Postprandial Glucose Metabolism Research Articles

Effects of electrical stimulation of the lower extremities on postprandial hyperglycemia and arterial stiffness.

To compare the acute effects of electrical stimulation (ES) of the lower extremities on postprandial hyperglycemia and arterial stiffness during oral glucose tolerance testing (OGTT). In a randomized crossover study, eight healthy young men completed three experimental trials in which they underwent ES for 30 min, starting 60 min before (Before) or 30 min after (After) ingesting 75 g of glucose; ES was not performed in the control trial (Control). The subjects' blood glucose levels and brachial-ankle pulse wave velocity (baPWV) were measured as an index of arterial stiffness at baseline and 30, 60, and 120 min after glucose ingestion. Serum insulin levels were measured at baseline and 60 min after glucose ingestion. The subjects' glucose intake led to an increase in their blood glucose concentration in all trials, however, in the After trial, ES resulted in significantly lower blood glucose concentrations at 60 min post glucose ingestion compared to the Control and Before trials. The area under the curve (AUC) of serum insulin concentrations during the OGTT in the After trial was significantly lower than that in the other two trials. Moreover, glucose ingestion did not increase the baPWV, however, 30 min of ES during the postprandial state acutely reduced the baPWV. These results suggest that ES is most effective in reducing postprandial hyperglycemia when administered after a meal. Thus, lower extremity ES may be an alternative exercise method to activate postprandial glucose metabolism in healthy individuals.

Association Between the Postprandial Response to an Oral Glucose Tolerance Test and Anthropometric Changes After an 8-Week Low-Calorie Formula Diet - Results From the Lifestyle Intervention (LION) Study.

Interindividual variations in postprandial metabolism and weight loss outcomes have been reported. The literature suggests links between postprandial metabolism and weight regulation. Therefore, the study aims to evaluate if postprandial glucose metabolism after a glucose load predicts anthropometric outcomes of a weight loss intervention. Anthropometric data from adults with obesity (18-65 years, body mass index [BMI] 30.0-39.9kgm-2) are collected pre- and post an 8-week formula-based weight loss intervention. An oral glucose tolerance test (OGTT) is performed at baseline, from which postprandial parameters are derived from glucose and insulin concentrations. Linear regression models explored associations between these parameters and anthropometric changes (∆) postintervention. A random forest model is applied to identify predictive parameters for anthropometric outcomes after intervention. Postprandial parameters after an OGTT of 158 participants (63.3% women, age 45 ± 12, BMI 34.9 ± 2.9kgm-2) reveal nonsignificant associations with changes in anthropometric parameters after weight loss (p>0.05). Baseline fat-free mass (FFM) and sex are primary predictors for ∆ FFM [kg]. Postprandial glucose metabolism after a glucose load does not predict anthropometric outcomes after short-term weight loss via a formula-based low-calorie diet in adults with obesity.

A randomised, double-blind, placebo-controlled trial to assess dose-dependent effects of blueberries on blood pressure, glucose and cognition

Obesity can increase the risk of diseases such as type 2 diabetes mellitus and cardiovascular disease(1). Glucose control is critical to both preventing and managing diabetes and can be achieved by enhancing secretion of insulin, limiting absorption of glucose from the gut and by upregulating the use of glucose in the muscles(2). Abnormalities in glucose management(3) and blood pressure control(4) are known to impair cognitive function. Epidemiological studies report an inverse risk of type 2 diabetes with increased intake of polyphenols. These data are also supported by in vitro and animal studies reporting positive effects of polyphenols on insulin sensitivity, carbohydrate digestion and glucose regulation(5). Here we aimed to evaluate postprandial glucose metabolism, blood pressure and cognitive function following a high carbohydrate meal accompanied by different doses of anthocyanin containing blueberry drinks.A double-blind, placebo-controlled, dose-response study was designed and received ethical approval and 22 participants were recruited. Each participant attended four study days in a crossover design, separated by a minimum of 5 days during which, they consumed a high carbohydrate meal consisting of two slices of toast and one of three doses of blueberry beverage or a control beverage. Memory performance was assessed using the visual verbal learning test (VVLT), measured at baseline and 90 minutes post consumption. Glucose was monitored every 15 minutes using a continuous glucose monitor which was worn across 10 days, and blood pressure was assessed every 30 minutes for a period of 4 hours in the laboratory. Glucose area under the curve (AUC) were analysed using linear mixed models. Blood pressure and VVLT data were analysed using repeated measures ANOVA.The analysis was performed blind to condition. In total, 22 participants completed all four study visits (mean age 28 ± 5.9, mean weight 61kg ± 10.4, mean height, 1.64m ± 0.9, mean BMI 22.7 ± 2.27, N=20 female, N=2 male). There was a significant effect of treatment on total words recalled in the VVLT with best performance following condition B compared to condition C, and condition D compared to condition C (p < 0.05). Condition B also resulted in significant systolic blood pressure lowering compared to condition C (-2.47mmHg, P <0.003). There was no effect of treatment on area under the curve for glucose over 3 hours postprandial (p > 0.05).Taken together these results suggest that condition B conferred greatest benefit for memory performance and that this was associated with anthocyanin related effects on systolic blood pressure.This study was funded by the Wild Blueberry Association of North America (WBANA).

Post-absorptive and post-prandial glucose and fat metabolism in post-menopausal women with breast cancer after chemotherapy compared to healthy controls

Post-absorptive and post-prandial glucose and fat metabolism in post-menopausal women with breast cancer after chemotherapy compared to healthy controls

Effect of vegetable consumption with chewing on postprandial glucose metabolism in healthy young men: a randomised controlled study

Although thorough chewing lowers postprandial glucose concentrations, research on the effectiveness of chewing vegetables in different forms on postprandial glucose metabolism remains limited. This study examined the effects of vegetables consumed in solid versus puree forms on postprandial glucose metabolism. Nineteen healthy young men completed two 180-min trials on separate days in a random order: the chewing trial involved the consumption of shredded cabbage with chewing and the non-chewing trial involved the consumption of pureed cabbage without chewing. Energy jelly was consumed immediately after the consumption of shredded or puree cabbage. Blood samples were collected at 0, 30, 45, 60, 90, 120 and 180 min. Circulating concentrations of glucose, insulin, total glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) concentrations were measured from the plasma. Although plasma glucose concentrations did not differ between the trials, the plasma insulin and GIP incremental area under the curve values were higher in the chewing than in the non-chewing trial. Postprandial total GLP-1 concentrations were higher in the chewing than in the non-chewing trial at 45, 60 and 90 min. This study demonstrates that consuming shredded cabbage while chewing enhances postprandial incretin secretion but has no effect on postprandial glucose concentration.Trial registration: Clinical trial registration ID.: UMIN000052662, registered 31 October 2023.

Human Metabolism and Excretion of Kawakawa (Piper excelsum) Leaf Chemicals.

Piper excelsum (kawakawa) has a history of therapeutic use by Māori in Aotearoa New Zealand. It is currently widely consumed as a beverage and included as an ingredient in "functional" food product. Leaves contain compounds that are also found in a wide range of other spices, foods, and medicinal plants. This study investigates the human metabolism and excretion of kawakawa leaf chemicals. Six healthy male volunteers in one study (Bioavailability of Kawakawa Tea metabolites in human volunteers [BOKA-T]) and 30 volunteers (15 male and 15 female) in a second study (Impact of acute Kawakawa Tea ingestion on postprandial glucose metabolism in healthy human volunteers [TOAST]) consume a hot water infusion of dried kawakawa leaves (kawakawa tea [KT]). Untargeted Liquid Chromatography-Tandem Mass spectrometry (LC-MS/MS) analyses of urine samples from BOKA-T identified 26 urinary metabolites that are significantly associated with KT consumption, confirmed by the analysis of samples from the independent TOAST study. Seven of the 26 metabolites are also detected in plasma. Thirteen of the 26 urinary compounds are provisionally identified as metabolites of specific compounds in KT, eight metabolites are identified as being derived from specific compounds in KT but without resolution of chemical structure, and five are of unknown origin. Several kawakawa compounds that are also widely found in other plants are bioavailable and are modified by phase 1 and 2 metabolism.

Postabsorptive and postprandial glucose and fat metabolism in postmenopausal women with breast cancer—Preliminary data after chemotherapy compared to healthy controls

BackgroundBreast cancer survivors are a growing population due to improved treatment. It is known that postmenopausal women treated for breast cancer may experience weight gain and increased insulin resistance, but detailed knowledge on how chemotherapy impact metabolic and endocrine mechanisms remain unknown. ObjectivesWe performed a thorough, preliminary study to elucidate the differing mechanisms of postprandial absorption and metabolism in postmenopausal early breast cancer (EBC) patients treated with adjuvant chemotherapy compared to healthy controls. We hypothesize that chemotherapy has a negative impact on metabolism in EBC patients. MethodsWe examined four postmenopausal women shortly after treatment with chemotherapy for EBC and four age-matched healthy women who served as controls using isotopic tracers during a mixed meal-test. Blood was sampled during the 240 min meal-test to examine postprandial absorption and endogenous synthesis of lipid and carbohydrate metabolites. ResultsWe found that insulin concentrations were numerically higher before the meal-test in the EBC patients compared to controls (76.3 pmol/L vs 37.0 pmol/L; P = 0.06). Glucose kinetics was increased postprandial (most pronounced at 30 min, 9.46 mmol/L vs 7.33 mmol/L; P = 0.51), with no difference between the groups regarding liver glucose output. Fatty acid kinetics showed a numeric increase in oleic acid rate of appearance in BC patients, but only during the first hour after the mixed meal. There was no significant difference in VLDL-TAG synthesis between the two groups. ConclusionsThis preliminary study is unique in using advanced tracer methods to investigate in vivo metabolism of EBC patients after chemotherapy although no statistical differences in glucose and fatty acid kinetics was seen compared to controls. However, during the first two postprandial hours, oral glucose and oleic acid appearance in the systematic circulation was elevated in the EBC patients. This could be due to changes in gastrointestinal uptake and further studies with altered set-up could provide valuable insights.

Use of malted pulses to formulate gluten-free fresh-egg pasta

In spite of the fact that legumes are rich in proteins, dietary fibers, and micronutrients, their average per capita consumption is limited because of their lengthy cooking period, unpleasant flavor, low-digestible proteins, and gastrointestinal problems. This study was aimed at assessing the effectiveness of the malting process of three typical pulse seeds of the Italian Latium region (i.e. Gradoli Purgatory beans [GPB]; Onano lentils [OL]; and Solco Dritto chickpeas [SDC]) to minimize their anti-nutrient content and test their use as ingredient in the preparation of gluten-free fresh egg pastas. All these fresh egg pastas were devoid of flatulence-inducing oligosaccharides with low phytate content (0.6–0.80 g/100 g of dry matter, dm), a crude protein content of around 20 g/100 g dm and in vitro glycemic index ranging from 28% to 38%. However, the only fresh egg pasta, including malted GPB flour, exhibited not only a significantly smaller glycemic index (28%±3%) but also a resistant starch–total starch ratio by far greater than the threshold value (14%) specified by the European Commission Regulation 432/2012 to label foods with the health claim indicating improvement in postprandial glucose metabolism.

A type 4 resistant potato starch alters the cecal microbiome and gene expression in mice fed a western diet based on NHANES data.

Four major types of resistant starch (RS1-4) are present in foods, all of which can alter the microbiome and are fermented in the cecum and colon to produce short-chain fatty acids (SCFAs). Type 4 RSs are chemically modified starches, not normally found in foods, but have become a popular food additive as their addition increases fiber content. Multiple studies, in humans and rodents, have explored how different RS4 affect post-prandial glucose metabolism, but fewer studies have examined the effects of RS4 consumption on the microbiome. In addition, many RS studies conducted in rodents use high-fat diets that do not approximate what is typically consumed by humans. To address this, mice were fed a Total Western Diet (TWD), based on National Health and Nutrition Examination Survey (NHANES) data that mimics the macro and micronutrient composition of a typical American diet, for six weeks, and then supplemented with 0, 2, 5, or 10% of the RS4, Versafibe 1490™ (VF), a phosphorylated and cross-linked potato starch, for an additional three weeks. The cecal contents were analyzed for SCFA content and microbiota composition. Butyrate production was increased while branched chain SCFA production decreased. The alpha-diversity of the microbiome decreased in mice fed the TWD with 10% VF 1490 added while the beta-diversity plot showed that the 5% and 10% VF groups were distinct from mice fed the TWD. Similarly, the largest changes in relative abundance of various genera were greatest in mice fed the 10% VF diet. To examine the effect of VF consumption on tissue gene expression, cecal and distal colon tissue mRNA abundance were analyzed by RNASeq. Gene expression changes were more prevalent in the cecum than the colon and in mice fed the 10% VF diet, but the number of changes was substantially lower than we previously observed in mice fed the TWD supplemented with native potato starch (RPS). These results provide additional evidence that the structure of the RS is a major factor determining its effects on the microbiome and gene expression in the cecum and colon.

Postprandial glucose metabolism in children and adolescents with type 1 diabetes mellitus: potential targets for improvement.

The main goal of therapeutic management of type 1 Diabetes Mellitus (T1DM) is to maintain optimal glycemic control to prevent acute and long-term diabetes complications and to enable a good quality of life. Postprandial glycemia makes a substantial contribution to overall glycemic control and variability in diabetes and, despite technological advancements in insulin treatments, optimal postprandial glycemia is difficult to achieve. Several factors influence postprandial blood glucose levels in children and adolescents with T1DM, including nutritional habits and adjustment of insulin doses according to meal composition. Additionally, hormone secretion, enteroendocrine axis dysfunction, altered gastrointestinal digestion and absorption, and physical activity play important roles. Meal-time routines, intake of appropriate ratios of macronutrients, and correct adjustment of the insulin dose for the meal composition have positive impacts on postprandial glycemic variability and long-term cardiometabolic health of the individual with T1DM. Further knowledge in the field is necessary for management of all these factors to be part of routine pediatric diabetes education and clinical practice. Thus, the aim of this report is to review the main factors that influence postprandial blood glucose levels and metabolism, focusing on macronutrients and other nutritional and lifestyle factors, to suggest potential targets for improving postprandial glycemia in the management of children and adolescents with T1DM.

The Effect of the Timing of Banana Intake on Postprandial Glucose Spike: Randomized Parallel-Group Comparison Study

Objective: To elucidate the effects of the timing of banana intake on postprandial glucose spike and glucose metabolism. Methods: This randomized parallel-group comparison study was designed to randomize 54 adults aged 41- 60 years into three groups. The first group consumed 120 g of banana at breakfast daily for 2 weeks, the second group consumed 120 g of banana after dinner daily for 2 weeks, and the third consumed no banana or banana-containing food for 2 weeks. The participants in each group wore a continuous glucose monitor on their arms for 2 weeks to measure their blood glucose trend. Body composition and serum biomarkers were evaluated before and after intervention. Results: There were 16 participants in the banana-at-breakfast group, 16 in the banana-after-dinner group, and 15 in the control group. We defined a postprandial blood glucose increase of >140 mg/dL as a “glucose spike.” When comparing the glucose spike incidence ratio (incidence of glucose spikes divided by number of times measured), the point estimate of the incidence ratio of banana-at-breakfast group at dinner compared with breakfast was 1.55 (point estimate. 95% confidence interval: 1.09- 2.20), that of banana-after dinner group 1.83 (point estimate. 95% confidence interval: 1.28-2.61), and control group 2.03 (point estimate. 95% confidence interval: 1.36-3.04). In addition, the banana-afterdinner and control groups showed a higher incidence ratio, compared with the banana-at-breakfast group. Glycoalbumin decreased significantly in the banana-at- breakfast group compared with the other groups. Conclusions: The results showed that glucose spikes were less generated when consuming bananas at breakfast than when consuming them after dinner or not consuming them at all. The level of glycoalbumin, an index for average blood glucose, was lower in the banana-at-breakfast group than in the banana-after-dinner and control groups within 2 weeks. Clinical Trial Registry: UMIN 000050025

Assessment of the Malting Process of Purgatory Bean and Solco Dritto Chickpea Seeds.

This study was aimed at minimizing the anti-nutrient content of the Gradoli Purgatory bean (GPB: Phaseolus vulgaris) and Solco Dritto chickpea (SDC: Cicer arietinum) seeds grown in the Latium region of Italy by defining the three steps of their malting process. The water steeping and germination phases were carried out in a 1.0-kg bench-top plant at 18, 25, or 32 °C. By soaking both seeds at 25 °C for 3 h, 95 to 100% of seeds sprouted. There was no need for prolonging their germination process after 72 h, the degradation degree of raffinose in germinated GPBs or SDCs being about 63%, while that of phytic acid being ~32% or 23%, respectively. The steeping and germination kinetics of both seeds were mathematically described via the Peleg and first-order reaction models, respectively. The third step (kilning) was carried out under fluent dry air at 50 °C for 24 h and at 75 °C for 3 h, and yielded cream-colored malted seeds, the cotyledons of which were cyclonically separated from the cuticles and finally milled. Owing to their composition, the decorticated malted pulse flours might be used in the formulation of specific gluten-free food products high in raw proteins and low in phytate, α-oligosaccharides and in vitro glycemic index (GI). Even if their low GI trait was preserved after malting, only the GPB malt flour having a resistant starch-to-total starch ratio ≥ 14% has the potential to be labeled with the health claim for improving postprandial glucose metabolism according to EU Regulation 432/2012.

254-LB: In Vivo Mapping of Postprandial Hepatic Glucose Metabolism Using Stable Isotope-Assisted Metabolic Imaging in Roux-en-Y Gastric Bypass Adults and Nonoperated Controls

We aimed to assess the impact of Roux-en-Y gastric bypass (RYGB) on hepatic glucose (glc) kinetics using stable isotope-assisted magnetic resonance spectroscopy (MRS). Ten post-RYGB adults (2M, age=39.2±3.1 y, BMI=28±1 kg/m2; mean±SE) and ten non-operated adults (HC; 5M, age=36.4±3.2 y, BMI=26±1 kg/m2) underwent metabolic imaging in a 7T (Terra, Siemens) scanner with a triple-tuned surface coil over the liver. Scanning was performed before (T0) and up to 150 min (T150) after oral intake of 60g of deuterated [6,6′-2H2]-Glc using interleaved sequences of 2H2-MRS imaging (hepatic 2H2-glc signal) and 13C-MRS (glycogen). Blood samples were collected for profiling of plasma glc, glc enrichment, insulin and glucagon. General Additive Mixed Models were used for comparative analyses. We observed distinct postprandial profiles of hepatic glc signal (Fig 1). RYGB subjects showed earlier and higher glc peaks, which were mirrored by hepatic glc signal in both groups. Insulin peak levels were higher and glc nadir lower in RYGB. Postprandial endogenous glc was higher in RYGB, which was paralleled by a fall in hepatic glc. In HC, hepatic glc remained elevated until the end of the experiment. Non-invasive stable isotope-assisted MRS imaging has the potential to unravel changes in postprandial hepatic metabolism induced by RYGB and other treatments. Disclosure N. F. Lange: None. S. Poli: None. D. Herzig: None. M. Schiavon: None. C. Dalla man: Research Support; Sanofi-Aventis Deutschland GmbH, Becton, Dickinson and Company. R. Kreis: None. L. Bally: Research Support; Dexcom, Inc., Ypsomed AG. Funding Swiss National Science Foundation (PCEGP3_186978)

254-OR: Effects of Roux-en-Y Gastric Bypass on Postprandial Glucose Turnover Assessed through the Single-Tracer Oral Minimal Model

Rearrangements of gastrointestinal anatomy after Roux-en-Y gastric bypass (RYGB) surgery alter postprandial glucose metabolism. However, the impact on different components of glucose homeostasis remain incompletely understood. Here, we aim to evaluate the effects of RYGB on postprandial glucose turnover, production (P) and disposal (D) glucose effectiveness (GEP, GED) and production and disposal sensitivity to insulin (SIP, SID). Ten RYGB (2M, age=39.2±3.1 y, BMI=28±1 kg/m2- mean±SE) subjects and 10 healthy controls (5M, age=36.4±3.2 y, BMI=26±1 kg/m2) ingested 60g of glucose (G) labelled with [6,6-2H2]-glucose. Plasma samples were frequently drawn to measure G, insulin (I) and tracer concentrations in the following 180 min. The Single-Tracer Oral Minimal Model was used to estimate meal glucose rate of appearance (Ra), endogenous glucose production (EGP), glucose disposal (Rd), GEP, GED, SIP and SID. Incremental area under the G curve (iAUC(G)) was not different in the two groups, while iAUC(I) was significantly higher in RYGB (8346±803 vs. 5451±602 μU/mL*min, p=0.011); iAUC(Ra) normalized to the G dose was significantly higher in the first 60 min after the meal (0.72±0.04 vs. 0.28±0.03, p<0.001) while, throughout the experiment, EGP suppression (EGPs) normalized to basal (EGPb) was significantly lower (0.31±0.06 vs. 0.55±0.05, p=0.006) and iAUC(Rd) normalized to basal (Rdb) was higher (3.46±0.10 vs. 2.82±0.08, p<0.001) in RYGB than controls. Model predicted SIP was significantly lower in RYGB than controls (2.0±0.5 vs. 5.1±1.2 10-4 dL/kg/min per μU/mL, p=0.033) while no differences were observed in GEP, GED and SID. We concluded that the abnormally high I concentration in RYGB was responsible for the higher iAUC(Rd) in the operated individuals, while the reduced SIP likely works as a protective mechanism against postprandial hypoglycaemia by reducing EGPs despite the high circulating I. Disclosure A.Brunasso: None. C.Dalla man: Research Support; Sanofi-Aventis Deutschland GmbH, Becton, Dickinson and Company. D.Herzig: None. L.Bally: Research Support; Dexcom, Inc., Ypsomed AG. M.Schiavon: None. Funding Italian Minister for Education (Law 232/2016); Swiss National Science Foundation (PCEGP3_186978)

Effects of acute changes in fasting glucose and free fatty acid concentrations on indices of β-cell function and glucose metabolism in subjects without diabetes.

Elevated fasting free fatty acids (FFAs) and fasting glucose are additively associated with impaired glucose tolerance (IGT) and decreased β-cell function [quantified as disposition index (DI)]. We sought to examine how changes in fasting FFA and glucose alter islet function. We studied 10 subjects with normal fasting glucose (NFG) and normal glucose tolerance (NGT) on two occasions. On one occasion, Intralipid and glucose were infused overnight to mimic conditions present in IFG/IGT. In addition, we studied seven subjects with IFG/IGT on two occasions. On one occasion, insulin was infused to lower overnight FFA and glucose concentrations to those observed in people with NFG/NGT. The following morning, a labeled mixed meal was used to measure postprandial glucose metabolism and β-cell function. Elevation of overnight fasting FFA and glucose in NFG/NGT did not alter peak or integrated glucose concentrations (2.0 ± 0.1 vs. 2.0 ± 0.1 Mol per 5 h, Saline vs. Intralipid/glucose, P = 0.55). Although overall β-cell function quantified by the Disposition Index was unchanged, the dynamic component of β-cell responsivity (ϕd) was decreased by Intralipid and glucose infusion (9 ± 1 vs. 16 ± 3 10-9, P = 0.02). In people with IFG/IGT, insulin did not alter postprandial glucose concentrations or indices of β-cell function. Endogenous glucose production and glucose disappearance were also unchanged in both groups. We conclude that acute, overnight changes in FFA, and glucose concentrations do not alter islet function or glucose metabolism in prediabetes.NEW & NOTEWORTHY This experiment studied the effect of changes in overnight concentrations of free fatty acids (FFAs) and glucose on β-cell function and glucose metabolism. In response to elevation of these metabolites, the dynamic component of the β-cell response to glucose was impaired. This suggests that in health overnight hyperglycemia and FFA elevation can deplete preformed insulin granules in the β-cell.

Interactions between Intestinal Homeostasis and NAD+ Biology in Regulating Incretin Production and Postprandial Glucose Metabolism

The intestine has garnered attention as a target organ for developing new therapies for impaired glucose tolerance. The intestine, which produces incretin hormones, is the central regulator of glucose metabolism. Glucagon-like peptide-1 (GLP-1) production, which determines postprandial glucose levels, is regulated by intestinal homeostasis. Nicotinamide phosphoribosyltransferase (NAMPT)-mediated nicotinamide adenine dinucleotide (NAD+) biosynthesis in major metabolic organs such as the liver, adipose tissue, and skeletal muscle plays a crucial role in obesity- and aging-associated organ derangements. Furthermore, NAMPT-mediated NAD+ biosynthesis in the intestines and its upstream and downstream mediators, adenosine monophosphate-activated protein kinase (AMPK) and NAD+-dependent deacetylase sirtuins (SIRTs), respectively, are critical for intestinal homeostasis, including gut microbiota composition and bile acid metabolism, and GLP-1 production. Thus, boosting the intestinal AMPK-NAMPT-NAD+-SIRT pathway to improve intestinal homeostasis, GLP-1 production, and postprandial glucose metabolism has gained significant attention as a novel strategy to improve impaired glucose tolerance. Herein, we aimed to review in detail the regulatory mechanisms and importance of intestinal NAMPT-mediated NAD+ biosynthesis in regulating intestinal homeostasis and GLP-1 secretion in obesity and aging. Furthermore, dietary and molecular factors regulating intestinal NAMPT-mediated NAD+ biosynthesis were critically explored to facilitate the development of new therapeutic strategies for postprandial glucose dysregulation.

E-DES-PROT: A novel computational model to describe the effects of amino acids and protein on postprandial glucose and insulin dynamics in humans.

Current computational models of whole-body glucose homeostasis describe physiological processes by which insulin regulates circulating glucose concentrations. While these models perform well in response to oral glucose challenges, interaction with other nutrients that impact postprandial glucose metabolism, such as amino acids (AAs), is not considered. Here, we developed a computational model of the human glucose-insulin system, which incorporates the effects of AAs on insulin secretion and hepatic glucose production. This model was applied to postprandial glucose and insulin time-series data following different AA challenges (with and without co-ingestion of glucose), dried milk protein ingredients, and dairy products. Our findings demonstrate that this model allows accurate description of postprandial glucose and insulin dynamics and provides insight into the physiological processes underlying meal responses. This model may facilitate the development of computational models that describe glucose homeostasis following the intake of multiple macronutrients, while capturing relevant features of an individual's metabolic health.

Abstract MP09: Diets Varying in Glycemic Index and Carbohydrates With Meal-Timing Specific 12-hour Postprandial Metabolic Changes: The Omnicarb Trial

Background: Both the glycemic index (GI) and amounts of carbohydrates are important determinants of postprandial glucose changes. Recent studies suggest the effects of carbohydrate intake on postprandial glucose metabolism may differ according to meal timing, showing circadian patterns. Hypothesis: We investigated whether the relations of altering both GI levels and the carbohydrate amount with postprandial response of glucose, insulin, and c-peptide differed by meal timing (breakfast, lunch, and dinner), in overweight and obese adults. Methods: The OmniCarb trial was a randomized trial with a crossover design in which participants were given 4 diets varying in GI levels and carbohydrate content. We included 61 participants attended the 12-h postprandial study and completed at least two diets. Area under the curve increment (AUCi) of glucose, insulin, and c-peptide after breakfast (180 min), lunch (240 min), and dinner (120 min), was calculated as outcome. Results: After consuming each diet for 5 weeks, we observed that the diet replacing effects on the postprandial responses in glucose, insulin and c-peptide significantly differed by meal timing. For postprandial glucose response to breakfast, the beneficial effects (lowered AUCi) of replacing high- by low-GI in high-carb diet, replacing high- by low-carb in high-GI diet, and replacing high-GI/high-carb by low-GI/low-carb diet were consistently observed. Such beneficial effects were less significant for lunch and dinner (Figure). For the response of insulin, the beneficial effects of the corresponding diet replacements were more consistently observed in dinner, followed by breakfast. For the response of C-peptide, similar beneficial effects of the corresponding diet replacements were observed for breakfast and dinner, but not lunch. Conclusion: Our results indicate that the beneficial effects of replacing high-GI and/or high-carbohydrate diets by low-GI and/or low-carbohydrate diets on postprandial metabolic changes may differ according to meal timing.

Effects of the timing of acute mulberry leaf extract intake on postprandial glucose metabolism in healthy adults: a randomised, placebo-controlled, double-blind study

Background/ObjectivesGlucose tolerance is controlled by the internal clock and is worse in the evening. From a chrononutrition perspective, diabetes prevention requires evaluating the antidiabetic effects of the timing of functional ingredients and nutrient intake. The purpose of this study was to investigate the timing effects of acute mulberry leaf extract (MLE) intake on postprandial glucose levels in young adults.Subjects/MethodsTwelve young adults underwent four trials. Blood samples were collected in a fasting state and at 30, 60, 120, and 180 min after eating a mixed meal. The study had a randomised, placebo-controlled, double-blind trial design involving: (1) morning placebo trial (08:00 h; MP trial), (2) evening placebo trial (18:00 h; EP trial), (3) morning MLE trial (08:00 h; MM trial), and (4) evening MLE trial (18:00 h; EM trial).ResultsThe incremental area under the blood glucose curve (iAUC) in the EM trials was significantly lower than that in the EP trials (P = 0.010). The postprandial glucose concentrations 120 min after the meal were significantly lower in the EM trials than those in the EP trials (P = 0.006). The postprandial insulin concentrations at 120 min were significantly lower in the MM trials than those in the MP trials (P = 0.034). Moreover, the postprandial insulin concentrations 180 min after the meal were significantly lower in the EM trials than those in the EP trials (P = 0.034).ConclusionsMLE intake in the evening, but not in the morning, was effective in improving glucose tolerance.Trial registrationClinical trial reference: UMIN 000045301; website of trial registry: https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000051340.

Cannabidiol (CBD) ingestion increases ad libitum energy intake in healthy adults but does not affect postprandial glucose or lipid metabolism

Cannabidiol (CBD) ingestion increases ad libitum energy intake in healthy adults but does not affect postprandial glucose or lipid metabolism