesterol absorption and bile acids in patients with obesity

American Journal of Physiology-Gastrointestinal and Liver Physiology | June 21, 2022 | Volume: 323 | Issue: 3 | Pages: G157-G164

10.1152/ajpgi.00108.2022 | PMID 35727128

We show how switching from a regular diet to an HCHF increases cholesterol absorption in patients with normal weight and obesity. The decrease in cholesterol absorption from an HCHF to an LCLF, on the other hand, was only seen in normal-weight controls, underlining the importance of body weight in this regulation. In addition, changes in caloric and fat content had an immediate and direct effect on hepatic bile acid production.
Association of gastric emptying with postprandial appetite and satiety sensations in obesity

Obesity | July 27, 2021 | Volume: 29 | Issue: 9 | Pages: 1497-1507

10.1002/oby.23204 | PMID 34313001

AbstractObjectiveSatiety, defined as the duration of the sensation of fullness, is usually measured by validated visual analog scales (VAS) for appetite. Gastric function plays a key role in food intake regulation. However, the association between gastric emptying (GE) and VAS appetite is unknown.MethodsIn this cross‐sectional study, 134 participants (mean [SEM] age = 39 [0.8] years, mean [SEM] BMI = 38 [0.5] kg/m2, 67% females) completed simultaneous measurements of GE and VAS appetite. After a 320‐kcal meal, GE was measured by scintigraphy and appetite by validated 100‐mm VAS for 240 minutes. Satiation was defined as calories consumed to terminate meal and was measured by an ad libitum meal. GE, VAS, and ad libitum meal tests were measured on the same day. Percent of meal retention in the stomach, VAS area under curve (AUC0‐240 min), and overall appetite score (OAS) were calculated. Pearson correlation (ρ) determined the association of GE with VAS appetite and satiation. Appetite components were also analyzed by quartiles based on GE120 min.ResultsGE120 min was correlated with sensation of VAS hungerAUC(0‐240 min) (ρ = 0.24, p = 0.004), fullnessAUC(0‐240 min) (ρ = 0.16, p = 0.05), and OASAUC(0‐240 min) (ρ = 0.20, p = 0.02). Patients with rapid GE120 min had a mean increase in VAS hungerAUC(0‐240 min) by 32 mm/min (15.62%, p = 0.03) compared with normal/slow GE120 min.ConclusionsGE is associated with the sensations of appetite, and rapid GE is associated with increased appetite, which may contribute to weight gain.
Precision Medicine for Obesity

Digestive Disease Interventions | May 17, 2021 | Volume: 05 | Issue: 03 | Pages: 239-248

10.1055/s-0041-1729945 | PMID 36203650

Abstract Obesity is a multifactorial disease with a variable and underwhelming weight loss response to current treatment approaches. Precision medicine proposes a new paradigm to improve disease classification based on the premise of human heterogeneity, with the ultimate goal of maximizing treatment effectiveness, tolerability, and safety. Recent advances in high-throughput biochemical assays have contributed to the partial characterization of obesity's pathophysiology, as well as to the understanding of the role that intrinsic and environmental factors, and their interaction, play in its development and progression. These data have led to the development of biological markers that either are being or will be incorporated into strategies to develop personalized lines of treatment for obesity. There are currently many ongoing initiatives aimed at this; however, much needs to be resolved before precision obesity medicine becomes common practice. This review aims to provide a perspective on the currently available data of high-throughput technologies to treat obesity.
Selection of Antiobesity Medications Based on Phenotypes Enhances Weight Loss: A Pragmatic Trial in an Obesity Clinic

Obesity | March 24, 2021 | Volume: 29 | Issue: 4 | Pages: 662-671

10.1002/oby.23120 | PMID 33759389

ObjectiveLittle is known about the predictors of response to obesity interventions.MethodsIn 450 participants with obesity, body composition, resting energy expenditure, satiety, satiation, eating behavior, affect, and physical activity were measured by validated studies and questionnaires. These variables were used to classify obesity phenotypes. Subsequently, in a 12‐month, pragmatic, real‐world trial performed in a weight management center, 312 patients were randomly assigned to phenotype‐guided treatment or non‐phenotype‐guided treatment with antiobesity medications: phentermine, phentermine/topiramate, bupropion/naltrexone, lorcaserin, and liraglutide. The primary outcome was weight loss at 12 months.ResultsFour phenotypes of obesity were identified in 383 of 450 participants (85%): hungry brain (abnormal satiation), emotional hunger (hedonic eating), hungry gut (abnormal satiety), and slow burn (decreased metabolic rate). In 15% of participants, no phenotype was identified. Two or more phenotypes were identified in 27% of patients. In the pragmatic clinical trial, the phenotype‐guided approach was associated with 1.75‐fold greater weight loss after 12 months with mean weight loss of 15.9% compared with 9.0% in the non‐phenotype‐guided group (difference −6.9% [95% CI −9.4% to −4.5%], P < 0.001), and the proportion of patients who lost >10% at 12 months was 79% in the phenotype‐guided group compared with 34% with non‐phenotype‐guided treatment group.ConclusionsBiological and behavioral phenotypes elucidate human obesity heterogeneity and can be targeted pharmacologically to enhance weight loss.
Pharmacogenomics of Medication‐Induced Weight Gain and Antiobesity Medications

Obesity | January 25, 2021 | Volume: 29 | Issue: 2 | Pages: 265-273

10.1002/oby.23068 | PMID 33491309

Obesity is a chronic, multifactorial disease associated with a large number of comorbidities. The clinical management of obesity involves a stepwise integrated approach, beginning with behavioral and lifestyle modification, followed by antiobesity medications, endobariatric procedures, and bariatric surgery. Weight gain and subsequent obesity are common side effects of medications, such as prednisone or antipsychotics. In this era of precision medicine, it is essential to identify patients at the highest risk of weight gain as a result of medication use. Pharmacogenomics could play an important role in obesity management by optimizing use of antiobesity medications as well as minimizing adverse weight gain. This review aims to provide a comprehensive analysis of the current literature on the role of pharmacogenomics in obesity and medication‐induced weight gain. In summary, there are more robust studies of medication associated with weight gain and pharmacogenomics, and more studies are needed to understand the role of pharmacogenomics in antiobesity medications.