Glucose iAUC Research Articles

Differently Processed Low Doses of β-Glucan from Oat Bran Similarly Attenuate Postprandial Glycemic Response

Incorporating β-glucan-rich oat bran (OB) can attenuate postprandial glycemic response (PPGR) in solid foods, but its effect in liquid matrices is unclear. This study investigated the ability of differently processed low-dose-β-glucan-containing beverages to lower PPGR, and the mechanisms of action. Twenty participants consumed five malt beverages made from cocoa powder: intact OB (Intact), OB treated with enzymatic hydrolysis (EnzymA, EnzymB) or extrusion (Extr), or no OB (Ctrl). Four-hour postprandial incremental areas under the curve (iAUC) and peak incremental concentrations (iCmax) of glucose, insulin, glucagon-like peptide 1 (GLP-1), gastric inhibitory polypeptide (GIP), and paracetamol were evaluated. The molecular weight (MW) and extractability of the β-glucan in all the test products were also assessed. The three-hour glucose iAUC significantly decreased by −26%, −28%, −32%, and −38% in Intact, EnzymA, EnzymB, and Extr, respectively, and the insulin levels of the oat-containing products were also significantly lower compared to Ctrl. Intact and Extr elicited a lower insulin iCmax and GLP-1 3 h iAUC compared to Ctrl. However, the GIP and paracetamol levels were not changed. All the processed OBs improved β-glucan extractability and lowered the MW of β-glucan compared to Intact. In conclusion, low-dose oat β-glucan in a beverage significantly reduced PPGR, with effects maintained across different oat processing methods.

Light Walking Patterns and Postprandial Cardiometabolic Responses in Young Obese Adults: A Randomized Crossover Study

Abstract Context Recent studies suggest that light-intensity physical activity may enhance cardiometabolic health and reduce mortality risk in adults. However, more information is required to understand the patterns of light-intensity physical activity and postprandial cardiometabolic health. Objective This study examined the effects of different light-intensity walking patterns on postprandial cardiometabolic responses in young obese adults. Design A randomized crossover trial was conducted. Setting The study was conducted in the laboratory. Participants The study analyzed baseline (fasting) and 6-hour postprandial concentrations of glucose, insulin, triglycerides, and blood pressure (BP) in 16 young obese adults. Interventions Participants underwent four 7-hour experimental conditions with a 7–20-day washout period: uninterrupted sitting (SIT), 30-minute light-intensity walking (EX+SIT), 3-minute light-intensity walking every 30 minutes (BR), and 30-minute light-intensity walking with 3-minute light-intensity walking every 30 minutes (EX+BR). Main Outcome Measures Incremental areas under the curve (iAUC) for each outcome and average BP were compared between SIT and walking conditions. Results Compared with SIT, all walking conditions reduced iAUCs for glucose and average diastolic BP (all p<0.05). Only EX+SIT and EX+BR reduced iAUCs for insulin (p<0.05). No significant differences were found for triglycerides iAUC and systolic BP between the four conditions (all p>0.05). Conclusions All patterns of light-intensity walking reduced postprandial glucose concentrations and diastolic BP in young obese adults, suggesting benefits for glycemic control. Continuous 30-minute light-intensity walking alone, or combined with brief 3-min bouts also attenuated postprandial insulin concentrations, highlighting light-intensity walking as a promising strategy for improving cardiometabolic health in young obese adults.

Effect of Interrupting Prolonged Sitting with Frequent Activity Breaks on Postprandial Glycemia and Insulin Sensitivity in Adults with Type 1 Diabetes on Continuous Subcutaneous Insulin Infusion Therapy: A Randomized Crossover Pilot Trial.

Objective: This study examined acute effects of interrupting prolonged sitting with short activity breaks on postprandial glucose/insulin responses and estimations of insulin sensitivity in adults with type 1 diabetes (T1D). Method: In a randomized crossover trial, eight adults (age = 46 ± 14 years [mean ± SD], body mass index [BMI] = 27.2 ± 3.8 kg/m2) receiving continuous subcutaneous insulin infusion (CSII) therapy completed two 6-h conditions as follows: uninterrupted sitting (SIT) and sitting interrupted with 3-min bouts of simple resistance activities (SRAs) every 30 min. Basal and bolus insulin were standardized across conditions except in cases of hypoglycemia. Postprandial responses were assessed using incremental area-under-the-curve (iAUC) and total AUC (tAUC) from half-hourly venous sampling. Meal-based insulin sensitivity determined from glucose sensor and insulin pump (SiSP) was assessed from flash continuous glucose monitor and insulin pump data. Outcomes were analyzed using mixed models adjusted for sex, BMI, treatment order, and preprandial values. Results: Glucose iAUC did not differ by condition (SIT: 19.8 ± 3.0 [estimated marginal means ± standard error] vs. SRA: 14.4 ± 3.0 mmol.6 h.L-1; P = 0.086). Despite CSII being standardized between conditions, insulin iAUC was higher in SRA compared to SIT (137.1 ± 22.7 vs. 170.9 ± 22.7 mU.6 h.L-1; P < 0.001). This resulted in a lower glucose response relative to the change in plasma insulin in SRA (tAUCglu/tAUCins: 0.32 ± 0.02 vs. 0.40 ± 0.02 mmol.mU-1; P = 0.03). SiSP was also higher at dinner following the SRA condition, with no between-condition differences at breakfast or lunch. Conclusion: Regularly interrupting prolonged sitting in T1D may increase plasma insulin and improve insulin sensitivity when meals and CSII are standardized. Future studies should explore underlying mechanistic determinants and the applicability of findings to those on multiple daily injections. Trial Registration: Australian and New Zealand Clinical Trial Registry Identifier-ACTRN12618000126213 (www.anzctr.org.au).

Postprandial Effects of Four Test Meals Containing Wholegrain Rye or Refined Wheat Foods on Circulating Incretins, Ghrelin, Glucose, and Inflammatory Markers

BackgroundHigh intake of whole grains has consistently been associated with reduced risk of obesity, coronary heart disease, and type 2 diabetes. Dietary interventions have shown beneficial metabolic effects of whole grain, but the metabolic response varies with different types of cereals. ObjectivesWe evaluate the metabolic effects of substituting refined wheat with wholegrain rye foods within a complex diet, examining day-long postprandial response of glucose-dependent insulinotropic peptide, (GIP), glucagon-like peptide-1 (GLP-1), ghrelin, glucose, and inflammatory biomarkers in overweight and obese individuals. MethodsTwenty-nine healthy adults, BMI 32 ± 9 kg/m2 were randomly assigned to three intervention days, separated by one-week washout. Participants adhered to a hypocaloric diet rich in wholegrain rye for one intervention and refined wheat for the second intervention and were randomized to either diet for the third intervention with continuous blood sampling. ResultsNo differences in GIP, GLP-1 or ghrelin levels were found between the diets when measured throughout the whole intervention day. GIP tAUC following the rye-based lunch was 31% (p < 0.05) lower compared with the wheat-based lunch and ghrelin concentrations were 29% (p < 0.05) lower after the rye-based dinner. Baseline HOMA-IR adjusted model, showed 61% (p = 0.015) lower whole-day GLP-1 and 40% (p = 0.03) lower GIP following the rye-based diet. Day-long glucose iAUC was 30% (p <0.001) lower following the rye-based diet and glycemic variability measured as SD reduced (−0.13 mmol/L p = 0.04). The rye-based diet vs refined wheat induced higher glycoprotein N-acetylation A by z-scores (0.36, p = 0.014). ConclusionsOverall, no day-long differences in gut hormone levels were observed, but the wholegrain rye-based vs refined wheat-based dinner showed lower postprandial ghrelin concentrations. The rye-based diet improved day-long glycemic control in individuals with overweight and obesity. Observations of diet-induced inflammation following whole-grain rye intake warrant further investigation. This study was prospectively registered at ClinicalTrials.gov (NCT05004584)https://clinicaltrials.gov/study/NCT05004584?locStr=Gothenburg,%20Sweden&country=Sweden&state=V%C3%A4stra%20G%C3%B6taland%20County&city=Gothenburg&distance=50&term=appetite&aggFilters=status:com&rank=1

Postprandial Blood Glucose and Insulin Response in Healthy Adults When Lentils Replace High-Glycemic Index Food Ingredients in Muffins, Chilies and Soups.

This study aimed to assess postprandial blood glucose response (PBGR), relative glycemic response (RGR) and insulin response when 25 g available carbohydrates (AC) is replaced with cooked lentils in the formulation of muffins, chilies and soups. In randomized, crossover studies, healthy adults consumed foods containing 25 g AC from green lentils, red lentils or a control (wheat muffin, n = 24; rice chili, n = 24; potato soup, n = 20). Blood collected at fasting and at 15, 30, 45, 60, 90 and 120 min was analyzed to derive the incremental area under the response curve (iAUC) for glucose, insulin, RGR and maximum concentration (CMAX). Treatment effects were assessed with repeated measures ANOVA. A replacement of 25 g AC with green lentils significantly decreased glucose iAUC compared to chili and soup (p < 0.0001), but not muffin (p = 0.07) controls, while also eliciting a significantly lower insulin iAUC for all three foods (muffin p = 0.03; chili p = 0.0002; soup p < 0.0001). Red lentil foods significantly decreased glucose iAUC (muffin p = 0.02; chili p < 0.0001; soup p < 0.0001) compared to controls, with a significantly lower insulin iAUC for chili and soup (p < 0.0001) but not muffins (p = 0.09). The RGR for muffins, chilies and soups was 88, 58 and 61%, respectively, for green lentils, and 84, 48 and 49%, respectively, for red lentils. PBGR, insulin and RGR are decreased when lentils are incorporated into food products, providing credible evidence to promote carbohydrate replacement with lentil-based foods.

Oligomalt, a New Slowly Digestible Carbohydrate, Reduces Post-Prandial Glucose and Insulin Trajectories Compared to Maltodextrin across Different Population Characteristics: Double-Blind Randomized Controlled Trials in Healthy Individuals, People with Obesity, and People with Type 2 Diabetes.

We assessed the glucometabolic effects of oligomalt, a novel fully slowly digestible carbohydrate, compared with maltodextrin, in cross-over randomized controlled trials (NCT05058144; NCT05963594) involving healthy volunteers (HV), people with overweight or obesity (PwO), and people with type 2 diabetes (T2D). We tested 33 g and/or 50 g of oligomalt/maltodextrin, which were dissolved in 300 mL of water and consumed after fasting in the morning. The primary exploratory endpoint was the incremental area under the curve (iAUC) for postprandial glucose, assessed by frequent blood sampling over 3 h. Insulin levels were also assessed. In the HV cohort, a 4 h hydrogen breath test was performed with 15 g of inulin as a positive control. Analysis was performed by a mixed model. Oligomalt elicited a lower post-prandial glucose response compared to maltodextrin in HV (50 g, n = 15 [7 women], mean age/BMI 31 years/22.6 kg/m2), in PwO (33 g and 50 g, n = 26 [10 women], age/BMI 44 years/29.9 kg/m2, mean HbA1c 5.3%), and in people with T2D (50 g, n = 22 [13 women], age/BMI 61 years/31.8 kg/m2, HbA1c 7.4%), with significant reductions observed in PwO and T2D for the 0-1 h window (HV: -19% [p = 0.149]/PwO33g-38% [p = 0.0002]/PwO50g-28% [p = 0.0027]/T2D-38% [p < 0.0001]; the 0-2 h window (HV: -17% [p = 0.311]/PwO33g-34% [p = 0.0057]/PwO50g-21% [p = 0.0415]/T2D-37% [p < 0.0001]), and the 0-3 h window (HV: -15% [p = 0.386]/PwO33g-30% [p = 0.0213]/PwO50g0-19% [p = 0.0686]/T2D-37% [p = 0.0001]). The post-prandial insulin response was significantly lower, by 38-60%, across all populations, dose, and time points, with oligomalt. In HV, the breath-hydrogen pattern was comparable between oligomalt and maltodextrin, but increased significantly with inulin. These data support the glucometabolic advantages of oligomalt over maltodextrin, hence confirming it as a healthier carbohydrate, and underscoring its full digestibility. This therefore opens up the possibility for the incorporation of oligomalt in relevant food products/matrices.

Effects of exercise modality combined with moderate hypoxia on blood glucose regulation in adults with overweight.

Purpose: This study aimed to investigate the combined effects of moderate hypoxia with three different exercise modes on glucose regulation in healthy overweight adults. Methods: Thirteen overweight males (age: 31 ± 4years; body fat 26.3 ± 3.2%) completed three exercise trials in a randomized crossover design involving 60min cycling exercise at 90% lactate threshold (LOW), sprint interval training (20 × 4s all-out; SIT) and lower limb functional bodyweight exercises (8 sets of 4 × 20s; FEX) under moderate hypoxia (FiO2 = 16.5%). Post-exercise oral glucose tolerance test (OGTT) was performed following each trial. Heart rate, oxygen saturation (SpO2), physical activity enjoyment scale (PACES), and perceptual measures were recorded during each exercise session. Venous blood was collected pre-, immediately post-, and 24h post-exercise and analysed for plasma glucose and insulin, incremental area under curve (iAUC), and circulating microRNA expression (c-miRs-486-5p, -126-5p, and -21-5p). Interstitial glucose concentrations were measured using continuous glucose monitoring (CGM). Results: Post-exercise OGTT iAUC for plasma glucose and insulin concentration were lower in SIT and LOW vs. control (p < 0.05) while post-exercise interstitial glucose iAUC and c-miRs were not different between exercise modes. Heart rate was greater in SIT vs. LOW and FEX, and FEX vs. LOW (p < 0.05), SpO2 was lower in SIT, while PACES was not different between exercise modes. Perceptual measures were greater in SIT vs. LOW and FEX. Conclusion: Acute SIT and LOW under moderate hypoxia improved post-exercise plasma insulin compared to FEX exercises. Considering SIT was also time-efficient, well tolerated, and enjoyable for participants, this may be the preferred exercise modality for improving glucose regulation in adult males with overweight when combined with moderate hypoxia.

Understanding the Impact of Different Doses of Reducose® Mulberry Leaf Extract on Blood Glucose and Insulin Responses after Eating a Complex Meal: Results from a Double-Blind, Randomised, Crossover Trial.

Non-communicable diseases (NCDs) are becoming an increasingly important health concern due to a rapidly ageing global population. The fastest growing NCD, type 2 diabetes mellitus (T2DM), is responsible for over 2 million deaths annually. Lifestyle changes, including dietary changes to low glycemic response (GR) foods, have been shown to reduce the risk of developing T2DM. The aim of this study was to investigate whether three different doses of Reducose®, a mulberry leaf extract, could lower the GR and insulinemic responses (IR) to a full meal challenge in healthy individuals. A double-blind, randomised, placebo-controlled, repeat-measure, crossover design trial was conducted by the Oxford Brookes Centre for Nutrition and Health; 37 healthy individuals completed the study. Participants consumed capsules containing either 200 mg, 225 mg, 250 mg Reducose® or placebo before a test meal consisting of 150 g white bread and egg mayo filler. Capillary blood samples were collected at 15-min intervals in the first hour and at 30-min intervals over the second and third hours to determine glucose and plasma insulin levels. The consumption of all three doses of Reducose® resulted in significantly lower blood glucose and plasma insulin levels compared to placebo. All three doses of Reducose® (200 mg, 225 mg, 250 mg) significantly lowered glucose iAUC 120 by 30% (p = 0.003), 33% (p = 0.001) and 32% (p = 0.002), respectively, compared with placebo. All three doses of Reducose® (200 mg, 225 mg, 250 mg) significantly lowered the plasma insulin iAUC 120 by 31% (p = 0.024), 34% (p = 0.004) and 38% (p < 0.001), respectively. The study demonstrates that the recommended dose (250 mg) and two lower doses (200 mg, 225 mg) of Reducose® can be used to help lower the GR and IR of a full meal containing carbohydrates, fats and proteins.

Gastric emptying of a glucose drink is predictive of the glycaemic response to oral glucose and mixed meals, but unrelated to antecedent glycaemic control, in type 2 diabetes.

Gastric emptying (GE), with wide inter-individual but lesser intra-individual variations, is a major determinant of postprandial glycaemia in health and type 2 diabetes (T2D). However, it is uncertain whether GE of a carbohydrate-containing liquid meal is predictive of the glycaemic response to physiological meals, and whether antecedent hyperglycaemia influences GE in T2D. We evaluated the relationships of (i) the glycaemic response to both a glucose drink and mixed meals with GE of a 75 g glucose drink, and (ii) GE of a glucose drink with antecedent glycaemic control, in T2D. Fifty-five treatment-naive Chinese adults with newly diagnosed T2D consumed standardised meals at breakfast, lunch and dinner with continuous interstitial glucose monitoring. On the subsequent day, a 75 g glucose drink containing 150 mg 13C-acetate was ingested to assess GE (breath test) and plasma glucose response. Serum fructosamine and HbA1c were also measured. Plasma glucose incremental area under the curve (iAUC) within 2 hours after oral glucose was related inversely to the gastric half-emptying time (T50) (r = -0.34, P = 0.012). The iAUCs for interstitial glucose within 2 hours after breakfast (r = -0.34, P = 0.012) and dinner (r = -0.28, P = 0.040) were also related inversely to the T50 of oral glucose. The latter, however, was unrelated to antecedent fasting plasma glucose, 24-hour mean interstitial glucose, serum fructosamine, or HbA1c. In newly diagnosed, treatment-naive, Chinese with T2D, GE of a 75 g glucose drink predicts the glycaemic response to both a glucose drink and mixed meals, but is not influenced by spontaneous short-, medium- or longer-term elevation in glycaemia.

Effect of 100% Orange Juice and a Volume-Matched Sugar-Sweetened Drink on Subjective Appetite, Food Intake, and Glycemic Response in Adults.

Dietary recommendations to reduce the consumption of free sugars often group 100% fruit juice with other sugar-containing beverages. The objective of this study was to determine the effect of consuming 100% orange juice compared to an orange drink on next-meal food intake (FI), glycemic response, average appetite, emotions, and sensory characteristics in normal-weight adults. Thirty-six normal-weight adults (age: 26.8 ± 0.9 years) consumed, in random order and at least 5 days apart, three 240 mL test beverages as follows: (a) 100% orange juice, (b) orange drink, or (c) water. Subjective sweetness and pleasantness were determined immediately after test beverage consumption. Glycemic response, average appetite, and subjective emotions were measured every 15 min for 60 min. Food intake was determined at a pizza lunch 60 min later. Rest-of-day glycemic response and energy intake (EI) were determined using a continuous glucose monitor and food record, respectively. Lunch FI (p = 0.054) and total EI (p = 0.01) were both lower after 100% orange juice compared with the orange drink. Caloric compensation was 84% after 100% orange juice and -25% after the orange drink (p = 0.047). Average appetite was not significantly different between the test beverages (p > 0.05). Blood glucose iAUC adjusted for available carbohydrate was lower after 100% orange juice compared with the orange drink (p < 0.001). Rest-of-day blood glucose concentrations were lower after 100% orange juice compared with the orange drink (p = 0.03) and water control (p < 0.001). In conclusion, consumption of 100% orange juice as a preload resulted in higher caloric compensation, lower total daily EI, and lower blood glucose concentrations compared to the orange drink.

Effectiveness of Chickpeas on Blood Sugar: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Diabetes affects one in eleven adults globally, with rising cases in the past 30 years. Type 1 and type 2 cause blood sugar problems, increasing cardiovascular risks. Dietary control, including chickpeas, is suggested but needs more research. Comprehensive searches were conducted across multiple databases for the randomized controlled trial efficacy of chickpea consumption to lower blood sugar levels to a healthy range, with data extraction and risk of bias assessment performed independently by two researchers. Statistical analysis was performed using RevMan 5.4, expressing continuous data as mean differences and risk ratios with 95% confidence intervals, and a summary of the findings is provided considering the variations in study characteristics. A total of 118 articles were initially identified from seven databases, primarily from Anglo-American countries, resulting in 12 selected studies after the identification and screening processes. These studies involved 182 participants, focusing on healthy or normoglycemic adults, and assessed the effects of chickpeas compared to various foods such as wheat, potatoes, pasta, sauce, cheese, rice, and corn. A meta-analysis involving a subset of studies demonstrated that chickpeas were more effective in reducing blood glucose iAUC compared to potatoes and wheat. Chickpeas offer the potential for blood sugar control through low starch digestibility, high fiber, protein, and hormonal effects. Although insulin benefits are seen, statistical significance varies, supporting their role in diabetic diets focusing on nutrient-rich foods over processed carbs.

Metformin and exercise effects on postprandial insulin sensitivity and glucose kinetics in pre-and-diabetic adults.

The potential interaction between metformin and exercise on glucose-lowering effects remains controversial. We studied the separated and combined effects of metformin and/or exercise on fasting and postprandial insulin sensitivity in individuals with pre- and - type 2 diabetes (T2D). Eight T2D adults (60±4 years) with overweight/obesity (32±4 kg·m-2) under chronic metformin treatment (9±6 years; 1281±524 mg·day-1) underwent four trials; a) taking their habitual metformin treatment (MET), b) substituting during 96 h their metformin medication by placebo (PLAC), c) placebo combined with 50 min bout of high-intensity interval exercise (PLAC+EX), and d) metformin combined with exercise (MET+EX). Plasma glucose kinetics using stable isotopes (6,6-2H2 and [U-13C] glucose), and glucose oxidation by indirect calorimetry, were assessed at rest, during exercise, and in a subsequent oral glucose tolerance test (i.e., OGTT). Postprandial glucose and insulin concentrations were analyzed as mean and incremental area under the curve (iAUC), and insulin sensitivity was calculated (i.e., MATSUDAindex and OGISindex). During OGTT, metformin reduced glucose iAUC (i.e., MET and MET+EX lower than PLAC and PLAC+EX, respectively; P=0.023). MET+EX increased MATSUDAindex above PLAC (4.8±1.4 vs 3.3±1.0, respectively; P=0.018) and OGISindex above PLAC (358±52 vs 306±46 mL·min-1·m-2, respectively; P=0.006). Metformin decreased plasma appearance of the ingested glucose (Ra OGTT; MET vs PLAC, -3.5; 95% CI -0.1 to -6.8 µmol·kg-1·min-1; P=0.043). Metformin combined with exercise potentiates insulin sensitivity during an OGTT in individuals with pre- and - type 2 diabetes. Metformin's blood glucose-lowering effect seems mediated by decreased oral glucose entering the circulation (gut-liver effect) an effect partially blunted after exercise.

Breaking prolonged sitting increases 24-h physical activity and self-perceived energy levels but does not acutely affect cognition in healthy adults.

It is unknown whether predetermined (un)interrupted sitting within a laboratory setting will induce compensatory changes in human behaviours (energy intake and physical activity) once people return to a free-living environment. The effects of breaking up prolonged sitting on cognition are also unclear. Twenty-four (male = 13) healthy participants [age 31 ± 8 y, BMI 22.7 ± 2.3kg/m2 (mean ± SD)] completed 320min mixed-feeding trials under prolonged sitting (SIT) or with 2min walking at 6.4km/h every 20min (ACTIVE), in a randomised crossover design. Human behaviours were recorded post-trial under free-living conditions until midnight. Cognitive performance was evaluated before and immediately after SIT and ACTIVE trials. Self-perceived sensations (appetite, energy and mood) and finger prick blood glucose levels were collected at regular intervals throughout the trials. There were no differences between trials in eating behaviour and spontaneous physical activity (both, p > 0.05) in free-living conditions, resulting in greater overall total step counts [11,680 (10740,12620) versus 6049 (4845,7253) steps] and physical activity energy expenditure (PAEE) over 24-h period in ACTIVE compared to SIT (all, p < 0.05). Greater self-perceived levels of energy and lower blood glucose iAUC were found in ACTIVE trial compared to SIT trial (both, p < 0.05). No differences were found in cognitive performance between trials (all, p > 0.05). Breaking up sitting does not elicit subsequent behavioural compensation, resulting in greater 24-h step counts and PAEE in healthy adults. Breaking up sitting reduces postprandial glucose concentrations and elicits greater self-perceived energy levels, but these positive effects do not acutely translate into improved cognitive function.

Cross-linked phosphorylated RS4 wheat starch reduces glucose and insulin responses after 3 days of pre-feeding in healthy adults: an acute, double-blind, randomized controlled clinical trial

When this project was designed, there was no evidence that adding resistant starch to available carbohydrate (avCHO) reduced glycaemic and insulinaemic responses (GIR). We compared GIR elicited by a cookie containing cross-linked phosphorylated RS4 wheat starch (Fibersym®) (RS4XL) versus an avCHO-matched control-cookie (CC) after n = 15 adults had consumed RS4XL or CC daily for 3-days using a double-blind, randomised, cross-over design. The difference in glucose iAUC over 0–2 h (primary endpoint) (mmol × min/L) after RS4XL, (mean ± SEM) 106 ± 16, versus CC, 124 ± 16, was not significant (p = 0.087). However, RS4XL reduced 0–90 min glucose iAUC (72 ± 9 vs 87 ± 9, p = 0.022), peak glucose concentration (6.05 ± 0.36 vs 6.57 ± 0.31 mmol/L, p = 0.017) and 0–2 h insulin iAUC (189 ± 21 vs 246 ± 24 nmol × h/L, p = 0.020). These results show that RS4XL reduced postprandial glycaemic and insulinaemic responses when added to avCHO, but do not prove that the products of its colonic fermentation are required for this effect.

1657-P: Post–Mixed Meal Glucagon Secretion Is Not Influenced by Residual Beta-Cell Function in Type 1 Diabetes

Aims: Postprandial glucose excursions contribute to dysglycemia in type 1 diabetes (T1D). Hyperglucagonaemia may play a role but the relationship between beta and alpha-cell dysfunction together with incretin response remains unclear. We sought to elucidate this in people with established T1D with and without C-peptide. Methods: Participants (n=29, age 38 ± 12 years, HbA1c 57 ± 9 mmol/mol, T1D duration 20 ± 13 years) with a range of postprandial urine C-peptide were recruited. A Meal Tolerance Test (MTT, 240 mL Fortisip: 360kcal, 14.4g protein, 13.92g fat, 44.16g carbohydrate) was completed after an overnight fast, maintaining normal basal insulin, without an insulin bolus. Blood samples were taken pre and 30min intervals for 180 minutes post-drink and analysed for glucose, C-peptide, glucagon, proinsulin, GLP-1 and GIP. Participants were grouped by peak C-peptide (high &amp;gt;200 pmol/L, low 3-200pmol/L, undetectable). [Incremental] area under the curves ([i]AUC) were compared by one way ANOVA, Spearman's correlation and multiple regression with significance accepted p≤0.05. Results: Ten participants had high peak C-peptide (680 ± 426 pmol/L), 8 low (39 ± 34 pmol/L), and 11 undetectable. Glucagon was comparable in all groups with mean AUC 1721 ± 890 pmol/L*180min (p=0.84). Glucagon correlated with GLP-1 (r=0.81, p&amp;lt;0.01) and GIP (r=0.43, p=0.02) response, but not C-peptide (R=-0.10, p=0.61), proinsulin (r=-0.18, p=0.35) or proinsulin/C-peptide ratio (r=0.04, p=0.85). C-peptide predicted glucose AUC using multiple regression (R2 = 44.3%, F(1, 27) = 21.4, p&amp;lt;0.01). C-peptide in combination with glucagon predicted glucose iAUC (R2 = 41.1% F(2, 26) = 9.1, p&amp;lt;0.01). Conclusion: Residual C-peptide is a predictor of MTT glucose excursions but not glucagon response in established T1D. Postprandial glucagon contributed to glucose excursion as well as correlating with incretin response. This supports altered alpha-cell phenotype in T1D, aberrantly responding to or secreting incretin. Disclosure G.Taylor: None. K.Smith: None. A.Bashir: None. T.J.Mcdonald: None. E.J.Stevenson: None. J.A.Shaw: Advisory Panel; Betalin Therapeutics, Provention Bio, Inc., Consultant; Mogrify. D.J.West: None. Funding Diabetes Research and Wellness Foundation (SCA/OF/12/15); Francis James Bell Endowment Fund; Country Durham Community Foundation

Comparison of postprandial glycemic and insulinemic response of allulose when consumed alone or when added to sucrose: A randomized controlled trial

Allulose is a naturally occurring monosaccharide with ∼70% sweetness of sucrose which may blunt postprandial glucose when consumed with a carbohydrate-containing meal. Whether a higher allulose to carbohydrate ratio further inhibits both glycemic and insulinemic responses remains unclear. In an acute, double-blind, randomized design, 14 individuals without diabetes (age:51 ± 15 years, BMI:27.2 ± 4.1 kg/m2) were studied over 120 min on three separate occasions after consuming beverages containing 15 g allulose, 15 g allulose plus 30 g sucrose, or 30 g sucrose. After allulose, allulose + sucrose, and sucrose beverages, respectively, glucose iAUC (mean ± SEM; 0.6 ± 0.2, 86.0 ± 9.5, and 118.1 ± 11.3 mmol × min/L), and peak rise (0.05 ± 0.02, 1.69 ± 0.13, and 3.15 ± 0.23 mmol/L) all differed significantly (p < 0.05). Similarly, insulin iAUC and peak rise were significantly different between all beverages. This study demonstrated that allulose added to sucrose attenuated both postprandial glucose and insulin responses. Thus, dietary substitution of sucrose with allulose may be advantageous, but longer-term studies are needed to confirm long term benefits.

Effects of fructose added to an oral glucose tolerance test on plasma glucose excursions in healthy adults

Background and objectivePrevious experimental studies have shown that fructose interacts with glucose metabolism by increasing hepatic glucose uptake. However, human studies investigating the effects of small (‘catalytic’) amounts of fructose, added to an oral glucose load, on plasma glucose levels remain inconclusive. The aim of this study, therefore, was to repeat and extend these previous studies by examining the plasma glucose response during a 75 g oral glucose tolerance test (OGTT) with the addition of different doses of fructose. MethodsHealthy adults (n = 13) received an OGTT without addition of fructose and OGTTs with addition of different doses of fructose (1, 2, 5, 7.5 and 15 g) in a random order, on six separate occasions. Plasma glucose levels were measured every 15 min for 120 min during the study. FindingsThe plasma glucose incremental area under the curve (iAUC) of the OGTT without addition of fructose was not significantly different from any OGTT with fructose (p ≥ 0.2 for all fructose doses). Similar results were observed when these data were clustered with data from a similar, previous study (pooled mean difference: 10.6; 95%CI: 45.0; 23.8 for plasma glucose iAUC of the OGTT without addition of fructose versus an OGTT with 5 g fructose; fixed-effect meta-analysis, n = 38). Of interest, serum fructose increased from 4.8 μmol/L (interquartile range: 4.1–5.9) at baseline to 5.3 μmol/L (interquartile range: 4.8–7.5) at T = 60 min during an OGTT without addition of fructose (p = 0.002). ConclusionLow doses of fructose added to an OGTT do not affect plasma glucose levels in healthy adults. The role of endogenous fructose production, as a potential explanation of these null-findings, deserves further investigation.

Physical Activity, but Not Glycaemic Load, Is Associated with Lower Real-Time Glycaemic Control in Free-Living Women with Gestational Diabetes Mellitus.

Maintaining blood glucose within the target range is the primary treatment goal for women with gestational diabetes mellitus (GDM). Foods with low glycaemic loads are recommended in clinical practice; however, the relative importance of other key lifestyle variables is unexplored. This pilot study explored the associations of glycaemic load, carbohydrates and physical activity parameters on blood glucose concentrations in free-living women with GDM. Twenty-nine women (28-30 weeks gestation, 34 ± 4 years) with GDM were enrolled. Continuous glucose monitoring, physical activity (ActivPAL inclinometer) and dietary intake and dietary quality were measured concurrently for 3 days. Pearson correlation analyses determined the association between glucose levels and lifestyle variables. Despite all receiving the same nutrition education, only 55% of women were following a low glycaemic load diet with a large range of carbohydrate intakes (97-267 g/day). However, the glycaemic load did not correlate with 3-hr postprandial glucose (r2 = 0.021, p = 0.56) or 24-h glucose iAUC (r2 = 0.021, p = 0.58). A significant relationship between total stepping time and lower 24-h glucose iAUC (r2 = 0.308, p = 0.02) and nocturnal glucose (r2 = 0.224, p = 0.05) was found. In free-living women with diet-controlled GDM, more physical activity, i.e., steps accumulated across the day, may be a simple and effective strategy for improving maternal blood glucose concentrations.

Combined effects of exercise and different levels of acute hypoxic severity: A randomized crossover study on glucose regulation in adults with overweight.

Purpose: The aim of this study was to investigate the influence of manipulating hypoxic severity with low-intensity exercise on glucose regulation in healthy overweight adults. Methods: In a randomized crossover design, 14 males with overweight (age: 27 ± 5years; body mass index (BMI) 27.1 ± 1.8kg⋅m2) completed three exercise trials involving 60min aerobic exercise cycling at 90% lactate threshold in normoxia (NM, FiO2 = 20.9%), moderate hypoxia (MH, FiO2 = 16.5%) and high hypoxia (HH, FiO2 = 14.8%). A post-exercise oral glucose tolerance test (OGTT) was performed. Venous blood samples were analyzed for incremental area under the curve (iAUC), plasma glucose and insulin, as well as exerkine concentrations (plasma apelin and fibroblast growth factor 21 [FGF-21]) pre- and post-exercise. A 24-h continuous glucose monitoring (CGM) was used to determine interstitial glucose concentrations. Heart rate, oxygen saturation (SpO2) and perceptual measures were recorded during exercise. Results: Post-exercise OGTT iAUC for plasma glucose and insulin concentrations were lower in MH vs. control (p = 0.02). Post-exercise interstitial glucose iAUC, plasma apelin and FGF-21 were not different between conditions. Heart rate was higher in HH vs. NM and MH, and MH vs. NM (p < 0.001), while SpO2 was lower in HH vs. NM and MH, and MH vs. NM (p < 0.001). Overall perceived discomfort and leg discomfort were higher in HH vs. NM and MH (p < 0.05), while perceived breathing difficulty was higher in HH vs. NM only (p = 0.003). Conclusion: Compared to higher hypoxic conditions, performing acute aerobic-based exercise under moderate hypoxia provided a more effective stimulus for improving post-exercise glucose regulation while concomitantly preventing excessive physiological and perceptual stress in healthy overweight adults.

A Randomized, Placebo-Controlled Crossover Study to Evaluate Postprandial Glucometabolic Effects of Mulberry Leaf Extract, VitaminD, Chromium, and Fiber in People with Type2 Diabetes.

Reducing postprandial (PP) hyperglycemia and PP glucose excursions is important for overall glycemic management. Although most therapeutic lifestyle interventions that reduce caloric intake would affect this, there is no particular nutritional intervention favored. We evaluated the effects of a novel natural food adjuvant combining mulberry leaf extract (MLE) with other bioactive ingredients, in people with type2 diabetes (T2D) originating from Asia, on improving PP glucometabolic response in a randomized controlled exploratory crossover, two-center study (USA, Singapore). A 2-g blend of 250mg MLE [containing 12.5mg of 1-deoxynojirimycin (DNJ)], fiber (1.75g), vitamin D3 (0.75μg), and chromium (75μg), compared with a similar blend without the MLE, was sprinkled over a 350-kcal breakfast meal (55.4g carbs) and PP blood glucose (primary exploratory endpoint), insulin, and incretin hormones (GLP-1, GIP) were evaluated in blood samples over 3h. Changes in incremental areas under the concentration curve (iAUC) and maximum concentrations (Cmax) were compared. Thirty individuals (12 women, mean age 59years, HbA1c 7.1%, BMI 26.5kg/m2) were enrolled and the MLE-based blend relative to the blend without MLE significantly reduced glucose iAUC at 1h (- 20%, p < 0.0001), 2h (- 17%, p = 0.0001), and 3h (- 15%, p = 0.0032) and Cmax [mean (95% CI) difference - 0.8 (- 1.2, - 0.3) mmol/L, p = 0.0006]. A statistically significant reduction in 1h insulin iAUC (- 24%, p = 0.0236) was observed, but this reduction was no longer present at either 2h or 3h. No difference in GLP-1 was seen, but GIP response (iAUC and Cmax) was less with the MLE-based blend. The observation of a significant glucose reduction paralleled with a significant lower insulin response supports a reduced gastrointestinal glucose absorption. These results support the use of a 2-g natural blend of MLE, fiber, vitaminD, and chromium in T2D as a convenient dietary adjuvant to improve PP glucometabolic response. gov identifier NCT04877366.