A Study Comparing Pre-Ingested L-Leucine and L-Isoleucine on Glycemic Responses in Healthy Inactive Adults: Preliminary Data.

Background The co-ingestion of amino acids with a glucose drink has been shown to blunt the elevated post-prandial glucose response. Though not entirely clear, some suggest amino acids will facilitate an incretin-driven insulin response that improves glucose sensitivity. Therefore, the purpose of this study is to examine the “priming” effect of pre-ingested amino acids on glycemic control in healthy inactive adults. We present here some preliminary data from 7 adults. Hypothesis We hypothesize that the pre-ingested amino acids would attenuate the post-prandial rise in glucose during a 75 g glucose tolerance test. Methods To test this, seven healthy adults (Females: n =4, Males: n=3, Age 27.17 ± 4.7 y; Height 165.84 ± 9.53 cm; Weight 82.47 ± 14.63 kg; BMI 30.14 ± 7.54 kg/m2; Lean body mass (LBM) 56.83 ± 20.56 kg; Fasting blood glucose (FBG) 87.43 ± 5.29 mg/dL) completed four trials in a randomized, single blinded fashion. The four trials required participants to ingest either Leucine (LEU), L-Isoleucine (ISO), an equal combination of LEU/ISO combined and lastly a control. Each treatment was ingested 30-min prior to a 2 h 75-g oral glucose tolerance test. The amino acid drink (200 mL) was standardized by the participant LBM (0.3g/kg) while the control consisted of inert stevia and non-amino acid ingredients found in equal amounts as other treatment mixtures (3.54 g). Venous blood samples were taken at baseline, and at 10, 30, 40, 60, 90, 120, and 150-min post-treatment and 75 g glucose drink. Because data collection is ongoing, the researchers are still blinded to the composition of the amino acid drinks and thus results are presented as: Red A, Green B, Yellow C, and control (White D). Plasma glucose (GLU) was analyzed using a YSI 2900 analyzer (Yellow Springs Instruments) and insulin (INS), glucagon (GCG), glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1) concentrations were quantified by fluorescent bead-based technology (MAGPIX, Luminex xMAP technology). A 2-way RMANOVA was used to assess glucose data (Graphpad Software). Results Pre-ingestion of amino acid had no significant treatment effect on GLU compared to control (P = 0.5912). Currently, only 2 individuals have been analyzed for insulin, C-peptide, glucagon, GLP-1Active, and GIPTotal. However, we observed early and promising, non-statistical supported differences in concentrations between trials of insulin (Red A, Yellow C \u3e Green B, White D), GLP-1Active (Red A, Green B, Yellow C \u3e White D), and GIPTotal (Red A \u3e Green B, Yellow C, White D). Conclusion Based on these preliminary results, it appears that pre-ingestion of an amino acid drink does not influence glucose control in healthy and inactive young adults. It remains to be seen if pre-ingestion of the amino acids LEU and ISO, have any definitive effect on incretin secretion or subsequent insulin and glucagon responses

Effect of Omega-3 Fatty Acids on Lipoprotein Profile and Particle Size in Hispanic Women

The effect of increased Ω3 fatty acids on lipoprotein sub-fractions has not been well studied in Hispanic women, a group with a high prevalence of dyslipidemia and metabolic syndrome. The purpose of this randomized, placebo-controlled trial was to examine the effect of a 90-day (90D) combined EPA+DHA supplementation on lipoprotein profiles of Hispanic women. Twenty-seven non-diabetic women were randomly assigned to the Ω3 group (n=17, 1.9 g/day EPA+DHA) or the placebo group (n=10, 2 g/day oleic acid). At baseline (0D) and 90D a fasting blood sample was drawn for determination of lipoprotein profile and lipoprotein particle sub-fractions. For the Ω3 group, total cholesterol increased 6.5%, triglycerides were reduced 14.8%, LDL concentration increased 5.6%, and total LDL particle size concentration increased 8.2% (P \u3c 0.05). Large LDL particle size concentration increased 16% from 0D to 90D, this change was not significant (P = 0.051). At 90D, total cholesterol, LDLs, and LDL particle concentration were higher in the Ω3 group compared to placebo (P \u3c 0.05). Omega-3 supplementation resulted in reduced plasma TGs and an increase in large LDL particle size concentration, yet had no effect on HDL particle size or concentration. Further research is necessary to examine the effects of increased Ω3 fatty acid intake in Hispanic women on dyslipidemia and related co-morbidities

Cardiorespiratory Responses during Aquatic Treadmill Exercise and Land Treadmill Exercise in Adults with Diabetes

The purpose of this study was to compare the effect of aquatic treadmill (ATM) exercise to land treadmill (LTM) exercise in adults with type 2 diabetes. Five participants with type 2 diabetes (T2D group; 4 females, 1 male; age = 51±6 years; height = 170±7 cm; weight = 96±24 kg; body fat = 31.6±2.2%) and five participants without type 2 diabetes (control group; 4 females, 1 male; age = 51±6 years; height = 170±6 cm; weight = 71±15 kg; body fat = 26.8±4.6%) completed the study. Protocols for both ATM exercise and LTM exercise began at 2 mph with 0% grade and increased by 1 mph after 5 minutes at each stage. Termination occurred after participants completed the protocol or reached 85% of heart rate reserve. Heart rate, absolute and relative VO2, and systolic and diastolic blood pressure were measured at rest and during steady-state exercise at each intensity. Mean arterial pressure (MAP) was calculated. A 2 x 2 x 3 Mixed Factorial ANOVA and Bonferroni post hoc test with a significance level of .0125 were used. There was a significant difference (p2 of the two groups at 4 mph while performing the land treadmill exercise (T2D: 14.1±1.4 ml/kg/min vs. control: 18.4±1.6 ml/kg/min, p2 between participant groups or modes of exercise. Those with type 2 diabetes had an increased MAP versus those without type 2 diabetes while performing the land treadmill exercise at 2 mph (T2D: 93±3 mmHg vs. control: 81±5 mmHg, p2, and MAP respond similarly in both groups during ATM and LTM exercise at most treadmill speeds

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

High Intensity Interval Exercise Does Not Influence Overnight GH Secretion in Overweight Sedentary Young Women

Exercise and sleep are the two major factors that influence growth hormone (GH) secretion and it has been well established that there is a strong positive relationship between exercise intensity and GH release. This dose-dependent response may also be correlated with the lactate response to exercise, with steady-state exercise intensities above the lactate threshold eliciting a greater GH pulse. It has yet to be determined, however, if high-intensity interval exercise (HIE) can influence overnight pulsatile GH secretion, which accounts for the majority of daily GH release. PURPOSE: To determine if HIE significantly increased overnight GH secretion compared to continuous moderate-intensity exercise (MOD), or no exercise (CON) in young women. METHODS: Five young, sedentary women (mean ± SD age: 22.6 ± 1.3 y; BMI: 27.4 ± 3.1 kg/m2; body fat: 39.2 ± 1.7 %; VO2max: 29.4 ± 5.7 mL/kg/min) were studied on three different occasions during the follicular phase of their menstrual cycle (CON: no exercise; MOD: 30-min of continuous cycling at 50% of peak power determined from the VO2max test; and HIE: 4 30-s “all-out” sprints at a resistance equal to 6.5% body mass with 4.5-min recovery. Each trial was randomly assigned and separated by a minimum of one month. For each visit, participants reported to the lab at 1700h, exercised from 1730h – 1800h, and remained in the lab until 0700h the following morning. The overnight GH secretory profile of each trial was determined from 10-min sampling of venous blood from 1730h – 0600h (12.5 h) using deconvolution analysis. RESULTS: Mean power output during MOD was 80.6 ± 6.3 W (68.2 ± 9.7 %VO2max). Estimated exercising energy expenditure for MOD (145.1 ± 11.2 kcal) was significantly lower than HIE (204.5 ± 15.5 kcal, P = 0.002). Peak lactate was significantly higher during MOD (4.7 ± 0.9 mmol/L) compared to CON (0.9 ± 0.2 mmol/L, P = 0.002) and was highest during HIE (11.2 ± 2.1 mmol/L) compared to MOD (P \u3c 0.001) and CON (P \u3c 0.001). Calculated GH AUC (0 – 120 min) was significantly greater in HIE (1018.2 ± 576.1 ng· min/mL) than CON (181.7 ± 138.9 ng· min/mL, P = 0.009), but not MOD (544.7 ± 160.7 ng· min/mL). Overnight GH production rate (ng/mL/min) determined by deconvolution analysis was not significantly different between CON (1040.3 ± 242.0), MOD (1429.2 ± 206.0), and HIE (1831.2 ± 873.8, P = 0.107). Other GH secretory variables: basal GH concentration (ng/mL), number of GH peaks, GH pulse amplitude and mass, and interpulse interval were not different between the three trials. CONCLUSION: For these untrained, overweight sedentary young women, a single bout of exercise was insufficient to significantly affect overnight pulsatile GH secretion. Adiposity is a negative determinant of GH secretion, and the GH response to exercise in these women was extremely variable. Aerobic fitness, prior training, as well as several metabolic factors associated with obesity (e.g., increased insulin and circulating free fatty acids) can also influence GH secretion and should be taken into account as potential mediators of the GH response to exercise

Concentration-Dependent Effects of a Dietary Ketone Ester on Components of Energy Balance in Mice

Exogenous ketones may provide therapeutic benefit in treatment of obesity. Administration of the ketone ester (KE) R,S-1,3-butanediol acetoacetate diester (BD-AcAc) decreases body weight in mice, but effects on energy balance have not been extensively characterized. The purpose of this investigation was to explore concentration-dependent effects of BD-AcAc on energy intake and expenditure in mice. Forty-two male C57BL/6J mice were randomly assigned to one of seven isocaloric diets ( = 6 per group): (1) Control (CON, 0% KE by kcals); (2) KE5 (5% KE); (3) KE10 (10% KE); (4) KE15 (15% KE); (5) KE20 (20% KE); (6) KE25 (25% KE); and (7) KE30 (30% KE) for 3 weeks. Energy intake and body weight were measured daily. Fat mass (FM), lean body mass (LBM), and energy expenditure (EE) were measured at completion of the study. Differences among groups were compared to CON using ANOVA and ANCOVA. Mean energy intake was similar between CON and each concentration of KE, except KE30 which was 12% lower than CON ( \u3c 0.01). KE25 and KE30 had lower body weight and FM compared to CON, while only KE30 had lower LBM ( \u3c 0.03). Adjusted resting and total EE were lower in KE30 compared to CON ( \u3c 0.03), but similar for all other groups. A diet comprised of 30% energy from BD-AcAc results in lower energy intake, coincident with lower body weight and whole animal adiposity; while KE20 and KE25 have significantly lower body weight and adiposity effects independent of changes in energy intake or expenditure

Concentration-Dependent Effects of a Dietary Ketone Ester on Components of Energy Balance in Mice

Objectives: Exogenous ketones may provide therapeutic benefit in treatment of obesity. Administration of the ketone ester (KE) R,S-1,3-butanediol acetoacetate diester (BD-AcAc2) decreases body weight in mice, but effects on energy balance have not been extensively characterized. The purpose of this investigation was to explore concentration-dependent effects of BD-AcAc2 on energy intake and expenditure in mice.Methods: Forty-two male C57BL/6J mice were randomly assigned to one of seven isocaloric diets (n = 6 per group): (1) Control (CON, 0% KE by kcals); (2) KE5 (5% KE); (3) KE10 (10% KE); (4) KE15 (15% KE); (5) KE20 (20% KE); (6) KE25 (25% KE); and (7) KE30 (30% KE) for 3 weeks. Energy intake and body weight were measured daily. Fat mass (FM), lean body mass (LBM), and energy expenditure (EE) were measured at completion of the study. Differences among groups were compared to CON using ANOVA and ANCOVA.Results: Mean energy intake was similar between CON and each concentration of KE, except KE30 which was 12% lower than CON (P < 0.01). KE25 and KE30 had lower body weight and FM compared to CON, while only KE30 had lower LBM (P < 0.03). Adjusted resting and total EE were lower in KE30 compared to CON (P < 0.03), but similar for all other groups.Conclusions: A diet comprised of 30% energy from BD-AcAc2 results in lower energy intake, coincident with lower body weight and whole animal adiposity; while KE20 and KE25 have significantly lower body weight and adiposity effects independent of changes in energy intake or expenditure

Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo

Meeting Abstracts: Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo Clearwater Beach, FL, USA. 9-11 June 201

Relationship of leptin, resting metabolic rate, and body composition in pre-menopausal Hispanic and non-Hispanic White women

Understanding metabolic and hormonal influences on energy expenditure among pre-menopausal women may help discern factors that influence racial/ethnic disparities in overweight and obesity among women. Purpose. To evaluate the relationship between fasting serum leptin, resting metabolic rate (RMR), and body composition in pre-menopausal Hispanic and non-Hispanic White (White) women. Methods. Participants were 67 Hispanic [mean ± SE age: 42.8 ± 0.6 y; ht: 161.5 ± 0.6 cm; mass: 69.7 ± 1.8 kg; BMI: 26.7 ± 0.7 kg/m2] and 43 White [age: 43.4 ± 0.6 y; ht: 165.5 ± 1.0 cm; mass: 66.6 ± 1.9 kg; BMI: 24.3 ± 0.6 kg/m2] women. Participants arrived at the lab in a fasted state for measurement of RMR by indirect calorimetry. Bone mineral content was measured by DXA and body density was determined by hydrodensitometry. Percentage of body fat was estimated using a 3-compartment equation (Lohman, 1986). Serum leptin levels were determined by EIA. Results. Overall, a strong correlation was observed between leptin and fat mass (FM) (r = 0.51; P \u3c 0.001). When separated by race, Hispanics showed a strong correlation (r = 0.62; P \u3c 0.001), while Whites showed a weak correlation (r = 0.16; P \u3e 0.05) between leptin and FM. There was a moderate correlation between leptin and RMR (r = 0.36; P \u3c 0.001) for both groups combined. Hispanic women demonstrated a moderate correlation (r = 0.47; P \u3c 0.001), while White women demonstrated no correlation (r = 0.07; P \u3e 0.05) between leptin and RMR. There was a high correlation (r = 0.71; P \u3c 0.001) between RMR and lean body mass (LBM) for both groups combined. Independently, both Hispanics and Whites showed a strong correlation (r = 0.70, 0.76, respectively; P \u3c 0.001) between RMR and LBM. Multiple regression analysis revealed that body mass and LBM were the best predictors of RMR. Leptin was not a significant predictor of RMR. Conclusion. These data indicate that leptin was not a predictor of RMR in pre-menopausal Hispanic women. However, body mass and LBM was associated with RMR for both Hispanic and White women. Further research examining the relationship between leptin and energy expenditure is needed