Dose Effect of Whey Protein on Gut Hormone Responses in Pre-Diabetics and Type 2 Diabetics

GLP-1 and GIP have been shown to increase following a 50 g dose of whey protein prior to a high glycemic load in type 2 diabetics. However, this increase is reduced in diabetics compared to healthy individuals. Pancreatic polypeptide (PP) and peptide tyrosine tyrosine (PYY) also increase, while ghrelin decreases after the consumption of whey protein; however, it is not known if a similar hormone response occurs with a lower dose of whey protein prior to a glycemic load or if there is a dose effect. Our hypothesis was that 20 g and 30 g of whey protein would increase GLP-1, GIP, PP, and PYY and decrease ghrelin in a dose dependent manner. PURPOSE: The purpose of this study was to examine the effect of two different doses of whey protein ingested 30 min prior to a 50 g OGTT on gut hormone and incretin response. METHODS: Nine diabetic and pre-diabetic participants (n=9, mean ± SD; age: 64.3 + 8.1 yrs.; BMI: 29.4 + 6.0 kg/m2; HbA1c: 6.4 + 0.6%) completed three trials. The randomly assigned trials consisted of: ingestion of 250ml of water (CON); 250 ml of water + 20 g whey (20g); 250ml of water + 30 g whey (30g), prior to completing a 50 g OGTT. Blood was collected at -30, 0, 15, 30, 60, 90, 120, and 150 min for the measurement of GIP, GLP-1, ghrelin, PP, and PYY. The whey protein was administered immediately following the -30 min and the 50 g OGTT began immediately after the 0 min blood draw. Metabolites were measured using multiplex fluorescent detection. One-way repeated measure ANOVA was used for statistical analysis for each dependent variable (P \u3c 0.05). RESULTS: 20g and 30g of whey protein significantly increased incremental area under the curve (AUC) of GIP 32% and 38% compared to CON. 30g significantly decreased ghrelin AUC -13.9% and -20% compared to 20g and CON. 30g significantly increased PP AUC 28% compared to CON only. There were no differences in ghrelin and PP AUC between 20g and CON. There were no significant differences for GLP-1 and PYY between all trials. CONCLUSION: 30 g of whey protein prior to a glucose challenge increased secretion of GIP and PP and decreased ghrelin in type 2 and pre-diabetics. There seems to be a dose effect relationship between whey, ghrelin, and PP. 30 g of whey preload may induce insulinotropic and satiety effects from GIP, PP, and ghrelin responses in type 2 and pre-diabetics

The Dose Effect of Whey Protein on Insulin Responses in Pre-Diabetics and Type 2 Diabetics

People with pre-diabetes and type 2 diabetes have shown an increase in insulin secretion after ingesting 55 g of whey protein coupled with a glycemic challenge. However, the effect of lower amounts of whey protein on insulin responses remains unclear. Our hypothesis was that both 20 g and 30 g of whey consumption prior to an oral glucose tolerance test (OGTT) would produce an increase in insulin secretion, with 30 g producing the greatest increase compared to a control. PURPOSE: The purpose of this study was to examine the effect of two different doses of whey protein ingested 30 min prior to a 50 g OGTT on glucose, insulin, C-peptide, and glucagon responses. METHODS: Diabetic or pre-diabetic participants (n=9, mean ± SD; age: 64.3 + 8.1 yrs; BMI: 29.4 + 6.0 kg/m2; body fat percentage: 42.5 + 7.8 %; fasting plasma glucose: 6.9 + 1.2 mmol/l; HbA1c: 6.4 + 0.6 %) completed three trials. The randomly assigned trials consisted of: 250 ml of water (CON), 250 ml of water + 20 g whey (20g), and 250 ml of water + 30 g whey (30g), followed by an OGTT. Blood was collected at -30, 0, 15, 30, 60, 90, 120, and 150 min for the measurement of glucose, insulin, C-peptide, and glucagon. The whey protein mixture was administered immediately following the -30 min blood draw, and the 50 g OGTT began immediately following the 0 min blood draw. Glucose was analyzed using a YSI 2900D glucose analyzer and insulin, C-peptide, and glucagon were measured via multiplex fluorescent detection (MagPix). A one-way repeated measures ANOVA (pRESULTS: Incremental area under the curve (AUC) for glucose presented no difference between the 3 trials. Insulin AUC was significantly increased from CON to 20g (p=0.004, 36.3%), CON to 30g (p=0.002, 61.7%), and 20g to 30g (p=0.030, 18.6%). C-peptide and glucagon AUC significantly increased from CON to 20g (p=0.018, 20.6%; p=0.046, 33.1%) and CON to 30g (p=0.001, 30.1%; p=0.017, 33.7%). CONCLUSION: Whey protein elicited a dose response on plasma insulin, increasing concentrations from CON to 20g, and 20g to 30g, however plasma glucose was unaffected. 20g and 30g displayed similar responses for glucagon. Neither 20 g nor 30 g of whey protein may be adequate to provide glycemic improvement in the disease management of type 2 or pre-diabetes

Effects of CO₂ and Soil Moisture Treatments on Morphological and Allometric Trait Variation in Coppiced Seedlings: A Study of Four Early-Successional Deciduous Species

Atmospheric CO2 levels have been increasing, and likewise, increasing drought events have been following increasing temperatures. There is very little literature on the effects of climate change factors on early-successional deciduous species used for ecological restoration. Thus, morphological and allometric variation in four coppiced early-successional deciduous species was examined in response to a 2 × 2 factorial of ambient CO2 (aCO2, 400 ppm) and elevated CO2 (eCO2, 800 ppm), as well as well-watered and drought treatments with 15%–20% and 5%–10% volumetric moisture content, respectively, grown in sandy soil with low soil nitrogen (N) under greenhouse conditions. The four species examined were as follows: green alder (Alnus viridis subsp. crispa (Ait.) Turrill), speckled alder (A. incana subsp. rugosa (Du Roi) R.T. Clausen), gray birch (Betula populifolia (Marshall)), and white birch (B. papyrifera (Marshall)), and all are from the same phylogenetic family, Betulaceae. Genus differences in morphological and growth traits were large, especially in response to the environmental treatments used. Alders upregulated all growth traits under eCO2 because of the strong coppicing sink effect and the additional foliar N provided by the actinorhizal ability of the genus, whereas birches remained the same or slightly decreased under eCO2. As a result, alders have a significantly greater foliar N than birches, with 2.8 and 1.0%, respectively. All species reduced growth under drought, and green alder had the greatest stem dry mass growth, followed by speckled alder and then the birches. Under drought, eCO2 not only mitigated the alder drought dry mass but, in fact, doubled the stem dm, whereas eCO2 only just mitigated the birches drought response. When corrected for size using stem height, alders allocated more to stem and leaf and less to root dry mass than birches. Atmospheric CO2 and soil moisture treatments changed organ biomass allocation. The tallest stem height was the best predictor of total (above and below) dry mass. With increasing atmospheric CO2, particularly on low nutrient sites, the results show alders are capable of sequestering far more carbon than birches. In addition, with more atmospheric CO2, alders can mitigate against drought conditions better compared to birches

Quantification and characterization of bioaerosols (offline techniques).

International audienc

Physiological and Fitness Adaptations Following Eight Weeks of CrossFit® Exercise

Over the past decade, CrossFit® has been rapidly growing in popularity. There are currently over 5,000 CrossFit® gyms around the world and the number of gyms is increasing each year. Health professionals are unable to provide clear recommendations for CrossFit® due to the limited amount of existing research that includes the program as an exercise intervention. PURPOSE: To characterize the cardiorespiratory responses, body composition, and other health-related physical fitness parameters before and after 8 weeks of CrossFit® exercise in sedentary adults. METHODS: Fourteen participants, including men (n = 4; age = 30 ± 8 yrs; height = 176.03 ± 7.57 cm; weight = 114.6 ± 43.56 kg) and women (n = 10; age = 26 ± 6 yrs; height = 163.21 ± 7.53 cm; weight = 70.71 ± 18.28 kg) who were inexperienced with CrossFit® and had not performed regular structured physical activity for the past 12 months, completed all procedures. All participants completed 8 weeks of CrossFit®, exercising 3 days per week at a CrossFit® gym in Lewisville, TX. Each workout lasted about 1 hour and consisted of a warm-up, resistance exercise, circuit training that included a combination of aerobic and resistance exercise, and flexibility training. Resting heart rate, resting blood pressure, cardiorespiratory fitness, body composition, muscular strength, muscular endurance, and muscular flexibility were assessed before and after the 8-week protocol. Dependent t-Tests were performed to determine any differences between the two time points. A significance level of 0.05 was used. RESULTS: Following the 8-week CrossFit® program, resting heart rate (73 ± 12 vs. 68 ± 11 bpm; p = 0.006) and resting diastolic blood pressure (71 ± 7 vs. 65 ± 6 mmHg; p = 0.01) were reduced, while resting systolic blood pressure (112 ± 13 vs. 108 ± 12 mmHg; p = 0.13) remained unchanged. Absolute VO2peak (2.53 ± 0.68 vs. 2.69 ± 0.66 L/min; p = 0.003) and relative VO2peak (32.51 ± 8.84 vs. 34.31 ± 8.63 ml/kg/min; p = 0.003) were improved. Lean body mass (106.03 ± 29.41 vs. 108.38 ± 30.38 lbs; p = 0.006) was increased, but fat mass (71.57 ± 44.98 vs. 70.22 ± 44.52 lbs; p = 0.23) did not change. Performance on the leg press (5RM; 362 ± 120 vs. 444 ± 149 lbs; p \u3c 0.001), bench press (5RM; 86 ± 44 vs. 102 ± 47 lbs; p \u3c 0.001), YMCA bench press (26 ± 13 vs. 37 ± 16 reps; p \u3c 0.001), one-minute sit-up (25 ± 9 vs. 32 ± 10 reps; p \u3c 0.001), and sit-and-reach (30.36 ± 11.36 vs. 32.14 ± 9.66 cm; p = 0.01) were all increased. No significant or chronic injuries were reported. CONCLUSION: CrossFit® may be a safe and effective exercise program for improving health-related physical fitness parameters in sedentary adults

Sampling techniques.

International audienc

Main Biological aerosols, specificities, abundance and diversity.

International audienc