Peak Blood Glucose Concentration Research Articles

Detemir improves diabetic regulation in poorly controlled diabetic dogs with concurrent diseases.

This study evaluated the use of detemir for treating diabetic dogs with comorbidities that were poorly controlled with intermediate-acting insulins. 7 insulin-treated diabetic dogs. Retrospective pilot study. Dogs were treated with detemir for at least 3 months, and glycemia was assessed by the owners at home initially 2 to 4 times daily for 6 to 8 weeks and twice daily thereafter. Clinical evaluations occurred on days 7 to 14, day 30, and then every 60 to 90 days, and dosage adjustments of detemir occurred as needed to control glycemia. The mean, peak, nadir, morning, and evening preinsulin daily blood glucose concentrations were significantly lower after dosing with detemir for 1, 3, or 6 months and during the last month of treatment compared to the final month of treatment with intermediate-acting insulin. Intermediate-acting insulins resulted in significantly worse glycemic control than detemir in all 3 categories of control. The odds of a biochemical hypoglycemic measurement with detemir were not significantly different compared to intermediate-acting insulins. Clinical hypoglycemia did not occur following detemir treatment. When insulin was withheld because of low morning preinsulin blood glucose concentration < 6.7 mmol/L (≤ 120 mg/dL) and dogs were fed, mean blood glucose concentration was significantly higher 1 hour later. Glucose concentrations were also significantly higher 12 hours later on days when insulin was withheld in the morning or evening for either 1 or 12 hours. Detemir is useful in diabetic dogs with other comorbidities and can be considered an alternative treatment in poorly controlled diabetic dogs.

Comparison of blood glucose responses by cane sugar (Saccharum officinarum) versus coconut jaggery (Cocos nucifera) in type 2 diabetes patients

Type 2 diabetic mellitus is a predominant metabolic disorder that has a direct impact on human health. Although scientific data are deficit, coconut jaggery has been suggested as a better alternative for cane sugar by some individuals. This study was conducted to assess the credibility of this claim. Coconut jaggery was prepared at Coconut Research Institute, Sri Lanka and nutritional composition of coconut jaggery was compared with cane sugar using standard methods. Significantly higher ( P < 0.05) moisture (8.92 ± 0.22)%, ash (2.09 ± 0.33)%, protein (1.91 ± 0.28)%, fat (0.14 ± 0.02)% and fiber (0.05 ± 0.03)% contents were observed in coconut jaggery compared to cane sugar. The total starch and total sugar content of the coconut jaggery was significantly ( P < 0.05) lower than that of the cane sugar. Forty-three patients (Male: 16, Female: 27) with type 2 diabetes from the Endocrinology unit, National Hospital Colombo, Sri Lanka were voluntarily engaged in the study, subjected to an initial health screening. Then, determination of postprandial blood glucose responses after intake of the standard (glucose), cane sugar and coconut jaggery. Average age of the selected group was (48.19 ± 7.95) years and they were all overweight (BMI > 23.0). The mean fasting blood glucose level and HbA 1c of the subjects were (149.05 ± 54.88) mg/dL and (9.170 ± 2.022)%, respectively. There was no significant difference ( P > 0.05) in peak blood glucose concentrations or incremental area under the curve in blood glucose response of two test food. Therefore, coconut jaggery cannot be considered as a healthy substitute for cane sugar in type 2 diabetic patients.

A Review of the Relationship between Lentil Serving and Acute Postprandial Blood Glucose Response: Effects of Dietary Fibre, Protein and Carbohydrates.

Pulse consumption has been shown to confer beneficial effects on blood glucose and insulin levels. Lentil consumption, in particular, consistently lowers acute blood glucose and insulin response when compared to starchy control foods. The mechanism by which lentils lower postprandial blood glucose response (PBGR) and insulin levels is unclear; however, evidence suggests that this effect may be linked to macronutrients and/or the amount of lentils consumed. This review attempts to consolidate existing studies that examined lentil consumption and glycemic and/or insulinemic responses and declared information on macronutrient composition and dietary fibre content of the foods tested. Collectively, these studies suggest that consumption of lentils reduces PBGR, with the minimum effective serving being ~110g cooked to reduce PBGR by 20%. Reductions in PBGR show modest-to-strong correlations with protein (45–57 g) and dietary fibre (22–30 g) content, but has weaker correlations with available carbohydrates. Increased lentil serving sizes were found to moderately influence relative reductions in peak blood glucose concentrations and lower the area under the blood glucose curve (BG AUC). However, no clear relationship was identified between serving and relative reductions in the BG AUC, making it challenging to characterize consistent serving–response effects.

Cinnamomum zeylanicum and Curcuma longa incorporated dairy yoghurts with hindered glycaemic properties for healthy people

This study mainly compare glycaemic responses of a control yoghurt (typical dairy yoghurt) against two novel yoghurt products with added spices oleoresins (Cinnamon yoghurt - Cinnamomum zeylanicum , turmeric yoghurt - Curcuma longa ) using 16 healthy volunteers in a randomized crossover study. Blood glucose concentrations were measured at fasting state and 30, 45, 60, 90, 120 min following the ingestion, using a Blood Glucose Monitoring System and blood glucose response curves were plotted. Nutritional and physicochemical properties were also compared and no significant differences ( P > 0.05) were observed between novel yoghurts and the control within the storage period. Significant reductions in peak blood glucose concentration and area under the curve (AUC) ( P < 0.05) for both novel products compared to standard dairy yoghurt was observed; revealing the reduction of glycaemic impact by spice ingredients. Peak reductions of glucose concentration for cinnamon yoghurt was 9.61%, for turmeric yoghurt was 9.26%; they were considerably lower compared to the control. Mean peak serum glucose concentration for control, cinnamon yoghurt and turmeric yoghurt were (113.38 ± 6.39), (102.50 ± 6.00), (102.88 ± 5.38) mg/dL respectively and mean AUC were (11 951 ± 523), (11 012 ± 611), (10 941 ± 530) ((mg/dL)*min) respectively. Hence novel yoghurt products are proven to be excellent sources in reducing postprandial blood glucose responses.

Maternal and neonatal glycaemic control after antenatal corticosteroid administration in women with diabetes in pregnancy: A retrospective cohort study.

ObjectiveTo describe maternal and neonatal glycaemic control following antenatal corticosteroid administration to women with diabetes in pregnancy.DesignRetrospective cohort studySettingA tertiary hospital in Auckland, New ZealandPopulationWomen with diabetes in pregnancy who received antenatal corticosteroids from 2006–2016.MethodsCorticosteroid administration, maternal and neonatal glycaemia data were retrieved from electronic patient records. Demographic data were downloaded from the hospital database. Relationships between variables were analysed using multivariate analysis.Main outcome measuresMaternal hyperglycaemia and neonatal hypoglycaemiaResultsCorticosteroids were administered to 647 of 7317 of women with diabetes (8.8%) who gave birth to 715 babies. After an initial course of corticosteroids, 92% and 52% of women had blood glucose concentrations > 7 and > 10 mmol/L respectively. Median peak blood glucose concentration of approximately 10 mmol/L occurred 9 hours after corticosteroid administration and hyperglycaemia lasted approximately 72 hours. Thirty percent of women gave birth within 72 hours of the last dose of corticosteroids. Babies of women who were hyperglycaemic within 24 hours of birth were more likely to develop hypoglycaemia (< 2.6 mmol/L, OR 1.51 [95% CI 1.10–2.07], p = 0.01) and severe hypoglycaemia (≤ 2.0 mmol/L, OR 2.00 [95% CI 1.41–2.85], p < 0.0001) than babies of non-hyperglycaemic mothers. There was no association between maternal glycaemia within 7 days of the last dose of corticosteroids and neonatal hypoglycaemia.ConclusionsHyperglycaemia is common in women with diabetes in pregnancy following antenatal corticosteroid administration. Maternal hyperglycaemia in the 24 hours prior to birth is associated with increased risk of neonatal hypoglycaemia. Limitations included the retrospective study design, so that not all data were available for all women and babies and the glucose testing schedule was variable.

Timing of acute passive heating on glucose tolerance and blood pressure in people with type 2 diabetes: a randomized, balanced crossover, control trial.

Type 2 diabetes mellitus (T2DM) is characterized by chronic hyperglycemia and progressive insulin resistance, leading to macro and microvascular dysfunction. Passive heating has potential to improve glucose homeostasis and act as an exercise mimetic. We assessed the effect of acute passive heating before or during an oral glucose tolerance test (OGTT) in people with T2DM. Twelve people with T2DM were randomly assigned to the following three conditions: 1) 3-h OGTT (control), 2) 1-h passive heating (40°C water) 30 min before an OGTT (HOT-OGTT), and 3) 1-h passive heating (40°C water) 30 min after commencing an OGTT (OGTT-HOT). Blood glucose concentration, insulin sensitivity, extracellular heat shock protein 70 (eHSP70), total energy expenditure (TEE), heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were recorded. Passive heating did not alter blood glucose concentration [control: 1,677 (386) arbitrary units (AU), HOT-OGTT: 1,797 (340) AU, and OGTT-HOT: 1,662 (364) AU, P = 0.28], insulin sensitivity (P = 0.15), or SBP (P = 0.18) but did increase eHSP70 concentration in both heating conditions [control: 203.48 (110.81) pg·mL-1; HOT-OGTT: 402.47 (79.02) pg·mL-1; and OGTT-HOT: 310.00 (60.53) pg·mL-1, P < 0.001], increased TEE (via fat oxidation) in the OGTT-HOT condition [control: 263 (33) kcal, HOT-OGTT: 278 (40) kcal, and OGTT-HOT: 304 (38) kcal, P = 0.001], increased HR in both heating conditions (P < 0.001), and reduced DBP in the OGTT-HOT condition (P < 0.01). Passive heating in close proximity to a glucose challenge does not alter glucose tolerance but does increase eHSP70 concentration and TEE and reduce blood pressure in people with T2DM.NEW & NOTEWORTHY This is the first study to investigate the timing of acute passive heating on glucose tolerance and extracellular heat shock protein 70 concentration ([eHSP70]) in people with type 2 diabetes. The principal novel findings from this study were that both passive heating conditions: 1) did not reduce the area under the curve or peak blood glucose concentration, 2) elevated heart rate, and 3) increased [eHSP70], which was blunted by glucose ingestion, while passive heating following glucose ingestion, 4) increased total energy expenditure, and 5) reduced diastolic blood pressure.

Glycemic Response to a Renal‐Specific Oral Nutritional Supplement in Patients With Diabetes Undergoing Hemodialysis: A Randomized Crossover Trial

Diabetes and malnutrition are common in patients with kidney failure. We aimed to evaluate the postprandial glucose response to oral nutritional supplement drinks (ONSs) in patients with diabetes undergoing hemodialysis treatment. A randomized, single-blind crossover study was conducted in patients with diabetes, and requiring chronic hemodialysis. Patients consumed either a renal-specific ONS, macronutrient-matched ONS, or standard ONS on 3 separate study days, during dialysis, following an overnight fast. Blood was collected before and 15, 30, 45, 60, 90, 120, and 180 minutes post ingestion. Mean net incremental area under the curve (iAUC) and peak incremental blood glucose concentration were compared across conditions, using analyses of variance. Consumption of the renal-specific ONS resulted in the lowest mean net iAUC (87.9 ± 169.0 mmol/L per 3 hours) compared with macronutrient-matched (188.0 ± 127.5 mmol/L per 3 hours) and standard ONS (199.5 ± 169.2 mmol/L per 3 hours) (F2,30 = 5.115, P = 0.012, partial n2 = 0.254). Pairwise comparisons demonstrated a mean difference of 100.1 mmol/L per 3 hours (95% CI, -2.8 to 202.9) in mean iAUC between the renal-specific ONS and macronutrient-matched ONS (P = 0.058). Peak blood glucose concentration, corrected for baseline, was significantly lower after the renal-specific ONS (1.40 ± 1.0 mmol/L) compared with both macronutrient-matched (2.02 ± 0.71 mmol/L, P = 0.036) and standard ONS (2.3 ± 1.06 mmol/L, P = 0.017). A renal-specific ONS elicits a lower postprandial glucose response than either macronutrient-matched ONS or standard ONS in patients with diabetes during hemodialysis.

Nocturnal whey protein ingestion impairs post-prandial glucose tolerance at breakfast.

Poor post-prandial glucose control is a risk factor for multiple health conditions. The second-meal effect refers to the progressively improved glycaemic control with repeated feedings, an effect which is achievable with protein ingestion at the initial eating occasion. The most pronounced glycaemic response each day therefore typically occurs following breakfast, so the present study investigated whether ingesting protein during the night could improve glucose control at the first meal of the day. In a randomised crossover design, fifteen adults (seven males, eight females; age, 22 (sd 3) years; BMI, 24·0 (sd 2·8) kg/m2; fasting blood glucose, 4·9 (sd 0·5) mmol/l) woke at 04.00 (sd 1) hours to ingest 300 ml water with or without 63 g whey protein. Participants then completed a mixed-macronutrient meal tolerance test (1 g carbohydrate/kg body mass, 2356 (sd 435) kJ), 5 h 39 min following the nocturnal feeding. Nocturnal protein ingestion increased the glycaemic response (incremental AUC) to breakfast by 43·5 (sd 55·5) mmol × 120 min/l (P = 0·009, d = 0·94). Consistent with this effect, individual peak blood glucose concentrations were 0·6 (sd 1·0) mmol/l higher following breakfast when protein had been ingested (P = 0·049, d = 0·50). Immediately prior to breakfast, rates of lipid oxidation were 0·02 (sd 0·03) g/min higher (P = 0·045) in the protein condition, followed by an elevated post-prandial energy expenditure (0·38 (sd 0·50) kJ/min, P = 0·018). Post-prandial appetite and energy intake were similar between conditions. The present study reveals a paradoxical second-meal phenomenon whereby nocturnal whey protein feeding impaired subsequent glucose tolerance, whilst increasing post-prandial energy expenditure.

Short communication: Effect of glucose infusion dose and stage of lactation on glucose tolerance test kinetics in lactating dairy cows

The objective for this study was to determine the effect of glucose dose and days following peak milk yield on plasma glucose, serum insulin, and plasma nonesterified fatty acids (NEFA) kinetics during an intravenous glucose tolerance test (IVGTT) in lactating dairy cattle. Six lactating Holstein dairy cows (3 primiparous and 3 multiparous) were assigned to 2 squares and received 0.092, 0.15, or 0.3 g of glucose/kg of body weight (BW) during an IVGTT at 74 and 221 d in milk (DIM), representing early (post-peak) lactation and mid lactation, respectively. Treatments were applied in a replicated Latin square design using contiguous 7-d periods within each stage of lactation. Milk production and dry matter intake were determined daily during the first 6 d of each period. The IVGTT was performed on d 7. For the IVGTT, cows were prepared with indwelling catheters in each jugular vein, and blood samples were collected at -15, -10, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min relative to the glucose infusion. Samples were analyzed for plasma glucose, serum insulin, and plasma NEFA concentrations. Increasing the glucose dose during the IVGTT increased plasma glucose area under the curve (AUC), decreased glucose half-life, and increased maximal plasma glucose concentrations in plasma during the IVGTT. Greater glucose dose during the IVGTT elevated serum insulin AUC and increased nadir NEFA concentrations. Maximal plasma glucose concentration during the IVGTT was lower, whereas maximum NEFA concentration, NEFA AUC, and NEFA clearance rate were greater at 74 than at 221 DIM. Only glucose half-life was responsive to stage of lactation × glucose dose effects during the IVGTT, and the decrease in glucose half-life with increasing glucose dose was greater at 74 than at 221 DIM. Glucose AUC was greater and NEFA AUC lower for cows at 74 than at 221 DIM. For the doses tested, a glucose dose greater than 0.092 g/kg of BW resulted in peak blood glucose concentration that exceeded the previously reported renal glucose excretion threshold of 8.3 mM. There is a need for accompanying data to determine if this is the case for the glucose doses evaluated in this experiment. Based on maximal peak glucose concentrations and effects on glucose half-life, we identify 0.092 g of glucose/kg of BW (0.46 g/kg of metabolic body weight) as the preferred dose for the IVGTT for cows at 74 and 221 DIM in this study.

Differential glucose bioaccessibility from native and modified taro-starches in the absence or presence of beet juice

ABSTRACT The speed of starch-digestion defines peak blood-glucose concentrations. Slow digestion is beneficial for diabetic individuals. To investigate the effects on blood-glucose it is important to be able to predict the amount of digestible starch. Therefore, the aim of this study was to compare the digestibility of different starches in a validated in-vitro model of the upper gastrointestinal (GI) tract. Digestion was performed in the TNO dynamic, computer-controlled in-vitro model of the upper GI-tract (TIM-1). Release of glucose was measured over time. Products tested were taro-flour, native-, and modified taro-starch. The latter two were also tested with beet-juice adsorbed. These were compared to wheat-flour and a glucose-solution. Modified taro-starch showed a similar glucose-bioaccessibility as wheat-flour (81–83%), while the other products tested had a lower bioaccessibility (60–75%). Adsorption of beet-juice affected digestibility of the modified taro-starch, but not the native-starch. Taro-based products can be used to lower plasma glucose concentrations in diabetic individuals.

Glycemic Status in Febrile Seizures

AbstractStress hyperglycemia is commonly identified in children with severe illness and previously normal glucose homeostasis. In the pediatric population febrile seizures are reported among stress-related conditions associated with stress hyperglycemia. The objective of this prospective study was to evaluate the possible association between blood glucose level and febrile seizure severity defined by fever degree, seizure type, seizure duration and hospitalization length. Among 167 febrile seizures the prevalence of stress hyperglycemia (blood glucose concentration over 150mg/dl) was 13.22%. There was a highly significant statistical association between seizure duration (exceeding 15 minutes) and increased blood glucose concentration (p= 0.001). Prolonged febrile seizures combined with high fever were significant risk factors for stress hyperglycemia. Further analysis on acute fluctuation of glycemia, persistence of hyperglycemia should be taken in consideration as possible prebdictive factor for stress hyperglycemia, by comparison to the peak blood glucose concentration .

A Single-Dose of a Polyphenol-Rich Fucus Vesiculosus Extract is Insufficient to Blunt the Elevated Postprandial Blood Glucose Responses Exhibited by Healthy Adults in the Evening: A Randomised Crossover Trial.

When healthy adults consume carbohydrates at night, postprandial blood glucose responses are elevated and prolonged compared to daytime.Extended postprandial hyperglycaemia is a risk factor for type 2 diabetes. Polyphenols are bioactive secondary metabolites of plants and algae with potential to moderate postprandial glycaemia. This study investigated whether a polyphenol-rich alga (Fucus vesiculosus) extract moderated postprandial glycaemia in the evening in healthy adults. In a double blind, placebo-controlled, randomised three-way crossover trial, 18 participants consumed a polyphenol-rich extract, a cellulose placebo and rice flour placebo (7:15 p.m.) prior to 50 g available carbohydrate from bread (7:45 p.m.), followed by three hours of blood sampling to assess glucose and insulin. A subset of participants (n = 8) completed the same protocol once in the morning with only the cellulose placebo (7:15 a.m.). No effect of the polyphenol-rich extract was observed on postprandial glycaemia in the evening, compared with placebos, in the group as a whole. However, in females only, peak blood glucose concentration was reduced following the polyphenol-rich extract. In the subset analysis, as expected, participants exhibited elevated postprandial blood glucose in the evening compared with the morning following the cellulose placebo. This was the first study to investigate whether a polyphenol intervention moderated evening postprandial hyperglycaemia. The lowering effect observed in females suggests that this warrants further investigation.

Fructose replacement of glucose or sucrose in food or beverages lowers postprandial glucose and insulin without raising triglycerides: a systematic review and meta-analysis

Background: Conflicting evidence exists on the effects of fructose consumption in people with type 1 and type 2 diabetes mellitus. No systematic review has addressed the effect of isoenergetic fructose replacement of glucose or sucrose on peak postprandial glucose, insulin, and triglyceride concentrations.Objective: The objective of this study was to review the evidence for postprandial glycemic and insulinemic responses after isoenergetic replacement of either glucose or sucrose in foods or beverages with fructose.Design: We searched the Cochrane Library, MEDLINE, EMBASE, the WHO International Clinical Trials Registry Platform Search Portal, and clinicaltrials.gov The date of the last search was 26 April 2016. We included randomized controlled trials measuring peak postprandial glycemia after isoenergetic replacement of glucose, sucrose, or both with fructose in healthy adults or children with or without diabetes. The main outcomes analyzed were peak postprandial blood glucose, insulin, and triglyceride concentrations.Results: Replacement of either glucose or sucrose by fructose resulted in significantly lowered peak postprandial blood glucose, particularly in people with prediabetes and type 1 and type 2 diabetes. Similar results were obtained for insulin. Peak postprandial blood triglyceride concentrations did not significantly increase.Conclusions: Strong evidence exists that substituting fructose for glucose or sucrose in food or beverages lowers peak postprandial blood glucose and insulin concentrations. Isoenergetic replacement does not result in a substantial increase in blood triglyceride concentrations.

Effect of High Intensity Intermittent Games-Based Activity on Adolescent Cardio-Metabolic Health

In adults emerging evidence suggests that games-based activity acutely stimulates anti-inflammatory and inhibits pro-inflammatory cytokine production, proposed to induce cardio-metabolic health benefits. The acute effects of high-intensity intermittent games on adolescent cardio-metabolic health remain unexplored. PURPOSE: To examine the effects of an acute bout of games-based activity on adolescent cardio-metabolic health. METHODS: Following ethical approval 18 adolescents (12.5±0.6 y) completed an exercise (E) and resting (R) trial in a counter-balanced, randomised crossover design. Following a standardised breakfast (1.5 g.kg-1 bm carbohydrate), participants completed 1 h games-based activity (basketball). Capillary blood samples were taken at baseline, immediately and 1 h post-exercise. A standardised lunch was consumed (1.5 g.kg-1 bm carbohydrate) and capillary blood samples were taken 30, 60 and 120 min post-lunch. A final blood sample was taken the following morning. Capillary blood samples were analysed for blood glucose, plasma insulin and cytokine (IL-6, IL-10, IL-1ra, IL-1β, IL-8 and TNF-α) concentrations. Data were analysed using repeated measures ANOVA and paired sample t-tests in SPSS. RESULTS: The blood glucose response to lunch was attenuated following exercise (trial*time interaction, p=0.008), with a tendency for a lower peak blood glucose concentration on the exercise trial (E: 5.6±0.7 mmol.L-1, R: 6.3±1.4 mmol.L-1, p=0.070). Similarly, the plasma insulin response was attenuated (trial*time interaction, p=0.002), with a lower peak plasma insulin concentration on the exercise trial (E: 217.2±29.2 pmol.L-1, R: 366.1±45.3 pmol.L-1, p <0.001). IL-6 concentration was higher (E: 4.22±0.80 pg.mL-1, R: 3.46±0.69 pg.mL-1, p=0.005) and there was a tendency for TNF-α to be attenuated (E: 1.24±0.22 pg.mL-1, R: 1.34±0.23 pg.mL-1, p=0.081) on the exercise trial. Exercise had no effect on the remaining cytokines. CONCLUSION: High-intensity intermittent games-based activity attenuated postprandial blood glucose and plasma insulin concentrations, whilst demonstrating an increase in IL-6 concentration, potentially mediating the reduced TNF-α concentrations. Thus high-intensity games-based physical activity elicits cardio-metabolic health benefits in adolescents.

Effect of exercise timing on elevated postprandial glucose levels.

There is no consensus regarding optimal exercise timing for reducing postprandial glucose (PPG). The purpose of the present study was to determine the most effective exercise timing. Eleven participants completed four different exercise patterns 1) no exercise; 2) preprandial exercise (jogging); 3) postprandial exercise; and 4) brief periodic exercise intervention (three sets of 1-min jogging + 30 s of rest, every 30 min, 20 times total) in a random order separated by a minimum of 5 days. Preprandial and postprandial exercise consisted of 20 sets of intermittent exercise (1 min of jogging + 30 s rest per set) repeated 3 times per day. Total daily exercise volume was identical for all three exercise patterns. Exercise intensities were 62.4 ± 12.9% V̇o2peak Blood glucose concentrations were measured continuously throughout each trial for 24 h. After breakfast, peak blood glucose concentrations were lower with brief periodic exercise (99 ± 6 mg/dl) than those with preprandial and postprandial exercise (109 ± 10 and 115 ± 14 mg/dl, respectively, P < 0.05, effect size = 0.517). After lunch, peak glucose concentrations were lower with brief periodic exercise than those with postprandial exercise (97 ± 5 and 108 ± 8 mg/dl, P < 0.05, effect size = 0.484). After dinner, peak glucose concentrations did not significantly differ among exercise patterns. Areas under the curve over 24 h and 2 h postprandially did not differ among exercise patterns. These findings suggest that brief periodic exercise may be more effective than preprandial and postprandial exercise at attenuating PPG in young active individuals.NEW & NOTEWORTHY This was the first study to investigate the effect of different exercise timing (brief periodic vs. preprandial vs. postprandial exercise) on postprandial glucose (PPG) attenuation in active healthy men. We demonstrated that brief periodic exercise attenuated peak PPG levels more than preprandial and postprandial exercise, particularly in the morning. Additionally, PPG rebounded soon after discontinuing postprandial exercise. Thus, brief periodic exercise may be better than preprandial and postprandial exercise at attenuating PPG levels.

Sex differences in adolescents' glycaemic and insulinaemic responses to high and low glycaemic index breakfasts: a randomised control trial.

During puberty young people undergo significant hormonal changes which affect metabolism and, subsequently, health. Evidence suggests there is a period of transient pubertal insulin resistance, with this effect greater in girls than boys. However, the response to everyday high and low glycaemic index (GI) meals remains unknown. Following ethical approval, forty adolescents consumed a high GI or low GI breakfast, in a randomised cross-over design. Capillary blood samples were taken during a 2-h postprandial period, examining the glycaemic and insulinaemic responses. Maturity offset and homoeostatic model assessment (HOMA) were also calculated. The glycaemic response to the breakfasts was similar between boys and girls, as shown by similar peak blood glucose concentrations and incremental AUC (IAUC) following both high and low GI breakfasts (all P>0·05). Girls exhibited a higher peak plasma insulin concentration 30 min post-breakfast following both high GI (P=0·043, g=0·69) and low GI (P=0·010, g=0·84) breakfasts, as well as a greater IAUC following high GI (P=0·041, g=0·66) and low GI (P=0·041, g=0·66) breakfasts. HOMA was positively correlated with the insulinaemic responses (all P<0·0005) and maturity offset (P=0·037). The findings of the present study suggest that pubertal insulin resistance affects the postprandial insulinaemic responses to both high and low GI meals. Specifically, girls exhibit a greater insulinaemic response than boys to both meals, despite similar glycaemic responses. This study is the first to report the glycaemic and insulinaemic responses to everyday meals in boys and girls, supporting the recommendation for young people to base their diet on low GI carbohydrates.

Cassia Cinnamon Supplementation Reduces Peak Blood Glucose Responses but Does Not Improve Insulin Resistance and Sensitivity in Young, Sedentary, Obese Women

ABSTRACTCassia cinnamon has been suggested to lower blood glucose (BG) and serum insulin (SI) due to an improvement in insulin resistance (IR) and sensitivity (IS). This study compared the effects Cassia cinnamon had on calculated IR and IS values and BG and SI in response to an oral glucose tolerance test (OGTT) in young, sedentary, and obese women. On three separate days, 10 women had a fasted venous blood sample obtained. Participants were given 5 g of encapsulated placebo (PLC) or 5 g of encapsulated Cassia cinnamon bark (CASS). Three hours after the initial blood sample, another blood sample was obtained to calculate values for IS and IR. The participants then completed an OGTT by consuming a 75 g glucose solution. Blood was obtained 30, 60, 90, and 120 min following glucose ingestion. IS and IR were not significantly different between placebo and Cassia (p > .05). The peak BG concentration in response to the OGTT was significantly lower at the 30 min time point for CASS, as compared to PLC (140 ± 5.8 and 156 ± 5.2 mg/dL, p = .025); however, there was no significant difference between treatments for SI (p > .05). The area-under-the-curve responses for BG and SI were not significantly different between PLC and CASS (p > .05). This study suggests that a 5 g dose of Cassia cinnamon may reduce the peak BG response and improve glucose tolerance following an OGTT, but with no improvement in IS and IR in young, sedentary, obese women.

Impact of resistant starch in three plantain (Musa AAB) products on glycaemic response of healthy volunteers.

Plantains can be eaten in various forms providing a good opportunity to study the effect of starch type on glycaemic response, and so three products differing in their types of available carbohydrate and contents of resistant starch were tested. Boiled unripe plantain (BUP), boiled unripe plantain crisps (BUPC), ripe raw plantain (RRP) and white bread as reference (all 25g available carbohydrate portion) were given to ten pre-screened healthy individuals. Postprandial glycaemic responses and glycaemic indices (GI) were measured. Peak blood glucose for BUP, BUPC and RRP was at 45, 45 and 30min post-meal time, respectively. The peak blood glucose concentrations for BUP, BUPC and RRP (1.8±0.8, 2.3±0.8, 1.9±0.7mmol/L, n=10, respectively) reflected the in vitro quantities/types of rapidly available glucose (RAG) in the samples. On the other hand, mean GI±SEM values obtained for the test products (BUP=44.9±3.6, BUPC=55.0±4.2, RRP=38±4.4, n=10) were neither significantly different nor directly correlated with RAG. The results show a potential link between RAG and GI, but the correlation is confounded by the presence of other constituents in the plantains.

High Endogenous Salivary Amylase Activity Is Associated with Improved Glycemic Homeostasis following Starch Ingestion in Adults1–3

In the current study, we determined whether increased digestion of starch by high salivary amylase concentrations predicted postprandial blood glucose following starch ingestion. Healthy, nonobese individuals were prescreened for salivary amylase activity and classified as high (HA) or low amylase (LA) if their activity levels per minute fell 1 SD higher or lower than the group mean, respectively. Fasting HA (n= 7) and LA (n= 7) individuals participated in 2 sessions during which they ingested either a starch (experimental) or glucose solution (control) on separate days. Blood samples were collected before, during, and after the participants drank each solution. The samples were analyzed for plasma glucose and insulin concentrations as well as diploidAMY1gene copy number. HA individuals had significantly moreAMY1gene copies within their genomes than did the LA individuals. We found that following starch ingestion, HA individuals had significantly lower postprandial blood glucose concentrations at 45, 60, and 75 min, as well as significantly lower AUC and peak blood glucose concentrations than the LA individuals. Plasma insulin concentrations in the HA group were significantly higher than baseline early in the testing session, whereas insulin concentrations in the LA group did not increase at this time. Following ingestion of the glucose solution, however, blood glucose and insulin concentrations did not differ between the groups. These observations are interpreted to suggest that HA individuals may be better adapted to ingest starches, whereas LA individuals may be at greater risk for insulin resistance and diabetes if chronically ingesting starch-rich diets.

Acute dietary nitrate consumption improves glucose tolerance

Insulin resistance is characterized by low nitric oxide (NO) bioavailability. Consistent with this observation, insulin sensitivity is improved with stimulation of NO generating pathways. Consumption of dietary nitrate (e.g. beet juice) has been purported to increase NO formation, mediated in part through the reduction of nitrate (NO3−) to nitrite (NO2−) by oral bacteria, and subsequent NO2− reduction to NO in blood. We hypothesized that acute dietary nitrate consumption would improve glucose tolerance. Accordingly, in 8 sedentary adults (23 ± 0 years, body mass index: 26.0 ± 0.8 kg/m2 (mean ± SE)) we determined the blood glucose response to oral consumption of 500 ml organic beet juice, supplemented with 25 g of sucrose (estimated carbohydrate load ~ 75g), with and without prior use of an antibacterial mouthwash to inhibit NO3− reduction to NO2−. In the absence of inhibition of oral bacteria NO3− reductase activity, peak blood glucose concentration (106 ± 4 vs. 118 ± 6 mg/dL; P = 0.04) and the area under the blood glucose response curve (93 ± 4%; P = 0.07) were decreased. These preliminary data suggest dietary nitrate consumption may promote glucose tolerance, and this effect may be attenuated following inhibition of NO3− conversion to NO2−.Support: America Diabetes Association 1‐09‐RA‐09