Low Insulin Response Research Articles

High consumption of smokeless tobacco (“snus”) predicts increased risk of type 2 diabetes in a 10-year prospective study of middle-aged Swedish men

Cigarette smoking increases the risk of type 2 diabetes (T2D). In Sweden and the US, people shift from smoking cigarettes to smokeless tobacco, i.e. oral moist snuff, "snus", to attain harm-reduction. There are limited and conflicting data as to whether snus increases the risk of T2D. The present study investigated if snus use predicts the risk of T2D incidence. This is a prospective population-based study where middle-aged Swedish men (n=2,383), without previously diagnosed T2D, were investigated with oral glucose tolerance test (OGTT) at baseline in 1992-94 and at follow-up 10 years later. Odds ratios (ORs) for newly diagnosed T2D at follow-up were assessed among those using snus, or cigarettes, at both baseline and follow-up, adjusted for major confounders. The OR for T2D was not significantly increased in the whole group of snus users. However, the risk of diabetes increased with increasing weekly snus consumption; ORs (CIs) for >four boxes of snus/week were 2.1 (CI 0.9-4.9), and for >five boxes/week 3.3 (CI 1.4-8.1). For comparison, men smoking at baseline and still smoking at follow-up had an increased risk of diabetes compared with never smokers, OR 1.5 (CI 0.8-3.0), most evident for those smoking >15 cigarettes per day, OR 2.4 (CI 1.0-5.8). Tobacco use was associated with estimations of low insulin response (OGTT), but not low insulin sensitivity (HOMA). High consumption of snus, like smoking, predicts risk of developing T2D. This should be considered when seeking harm-reduction by changing from use of cigarettes to snus. T2D risk from tobacco use may be mediated by effects on beta-cell function.

Effects of exercise before or after meal ingestion on fat balance and postprandial metabolism in overweight men

It is unclear how timing of exercise relative to meal ingestion influences substrate balance and metabolic responses. The present study aimed to compare the effects of exercise performed before or after breakfast on fat balance and postprandial metabolism. A total of ten sedentary overweight men (aged 28.1 (SEM 10.7) years, BMI 29.0 (SEM 2.8) kg/m2) underwent three trials in random order involving: (1) performing no exercise (CON), or walking for 60 min at 50% maximal O2 uptake either (2) before (Ex-Meal) or (3) after (Meal-Ex) consuming a standardised breakfast meal. In each trial an ad libitum lunch was provided 3.5 h after breakfast. Substrate utilisation was assessed by indirect calorimetry and blood was taken at regular intervals over an 8.5 h observation period. At the end of the observation period, fat balances in the Ex-Meal (-1043 (SEM 270) kJ) and Meal-Ex (-697 (SEM 201) kJ) trials were both significantly lower than CON (204 (SEM 165) kJ) and fat balance in the Ex-Meal trial was significantly lower than in the Meal-Ex trial (all P , 0.0001). Compared with the CON trial, the 8.5 h postprandial TAG response was only significantly lowered in the Ex-Meal trial (-17%, P = 0.025) and not in the Meal-Ex trial (-11%, P < 0.20). Both the Ex-Meal and Meal-Ex trials showed significantly lowered insulin responses relative to the CON trial (by 19 and 24%, respectively, P < 0.01 for both). There were no differences in lunch energy intake between trials. The present findings suggest that there may be an advantage for body fat regulation and lipid metabolism in exercising before compared with after breakfast. However, further study is needed to determine whether the present findings extend over the long term under free-living conditions.

Prognostic accuracy of immunologic and metabolic markers for type 1 diabetes in a high-risk population: receiver operating characteristic analysis.

OBJECTIVETo establish and compare the prognostic accuracy of immunologic and metabolic markers in predicting onset of type 1 diabetes in those with high risk in a prospective study.RESEARCH DESIGN AND METHODSA total of 339 subjects from the Diabetes Prevention Trial–Type 1 (DPT-1) parenteral study, who were islet cell antibody (ICA)-positive, with low first-phase insulin response (FPIR) and/or abnormal glucose tolerance at baseline, were followed until clinical diabetes onset or study end (5-year follow-up). The prognostic performance of biomarkers was estimated using receiver operating characteristic (ROC) curve analysis and compared with nonparametric testing of ROC curve areas. Pearson correlation was used to assess the relationship between the markers.RESULTSIndividually, insulin autoantibody titer, ICA512A titer, peak C-peptide, 2-h glucose, FPIR, and FPIR/homeostasis model assessment of insulin resistance provided modest but significant prognostic values for 5-year risk with a similar level of area under ROC curve ranging between 0.61 and 0.67. The combination of 2-h glucose, peak C-peptide, and area under the curve C-peptide significantly improved the prognostic accuracy compared with any solitary index (P < 0.05) with an area under ROC curve of 0.76 (95% CI 0.70–0.81). The addition of antibody titers and/or intravenous glucose tolerance test (IVGTT) markers did not increase the prognostic accuracy further (P = 0.46 and P = 0.66, respectively).CONCLUSIONSThe combination of metabolic markers derived from the oral glucose tolerance test improved accuracy in predicting progression to type 1 diabetes in a population with ICA positivity and abnormal metabolism. The results indicate that the autoimmune activity may not alter the risk of type 1 diabetes after metabolic function has deteriorated. Future intervention trials may consider eliminating IVGTT measurements as an effective cost-reduction strategy for prognostic purposes.

Effects of plane of nutrition and feed deprivation on insulin responses in dairy cattle during late gestation

Nonlactating Holstein cows (n=12) in late pregnancy were used to determine effects of plane of nutrition followed by feed deprivation on metabolic responses to insulin. Beginning 48 d before expected parturition, cows were fed to either a high plane (HP) or a low plane (LP) of nutrition (162 and 90% of calculated energy requirements, respectively). Cows were subjected to an intravenous glucose tolerance test [GTT; 0.25g of dextrose/kg of body weight (BW)] on d 14 of treatment and a hyperinsulinemic-euglycemic clamp (HEC; 1μg/kg of BW/h) on d 15. Following 24h of feed removal, cows were subjected to a second GTT on d 17 and a second HEC on d 18 after 48h of feed removal. During the feeding period, plasma nonesterified fatty acid (NEFA) concentrations were higher for cows fed the LP diet compared with those fed the HP diet (163.6 vs. 73.1μEq/L), whereas plasma insulin was higher for cows fed the HP diet during the feeding period (11.1 vs. 5.2μIU/mL). Glucose areas under the curve during both GTT were higher for cows fed the LP diet than for those fed the HP diet (4,213 vs. 3,750mg/dL × 60min) and was higher during the GTT in the feed-deprived state (4,878 vs. 3,085mg/dL × 60min) than in the GTT during the fed state, suggesting slower clearance of glucose during negative energy balance either pre-or post-feed deprivation. This corresponded with a higher dextrose infusion rate during the fed-state HEC than during the feed-deprived-state HEC (203.3 vs. 90.1 mL/h). Plasma NEFA decreased at a faster rate following GTT during feed deprivation compared with that during the fed state (8.7 vs. 2.9%/min). Suppression of NEFA was highest for cows fed the HP diet during the GTT conducted during feed deprivation, and lowest for cows fed the HP diet during the fed-state GTT (68.6 vs. 50.3% decrease from basal). Plasma insulin responses to GTT were affected by feed deprivation such that cows had a much lower insulin response to GTT by 24h after feed removal (995 vs. 3,957μIU/mL × 60min). During the fed-state HEC, circulating concentrations of NEFA were 21% below basal for cows fed the HP diet and 62% below basal for cows fed the LP diet; during feed deprivation, NEFA were 79 and 59% below basal for the HP and LP diets, respectively (diet × HEC). Cows that are fed below energy requirements or are feed deprived have slower clearance of glucose and greater NEFA responses to glucose challenge. Additionally, feed deprivation had a large effect on insulin secretion. Overall, effects of feed deprivation were larger than effects of plane of nutrition.

Postprandial Glycemia, Insulinemia, and Satiety Responses in Healthy Subjects after Whole Grain Rye Bread Made from Different Rye Varieties. 1

Rye products typically induce low insulin responses and appear to facilitate glucose regulation. The objective of this study was to investigate differences in postprandial glucose, insulin, and satiety responses between breads made from five rye varieties. Breads made from whole grain rye (Amilo, Rekrut, Dankowski Zlote, Nikita, and Haute Loire Pop) or a white wheat bread (WWB) were tested in a randomized cross-over design in 14 healthy subjects (50 g available starch). Metabolic responses were also related to the composition of dietary fiber and bioactive compounds in the breads and to the rate of in vitro starch hydrolysis. The Amilo and Rekrut rye breads induced significantly lower insulin indices (II) than WWB. Low early postprandial glucose and insulin responses (tAUC 0-60 min) were related to higher amounts of caffeic, ferulic, sinapic, and vanillic acids in the rye breads, indicating that the phenolic acids in rye may influence glycemic regulation. All rye breads induced significantly higher subjective feelings of fullness compared to WWB. A low II was related to a higher feeling of fullness and a lower desire to eat in the late postprandial phase (180 min). The data indicate that some rye varieties may be more insulin-saving than others, possibly due to differences in dietary fiber, rate of starch hydrolysis, and bioactive components such as phenolic acids.

Postprandial differences in the plasma metabolome of healthy Finnish subjects after intake of a sourdough fermented endosperm rye bread versus white wheat bread.

BackgroundThe mechanism behind the lowered postprandial insulin demand observed after rye bread intake compared to wheat bread is unknown. The aim of this study was to use the metabolomics approach to identify potential metabolites related to amino acid metabolism involved in this mechanism.MethodsA sourdough fermented endosperm rye bread (RB) and a standard white wheat bread (WB) as a reference were served in random order to 16 healthy subjects. Test bread portions contained 50 g available carbohydrate. In vitro hydrolysis of starch and protein were performed for both test breads. Blood samples for measuring glucose and insulin concentrations were drawn over 4 h and gastric emptying rate (GER) was measured. Changes in the plasma metabolome were investigated by applying a comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry metabolomics platform (GC×GC-TOF-MS).ResultsPlasma insulin response to RB was lower than to WB at 30 min (P = 0.004), 45 min (P = 0.002) and 60 min (P < 0.001) after bread intake, and plasma glucose response was significantly higher at time point 90 min after RB than WB intake (P = 0.045). The starch hydrolysis rate was higher for RB than WB, contrary to the in vitro protein digestibility. There were no differences in GER between breads. From 255 metabolites identified by the metabolomics platform, 26 showed significant postprandial relative changes after 30 minutes of bread intake (p and q values < 0.05). Among them, there were changes in essential amino acids (phenylalanine, methionine, tyrosine and glutamic acid), metabolites involved in the tricarboxylic acid cycle (alpha-ketoglutaric, pyruvic acid and citric acid) and several organic acids. Interestingly, the levels of two compounds involved in the tryptophan metabolism (picolinic acid, ribitol) significantly changed depending on the different bread intake.ConclusionsA single meal of a low fibre sourdough rye bread producing low postprandial insulin response brings in several changes in plasma amino acids and their metabolites and some of these might have properties beneficial for health.

The effect of high multivitamin diet during pregnancy on food intake and glucose metabolism in Wistar rat offspring fed low-vitamin diets post weaning.

Rat offspring born to dams fed a high multivitamin diet (HV) are shown to have increased risks of obesity and metabolic syndrome. We hypothesized that a low-vitamin postweaning diet would enhance these characteristics in offspring born to HV dams. During pregnancy, Wistar rats were fed the AIN-93G diet with or without a 10-fold increase in vitamin content. In Experiment 1, at weaning, males were fed the recommended diet (RV) or a diet with 1/3 the vitamin content (1/3 RV) for 12 weeks. In Experiment 2, males and females were fed the RV diet or 1/6 RV diet for 35 weeks. Body weight was measured on a weekly basis, food intake on a daily basis, and for 1 h after an overnight fast following glucose gavage at 6, 12 and 24 weeks. Blood glucose and insulin responses to an oral glucose load were measured at 30 weeks. Males from HV dams, compared with those from RV dams, gained more weight in Experiment 1 (+7%, P < 0.05) and Experiment 2 (+11%, P < 0.0001), along with higher glucose response (+33%, P < 0.05). The 1/6 RV pup diet led to lower weight gain in males (-16%, P < 0.0001) and females (-13%, P < 0.0005), and lower food intake in males (-9%, P < 0.01) independent of the gestational diet. Females on the 1/6 RV diet and from HV dams had higher 1 h food intake (+36%, P < 0.05) and lower insulin response (-25%, P < 0.05) compared with those from RV dams. Exposure of the offspring to low-vitamin diets did not amplify the expression of the metabolic syndrome observed in those born to dams fed an HV diet.

Whole Grain Products, Fish and Bilberries Alter Glucose and Lipid Metabolism in a Randomized, Controlled Trial: The Sysdimet Study

Background Due to the growing prevalence of type 2 diabetes, new dietary solutions are needed to help improve glucose and lipid metabolism in persons at high risk of developing the disease. Herein we investigated the effects of low-insulin-response grain products, fatty fish, and berries on glucose metabolism and plasma lipidomic profiles in persons with impaired glucose metabolism.Methodology/Principal Findings Altogether 106 men and women with impaired glucose metabolism and with at least two other features of the metabolic syndrome were included in a 12-week parallel dietary intervention. The participants were randomized into three diet intervention groups: (1) whole grain and low postprandial insulin response grain products, fatty fish three times a week, and bilberries three portions per day (HealthyDiet group), (2) Whole grain enriched diet (WGED) group, which includes principally the same grain products as group (1), but with no change in fish or berry consumption, and (3) refined wheat breads (Control). Oral glucose tolerance, plasma fatty acids and lipidomic profiles were measured before and after the intervention. Self-reported compliance with the diets was good and the body weight remained constant. Within the HealthyDiet group two hour glucose concentration and area-under-the-curve for glucose decreased and plasma proportion of (n-3) long-chain PUFAs increased (False Discovery Rate p-values <0.05). Increases in eicosapentaenoic acid and docosahexaenoic acid associated curvilinearly with the improved insulin secretion and glucose disposal. Among the 364 characterized lipids, 25 changed significantly in the HealthyDiet group, including multiple triglycerides incorporating the long chain (n-3) PUFA.Conclusions/SignificanceThe results suggest that the diet rich in whole grain and low insulin response grain products, bilberries, and fatty fish improve glucose metabolism and alter the lipidomic profile. Therefore, such a diet may have a beneficial effect in the efforts to prevent type 2 diabetes in high risk persons.Trial RegistrationClinicalTrials.gov NCT00573781

A bilberry drink with fermented oatmeal decreases postprandial insulin demand in young healthy adults

Backgroundin traditional medicine, blueberries have been used to facilitate blood glucose regulation in type 2 diabetes. Recent studies in diabetic mice have indicated facilitated glycaemic regulation following dietary supplementation with extracts from European blueberries, also called bilberries, (Vaccinium myrtillus). The purpose of the present study was to investigate the impact of fermented oat meal drinks containing bilberries or rosehip (Rosa canina) on glycaemic and insulinaemic responses.Methodsglycaemic and insulinaemic responses in young healthy adults were measured in two series. In series 1, two drinks based on oat meal (5%), fermented using Lactobacillus plantarum 299v, and added with fruit (10%); bilberries (BFOMD) or rose hip (RFOMD) respectively, were studied. In series 2, BFOMD was repeated, additionally, a drink enriched with bilberries (47%) was tested (BBFOMD). As control a fermented oat meal drink (FOMD) was served.Resultsin series 1 the bilberry- and rosehip drinks, gave high glucose responses similar to that after the reference bread. However, the insulin index (II) after the BFOMD was significantly lower (II = 65) (P < 0.05). In series 2 a favourably low insulin demand to BFOMD was confirmed. FOMD gave high glucose response (GI = 95) but, significantly lower insulin response (II = 76). BBFOMD gave remarkably low insulin response II = 49, and tended to lower glycaemia (GI = 79) (P = 0.0684).Conclusiona fermented oat meal drink added with bilberries induced a lower insulin response than expected from the glycaemic response. The mechanism for the lowered acute insulin demand is still unclear, but may be related to some bio-active component present in the bilberries, or to the fermented oat meal base.

Lupin and soya reduce glycaemia acutely in type 2 diabetes

Addition of fibre or protein to carbohydrate-rich foods can reduce the glycaemic response to those foods. This may assist with glycaemic management in individuals with type 2 diabetes. Lupin is a legume rich in fibre and protein. We assessed the acute effects of lupin- and soya-based beverages on glucose and insulin responses in type 2 diabetic individuals. We hypothesised that the lupin and soya beverages would lower the acute glycaemic response compared with a control beverage containing no protein or fibre, and that lupin would reduce the postprandial glucose more than soya. In a randomised, controlled, cross-over trial, twenty-four diabetic adults (nineteen men and five women) attended three testing sessions, each 1 week apart. At each session, participants consumed a beverage containing 50g glucose (control), 50g glucose plus lupin kernel flour with 12·5g fibre and 22g protein (lupin), or 50g glucose plus 12·5g fibre and 22g protein from soya isolates (soya). Serum glucose, insulin and C-peptide were measured periodically for 4h following beverage consumption. Compared with the control beverage, the 4h post-beverage glucose response was lower (P<0·001), and the 4h post-beverage insulin and C-peptide responses were higher (P<0·001) for lupin and soya. Glucose (P=0·25) and C-peptide (P=0·07) responses did not differ significantly between lupin and soya, but lupin resulted in a lower insulin response compared with soya (P=0·013). Adding lupin or soya to a carbohydrate-rich beverage reduces glycaemia acutely in type 2 diabetic individuals. This may have a beneficial role in glycaemic management.

Comparing glycaemic and insulinaemic responses of ponies and horses to dietary glucose

s / Journal of Equine Veterinary Science 31 (2011) 230-356 301 Comparing glycaemic and insulinaemic responses of ponies and horses to dietary glucose K.D. Tinworth , S.L. Raidal , P.A. Harris , M.N. Sillence , and G.K. Noble 1 1 Charles Sturt University, Wagga Wagga, NSW 2650, Australia, WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Leicestershire, UK, Queensland University of Technology, Brisbane, Qld 4001, Australia Introduction: It is known that horses are typically more insulin sensitive than ponies [1], and correlations have been shown between morphometry and insulin sensitivity [2]. The aim of this study was to quantify the glucose and insulin responses to the same meal in horses with moderate body condition scores (BCS) as well as obese ponies, thereby using both disparate breeds and morphometry. Materials and Methods: Eight mature pony mares (Shetlandand Welsh-cross, non-Cushingoid, no known history of laminitis) with a (mean SD) BW 201.4 48.8 kg, 10 3.3 yrs and BCS range 7 to 9 [3], presumed to be insulin-resistant (I-R) based on morphometry, with cresty neck scores (CNS) 3/5 [4], were compared with 12 mature light-breed mares, presumed nonI-R, with a BW 473 61.6 kg, 4.7 1.9 yrs, BCS range 3 to 5/9 and CNS 1/5. They were kept in groups in grass paddocks (non-structural carbohydrates (NSC) 10.5% dry matter (DM)) for 21 days prior to the study. They were stabled and given hay the night before the Oral Meal Tolerance Test (OMTT) when they were fed either hay + rice bran (Cool Conditioner, CopRice, Leeton, NSW Australia; H Meal: 1% BW oaten hay + 200 g rice bran, Pony NSC 621 127 g DM, Horse NSC 1214 151 g DM) or hay + rice bran + glucose (H+G Meal: 1% BW oaten hay + 0.75 g/kg BW glucose, Pony NSC 2319 478 g DM, Horse NSC 4549 569 g DM). Four ponies and six horses were fed the H Meal, and the other four ponies and six horses received the H+G Meal around 0900 h. All animals had consumed their rice bran glucose within 2 min and their hay within 60 min. The glucose (G) and insulin (I) responses to the meals were measured in blood samples taken every 15 min from the time of feeding (t1⁄40) for 180 min. G and I responses were analysed with repeated measures analysis over time, with 2 treatments, meal type and presumed I-R-status. An autoregressive first order model was used for correlation through time for individual animals. G and I values were Log10transformed to normalize the data. Significance was taken as being P < .05. Results and Discussion: The G and I responses to the two meals are shown in Figure 1. All comparisons showed highly significant effects of time and meal type, with interactions between time, meal type and presumed I-R-status (P < .001). H Meal Peak G concentrations [G] were similar (6.28 0.52 vs 5.48 0.36 mmol/L for horses vs ponies respectively) but the peak I concentrations [I] were higher (P < .001) in the ponies (36.67 20.4 vs 8.61 3.91 mU/mL). Horses maintained higher circulating [G], in keeping with their lower insulin response. In contrast, the ponies secreted proportionally more insulin than the horses and maintained their [G] at a lower level. H+G Meal Peak [G] for the horses was 9.05 .98 mmol/L. It is unclear whether the ponies had reached a peak [G] by 180 min but the maximum [G] recorded was 7.65 1.34 mmol. Peak [I] for the horses was higher (P < .001) than following the H Meal (25.4 8.16 mU/mL). However, the peak [I] for the ponies was markedly higher than for the horses (H or H+G) or ponies with the H meal, at 403 362.79 mU/mL by 120 min, and was still significantly elevated at 180 min. In response to the H+G Meal, the horses again attained higher circulating [G] than the ponies, but with significantly lower [I] effectively disposed of the glucose to return it to near-basal concentrations by 180min. In contrast, overall, the ponies, despite their enhanced insulinaemia, did not control the hyperglycaemia seen within the time period monitored. Conclusion: This study illustrated the magnitude of difference in G and I responses of horses and ponies to the same meals. We showed clearly how poorly ponies control their meal-derived glycaemia when challenged with free glucose. The prediction of insulin sensitivity using morphometry and breed was borne out by the G and I responses to a meal. It also showed how free glucose ingestion can cause a sustained hyperinsulinaemia in ponies. These results provide a possible insight into why obese ponies appear to be more at risk of laminitis [5] when exposed to grass high in simple sugars, than horses.

A study of Hassawi rice (Oryza sativa L.) in terms of its carbohydrate hydrolysis (in vitro) and glycaemic and insulinaemic indices (in vivo)

A high prevalence of Type 2 diabetes exists in Saudi Arabia. Epidemiological evidence suggests that low glycaemic index (GI) diets reduce diabetes risk. Yet, little is known about the GI of traditional Saudi Arabian staples such as Hassawi rice (HR). HR was evaluated in terms of its GI and insulinaemic index (II). Comparisons were made in vitro assessing glucose released enzymatically. A long-grain rice variety available in both United Kingdom and Saudi Arabia was studied as a comparison. For GI and II measurements, HR, Uncle Ben's rice (UBR) and a standard glucose solution were consumed by healthy subjects (n=13) on seven randomised occasions. Capillary bloods were collected at specific times over 2 h after food intake. Food and Agriculture Organization/World Health Organization protocols were used to determine GI and II. For the in vitro studies, cooked rice was incubated with hydrolytic enzymes under standardised conditions. Samples were taken at t=20 and t=120 min and rapidly available glucose (RAG) and slowly available glucose (SAG) were computed. Values of RAG and SAG were lower for HR compared with their respective values for UBR (P<0.001 and P=0.011, respectively). However, no significant difference was observed for GI (P>0.05) despite a lower insulin response noted for HR (P=0.007). HR had a similar GI to UBR, although a lower insulin response was evident. RAG and SAG values were different for the two rice varieties despite similar GI values. These differences may be important in terms of their metabolic impact and outcome on diabetes.

Effect of an aqueous Russian tarragon extract on glucose tolerance in response to an oral dextrose load in non-diabetic men

Effect of an aqueous Russian tarragon extract on glucose tolerance in response to an oral dextrose load in non-diabetic men Richard J Bloomer1, Robert E Canale1, Ivo Pischel21Cardiorespiratory/Metabolic Laboratory, The University of Memphis, Memphis, TN, USA; 2PhytoLab GmbH &amp; Co. KG, Vestenbergsgreuth, GermanyBackground: Russian tarragon extracts have been reported to have anti-diabetic activity in animals. This pilot study aimed to investigate the acute effects of an aqueous extract of Russian tarragon (RT) on serum glucose and insulin in response to an oral glucose tolerance test (OGTT).Methods: Using a randomized, double-blind, cross-over design, 12 non-diabetic men reported to the lab on 2 different mornings separated by 1 to 2 weeks, and ingested 75 g of dextrose in solution. Fifteen minutes before ingestion, subjects ingested either 2 g of RT or a placebo. Blood samples were collected before ingestion of the RT and placebo, and at 15, 30, 45, 60, and 75 minutes post ingestion of the dextrose load. Samples were assayed for serum glucose and insulin.Results: For serum glucose, no condition (P = 0.19) or condition &times; time (P = 0.99) effect was noted. A time effect was noted (P &lt; 0.0001), with values at 15 and 30 minutes higher than pre-ingestion (P &lt; 0.05). No area under the curve (AUC) effect (P = 0.54) was noted, although a 4.5% reduction in AUC was observed for RT (569 &plusmn; 92 mg &middot; dL&minus;1 &middot; 75 min&minus;1) vs placebo (596 &plusmn; 123 mg&nbsp;&middot; dL&minus;1&nbsp;&middot; 75 min&minus;1). Similar findings were noted for serum insulin, with no condition (P = 0.24) or condition &times; time (P = 0.98) effect noted. A time effect was noted (P &lt; 0.0001), with values at 15, 30, and 45 minutes higher than pre-ingestion (P &lt; 0.05). No AUC effect (P = 0.53) was noted, although a 17.4% reduction in AUC was observed for RT (114 &plusmn; 22 &micro;IU&nbsp;&middot; mL&minus;1&nbsp;&middot; 75 min&minus;1) vs placebo (138 &plusmn; 30 &micro;IU &middot; mL&minus;1&nbsp;&middot; 75 min&minus;1). Approximately two-thirds of subjects ingesting the RT experienced attenuation in both the glucose and insulin response to the OGTT.Conclusion: These data indicate that acute ingestion of RT results in a slight, non-statistically significant lowering of blood glucose in response to a dextrose load. This occurs in the presence of a slightly lower insulin response. These findings are specific to a small sample of healthy, non-diabetic men. Additional study is needed involving a larger sample of individuals with pre-diabetes or untreated diabetes.Keywords: Artemisia dracunculus L., glucose, insulin resistance, nutritional supplements, Russian tarragon

Effects of cereal breakfasts on postprandial glucose, appetite regulation and voluntary energy intake at a subsequent standardized lunch; focusing on rye products.

BackgroundRye products have been demonstrated to lower the acute insulin demand, induce a low and prolonged blood glucose response (high Glycemic Profile, GP) and reduce subclinical inflammation. These products may therefore contribute to a lowered risk of obesity, type 2 diabetes and cardio vascular disease. The objective of the present paper was to evaluate the mechanism for a reduced postprandial insulin demand with rye products, and to explore possible appetite regulating properties.Methods10 healthy subjects were served breakfast meals (50 g of available starch) with endosperm- or whole grain rye breads, with and without lactic acid, boiled whole grain rye- (RK) or wheat (WK) kernels, or white wheat bread reference (WWB) in random order in a cross-over design. Plasma concentrations of glucose, ghrelin, serum insulin, free fatty acids, adiponectin, breath hydrogen excretion (H2), and subjective satiety was evaluated during the postprandial phase. 270 min after the breakfast, an ad lib lunch buffet was served and the voluntary energy intake (EI) was registered.ResultsAll rye products and WK induced lower insulinemic indices (II) than WWB. A lower incremental insulin peak following breakfast correlated with a lower EI at lunch (r = 0.38). A low II was related to improved satiety in the early postprandial phase (fullness AUC 0-60 min, r = -0.36). RK induced a higher GP compared to WWB and WK. A higher GP was related to a lowered desire to eat before lunch (AUC 210-270) and to a lower concentration of ghrelin in the late postprandial phase after breakfast (270 min), r = -0.29 and -0.29), which in turn was related to a lower voluntary EI (r = 0.43 and 0.33). The RK breakfast improved satiety in the early postprandial phase (0-60 min) compared to WWB, and induced a lower EI at lunch (-16%). A high content of indigestible carbohydrates in the breakfast products was related to improved satiety (0-60 min, r = 0.68 for fullness), and a higher breath H2 in the late postprandial phase (120-270 and 270-390 min, r = 0.46 and 0.70). High H2 (AUC 120-270 min) also correlated with lower EI (r = -0.34).ConclusionsRye products, rich in indigestible carbohydrates, induce colonic fermentation already post the breakfast meal, and lowers acute insulin responses. A high excretion of breath H2 also correlated with a higher GP. Especially, rye kernels induced a high GP which was associated with a 16% lowering of energy intake at a subsequent lunch meal. The bulking effect of rye fiber, colonically derived fermentation metabolites, a high GP and a low insulin response possibly all contributes to the benefits on glucose- and appetite regulation seen in an acute and semi-acute perspective.

Evaluation of two dietary treatments in obese hyperinsulinemic adolescents

Hyperinsulinemia increases the risk of cardiovascular disease in obese children. Only a few treatments are available to decrease insulin resistance. The reduction of hyperinsulinemia by dietary means would be a simple, physiologic and economic way to reduce the risk of metabolic disease. To compare the effects of two low-energy diets on serum insulin concentrations and weight loss in obese hyperinsulinemic adolescents. Eighty-six randomly assigned insulin-resistant obese adolescents completed a 16 week calorie-restricted diet. The experimental diet had a reduced glycemic index designed to evoke a low insulin response (LIR), with carbohydrates and proteins ingested in separate meals. The control diet was a conventional (CD) with similar proportions (60%, 20% and 20%). Variables studied were blood glucose and insulin concentrations after an oral glucose load, body mass index, waist circumference, and insulin resistance (homeostasis model assessment, HOMA). Mean weight [+/- Standard Deviation (SD)] was significantly reduced after the LIR (-0.53 +/- 0.5) and the CD (-0.54 +/- 0.4), but a greater decrease of waist circumference (cm) was observed after the LIR (-9.1 +/- 4.8 vs. -6.6 +/- 4.6, p = 0.02). Fasting insulin concentrations (-17.9 +/- 27.9 vs. -9.4 +/- 14.8, p = 0.01) and HOMA dropped significantly more after the LIR than after the CD (-3.5 +/- 4.9SD vs. -2.4 +/- 1SD, p < 0.0001). The LIR diet reduces serum insulin concentrations and waist circumference more than conventional treatment and appears to be a promising alternative to a conventional diet in insulin-resistant obese adolescents. Long-term follow-up is needed to evaluate the maintenance of weight loss and metabolic parameters.

Gestational Diabetes in Korea: Incidence and Risk Factors of Diabetes in Women with Previous Gestational Diabetes

Korean women with a history of gestational diabetes mellitus (GDM) have a 3.5 times greater risk of developing postpartum diabetes than the general population. The incidence of type 2 diabetes mellitus in early postpartum is reported as 10-15% in Korean women. A prospective follow-up study on Korean women with GDM showed that approximately 40% of women with previous GDM were expected to develop diabetes within 5 years postpartum. Independent risk factors for the development of diabetes in Korean women with previous GDM are pre-pregnancy body weight, gestational age at diagnosis, antepartum hyperglycemia on oral glucose tolerance test, low insulin response to oral glucose load, and family history of diabetes. Women with postpartum diabetes have greater body mass indexes, body weight, and waist circumferences than women with normal glucose tolerance. Multiple logistic regression analysis has revealed that waist circumference is the strongest obesity index along with systolic blood pressure and that triglyceride levels are a major independent risk factor for developing diabetes. These results in Korean women with previous GDM underline the importance of postpartum testing in Korean women diagnosed with GDM, and demonstrate that impaired B-cell function, obesity, and especially visceral obesity, are associated with the development of diabetes.

Effect of the glycemic index on lipid oxidation and body composition.

Several studies have been conducted to evaluate the effects of the consumption of the slowly absorbed carbohydrates in a low glycemic index (GI) diet on fat oxidation, in order to obtain dietetic treatment that can favor the achievement of an adequate body composition. Therefore, the purpose of this study was to analyze studies in which the role of low GI diets on body composition, with emphasis on fat oxidation. An internet search for articles, in English or Portuguese, published since 1995, was conducted using the following key words: glycemic index, glycemic load, glycaemic index, glycaemic load, body fat, body composition, fat oxidation. Papers that described animals or humans clinical trials were selected. Data were collected from Web of Science, Science Direct, Pubmed. It was verified that the results of the majority of the analyzed studies indicated that low GI diets lead to a lower insulin response, increasing body fat oxidation. These results indicate that the consumption of low GI diet can be an important strategy to be used for the prevention and control of obesity and chronic diseases associated to it.

Androgen levels, insulin sensitivity, and early insulin response in women with polycystic ovary syndrome: a long-term follow-up study

Thirty-four women with polycystic ovary syndrome who previously had participated in studies with intravenous glucose tolerance test and hyperinsulinemic, euglycemic clamp between 1987 and 1995 underwent anthropometric, endocrine (T and sex-hormone binding globulin serum concentration), and metabolic (intravenous glucose tolerance test, hyperinsulinemic, euglycemic clamp, and androgens) measurements. Free androgen levels and β-cell function decreased over time in women with polycystic ovary syndrome, but insulin sensitivity remained unaltered.

Products deriving from microbial fermentation are linked to insulinaemic response in pigs fed breads prepared from whole-wheat grain and wheat and rye ingredients

The effects of wheat and rye breads made from whole-wheat grain (WWG), wheat aleurone flour (WAF) or rye aleurone flour (RAF) on net portal absorption of carbohydrate-derived nutrients (glucose, SCFA and lactate) and apparent insulin secretion were studied in a model experiment with catheterised pigs. The breads were similar in dietary fibre (DF, 120-125 g/kg DM) but differed in arabinoxylans (50-62 g/kg), β-glucans (4-9 g/kg) and content of soluble DF (13-29 g/kg). Six pigs in a repeated 3 × 3 crossover design were fitted with catheters in the portal vein and the mesenteric artery and a portal flow probe. Pigs were fed three meals daily (at 09.00, 14.00 and 19.00 hours), and blood profiles were collected repeatedly from 08.30 until 19.00 hours once weekly. Net portal absorption of glucose was similar among breads and between meals. In contrast, insulin secretion was lowest (P < 0·05) in pigs fed RAF bread (3·9 nmol/h), intermediate in pigs fed WAF bread (5·4 nmol/h) and highest in pigs fed WWG bread (5·9 nmol/h), indicating that RAF bread improved insulin economy. Portal concentrations of propionate, butyrate and valerate were high, intermediate and low (P < 0·05) when pigs were fed RAF, WAF and WWG breads, respectively. Insulin secretion was higher (P < 0·001), and portal absorption of SCFA was lower (P < 0·05) after the first daily meal than after the second daily meal (8·8 v. 4·4 nmol/h). A low insulin response was associated with high portal absorption of SCFA. In conclusion, RAF bread was able to improve insulin economy compared to WWG bread.

Detailed Physiological Characterization of the Development of Type 2 Diabetes in Hispanic Women With Prior Gestational Diabetes Mellitus

OBJECTIVETo identify physiological and clinical variables associated with development of type 2 diabetes up to 12 years after pregnancies complicated by gestational diabetes.RESEARCH DESIGN AND METHODSSeventy-two islet cell antibody–negative nondiabetic Hispanic women had oral (oGTT) and intravenous (ivGTT) glucose tolerance tests, glucose clamps, and body composition assessed between 15 and 30 months after pregnancies complicated by gestational diabetes mellitus (GDM). They returned for oGTTs at 15-month intervals until they dropped out, developed diabetes, or reached 12 years postpartum. Cox regression analysis was used to identify baseline predictors and changes during follow-up that were associated with development of type 2 diabetes.RESULTSAt baseline, relatively low insulin sensitivity, insulin response, and β-cell compensation for insulin resistance were independently associated with development of diabetes. During follow-up, weight and fat gain and rates of decline in β-cell compensation were significantly associated with diabetes, while additional pregnancy and use of progestin-only contraception were marginally associated with diabetes risk.CONCLUSIONSIn Hispanic women, GDM represents detection of a chronic disease process characterized by falling β-cell compensation for chronic insulin resistance. Women who are farthest along at diagnosis and/or deteriorating most rapidly are most likely to develop type 2 diabetes within 12 years after the index pregnancy. Weight gain, additional pregnancy, and progestin-only contraception are potential modifiable factors that increase diabetes risk.