Postprandial Blood Glucose Increase Research Articles

Determination the limit of postprandial blood glucose increase and the metabolism of acetylated wheat starch on healthy mice

Introduction: Nowadays, resistant starches are interested as a supplement food by effecting on the limit of postprandial blood glucose increase and supporting for the diabetes treatment. Recently, we have semisynthesized the acetylated wheat starch (AWS) oriented for supporting the treatment of diabetes mellitus, which is the RS4 formed by chemical structure modification. AWS has been proved itself to show strong resistance to amylase activity in-vitro as well as to be safety in-vivo. Materials and Methods: In this study, we continued to evaluate AWS’s ability to limit postprandial blood glucose increase and determined shortchain fatty acids (SCFAs) metabolized from AWS in the gastrointestinal tract of healthy mice by HPLC. Results: the mice fed AWS exhibited a very limited increase in blood glucose levels and remained stable for 2 hours after meals comparing with the control group (mice fed natural wheat starch) (NWS). Simultaneously, the content of SCFAs produced in the caecum of the mice fed AWS was significantly higher than mice fed NWS, especially with acetic and propionic acids by 28% and 26%, respectively. Conclusion: AWS has been shown to limit postprandial hyperglycemia in mice effectively through the resistance to amylase hydrolysis in the small intestine. When going into the caecum, it is fermented to form SCFAs that provide a part of the energy for the body’s activities and to avoid rotten fermentation causing digestive disorders, which are inherent restrictions of normal high cellulose and fiber food. Key words: acetylated wheat starch, natural wheat starch, SCFA, blood glucose

Structural Basis of Resistant Starch (RS) in Bread: Natural and Commercial Alternatives.

Bread is categorized as having a high amount of rapidly digested starch that may result in a rapid increase in postprandial blood glucose and, therefore, poor health outcomes. This is mostly the result of the complete gelatinization that starch undergoes during baking. The inclusion of resistant starch (RS) ingredients in bread formulas is gaining prominence, especially with the current positive health outcomes attributed to RS and the apparition of novel RS ingredients in the market. However, many RS ingredients contain RS structures that do not resist baking and, therefore, are not suitable to result in a meaningful RS increase in the final product. In this review, the structural factors for the resistance to digestion and hydrothermal processing of RS ingredients are reviewed, and the definition of each RS subtype is expanded to account for novel non-digestible structures recently reported. Moreover, the current in vitro digestion methods used to measure RS content are critically discussed with a view of highlighting the importance of having a harmonized method to determine the optimum RS type and inclusion levels for bread-making.

D-mannitol modulates glucose uptake ex vivo; suppresses intestinal glucose absorption in normal and type 2 diabetic rats

Mannitol is a widely used reduced-calorie sweetener with limited studies on its anti-hyperglycemic potential. The anti-hyperglycemic potential of mannitol was investigated using different experimental models. Mannitol inhibited α-glucosidase (IC50 = 180 ± 20% w/v) and α-amylase (IC50 = 75 ± 20% w/v) activities in a dose dependent (2.5–20% w/v) manner, in vitro, although the effective doses are not gastrointestinally tolerable. Mannitol inhibited glucose absorption (IC50 = 19 ± 3% w/v) in isolated rat jejunum in a dose dependent (2.5–20% w/v) manner, perhaps by entrapment of glucose molecules. Acute administration of 0.3 g/kg bw reduced small intestinal glucose absorption in type 2 diabetic rats, which was accompanied by reduced blood glucose. The reduced intestinal glucose absorption may be influenced by the concomitant delayed gastric emptying observed in the mannitol-treated diabetic animals. On the other hand, mannitol increased glucose uptake in a yeast cell suspension (GU50 = 4.7 ± 1.2% w/v), 3T3-L1 adipocytes (GU50 = 1.2 ± 0.4% w/v) and isolated rat muscle (GU50 = 25 ± 3% w/v) in a dose dependent manner. In silico docking suggested that GLUT-4 (binding energy = −15.5 kcal/mol) is a possible molecular target of mannitol. Data from this study suggest that mannitol may be used as a dietary supplement in controlling postprandial blood glucose increase by reducing intestinal glucose absorption and increasing muscle glucose uptake, which needs further study.

Mechanism of Suppression of Blood Glucose Level by Calcium Alginate in Rats.

Calcium alginate (Ca-Alg) is known to suppress the postprandial increase of blood glucose, and therefore may be helpful for preventing lifestyle-related diseases such as diabetes. In this work, we examined the mechanism of this effect. As α-amylase activity and α-glucosidase activity are involved in the digestion of starch, we examined the in vitro inhibitory effect of Ca-Alg on these enzymes. Ca-Alg showed little inhibition of α-amylase, but markedly inhibited α-glucosidase activity. The direct binding affinity of glucose for Ca-Alg was low. Also, Ca-Alg had essentially no effect on the membrane permeability of glucose. Therefore, we considered that the suppression of blood glucose by Ca-Alg is predominantly due to a decrease in the efficiency of starch digestion as a result of inhibition of α-glucosidase, possibly due to increased viscosity of the gastrointestinal contents. Next, we investigated the optimum amount in the diet and the optimum particle size of Ca-Alg for suppressing postprandial blood glucose level in rats orally administered a diet containing starch with various amounts and particle sizes of Ca-Alg. We found that 5% by weight of 270-mesh-pass Ca-Alg was most effective.

Randomized, Double-Blind, Crossover Clinical Trial of the Effect of Calcium Alginate in Noodles on Postprandial Blood Glucose Level.

We conducted a prospective, randomized, double-blind, 3-group, 3-phase crossover study to evaluate the effect of calcium alginate (Ca-Alg) on the postprandial increase of blood glucose in 15 healthy adult subjects who were given udon noodles containing or not containing Ca-Alg (5 or 8%). The value of ΔCmax (difference between the maximum (Cmax) and pre-feeding (C0) blood glucose levels) was significantly reduced in both Ca-Alg groups, and the area under the blood glucose level-time curve over 120 min (ΔAUC, with C0 as the baseline) was also significantly reduced. Thus, supplementation of noodles with Ca-Alg significantly suppressed both the peak postprandial blood glucose level and the total amount of glucose absorption. Blood calcium (Ca) concentration was significantly increased at 120 min after ingestion, but there was no marked change of other parameter values. A questionnaire indicated that addition of Ca-Alg did not affect the acceptability of the noodles. These results indicate that Ca-Alg might a useful food additive for helping to prevent lifestyle-related diseases without adversely affecting individual eating habits.

Effect of long‐term administration of heat‐processed onion (Allium cepa L.) extract on body weight, visceral fat accumulation, and plasma lipid profile in C57BL/6 mice fed high‐fat diets

In the previous study, it was found that Amadori rearrangement compounds‐rich heat‐processed onion reduced postprandial blood glucose increase by reducing absorption of glucose through inhibition of sucrase and α‐glucosidase in the small intestinal tract. This reduced absorption of carbohydrate might control body weight gain due to excessive carbohydrates consumption and induce calorie restriction. To investigate and prove the mechanism for the effects of heat‐processed onion extract (ONI_V) on body weight gain, body weight, plasma lipids, body fat mass, and lipid deposition were evaluated and compared to Garcinia cambogia (GC), a known competitive inhibitor of adenosine 5′‐triphosphate (ATP) citrate lyase in C57BL/6 mice model. Male C57BL/6 mice were fed high‐fat diet (60% kcal fat) with 2% ONI_V or GC used as a positive control. Supplementation of ONI_V effectively lowered the body weight gain, visceral fat accumulation, and plasma lipid concentrations. Compared to control, ONI_V increased the number of adipocytes with a smaller diameter. Interestingly, GC treatment did not change either adipocyte numbers or sizes although total weight of visceral fat pads was significantly reduced compared to control. These results indicate that ONI_V and GC may use different mechanisms in inhibiting weight gain under the current experimental conditions used in this study. Furthermore, ONI_V may reduce weight gain using a similar mechanism of anti‐diabetic drugs, thiazolidinediones (TZDs). TZDs in humans and animals have been shown to be a strong ligand for PPARγ, a nuclear transcription factor that enhances adipocyte differentiation, thereby increasing the number of adipocytes with smaller diameters, which is consistent with the effects of ONI_V observed in this study. According to the obtained results, ONI‐V may be effective not only in reducing weight gains, but also in ameliorating some of the metabolic abnormalities including hyperglycemia, oxidative stress, and inflammation associated with weight gain and obesity.Support or Funding InformationThis research was financially supported by the Ministry of Trade, Industry, and Energy (MOTIE), Korea, under the “Regional Specialized Industry Development Program” supervised by the Korea Institute for Advancement of Technology (KIAT).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Calorie Restriction Effect of Heat-Processed Onion Extract (ONI) Using In Vitro and In Vivo Animal Models.

Onion (Allium cepa L.) is widely consumed as food or medicinal plant due to its well-defined health benefits. The antioxidant and antihyperlipidemic effects of onion and its extracts have been reported well. However, very limited information on anti-hyperglycemic effect is available in processed onion extracts. In our previous study, we reported that Amadori rearrangement compounds (ARCs) produced by heat-processing in Korean ginseng can reduce carbohydrate absorption by inhibiting intestinal carbohydrate hydrolyzing enzymes in both in vitro and in vivo animal models. To prove the enhancement of anti-hyperglycemic effect and ARCs content by heat-processing in onion extract, a correlation between the anti-hyperglycemic activity and the total content of ARCs of heat-processed onion extract (ONI) was investigated. ONI has a high content of ARCs and had high rat small intestinal sucrase inhibitory activity (0.34 ± 0.03 mg/mL, IC50) relevant for the potential management of postprandial hyperglycemia. The effect of ONI on the postprandial blood glucose increase was investigated in Sprague Dawley (SD) rats fed on sucrose or starch meals. The maximum blood glucose levels (Cmax) of heat-processed onion extract were significantly decreased by about 8.7% (from 188.60 ± 5.37 to 172.27 ± 3.96, p < 0.001) and 14.2% (from 204.04 ± 8.73 to 175.13 ± 14.09, p < 0.01) in sucrose and starch loading tests, respectively. These results indicate that ARCs in onion extract produced by heat-processing have anti-diabetic effect by suppressing carbohydrate absorption via inhibition of intestinal sucrase, thereby reducing the postprandial increase of blood glucose. Therefore, enhancement of ARCs in onion by heat-processing might be a good strategy for the development of the new product on the management of hyperglycemia.

Regular Aerobic, Resistance, and Cross-Training Exercise Prevents Reduced Vascular Function Following a High Sugar or High Fat Mixed Meal in Young Healthy Adults.

The postprandial state can negatively influence flow mediated dilation (FMD), a predictor of atherosclerosis and cardiovascular disease. This investigation was designed to determine the effect of regular aerobic and/or resistance exercise on postprandial FMD after a high sugar or high fat mixed meal. Forty-five healthy participants were recruited from one of four groups: lean sedentary (SED), runners, weight lifters, and cross-trainers. Participants were randomly crossed over to a high sugar meal (HSM) and a high fat mixed meal (HFMM; both fat and carbohydrate). Pre-and postprandial endothelial function was assessed for both meals using brachial artery FMD. Plasma lipids, insulin, glucose, hs-CRP, and SOD were also measured with both meals. Endothelium-independent dilation was determined via sublingual nitroglycerin. Brachial artery FMD was reduced in SED following the HSM (9.9 ± 0.9% at baseline, peak reduction at 60 min 6.5 ± 1.0%) and the HFMM (9.4 ± 0.9% at baseline, peak reduction at 120 min 5.9 ± 1.2%; P < 0.05 for both, Mean ± SEM). There was no change in FMD after either HSM or HFMM in runners, weight lifters, and cross-trainers. Post-prandial increases in blood glucose, insulin and triglycerides were less pronounced in the exercisers compared to SED. In addition, exercisers presented lower baseline plasma hs-CRP and higher SOD activity. Nitroglycerin responses were similar among groups. These results suggest that endothelial function is reduced in sedentary adults after a HSM or HFMM, but not in regular aerobic or resistance exercisers. This response may be due to favorable postprandial metabolic responses or lower postprandial levels of inflammation and oxidative stress. These findings may help to explain the cardioprotective effect of exercise.

Erythritol reduces small intestinal glucose absorption, increases muscle glucose uptake, improves glucose metabolic enzymes activities and increases expression of Glut-4 and IRS-1 in type 2 diabetic rats.

Studies have reported that erythritol, a lowor non-glycemic sugar alcohol possesses anti-hyperglycemic and anti-diabetic potentials but the underlying mode of actions is not clear. This study investigated the underlying mode of actions behind the anti-hyperglycemic and anti-diabetic potentials of erythritol using different experimental models (experiment 1, 2 and 3). Experiment 1 examined the effects of increasing concentrations (2.5-20%) of erythritol on glucose absorption and uptake in isolated rat jejunum and psoas muscle, respectively. Experiments 2 and 3 examined the effects of a single oral dose of erythritol (1g/kg bw) on intestinal glucose absorption, gastric emptying and postprandial blood glucose increase, glucose tolerance, serum insulin level, muscle/liver hexokinase and liver glucose-6 phosphatase activities, liver and muscle glycogen contents and mRNA and protein expression of muscle Glut-4 and IRS-1 in normal and type 2 diabetic animals. Experiment 1 revealed that erythritol dose dependently enhanced muscle glucose ex vivo. Experiment 2 demonstrated that erythritol feeding delayed gastric emptying and reduced small intestinal glucose absorption as well as postprandial blood glucose rise, especially in diabetic animals. Experiment 3 showed that erythritol feeding improved glucose tolerance, muscle/liver hexokinase and liver glucose-6 phosphatase activities, glycogen storage and also modulated expression of muscle Glut-4 and IRS-1 in diabetic animals. Data suggest that erythritol may exert anti-hyperglycemic effects not only via reducing small intestinal glucose absorption, but also by increasing muscle glucose uptake, improving glucose metabolic enzymes activity and modulating muscle Glut-4 and IRS-1 mRNA and protein expression. Hence, erythritol may be a useful dietary supplement for managing hyperglycemia, particularly for T2D.

Warum ist eine Kombination von Basalinsulin mit einem GLP-1-Rezeptoragonisten bei vielen Patienten mit Typ-2-Diabetes sinnvoll?

In 2015, the combination of basal insulin and GLP-1 receptor agonist (RA) was incorporated into the guideline recommendations for type 2 diabetes as an option for the last escalation step. The two antidiabetics to be injected subcutaneously are complementary regarding their respective main effects and limitations. Basal insulin is predominantly active between meals and in the fasting state, whereas the main action of GLP-1 RA consists in preventing an excessive postprandial blood glucose increase. Moreover, GLP-1 RA is characterised by a low intrinsic risk of hypoglycaemia, body weight reduction and a positive impact on cardiovascular risk factors. Unlike GLP-1 RA, no upper dose limits are defined for basal insulin. However, initiation of insulin therapy is associated with disadvantages in terms of hypoglycaemia and weight increase. Therefore, patients achieving their treatment goals with GLP-1 RA alone are better treated without insulin. In a review, study results on combinations of basal insulin and GLP-1-RA versus comparative therapies are presented. Most of the studies were carried out in patients pre-treated with basal insulin. The add-on of GLP-1 RA was commonly associated with significant reductions of body weight and also resulted in additional HbA1c reductions compared with an increase of the basal insulin dose. The add-on of a short acting insulin to an existing basal insulin therapy enabled similar HbA1c reductions to the add-on of a GLP-1 RA, but simultaneously increased the number of episodes of hypoglycaemia and might lead to more unfavourable body weight developments. A fixed combination of insulin degludec and liraglutide (IDegLira) showed an effective and rather steady blood glucose reduction in a 24-hour interval vs. basal insulin or GLP-1 RA alone. Combinations of basal insulin and a GLP-1 RA improve glycaemic control in many patients with type 2 diabetes without any significant increase of the risk of hypoglycaemia and without weight gain, especially compared to a dose increase of the basal insulin or add-on of a short-acting insulin.

The Importance of the Bolus Calculator Use for Improving Glycemic Control in Patients on the Insulin Pump Therapy

Introduction: Bolus calculator is an advanced function of insulin pump (IP). The use of bolus calculator increases the accuracy of calculation of the proper meal or corrective dose of insulin in patients with type 1 diabetes (T1D). Aim of the Study: Compare the difference in the parameters of glycemic control (HbA1c, postprandial increase of blood glucose and number of hypoglycemic episodes per week) between the group of patients who use bolus calculator for <50% of the total daily boluses, and the group of patients who use bolus calculator for ≥50% of total daily boluses. Patients and Methods: This study included 36 patients aged over 18 years with T1D on IP therapy in the Republika of Srpska. All patients used IP for at least one year prior to participation in the study. Before the IP therapy was initiated, all the patients were trained for carbohydrate counting in course of flexible insulin therapy training (FIT). Professional software, CareLink Pro® Software (Medtronic Inc., Northridge, CA, USA) was used to download data from insulin pumps to a personal computer. The default frequency of bolus calculator use was ≥50% of total daily boluses. Results: No statistically significant difference was found in HbA1c (6.61 ± 1.10 vs. 0.84 ± 6:56, p = 0.896) or the number of hypoglycemic episodes (2.00 (1.00, 4.00) (1.0 - 6.0) vs 3.00 (2.00, 4:00) (1.0 - 5.0), p = 0.298) between the group of patients who used bolus calculator for <50% of the total daily boluses, and the group of patients who used bolus calculator for ≥50% of total daily boluses. Patients who used bolus calculator had significantly lower postprandial increase in blood glucose after breakfast. Conclusion: In order to maximize all the advantages of IP therapy, a regular reeducation of both patients and diabetologists about advanced IP functions is needed for improving the glycoregulation in T1DM.

Long-term effects of daily postprandial physical activity on blood glucose: a randomized controlled trial.

Previous studies have shown that a bout of moderate or light postprandial physical activity effectively blunts the postprandial increase in blood glucose. The objective of this study was to test whether regular light postprandial physical activity can improve glycemia in persons with hyperglycemia or with a high risk of hyperglycemia. We randomized 56 participants to an intervention or a control group. They were diagnosed as hyperglycemic, not using antidiabetics, or were categorized as high-risk individuals for type 2 diabetes. The intervention group was instructed to undertake a minimum 30 min of daily light physical activity, starting a maximum of 30 min after a meal in addition to their usual physical activity for 12 weeks. The control group maintained their usual lifestyle. Blood samples were taken pre- and post-test. Forty participants completed the study and are included in the results. The self-reported increase in daily physical activity from before to within the study period was higher in the intervention group compared with control (41 ± 25 vs. 2 ± 16 min, p < 0.001). Activity diaries and accelerometer recordings supported this observation. The activity in the intervention group started earlier after the last meal compared with control (30 ± 13 vs. 100 ± 57 min, p = 0.001). There were no within- or between-group differences in any glycemic variable from pre- to post-test. In conclusion, the present study does not seem to support the notion that regular light postprandial physical activity improves blood glucose in the long term in persons with hyperglycemia or with high risk of hyperglycemia.

Alpha-Amylase Inhibition and Antioxidative Capacity of Some Antidiabetic Plants Used by the Traditional Healers in Southeastern Nigeria.

Oxidative stress plays a significant role in the pathogenesis of metabolic syndrome including diabetes mellitus (DM). The inhibition of alpha-amylase is an important therapeutic target in the regulation of postprandial increase of blood glucose in diabetic patients. The present study investigated the alpha-amylase inhibitory and antioxidant potential of selected herbal drugs used in the treatment of DM by the traditional healers in Isiala Mbano and Ikwuano regions of southeastern Nigeria. Antioxidant activity was evaluated in terms of free radical scavenging, reducing power, and total phenolic (TPC) and flavonoid content (TFC) in consonance with the TLC profiling. The results showed that methanol crude extracts from Anacardium occidentale (AO) and Ceiba pentandra (CP) recorded higher TPC and TFC, potent free radical scavenging, and efficient reducing power (RP) as compared with other plant samples. All the plant extracts exhibited a relative alpha-amylase inhibition apart from Strophanthus hispidus (SH) extract with a negative effect. We discovered a mild to weak correlation between alpha-amylase inhibition or antioxidative capacity and the total phenol or flavonoid content. At least in part, the results obtained in this work support the traditional use of certain plant species in the treatment of patients with DM.

Postprandial glycaemic response of foxtail millet dosa in comparison to a rice dosa in patients with type 2 diabetes.

Background & objectives:Millets are rich source of dietary fibre and non-starchy polysaccharides with low glycaemic index (GI), hence can be used as a therapeutic diet. This study was conducted to estimate the effects of a millet-based dosa (foxtail dosa) compared to a rice dosa for breakfast on postprandial glucose levels in patients with type 2 diabetes mellitus (T2DM).Methods:The GI of rice dosa and foxtail millet dosa was estimated. A total of 105 T2DM participants were randomly selected for the study. The participants were on oral hypoglycaemic agents (OHA) and not on insulin. In this study, each individual served as their own control and experimental group. The postprandial increase in blood glucose was compared after a breakfast of rice dosa and millet dosa. Single and paired t test was used to note the change in blood glucose levels and the level of the significance.Results:The GI of foxtail millet dosa was 59.25 and rice dosa was 77.96. There was a significant reduction (P<0.001) in the postprandial glucose level of patients who consumed a millet-based dosa when compared to those who consumed a rice-based dosa. No significant reduction was observed in the fasting glucose levels.Interpretation & conclusions:The results suggested that replacing a rice-based breakfast item with a millet-based breakfast item lowers the postprandial blood glucose levels in T2DM patients. Thus, millets may have a protective role in the management of hyperglycaemia. Further studies need to be done in a systematic manner to confirm these findings.

Coffee polyphenol consumption improves postprandial hyperglycemia associated with impaired vascular endothelial function in healthy male adults

Epidemiological studies indicate that habitual coffee consumption lowers the risk of diabetes and cardiovascular diseases. Postprandial hyperglycemia is a direct and independent risk factor for cardiovascular diseases. We previously demonstrated that coffee polyphenol ingestion increased secretion of Glucagon-like peptide 1 (GLP-1), which has been shown to exhibit anti-diabetic and cardiovascular effects. We hypothesized coffee polyphenol consumption may improve postprandial hyperglycemia and vascular endothelial function by increasing GLP-1 release and/or reducing oxidative stress. To examine this hypothesis, we conducted a randomized, acute, crossover, intervention study in healthy male adults, measuring blood parameters and flow-mediated dilation (FMD) after ingestion of a meal with or without coffee polyphenol extract (CPE). Nineteen subjects consumed a test meal with either a placebo- or CPE-containing beverage. Blood biomarkers and FMD were measured at fasting and up to 180 minutes postprandially. The CPE beverage led to a significantly lower peak postprandial increase in blood glucose and diacron-reactive oxygen metabolite, and significantly higher postprandial FMD than the placebo beverage. Postprandial blood GLP-1 increase tended to be higher after ingestion of the CPE beverage, compared with placebo. Subclass analysis revealed that the CPE beverage significantly improved postprandial blood GLP-1 response and reduced blood glucose increase in the subjects with a lower insulinogenic index. Correlation analysis showed postprandial FMD was negatively associated with blood glucose increase after ingestion of the CPE beverage. In conclusion, these results suggest that coffee polyphenol consumption improves postprandial hyperglycemia and vascular endothelial function, which is associated with increased GLP-1 secretion and decreased oxidative stress in healthy humans.

Daily Physical Activity After Meals -long Term Effects On Blood Glucose

PURPOSE: The postprandial blood glucose concentration is an important risk factor for development of cardiovascular diseases and diabetes. Previous studies have shown that one bout of moderate or light post-meal physical activity effectively blunts the postprandial increase in blood glucose after carbohydrate intake. Pre-meal exercise does not generate such effect. Thus, the effect of exercise on postprandial glycemia depend on the timing of exercise. Even very light physical activity decreases postprandial glycemia when performed in the postprandial period. The purpose of this study was to investigate whether such activity performed each day for 12 weeks would influence blood variables related to glycemic control. METHODS: 40 subjects being ethnic Norwegians or of South Asian origin were randomized into an intervention or a control group. They were previously diagnosed as hyperglycemic, or with high risk of type 2 diabetes according to Ramachandran’s risc score. Control subjects were told to maintain their usual physical activity patterns during the study period, while the intervention subjects were instructed to undertake a minimum of 30 minutes of daily post-meal physical activity in addition to their usual activity patterns. Venous blood samples were taken before and after the 12 week intervention period. Plasma was analyzed for HbA1c and for fasting and 2hour (OGTT) values of glucose, insulin and c-peptide. The subjects kept a physical activity diary, answered questionnaires and used accelerometers to determine the level of physical activity. RESULTS: The intervention subjects reported an average of 1.3±0,8 bouts of physical activity each day (usual activity included), starting 29±13 min after the last meal, lasting 56±21 min, with an intensity of 11.3±1,0 on Borg RPE scale. This was an increase in post meal physical activity of 41±25 min/day compared to pre intervention (p<0.001). The control group did not change their activity habits. None of the glycemic variables changed from pre to post, neither in the intervention nor the control group (p>0.1). CONCLUSION: This study is not in support of the idea that daily post meal light physical activity might alter glycemia.

Anti‐hyperglycemic Effect and Mode of Action of Palatinose In vitro and Animal Models

Inhibition of α‐amylase and α‐glucosidase involved in the digestion carbohydrates can decrease the postprandial increase of blood glucose level after a mixed carbohydrate diet. In the course of screening these enzyme inhibitors, we screened isomaltulose (6‐0‐α‐D‐glucopyranosyl‐D‐fructose) using in‐vitro enzyme inhibition assay. Isomaltulose, known by the trade name Palatinose, is a disaccharide that is manufactured from sucrose via bacterial fermentation. Several studies showed that Palatinose had benefit effects on anti‐hyperglycemic effect in human clinical trials. However, there is limited information about the action mechanism on blood glucose lowering effect. Therefore, inhibitory activity of Palatinose against rat intestinal α‐glucosidases and porcine pancreatic α‐amylase were investigated in this study. The half‐maximal inhibitory concentration (IC50) of Palatinose on α‐amylase and α‐glucosidase were 30.8 and 91.8 mM, respectively. The postprandial blood glucose lowering effects of Palatinose was compared to a known type 2 diabetes drug (Acarbose), a strong α‐glucosidase inhibitor in the Sprague‐Dawley (SD) rat model. In rats fed on starch, the blood glucose level at 30 min after administration in Palatinose‐treated SD rats (0.1 g/kg‐body weight) was significantly lower than in untreated group (173.94 ± 10.15 vs. 195.80 ± 12.92 mg/dL, respectively). These results indicate that Palatinose may have anti‐hyperglycemic effect by suppressing carbohydrate absorption in the gastrointestinal level, and thereby reducing the postprandial increase of blood glucose.

Acute effect of glucose on cerebral blood flow, blood oxygenation, and oxidative metabolism.

While it is known that specific nuclei of the brain, for example hypothalamus, contain glucose-sensing neurons thus their activity is affected by blood glucose level, the effect of glucose modulation on whole-brain metabolism is not completely understood. Several recent reports have elucidated the long-term impact of caloric restriction on the brain, showing that animals under caloric restriction had enhanced rate of tricarboxylic acid cycle (TCA) cycle flux accompanied by extended life span. However, acute effect of postprandial blood glucose increase has not been addressed in detail, partly due to a scarcity and complexity of measurement techniques. In this study, using a recently developed noninvasive MR technique, we measured dynamic changes in global cerebral metabolic rate of O2 (CMRO2 ) following a 50 g glucose ingestion (N = 10). A time dependent decrease in CMRO2 was observed, which was accompanied by a reduction in oxygen extraction fraction (OEF) with unaltered cerebral blood flow (CBF). At 40 min post-ingestion, the amount of CMRO2 reduction was 7.8 ± 1.6%. A control study without glucose ingestion was performed (N = 10), which revealed no changes in CMRO2 , CBF, or OEF, suggesting that the observations in the glucose study was not due to subject drowsiness or fatigue after staying inside the scanner. These findings suggest that ingestion of glucose may alter the rate of cerebral metabolism of oxygen in an acute setting.

Comparisons of anti‐hyperglycemic effects of vitamin B4, vitamin B6 and vitamin C in animal model (829.31)

We selected 3 kinds of water soluble vitamins such as vitamin B₄, vitamin B₆, and vitamin C using Sprague Dawley(SD) rat model. The concentration of vitamin B₄and vitamin B₆ for sucrose loading test was 50 mg/kg, vitamin C was 0.1 and 0.5 g/kg. The effect of as vitamin B₄, vitamin B₆, and vitamin C on the postprandial blood glucose increase after meal was investigated in SD rats fed on sucrose. Three vitamin samples significantly reduced the postprandial blood glucose levels after sucrose loading. These results indicate that vitamin B₄, vitamin B₆, and vitamin C may have anti‐hyperglycemic effect by suppressing carbohydrate absorption in the gastrointestinal level, and thereby reducing the postprandial increase of blood glucose. These results indicate that vitamin B₄, vitamin B₆, and vitamin C may improve postprandial in blood glucose and glucose homeostasis since it inhibits intestinal sucrase and thus delays carbohydrate absorption, although clinical trials are needed.

Rat Intestinal Sucrase and α-Glucosidase Inhibitory Activities of Isocoumarin and Flavonoids from the Zanthoxylum schinifolium Stems

, Rutaceae, Isocoumarin, Flavonoid, Sucrase inhibitory activityHyperglycemia, an abnormal postprandial increase ofblood glucose level, has been linked to the onset of type 2insulin-dependent diabetes mellitus (NIDDM, Type 2 dia-betes) and associated cardiovascular complications includ-ing hypertension.