Unannounced Meal Challenges Using an Advanced Hybrid Closed-Loop System

Background: The advanced hybrid closed-loop (AHCL) algorithm combines automated basal rates and corrections yet requires meal announcement for optimal outcomes. We aimed to compare the performance of the MiniMed™ 780G AHCL algorithm with and without meal announcement. Methods: In a single-arm study involving 14 adults with type 1 diabetes, we evaluated the safety and efficacy of AHCL when meals were not announced. Participants stayed at a supervised environment for 5 days, during which the outcomes of not announcing meals (≤80 g of carbohydrate) were assessed. Next, participants entered a 90-day at-home "unannounced" phase, during which all meals (≤80 g of carbohydrate) were unannounced, followed by a 90-day at-home phase in which all meals were announced. Results: Time in range (TIR 70-180 mg/dL) was lower in the unannounced versus announced periods (67.5% ± 12.5% vs. 77.7% ± 9.5%; P < 0.01, respectively), with more time spent in hyperglycemia range 180-250 mg/dL (22.7% ± 7.7% vs. 15.7% ± 7.2%) and >250 mg/dL (7.9% ± 6.4% vs. 3.6% ± 2.7%), but less time in hypoglycemia range 54-70 mg/dL (1.6% ± 1% vs. 2.8% ± 1.8%) and <54 mg/dL (0.3% ± 0.4% vs. 0.7% ± 0.9%). Not announcing meals containing up to 60 g of carbohydrate did not lead to increase in postprandial extreme dysglycemia >250 mg/dL, and up to 20 g of unannounced carbohydrates did not significantly change the TIR 70-180 mg/dL compared with full announcement. Conclusion: The AHCL system is optimized for use with meal announcement. While not announcing meals of ≤80 g carbohydrates appears to be safe, it results in suboptimal postprandial glycemic control, especially with high-carbohydrate meals. Not announcing small meals (≤20 g carbohydrate) does not deteriorate glycemic control. Clinical Trial Registration number: NCT04479826.

Pure-protein load for children with type 1 diabetes: is any additional insulin needed? A randomized controlled study

AIMS

Study in adults with T1D showed that delivery of insulin for pure-protein meals may not be obligatory. The aim of this study was to assess the effects of whey isolate protein drink consisting of 50 g/200 kcal from pure protein on postprandial glycemia (PPG) following with square-wave insulin bolus in comparison with no insulin strategy in T1D children on insulin pumps.

METHODS

This was a randomized, double-blind, cross-over study including 58 children with mean: age 14.62 ± 3.64 years. Participants were randomly assigned into two treatment orders: NB-SQ (no bolus on the first day) and SQ-NB (square-bolus on the first day). The primary outcome was PPG during a 5-h follow-up. The secondary outcome was the frequency of hypoglycemia and glycemic variability parameters.

RESULTS

PPG [mg/dl] since 150 min of the follow-up was significantly lower when square-wave bolus was delivered (group SQ vs NB); at 150, 180, 210, 240, 270, 300 min: 130.6 versus 154.5 (p = 0.009), 153.4 versus 124.9 (p = 0.004), 151.0 versus 118.7 (p = 0.003), 146.4 versus 114.2 (p = 0.002), 141.2 versus 107.7 (p = 0.001), 131.0 versus 105.1 (p = 0.005). We observed statistically significant difference in overall rate of hypoglycemia < 70 mg/dl between groups SQ versus NB: 6.8% versus 2.5% (p = 0.001). The overall rate of hypoglycemia below 54 mg/dl was < 1% (p = 0.452).

CONCLUSIONS

A meal containing 50 g of pure protein may be consumed without additional insulin dose. An additional square-wave bolus may be beneficial in reducing PPG. To avoid hypoglycemia, lower insulin dose should be calculated for 100 kcal from protein than for individual insulin-to-carb ratio.

The 'early' postprandial glucagon response is related to the rate of gastric emptying in type 2 diabetes

Gastric emptying (GE) is a major determinant of the postprandial glycemic and insulinemic responses in health and type 2 diabetes (T2D). However, the effect of GE on the postprandial glucagon response, which is characteristically augmented in T2D, is unknown. This study examined the relationship between plasma glucagon and GE of a standardized mixed meal in individuals with well-controlled T2D. 89 individuals with T2D (HbA1c 6.6 ± 0.1%) consumed a mashed potato meal labeled with 100 µL ¹³C-octanoic acid between 0 and 5 min. Venous blood was sampled frequently over 4 h for measurements of blood glucose and plasma glucagon. The gastric half-emptying time (T50) was calculated by quantification of ¹³C in the breath. Blood glucose peaked at t = 90 min after the meal. Plasma glucagon increased to a peak at t = 30 min and then decreased to a nadir at t = 180 min. The T50 was 68.3 ± 1.6 min. The incremental area under the plasma glucagon curve between t = 0-30 min (glucagon iAUC_0-30 min) was related inversely to the T50 (r = -0.23, P = 0.029), while the increase in blood glucose at t = 30 min was related directly to the plasma glucagon iAUC_0-30 min (r = 0.25, P = 0.018). Accordingly, individuals with relatively faster GE exhibited higher postprandial glucagon and glucose levels (ANOVA: P<0.01 for each). In well-controlled T2D, the early postprandial glucagon response to a mixed meal is related to the rate of GE, and predictive of the initial glycemic response. These observations suggest that a reduction in plasma glucagon may contribute to the effect of dietary and pharmacological strategies which reduce postprandial glycemia in T2D by slowing GE.

Pulse consumption improves indices of glycemic control in adults with and without type 2 diabetes: a systematic review and meta-analysis of acute and long-term randomized controlled trials

PURPOSE

Findings from randomized controlled trials (RCTs) evaluating the effect of pulse intake on glycemic control are inconsistent and conclusive evidence is lacking. The aim of this study was to systematically review the impact of pulse consumption on post-prandial and long-term glycemic control in adults with and without type 2 diabetes (T2D).

METHODS

Databases were searched for RCTs, reporting outcomes of post-prandial and long-term interventions with different pulse types on parameters of glycemic control in normoglycemic and T2D adults. Effect size (ES) was calculated using random effect model and meta-regression was conducted to assess the impact of various moderator variables such as pulse type, form, dose, and study duration on ES.

RESULTS

From 3334 RCTs identified, 65 studies were eligible for inclusion involving 2102 individuals. In acute RCTs, pulse intake significantly reduced peak post-prandial glucose concentration in participants with T2D (ES  - 2.90; 95%CI  - 4.60,  - 1.21; p ≤ 0.001; I2 = 93%) and without T2D (ES  - 1.38; 95%CI  - 1.78,  - 0.99; p ≤ 0.001; I2 = 86%). Incorporating pulse consumption into long-term eating patterns significantly attenuated fasting glucose in normoglycemic adults (ES  - 0.06; 95%CI  - 0.12, 0.00; p ≤ 0.05; I2 = 30%). Whereas, in T2D participants, pulse intake significantly lowered fasting glucose (ES  - 0.54; 95%CI  - 0.83,  - 0.24; p ≤ 0.001; I2 = 78%), glycated hemoglobin A1c (HbA1c) (ES  - 0.17; 95%CI  - 0.33, 0.00; p ≤ 0.05; I2 = 78) and homeostatic model assessment of insulin resistance (HOMA-IR) (ES  - 0.47; 95%CI  - 1.25,  - 0.31; p ≤ 0.05; I2 = 79%).

CONCLUSION

Pulse consumption significantly reduced acute post-prandial glucose concentration > 1 mmol/L in normoglycemic adults and > 2.5 mmol/L in those with T2D, and improved a range of long-term glycemic control parameters in adults with and without T2D. PROSPERO REGISTRY NUMBER: (CRD42019162322).

Postprandial blood glucose and insulin responses to breads formulated with different wheat evolutionary populations (Triticum aestivum L.): A randomized controlled trial on healthy subjects

This study aimed to evaluate the effect of breads made with two different wheat evolutionary populations (EPs), compared with a modern variety, on postprandial blood glucose and insulin responses. A randomized controlled crossover postprandial study involving 12 healthy subjects was conducted. Seven non-commercial breads produced with flours from two different bread wheat (T. aestivum L.) EPs (Bio2, ICARDA) and a modern bread wheat variety (Bologna) were considered controls, with two different bread-making processes (Saccharomyces cerevisiae and sourdough), and were specifically formulated for the study. Postprandial incremental curves, incremental area under the curve (IAUC), maximum postprandial peaks for blood glucose and plasma insulin over 2 h after administration of isoglucidic portions of breads (50 g of available carbohydrates) were evaluated. The comparison of incremental curves, IAUC, and maximum postprandial peaks after consumption of breads formulated with EPs and control breads showed no differences among samples. Neither the flour nor the leavening technic used for the baking were effective in inducing a different postprandial response compared with the Bologna variety. EPs, being characterized by higher degree of crop genetic diversity, may have a relevant agronomic role to guarantee good and stable yields and quality under low input management in a changing climate; however, future studies are needed to better investigate their potential positive effect on human health.

Whey protein preload enhances the active GLP-1 response and reduces circulating glucose in women with polycystic ovarian syndrome

Polycystic ovary syndrome (PCOS) increases risk for development of type 2 diabetes. Whey protein ingestion before a carbohydrate load attenuates blood glucose. For our exploratory, case-control study design, we hypothesized that 35 g whey protein isolate (WPI) preloading would increase postprandial incretins and reduce hyperglycemia in women with PCOS. Twenty-nine age-matched women (PCO = 14 and CON = 15) completed oral glycemic tolerance tests (OGTT) following baseline (Day 0) as well as 35 g WPI acute (Day 1) and short-term supplementation (Day 7). Eight venous samples were collected during each test for quantification of glucose, and enteropancreatic hormones and to calculate area under the curve (AUC). Data was analyzed via repeated measures ANCOVA with significance set at P< .05. "Day x time x group" significantly influenced glucose (P = .01) and insulin changes (P = .03). In both groups, AUCglu were significantly lower on Day 7 than Day 0 (P< .05). Postprandial glucose excursions were lower on Days 1 and 7 than Day 0 in PCO and CON. Both, PCO and CON exhibited greater insulin changes on Days 1 and 7 compared to Day 0 (P< .05). AUCglucagon were higher on Days 1 and 7 than on Day 0 (P< .05). Changes in active GLP-1 were higher on Day 1 than Day 0 (P= .03). Overall, we showed that WPI preloading augmented insulin release and consequently lowered circulating glucose in women with and without PCOS. This insulinogenic effect can be attributed to enhanced active GLP-1 levels. We concluded that the incretin-mimetic effect of WPI may aid women with PCOS in achieving glycemic homeostasis.

Effect of high protein and fat diet on postprandial blood glucose levels in children and adolescents with type 1 diabetes in Cairo, Egypt

BACKGROUND AND AIMS

To determine the effect of high protein and high fat meals on post prandial glycemia in patients with type 1 diabetes.

METHODS

This study included 51 children and adolescents with type 1 diabetes who were following up at Diabetes, Endocrine and Metabolism Pediatric Unit (DEMPU), Abo Elrish Children's hospital, Cairo University. Post prandial blood glucose levels were recorded and compared following three breakfast meals with varying protein and fat content (standard carbohydrate meal, high fat meal, and high protein meal) over a period of 5 hours on 3 consecutive days.

RESULTS

High protein meal resulted in hyperglycemia with the peak level at 3.5 hours and continued for 5 hours post prandial while high fat meal caused early hyperglycemia reached the peak at 2 hours then declined towards 5 hours. Comparison of the three different breakfast meals revealed statistically significant difference regarding the postprandial glycemia at 30, 60, 90,120, 180, 210, 240, 270, 300 min.

CONCLUSION

Meals high in protein caused sustained increase in postprandial glucose levels over a period of 5 h. However, high fat meals caused early postprandial hyperglycemia. Protein and fat content of meals affect the timing and values of the peak blood glucose as well as the duration of postprandial hyperglycemia. Therefore, fat/protein unit should be taken in consideration while calculating the bolus insulin dose and anticipating the postprandial glucose response.

Effects of soluble dietary fibers on the viscosity property and digestion kinetics of corn starch digesta

Four soluble dietary fibers (SDFs) were fortified with corn starch (CS) at different concentrations to match the same viscosity equivalents. The mixtures were subjected to a simulated digestion procedure to study the effects of SDFs on viscosity properties and digestion kinetics of CS. Results showed that SDFs increased the hydration property and decreased the water mobility of digesta. During digestion process, SDFs increased the apparent viscosity of digesta to some extent, and showed significant difference to delay the decay of digesta viscosity (k_v). The amylolysis inhibitory ability was similar when each SDF was present at the same viscosity equivalent, however, significant differences were found on the digestion rate constant of k₂. Linear correlations between k_v and k₂ were established for 1 and 2 equivalent groups. These results demonstrated that SDFs could delay the digestion process as chemistry differences, which related to their ability on delaying the change of digesta viscosity.

Apple polyphenol-rich drinks dose-dependently decrease early-phase postprandial glucose concentrations following a high-carbohydrate meal: a randomized controlled trial in healthy adults and in vitro studies

BACKGROUND

Previous research demonstrated that a high dose of phlorizin-rich apple extract (AE) can markedly inhibit early-phase postprandial glycemia, but efficacy of lower doses of the AE is unclear.

OBJECTIVE

To determine whether lower AE doses reduce early-phase postprandial glycemia in healthy adults and investigate mechanisms.

DESIGN

In a randomized, controlled, double-blinded, cross-over acute trial, drinks containing 1.8 g (HIGH), 1.35 g (MED), 0.9 g (LOW), or 0 g (CON) of a phlorizin-rich AE were consumed before 75 g starch/sucrose meal. Postprandial blood glucose, insulin, C-peptide, glucose-dependent insulinotropic polypeptide (GIP) and polyphenol metabolites concentrations were measured 0-240 min, acetaminophen concentrations to assess gastric emptying rate, and 24 h urinary glucose excretion. Effects of AE on intestinal glucose transport were investigated in Caco-2/TC7 cells.

RESULTS

AE significantly reduced plasma glucose iAUC 0-30 min at all doses: mean differences (95% CI) relative to CON were -15.6 (-23.3, -7.9), -11.3 (-19.6, -3.0) and -8.99 (-17.3, -0.7) mmol/L per minute for HIGH, MEDIUM and LOW respectively, delayed T_max (HIGH, MEDIUM and LOW 45 min vs. CON 30 min), but did not lower C_max. Similar dose-dependent treatment effects were observed for insulin, C-peptide, and GIP. Gastric emptying rates and urinary glucose excretion did not differ. Serum phloretin, quercetin and epicatechin metabolites were detected postprandially. A HIGH physiological AE dose equivalent decreased total glucose uptake by 48% in Caco-2/TC7 cells.

CONCLUSIONS

Phlorizin-rich AE, even at a low dose, can slightly delay early-phase glycemia without affecting peak and total glycemic response.

Title: Differentiating the effects of whey protein and guar gum preloads on postprandial glycemia in type 2 diabetes

BACKGROUND AND AIMS

Whey protein and guar gum have both been reported to reduce postprandial glycemia in health and type 2 diabetes, associated with stimulation of glucagon-like peptide-1 (GLP-1) and/or slowing of gastric emptying. Our aim was to evaluate, in type 2 diabetes, the acute effects of low dose "preloads" of whey and guar, given alone or in combination before a meal, on postprandial glycemia, insulin, GLP-1, and gastric emptying.

METHODS

21 patients with type 2 diabetes, managed by diet or metformin alone, were each studied on 4 days. They received a preload "shake" 15min before a mashed potato meal (368.5 kcal) labeled with ¹³C-octanoic-acid. The preloads comprised either (i) 17 g whey (W), (ii) 5 g guar (G), (iii) 17 g whey + 5 g guar (WG) each sweetened with 60 mg sucralose, and (iv) 60 mg sucralose alone (control; C), all dissolved in 150 mL water. Venous blood was sampled frequently for measurements of glucose, insulin, and GLP-1 concentrations. Gastric half-emptying time (T50) was calculated from breath ¹³CO₂ excretion over 240 min.

RESULTS

Postprandial blood glucose concentrations were lower with W and WG compared to C (each P < 0.0001, treatment × time interaction), and lower after G than C only at 30min. Insulin, GLP-1, and glucagon concentrations were higher after W than WG, G, or C (P < 0.05, treatment × time interaction), without differences between the latter three. Gastric emptying was slower with W (T50: 179.6 ± 6.1 min, P < 0.05) and WG (T50: 197.6 ± 9.7 min, P < 0.0001) when compared to C (T50: 162.9 ± 6.2 min), but did not differ between G (T50: 171.3 ± 7.0) and C (P > 0.99).

CONCLUSION

Both whey and whey/guar preloads reduced postprandial glycemia, associated with slowing of gastric emptying. Low dose guar was less effective as a preload for glucose-lowering and did not slow gastric emptying.

CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE

Australian and New Zealand Clinical Trials Registry, Trial ID ACTRN12615001272583, http://www.anzctr.org.au.

Effects of Undaria pinnatifida (Wakame) on Postprandial Glycemia and Insulin Levels in Humans: a Randomized Crossover Trial

Postprandial hyperglycemia is a known risk factor for the development of several health disorders, including type 2 diabetes, obesity and cardiovascular disease. This study aimed to investigate the acute effect of Undaria pinnatifida (Wakame), a discriminative constituent of the Japanese diet, on postprandial blood glucose and insulin levels. The study was conducted using a crossover method among 26 subjects. Blood was sampled for glucose and insulin measurements at 0, 30, 60, 90 and 120 min after a subject consumed either 200 g of rice or 200 g rice with 4 g of dried wakame. Blood glucose and insulin levels were significantly lower at 30 min after consuming rice with wakame than after consuming rice alone. Moreover, the incremental areas under the curves for glucose and insulin were lower when wakame was included. Wakame intake can improve postprandial glucose homeostasis. Wakame intake may offer a simple behavioural strategy that can reduce glycemic excursions in prediabetes. This study was registered with the UMIN Clinical Trial Registry (UMIN000031050).

The prevalence and impact of low faecal elastase-1 in community-based patients with type 2 diabetes

AIMS

To determine the prevalence of low faecal elastase-1 (FE-1) (≤200 μg/g) in type 2 diabetes (T2DM), and to test the hypothesis that pancreatic enzyme replacement therapy (PERT) would reduce postprandial glycaemia after a high-fat, high-carbohydrate meal in T2DM subjects with low FE-1.

METHODS

Of 109 community-based patients who submitted stool samples, 10 had low FE-1 and 8 were recruited (6 male, 2 female, 67.8 ± 3.0 years). Participants were given a high-fat, high-carbohydrate meal (718 kcal) with either pancrelipase (50,000 units) or placebo in a randomised, double-blind, crossover fashion. The primary outcome was the difference in postprandial glycaemia following PERT vs placebo, as evaluated by the incremental area under the postprandial plasma glucose curve (iAUC). Secondary outcomes included differences in gastric half-emptying time (T50) measured using scintigraphy, and C-peptide iAUC.

RESULTS

The prevalence of low FE-1 in T2DM was 9.2% (95% CI 3.8-14.6%). There was no difference in postprandial glycaemia iAUC (P = 0.38), gastric emptying T50 (P = 0.69) or C-peptide iAUC (P = 0.25) after PERT compared to placebo.

CONCLUSIONS

Decreased FE-1 has a relatively low prevalence in community-based patients with T2DM, and PERT does not reduce postprandial glycaemia in these patients.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12617000349347.

Gastrointestinal effects of extra-virgin olive oil associated with lower postprandial glycemia in type 1 diabetes

OBJECTIVE

To explore the possible mechanisms behind the lower glycemic response observed when extra-virgin olive oil (EVOO) is added to a high-glycemic index meal in patients with type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

According to a randomized cross-over design, eleven T1D patients (6 women, 5 men) on insulin pump consumed in the metabolic ward, one week apart, three high-glycemic index meals differing only for amount and quality of fat: high-monounsaturated fat (EVOO), high-saturated fat (Butter), and low-fat (LF). Before and after the meals, blood glucose (continuous glucose monitoring), gastric emptying rate (ultrasound technique), and plasma concentrations of glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide GIP (ELISA), glucagon (RIA), and lipids (colorimetric assays) were evaluated.

RESULTS

Blood glucose iAUC (mmol/lx360 min) was lower after the EVOO (690 ± 431) than after the Butter (1320 ± 600) and LF meals (1007 ± 990) (M ± SD, p = 0.041 by repeated measures ANOVA). Gastric antrum volume was significantly larger in the early (60-90 min) postprandial phase (106 ± 21 vs. 90 ± 16 ml, p = 0.048) and significantly smaller in the late phase (330-360 min) (46 ± 10 vs. 57 ± 22 ml, p = 0.045) after the EVOO than after Butter meal. EVOO significantly increased postprandial GLP-1 iAUC (261 ± 311) compared to Butter (189 ± 349) (pmol/Lx180 min, p = 0.009). Postprandial GIP and glucagon responses were not significantly different between EVOO and Butter. Postprandial triglyceride iAUC was significantly higher after EVOO (100 ± 53) than after Butter (65 ± 60) (mmol/l × 360 min, p = 0.048).

CONCLUSIONS

Changes in gastric emptying and GLP-1 secretion and reduced glucose absorption through glucose-lipid competition may contribute to lower glycemia after a high-glycemic index meal with EVOO in T1D patients.

CLINICAL TRIALS NUMBER

NCT02330939.

Implication of neurohormonal-coupled mechanisms of gastric emptying and pancreatic secretory function in diabetic gastroparesis

Recently, diabetic gastroparesis (DGP) has received much attention as its prevalence is increasing in a dramatic fashion and management of patients with DGP represents a challenge in the clinical practice due to the limited therapeutic options. DGP highlights an interrelationship between the gastric emptying and pancreatic secretory function that regulate a wide range of digestive and metabolic functions, respectively. It well documented that both gastric emptying and pancreatic secretion are under delicate control by multiple neurohormonal mechanisms including extrinsic parasympathetic pathways and gastrointestinal (GI) hormones. Interestingly, the latter released in response to various determinants that related to the rate and quality of gastric emptying. Others and we have provided strong evidence that the central autonomic nuclei send a dual output (excitatory and inhibitory) to the stomach and the pancreas in response to a variety of hormonal signals from the abdominal viscera. Most of these hormones released upon gastric emptying to provide feedback, and control this process and simultaneously regulate pancreatic secretion and postprandial glycemia. These findings emphasize an important link between gastric emptying and pancreatic secretion and its role in maintaining homeostatic processes within the GI tract. The present review deals with the neurohormonal-coupled mechanisms of gastric emptying and pancreatic secretory function that implicated in DGP and this provides new insights in our understanding of the pathophysiology of DGP. This also enhances the process of identifying potential therapeutic targets to treat DGP and limit the complications of current management practices.

Analysis of Postprandial Glycemia in Relation to Metabolic Compensation and Other Observed Parameters of Outpatients with Type 2 Diabetes Mellitus in the Czech Republic

INTRODUCTION

The goal of the study was to determine the level of metabolic compensation expressed by glycosylated hemoglobin, fasting plasma glucose, and postprandial glucose as determined after a standardized breakfast; further, to evaluate interrelationships between the studied parameters and postprandial glucose levels.

METHODS

The study included 1055 patients with type 2 diabetes mellitus. Their fasting plasma glucose and postprandial glucose were measured before and after a standardized breakfast. Attending diabetologists completed a uniform questionnaire that included demographic data, type of antidiabetic treatment, duration of diabetes, latest glycosylated hemoglobin value, presence of dyslipidemia, and organic complications.

RESULTS

Glycosylated hemoglobin < 53 mmol/mol was achieved in 363 (34.2%), postprandial glucose < 7.5 mmol/l in 211 (19.9%), and fasting plasma glucose < 6 mmol/l in 251 (23.7%) patients. Excellent metabolic compensation, indicated by all the above mentioned glycosylated hemoglobin, fasting plasma glucose, and postprandial glucose values simultaneously, was achieved in only 71 (6.7%) patients. Comparable to fasting plasma glucose and postprandial glucose values, correlation with glycosylated hemoglobin levels is statistically significant; however, there is no difference at different glycosylated hemoglobin levels. There was a significant correlation between dyslipidemia and postprandial glycemia (p = 0.013).

CONCLUSION

The objective of care for patients with diabetes mellitus is to improve their long-term metabolic compensation; to that end, both fasting plasma glucose and postprandial glucose deserve equal attention.

Is there a justification for classifying GLP-1 receptor agonists as basal and prandial?

Several GLP-1 receptor agonists are currently available for treatment of type 2 diabetic patients. Based on their pharmacokinetic/pharmacodynamic profile, these drugs are classified as short-acting GLP-1 receptor agonists (exenatide and lixisenatide) or long-acting GLP-1 receptor agonists (exenatide-LAR, liraglutide, albiglutide, and dulaglutide). In clinical practice, they are also classified as basal or prandial GLP-1 receptor agonists to differentiate between patients who would benefit more from one or another based on characteristics such as previous treatment and the predominance of fasting or postprandial hyperglycemia. In the present article we examine available data on the pharmacokinetic characteristics of the various GLP-1 agonists and compare their effects with respect to the main parameters used to evaluate glycemic control. The article also analyzes whether the differences between the different GLP-1 agonists justify their classification as basal or prandial.

Drinks containing anthocyanin-rich blackcurrant extract decrease postprandial blood glucose, insulin and incretin concentrations

Blackcurrants are rich in polyphenolic glycosides called anthocyanins, which may inhibit postprandial glycemia. The aim was to determine the dose-dependent effects of blackcurrant extract on postprandial glycemia. Men and postmenopausal women (14M, 9W, mean age 46 years, S.D.=14) were enrolled into a randomized, double-blind, crossover trial. Low sugar fruit drinks containing blackcurrant extract providing 150-mg (L-BE), 300-mg (M-BE) and 600-mg (H-BE) total anthocyanins or no blackcurrant extract (CON) were administered immediately before a high-carbohydrate meal. Plasma glucose, insulin and incretins (GIP and GLP-1) were measured 0-120min, and plasma 8-isoprostane F_2α, together with arterial stiffness by digital volume pulse (DVP) was measured at 0 and 120min. Early plasma glucose response was significantly reduced following H-BE (n=22), relative to CON, with a mean difference (95% CI) in area over baseline (AOB) 0-30min of -0.34mmol/l.h (-0.56, -0.11, P<.005); there were no differences between the intermediate doses and placebo. Plasma insulin concentrations (AOB 0-30min) were similarly reduced. Plasma GIP concentrations (AOB 0-120min) were significantly reduced following H-BE, with a mean difference of -46.6ng/l.h (-66.7, -26.5, P<.0001) compared to CON. Plasma GLP-1 concentrations were reduced following H-BE at 90min. There were no effects on 8-isoprostane F_2α or vascular function. Consumption of blackcurrant extract in amounts roughly equivalent to 100-g blackcurrants reduced postprandial glycemia, insulinemia and incretin secretion, which suggests that inclusion of blackcurrant polyphenols in foods may provide cardio-metabolic health benefits. This trial was registered at clinicaltrials.gov as NCT01706653.

The relationship between carbohydrate and the mealtime insulin dose in type 1 diabetes

A primary focus of the nutritional management of type 1 diabetes has been on matching prandial insulin therapy with carbohydrate amount consumed. Different methods exist to quantify carbohydrate including counting in one gram increments, 10g portions or 15g exchanges. Clinicians have assumed that counting in one gram increments is necessary to precisely dose insulin and optimize postprandial control. Carbohydrate estimations in portions or exchanges have been thought of as inadequate because they may result in less precise matching of insulin dose to carbohydrate amount. However, studies examining the impact of errors in carbohydrate quantification on postprandial glycemia challenge this commonly held view. In addition it has been found that a single mealtime bolus of insulin can cover a range of carbohydrate intake without deterioration in postprandial control. Furthermore, limitations exist in the accuracy of the nutrition information panel on a food label. This article reviews the relationship between carbohydrate quantity and insulin dose, highlighting limitations in the evidence for a linear association. These insights have significant implications for patient education and mealtime insulin dose calculations.

Ethanol extraction preparation of American ginseng (Panax quinquefolius L) and Korean red ginseng (Panax ginseng C.A. Meyer): differential effects on postprandial insulinemia in healthy individuals

ETHNOPHARMACOLOGICAL RELEVANCE

Ginsenosides are the proposed bioactive constituent of ginseng, especially for the attenuation of postprandial glycemia (PPG). The efficacious proportion of total and specific ginsenosides, remains unknown. Alcohol extraction of whole ginseng root can be used to selectively manipulate the ginsenoside profile with increasing alcohol concentrations producing high yields of total ginsenosides and varying their individual proportions.

AIM OF THE STUDY

We aimed to compare the acute efficacy of different ethanol-extraction preparations of American ginseng (AG) and Korean red ginseng (KRG), with their whole-root origins, on PPG and insulin parameters in healthy adults.

MATERIALS AND METHODS

Following an overnight fast, 13 healthy individuals (Gender: 5M:8F, with mean ± SD, age: 28.9 ± 9.2 years, BMI: 26.3 ± 2.7 kg/m(2) and fasting plasma glucose: 4.21 ± 0.04 mmol/L) randomly received 3g of each of the following 10 different ginseng treatments on separate visits: whole root KRG and AG; 30%, 50% or 70% ethanol extracts of KRG and AG and 2 cornstarch placebos. Treatments were consumed 40 min prior to a 50 g oral glucose challenge test with capillary blood samples collected at baseline, 15, 30, 45, 60, 90 and 120 min. Insulin samples were collected at 0, 30, 60 and 120 min.

RESULTS

There was no difference in attenuation of PPG among the tested ginseng preparations. Measures of Insulin Sensitivity Index (ISI) showed increased insulin sensitivity (IS) with KRG-30% and AG-50% extracts compared to placebo (p<0.05).

CONCLUSIONS

The insulin sensitizing effects of KRG-30% and AG-50% extracts suggest that other root parts, including other ginsenosides not typically measured, may influence PPG and insulin parameters. There is potential for AG and KRG extracts to modulate IS, an independent predictor of type 2 diabetes.

Measurement of gastric emptying in diabetes

There has been a substantial evolution of concepts related to disordered gastric emptying in diabetes. While the traditional focus has hitherto related to the pathophysiology and management of upper gastrointestinal symptoms associated with gastroparesis, it is now apparent that the rate of gastric emptying is central to the regulation of postprandial glycemia. This recognition has stimulated the development of dietary and pharmacologic approaches to optimize glycemic control, at least in part, by slowing gastric emptying. With the increased clinical interest in this area, it has proved necessary to expand the traditional indications for gastric emptying studies, and consider the relative strengths and limitations of available techniques. Scintigraphy remains the 'gold standard' for the measurement of gastric emptying, however, there is a lack of standardization of the technique, and the optimal test meal for the evaluation of gastrointestinal symptoms may be discordant from that which is optimal to assess impaired glycemic control. The stable isotope breath test provides an alternative to scintigraphy and can be performed in an office-based setting. The effect of glucagon-like peptide-1 (GLP-1) and its agonists to reduce postprandial glycemia is dependent on the baseline rate of gastric emptying, as well as the magnitude of slowing. Because the effect of exogenous GLP-1 to slow gastric emptying is subject to tachyphylaxis with sustained receptor exposure, 'short acting' or 'prandial' GLP-1 agonists primarily target postprandial glycemia through slowing of gastric emptying, while 'long acting' or 'non-prandial' agents lower fasting glucose primarily through insulinotropic and glucagonostatic mechanisms. Accordingly, the indications for the therapeutic use of these different agents are likely to vary according to baseline gastric emptying rate and glycemic profiles.

Cystic fibrosis related diabetes--a new perspective on the optimal management of postprandial glycemia

As the average life expectancy of patients with cystic fibrosis (CF) improves, the long term co-morbidities assume increasing importance. CF related diabetes (CFRD) has adverse effects on both nutrition and pulmonary function, and is associated with increased mortality. Abnormalities of glucose metabolism in CF represent a continuum; however the predominant abnormality is postprandial, not pre-prandial, glycemia. Insulin is currently recommended as the treatment of choice for CFRD, but its use is associated with a number of limitations, including hypoglycemia. Both the rate of gastric emptying and the consequent release of the 'incretin' hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like-peptide-1 (GLP-1), from the gut are important determinants of overall glycemic control, particularly postprandial glycemia. Both are abnormal in conditions associated with exocrine pancreatic insufficiency. Incretin based therapies that have the capacity to slow gastric emptying and/or modulate the release of 'incretin' hormones, are now used widely in type 2 diabetes (T2D). This paper explores the determinants of glycemic control in CF, with a particular focus on the roles of gastric emptying and 'incretin' hormones, providing a rationale for the use of therapies that delay gastric emptying, including incretin mimetics, to minimize postprandial glycemia and improve nutritional status.