Effects of Glutamine on Gastric Emptying of Low- and High-Nutrient Drinks in Healthy Young Subjects-Impact on Glycaemia.

Glutamine is a potent stimulus for the release of glucagon-like peptide-1, which increases postprandial insulin and slows gastric emptying (GE). We determined the effects of glutamine on GE of, and glycaemic responses to, low- and high-nutrient drinks in eight healthy males (mean age 21.6 ± 0.7 years and BMI 22.9 ± 0.7 kg/m²). Participants were studied on four occasions on which they consumed either a low-nutrient (beef soup; 18 kcal) or high-nutrient (75 g dextrose; 255 kcal) drink, each with or without 30 g of glutamine (120 kcal), in a randomised, crossover design. GE (2D ultrasound), blood glucose and plasma insulin concentrations were measured concurrently. Glutamine slowed GE (half emptying time (T50)) of both low- (45 ± 3 min vs. 26 ± 2 min, p < 0.001), and high-nutrient, (100 ± 5 min vs. 77 ± 5 min, p = 0.03) drinks, however, there was no effect on GE of the high nutrient drinks when expressed as kcal/min (3.39 ± 0.21 kcal/min vs. 3.81 ± 0.20 kcal/min, p = 0.25). There was no change in blood glucose after the low-nutrient drinks with or without glutamine, despite a slight increase in plasma insulin with glutamine (p = 0.007). The rise in blood glucose following the high-nutrient drink (p = 0.0001) was attenuated during the first 60 min by glutamine (p = 0.007). We conclude that in healthy subjects, glutamine slows GE of both low- and high-nutrient drinks comparably and attenuates the rise in blood glucose after the high-nutrient glucose drink.

Addition of the apical oblique projection increases the detection of acute traumatic shoulder abnormalities in adults.

PURPOSE: Plain radiographic evaluation of acute shoulder trauma in adults requires a minimum of two projections, commonly the anteroposterior (AP) and lateral scapular projections, with additional projections taken for diagnosis. The aim of this retrospective study was to determine whether the addition of the apical oblique (AO) projection to the AP and lateral scapular projections increases the number and/or alters the types of abnormalities detected in the examination of acute shoulder trauma. METHODS: Examinations of 56 adults who had undergone three-projection (AP, lateral scapular, AO) radiographic shoulder examination for acute trauma were allocated into two-projection (AP, lateral scapular) and three-projection cases and assessed by a radiologist. The differences in number and types of abnormalities between the two-projection and three-projection cases were quantified using the one-tailed t test and chi-square goodness-of-fit test, respectively. RESULTS: Test-retest reliability was moderate (intra-class correlation coefficient [95%CI], 0.56 [0.15 to 0.80]) for number, and almost perfect (kappa [95%CI], 0.94 [0.85 to 1.00]) for types, of abnormalities detected. There was a significant increase in the number of abnormalities detected across all three-projection versus two-projection cases (difference in means [95%CI], 0.20 [0.01 to 0.39]) and for fractures (difference in means [95%CI], 0.30 [0.11 to 0.49]), but no difference in the types of abnormalities detected (χ 2 = 4.7, p = 0.19). CONCLUSION: This study suggests that adding the AO projection to two-projection examination of acute shoulder trauma increases the number of abnormalities detected; this has potential implications for patient management. Further research investigating differences in types of abnormalities detected between two-projection and three-projection cases is warranted.

Effects of Postprandial Blood Pressure on Gait Parameters in Older People.

Postprandial hypotension (PPH), a fall in systolic blood pressure (SBP) within 2 h of a meal, may detrimentally affect gait parameters and increase the falls risk in older people. We aimed to determine the effects of postprandial SBP on heart rate (HR), gait speed, and stride length, double-support time and swing time variability in older subjects with and without PPH. Twenty-nine subjects were studied on three days: glucose ("G"), water and walk ("WW"), glucose and walk ("GW"). Subjects consumed a glucose drink on "G" and "GW" and water on "WW". The "G" day determined which subjects had PPH. On "WW" and "GW" gait was analyzed. Sixteen subjects demonstrated PPH. In this group, there were significant changes in gait speed (p = 0.040) on "WW" and double-support time variability (p = 0.027) on "GW". The area under the curve for the change in gait parameters from baseline was not significant on any study day. Among subjects without PPH, SBP increased on "WW" (p < 0.005) and all gait parameters remained unchanged on all study days. These findings suggest that by changing gait parameters, PPH may contribute to an increased falls risk in the older person with PPH.

Acute load-dependent effects of oral whey protein on gastric emptying, gut hormone release, glycemia, appetite, and energy intake in healthy men.

BACKGROUND: In healthy individuals, intraduodenal whey protein load-dependently modulates gastrointestinal motor and hormonal functions and suppresses energy intake. The effect of oral whey, particularly the impact of load, has not been evaluated. OBJECTIVE: The purpose of this study was to quantify gastric emptying of 30 and 70 g of oral whey protein loads and their relation to gastrointestinal hormone, glycemic, and appetitive responses. DESIGN: On 3 separate occasions in a randomized, double-blind order, 18 lean men [mean ± SEM age: 24.8 ± 1.4 y; body mass index (in kg/m(2)): 21.6 ± 0.5] received iso-osmolar, equally palatable drinks (∼450 mL) containing 30 g pure whey protein isolate (L), 70 g pure whey protein isolate (H), or saline (control). Gastric emptying (with the use of 3-dimensional ultrasound), plasma cholecystokinin, glucagon-like peptide 1, glucose-dependent insulinotropic peptide, insulin, glucagon, total amino acids, and blood glucose were measured for 180 min after consumption of the drinks, and energy intake at a buffet-style lunch was quantified. RESULTS: Gastric emptying of the L and H drinks was comparable when expressed in kilocalories per minute (L: 2.6 ± 0.2 kcal/min; H: 2.9 ± 0.3 kcal/min) and related between individuals (r = 0.54, P < 0.01). Gastrointestinal hormone, insulin, and glucagon responses to the L and H drinks were comparable until ∼45-60 min after ingestion, after which time the responses became more differentiated. Blood glucose was modestly reduced after the H drink between t = 45 and 150 min when compared with the L drink (all P < 0.05). Energy intake was suppressed by both L and H drinks compared with control (P < 0.05) (control: 1174 ± 91 kcal; L: 1027 ± 81 kcal; and H: 997 ± 71 kcal). CONCLUSION: These findings indicate that, in healthy lean men, the rate of gastric emptying of whey protein is independent of load and determines the initial gastrointestinal hormone response. This study was registered at www.anzctr.org.au as 12611000706976.

Effects of exogenous glucagon-like peptide-1 on blood pressure, heart rate, gastric emptying, mesenteric blood flow and glycaemic responses to oral glucose in older individuals with normal glucose tolerance or type 2 diabetes.

AIMS/HYPOTHESIS: A postprandial fall in BP occurs frequently in older individuals and in patients with type 2 diabetes. The magnitude of this decrease in BP is related to the rate of gastric emptying (GE). Intravenous administration of glucagon-like peptide-1 (GLP-1) attenuates the hypotensive response to intraduodenal glucose in healthy older individuals. We sought to determine the effects of exogenous GLP-1 on BP, GE, superior mesenteric artery (SMA) flow and glycaemic response to oral ingestion of glucose in healthy older individuals and patients with type 2 diabetes. METHODS: Fourteen older volunteers (six men, eight women; age 72.1 ± 1.1 years) and ten patients with type 2 diabetes (six men, four women; age 68.7 ± 3.4 years; HbA1c 6.6 ± 0.2% [48.5 ± 2.0 mmol/mol]; nine with blood glucose managed with metformin, two with a sulfonylurea and one with a dipeptidyl-peptidase 4 inhibitor) received an i.v. infusion of GLP-1 (0.9 pmol kg(-1) min(-1)) or saline (154 mmol/l NaCl) for 150 min (t = -30 min to t = 120 min) in randomised order. At t = 0 min, volunteers consumed a radiolabelled 75 g glucose drink. BP was assessed with an automated device, GE by scintigraphy and SMA flow by ultrasonography. Blood glucose and serum insulin were measured. RESULTS: GLP-1 attenuated the fall in diastolic BP after the glucose drink in older individuals (p < 0.05) and attenuated the fall in systolic and diastolic BP in patients with type 2 diabetes (p < 0.05). GE was faster in patients with type 2 diabetes than in healthy individuals (p < 0.05). In both groups, individuals had slower GE (p < 0.001), decreased SMA flow (p < 0.05) and a lower degree of glycaemia (p < 0.001) when receiving GLP-1. CONCLUSIONS/INTERPRETATION: Intravenous GLP-1 attenuates the hypotensive response to orally administered glucose and decreases SMA flow, probably by slowing GE. GLP-1 and 'short-acting' GLP-1 agonists may be useful in the management of postprandial hypotension.