Medium chain triglycerides activate distal but not proximal gut hormones

BACKGROUND AND AIMS: Compared to long chain triglycerides (LCT), medium chain triglycerides (MCT) are considered an attractive caloric source in malabsorptive diseases because of their favorable physico-chemical characteristics. The use of MCTis, however, limited by the occurrence of gastrointestinal symptoms such as diarrhoea. We have, therefore, investigated the effects of MCT and LCT on proximal (cholecystokinin; CCK) and distal (peptide YY; PYY) gut hormone secretion. METHODS: Eight healthy volunteers participated in four experiments performed in random order during continuous intraduodenal administration for 360 min of a) saline (control); b) LCT15 mmol/h; c) MCT15mmol/h (equimolar); d) MCT 30 mmol/h (equicaloric). Plasma CCK and PYY were determined at regular intervals (radioimmunoassay). Duodenocecal transit (DCTT) was measured by lactulose H(2)breath test. RESULTS: DCTT during LCT (105 +/- 11 min) was not significantly different from saline (111 +/- 10 min). Both low dose MCT (54 +/- 5 min) and high dose MCT (61 +/- 6 min) significantly accelerated DCTT (P< 0.05). Plasma CCK increased significantly (P< 0.05) during LCT but not during MCT or saline. PYY increased significantly (P< 0.05) not only during LCT, but also during low and high dose MCT but not during saline. CONCLUSIONS: Intraduodenal MCTs a) accelerate intestinal transit; b) do not stimulate CCK release; c) but stimulate release of the distal gut hormone PYY. These results suggest that MCTs are not rapidly absorbed in the proximal gut but probably reach the ileocolonic region and stimulate PYY release.     

Coffee stimulation of cholecystokinin release and gallbladder contraction in humans

We studied the effect of the ingestion of 400 mL regular coffee on plasma cholecystokinin (CCK) concentrations and of 165 mL regular and decaffeinated coffee on plasma CCK and gallbladder contraction in six healthy regular coffee drinkers. Plasma CCK concentrations rose 3.3 +/- 0.4 pmol/L after 400 mL and 2.8 +/- 0.9 pmol/L after 165 mL regular coffee compared with 1.8 +/- 0.6 pmol/L after 165 mL decaffeinated coffee. These plasma CCK increments were greater than those after 400 and 165 mL of an isosmotic and isothermic sodium chloride solution (0.6 +/- 0.2 and 0.4 +/- 0.1 pmol/L, respectively). An average gallbladder contraction of 33 +/- 7% was observed after 165 mL regular coffee and 29 +/- 10% after 165 mL decaffeinated coffee, whereas after 165 mL sodium chloride the contraction was only 10 +/- 12%. We conclude that both regular coffee and decaffeinated coffee give rise to increments in plasma CCK and contractions of the gallbladder.     

Effect of intravenous fat on cholecystokinin secretion and gallbladder motility in man.

During total parenteral nutrition (TPN) gallbladder bile stasis and hypomotility have been well documented. Little is known, however, about the effect of the separate components of TPN on gallbladder motor function. Inasmuch as fat, administered intraduodenally, is a potent stimulus of cholecystokinin (CCK) secretion and gallbladder contraction we have investigated whether intravenous (IV) fat affects gallbladder motility. Six healthy volunteers were studied on two separate occasions, during infusion of Intralipid 10%, 200 mL/h or saline infusion (control) for 3 hours, to evaluate the effect of IV infusion of fat on (1) plasma CCK concentration and gallbladder volume and (2) CCK-induced gallbladder emptying. Intravenous infusion of Intralipid resulted in significant increases in serum triglycerides from 0.9 +/- 0.1 to 5.1 +/- 1.3 mmol/L (at 90 min). During fat infusion no significant changes in plasma CCK and gallbladder volume were noted when compared with basal values or to the control experiment. During IV fat, concomitant infusion of 0.25, 0.5, and 1.0 Ivy dog unit (IDU) per kilogram per hour of CCK-33 resulted in a significant reduction in gallbladder volume from 26 +/- 6 cm3 (basal) to 15 +/- 4 cm3 (p less than .05), 6 +/- 2 cm3 (p less than .05) and 2.5 +/- 1 cm3 (p less than .05), respectively. No significant differences in CCK-induced gallbladder emptying were observed between IV fat and saline infusion (control). It is concluded that, in contrast to intraduodenal fat, IV infusion of fat does not affect (1) basal plasma CCK and gallbladder volume and (2) CCK-induced gallbladder contraction.     

膳食碘过量对大鼠脑中胆囊收缩素基因表达的影响

目的 观察过量碘膳食对成年大鼠脑中胆囊收缩素(CCK)基因表达的影响,探讨发生机制.方法 选用断乳1月龄的Wistar大鼠,按体重随机分为5组,每组30只,摄碘量分别为6.15(A组)、30.75(B组)、61.5(C组)、307.5(D组)、615 μg/d(E组),各组均饲以正常鼠料,饮用含不同碘浓度的水,饲养3、6个月后处死,用放射免疫分析方法测定血清甲状腺激素水平;取脑组织,采用RT-PCR方法检测脑组织CCK mRNA的表达.结果 3个月时,E组大鼠血清总甲状腺素T4(TT4)(45.2±13.7)nmol/L、总甲状腺素T3(TT3)(0.65±0.20)nmol/L、游离甲状腺素T3(FT3)(0.93±0.45)pmol/L、游离甲状腺素T4(FT4)(7.07±2.43)pmol/L、反三碘甲状腺原氨酸(rT3)(0.15±0.04)nmol/L均明显低于A组的TT4(76.0±18.8)nmol/L、TT3(1.34±0.41)nmol/L、FT3(2.45±0.62)pmol/L、FT4(15.12±3.40)pmol/L、rT3(0.24±0.04)nmol/L(F值分别为14.68、16.03、21.16、20.25、13.52,P＜0.01);C组、D组的FT3水平与A、B组比较降低(F=21.16,P＜0.05);D组的rT3水平与A、B、C组比较也有降低(F=13.52,P＜0.05).6个月时,E组TT4(51.84±15.83)nmol/L、TT3(0.77±0.22)nmol/L、FT3(0.74±0.28)pmol/L、FT4(6.88±2.23)pmol/L、rT3(0.14±0.03)nmol/L均低于其余各组(F值分别为6.05、12.22、11.25、13.42、5.89,P＜0.05).E组大鼠脑中CCK mRNA水平在3个月和6个月时与其余各组比较均降低(F值分别为4.04、3.95,P＜0.01).相关分析结果显示:3、6个月时血清FT4水平与CCK mRNA水平间存在着线性相关趋势(r值分别为0.990、0.948,P＜0.05).3个月、6个月时血清FT3水平与CCK mRNA水平间不存在线性相关关系(r值分别为0.970、0.932).结论 高于正常100倍的碘摄入会引起大鼠脑中CCK mRNA水平的降低;在此过程中,FT4水平的改变较FT3而言可能起着更重要的作用.     

Gallbladder contraction after administration of intravenous amino acids and long-chain triacylglycerols in humans.

We examined the possible physiologic effects of intravenous (IV) amino acids (AAs) and long-chain triacylglycerols (LCTs) on gallbladder (GB) motility and release of cholecystokinin (CCK) on humans. GB contraction was studied in normal volunteers after administration of a fatty meal and IV infusion of AA and LCT. The GB contraction volume was calculated with ultrasound. Cholecystokinin-8 (CCK-8) and cholecystokinin-33/39 (CCK-33/39) were measured by radio-immunoassay. Administration of a fatty meal resulted in GB contraction by 60% of its basal volume and was accompanied by an increase in the serum levels of both CCK-8 and CCK-33/39. Administration of IV AA and LCT resulted in GB contraction by 17 and 37%, respectively, of its basal volume. The latter contractions were accompanied by increased levels of CCK-8 only. We conclude that IV administration of AA and LCT can result in human GB contraction and induce the release of only CCK-8. Continuous IV administration of AA and LCT for greater than 2h causes exhaustion of CCK-8 release, so that the GB returns to its initial volume.     

A carbohydrate-restricted diet alters gut peptides and adiposity signals in men and women with metabolic syndrome

Carbohydrate-restricted diets have been shown to enhance satiation- and other homeostatic-signaling pathways controlling food intake and energy balance, which may serve to reduce the incidence of obesity and metabolic syndrome. This study was designed as a correlational, observational investigation of the effects of a carbohydrate-restricted diet on weight loss and body fat reduction and associated changes in circulating leptin, insulin, ghrelin, and cholecystokinin (CCK) concentrations in overweight/obese patients (4 men and 16 women) with metabolic syndrome. Subjects received clinical instruction on the initiation and maintenance of the commercial South Beach Diet, consisting of 2 phases: Phase I (initial 2 wk of the study) and Phase II (remaining 10 wk). Participants showed a decrease (P < 0.05) in body weight (93.5 +/- 3.6 kg vs. 88.3 +/- 3.4 kg), BMI (33.9 +/- 1.3 kg/m(2) vs. 32.0 +/- 1.3 kg/m(2)), waist circumference (112.8 +/- 2.8 cm vs. 107.7 +/- 3.0 cm), and total percent body fat (40.2 +/- 1.5% vs. 39.2 +/- 1.5%) by study completion. Plasma fasting insulin and leptin concentrations decreased significantly from baseline concentrations (139.1 +/- 12.2 pmol/L and 44.1 +/- 4.5 microg/L, respectively) by the end of Phase I (98.6 +/- 2.6 pmol/L and 33.3 +/- 4.1 microg/L, respectively). Plasma fasting ghrelin concentrations significantly increased from baseline (836.7 +/- 66.7 ng/L) by Phase II (939.9 +/- 56.8 ng/L). The postprandial increase in plasma CCK concentrations (difference in plasma CCK concentrations from fasting to postprandial) after Phase I (2.4 +/- 0.3 pmol/L) and Phase II (2.5 +/- 0.4 pmol/L) was significantly greater than the postprandial increase at baseline (1.1 +/- 0.5 pmol/L). Collectively, these results suggest that in patients with metabolic syndrome, improved adiposity signaling and increased postprandial CCK concentrations may act together as a possible compensatory control mechanism to maintain low intakes and facilitate weight loss, despite an increase in fasting ghrelin concentrations and subjective measures of hunger.     

Comparison between dodecanedioic acid and long-chain triglycerides as an energy source in liquid formula diets

BACKGROUND: Dicarboxylic acids (DA) are water-soluble substances with high-energy density proposed as an alternative lipid substrate for nutrition purposes. The aim of the present study was to investigate the interaction between glucose and DA or long-chain triglyceride (LCT) metabolism after oral administration. METHODS: Two test meals containing either dodecanedioic acid (C12, the 12-atom DA) or LCT, together with glucose and amino acids, were each administered to five healthy volunteers. Tracer amounts of 14C-dodecanedioic acid were added to the C12 meal to recover expired traced CO2 and estimate the minimum rate of C12 oxidation. Glucose, insulin, and C12 plasma levels were measured for 360 minutes after the test meal. Indirect calorimetry was performed for the duration of the study. RESULTS: LCTs proved ineffective in promoting their own oxidation after oral administration. On the contrary, C12 was promptly oxidized, a minimum of 21.9%+/-8.3% of the administered amount giving rise to the recovered expired CO2. This difference in metabolic fate was reflected in a sparing effect on glucose: suprabasal respiratory quotient and suprabasal carbohydrate oxidation were significantly (p < .05) lower under C12 administration than under LCT administration, with a difference of 0.024+/-0.015 in respiratory quotient (RQ) and a difference of 0.791+/-0.197 kJ/min in carbohydrate oxidation. In particular, carbohydrate oxidation increased by 54% over basal with LCT but only by 28% with C12 administration. RQ increased over basal by 5.8% with LCT but only by 3.0% with C12 administration. CONCLUSIONS: These results show a fundamental metabolic difference between conventional lipids and DAs, which is the basis for a possible role of DAs in clinical nutrition. The fate of spared glucose is likely to be storage in glycogen form when dodecanedioic acid is made available as an energy source.     

The effects of a short-term long-chain-triglyceride infusion on the postoperative immune function of pediatric patients receiving a gastrointestinal surgical procedure

OBJECTIVE: This clinical trial investigates whether short-term administration of long chain triglycerides (LCT) has any influence on the immune function in children following gastrointestinal surgery. METHODS: Sixty pediatric patients receiving a gastrointestinal operation were randomly divided into the experimental group (n = 36) and the control group (n = 24). After abdominal operation, the subjects received parenteral nutrition (PN) support with or without LCT for 5 days. The patients' fasting blood samples were respectively collected at 24 hours preoperative, then 24 hours and 120 hours postoperative. Blood parameters related to the patients' immune function were measured. RESULTS: Before surgery and LCT treatment, the experimental group and control group did not differ significantly in overall state of health. Except for a small increase of serum IgM at 24 hours postsurgery (p < .05), all parameters representing the patients' immune function showed no significant difference between the LCT group and the control group with respect to peripheral blood mononuclear cell (PBMC), T lymphocyte, CD4, CD8, CD4/CD8, serum immunoglobulin A (IgA), IgG, IgM, complement C3, C4, interleukin (IL)-2, IL-4, IL-10, IL-12, tumor necrosis factor (TNF)-alpha and IFN-gamma (p > .05, respectively) before the operation, 24 hours and 120 hours after the operation. CONCLUSIONS: A short-term LCT administration at an appropriate dosage and infusion speed does not alter the pediatric patients' immune function after gastrointestinal surgery. The etiology and clinical significance of the slightly increased IgM 24 hours postsurgery need to be further investigated.     

Very-low-calorie diets with high and low protein content: impact on triiodothyronine, energy expenditure, and nitrogen balance

Optimal composition of reducing diets remains controversial. Seventeen obese inpatients received 440 kcal/d, either 41% protein plus 55% carbohydrate (CD) or 95% protein (PP), for 3 wk. There were no significant diet effects (all data CD vs PP) in weight loss (8.88 +/- 1.01 vs 8.74 +/- 0.79 kg), loss of lean mass (2.10 +/- 0.35 vs 1.61 +/- 0.39 kg), metabolic rate reduction (15.3 +/- 2.8 vs 13.0 +/- 5.2%), or meal-stimulated thermogenesis (26.6-37.9 vs 29.0-26.1 net kcal/3 h [time NS also]). Triiodothyronine (T3) responses differed (2.35 +/- 0.11 to 1.57 +/- 0.14 vs 2.43 +/- 0.11 to 1.47 +/- 0.12 nmol/L, p less than 0.01) as did free T3 (3.4 +/- 0.2 to 2.6 +/- 0.2 vs 3.2 +/- 0.2 to 2.0 +/- 0.2 pmol/L, (p less than 0.01]; thyroxine declined similarly in both groups. Subjects fed CD gained no advantage over subjects fed PP. Regression analyses revealed no relationship between thyroid hormones, energy deficit, or lean mass with nitrogen losses, suggesting that other or more complex processes govern endogenous protein metabolism during weight loss.     

Glycemic and insulinemic responses to protein supplements

OBJECTIVE: The effects of common servings of commercially marketed nutritional protein supplements on blood glucose and insulin responses were studied in 12 healthy men after ingestion of feedings that had varying carbohydrate and protein compositions. DESIGN: Fasting subjects consumed a 50-gram glucose drink, a white bagel, peanuts, a protein bar, or a protein drink in a counterbalanced fashion. SETTING: Subjects rested in a supine position and were not disturbed while blood samples were drawn at rest and at 10-minute intervals during the ensuing 2 hours. RESULTS: The area under the curve for glucose was greater in the glucose drink group vs all treatment groups except the white bagel group ( P <.05). At 20 to 40 minutes, plasma glucose was elevated in the glucose drink group vs the peanuts group, the protein bar group, and the protein drink group ( P <.05). The glycemic response was greater in the glucose drink group vs the white bagel group at 30 minutes (8.1+/-0.5 vs 6.5+/-0.3 mmol/L, respectively) ( P <.05). The area under the curve for insulin was lower in the peanuts group vs all treatment groups ( P <.05). Insulin concentrations peaked at 40 minutes in the glucose drink group (285.5+/-18.3 pmol) and was similar in all but the peanuts group (130.5+/-14.3 pmol) ( P <.05). CONCLUSIONS: A common serving of a commercially available protein supplement resulted in a marked insulin response with no glycemic response because of the lack of carbohydrate content. Inasmuch as many such supplements similar in composition are marketed on the bases of their nutritional energy benefits, these data underscore the need to educate consumers regarding appropriate fuel for exercise and nutritional supplement composition.     

Glycaemic and Appetite Suppression Effect of a Vegetable-Enriched Bread

Bread, a frequently consumed food, is an ideal vehicle for addition of ingredients that increase nutrient density and add health benefits. This experimental cross-over study sought to test the effect of a vegetable-enriched bread (VB) in comparison to commercial white bread (WB) and wheatmeal bread (WMB) on serum glucose, insulin response and subjective appetite suppression. On three separate occasions, 10 participants (23 ± 7 years) visited the laboratory and consumed after an overnight fast, in random order, a 75 g serve of WB, WMB or VB. Venous blood samples drawn twice before (0 min) and at 15, 30, 45, 60, 90 and 120 min after consumption of the bread were analysed for glucose and insulin. Participants rated their subjective feelings of hunger, fullness, satisfaction and desire to eat on a 150 mm Likert scale. The mean glucose iAUC over 120 min was not different among the breads. The mean insulin iAUC for the VB was significantly lower than the WB and WMB; difference VB and WB 12,415 pmol/L*minutes (95% CI 1918, 22,912 pmol/L*minutes, p = 0.025) and difference VB and WMB 13,800 pmol/L*minutes (95% CI 1623, 25,976 pmol/L*minutes p = 0.031). The VB was associated with a higher fullness feeling in the participants over the 120-min period. The consumption of VB was associated with less insulin release and higher satiety over 120 min which may be related to the higher fibre content and texture of VB. The role of vegetable and fruit fibres such as pectin in bread and insulin response should also be further explored.     

Motility of the gastrointestinal tract and gallbladder during long-term total parenteral nutrition in dogs

BACKGROUND: The motility of the gastrointestinal tract during total parenteral nutrition (TPN) remains poorly understood. The objective of this study was to determine the motility pattern not only in the gastrointestinal tract but also in the gallbladders of dogs maintained by TPN. METHODS: Central venous catheters were inserted through the external jugular vein of 5 dogs and 6 strain gauge force transducers were sewn to the stomach, small intestine, and gallbladder. Two weeks later, oral food was discontinued and motility was recorded for 24 hours after the first migrating motor complex (MMC) was confirmed in the stomach as pre-TPN. TPN was started and continued for 4 weeks, and patterns of motor activity during TPN were recorded for 24 hours at the end of each week. RESULTS: The durations of MMC in the stomach, duodenum, and gallbladder in pre-TPN were 118 +/- 3 minutes, 118 +/- 2 minutes, and 118 +/- 2 minutes, respectively, but in the first week of TPN they were 432 +/- 56 minutes, 431 +/- 56 minutes, and 386 +/- 29 minutes, respectively. TPN times were significantly longer than those of pre-TPN (corrected p < .005). The durations of MMC in jejunoileum did not alter between pre-TPN and TPN. The occurrences of phase III in the stomach, duodenum, and gallbladder in pre-TPN were 12/d, but during TPN they were reduced significantly (corrected p < .005). CONCLUSIONS: TPN did not affect the motility of the jejunoileum but did inhibit the motor activities of the stomach, duodenum, and gallbladder. The inhibition of gallbladder contraction observed during TPN may be one of the factors inducing gallbladder disease.     

Elevated plasma cholecystokinin and appetitive ratings after consumption of a liquid meal in humans

OBJECTIVE: This study had two objectives. The first was to evaluate the possibility that, in a previous study, a soup preload augmented the reduction of food intake in a test meal induced by an exogenous infusion of cholecystokinin (CCK) because the soup also endogenously released CCK. The second was to compare CCK release by soup between men and women to determine whether the increased satiating effectiveness of soup in women as opposed to men could have been partly attributable to differences in CCK release. METHODS: By using a bioassay that measures all of its known isoforms, we determined plasma CCK levels at baseline and at several times postprandially in eight healthy, non-obese men and women (four of each sex). Each subject ingested 800 g of tomato soup, which was followed 30 min later by 300 g of a yogurt shake. Appetitive ratings were also collected and related to CCK levels. RESULTS: Ingestion of tomato soup significantly increased plasma CCK levels by 3.81 pmol/L (+/- 1.21 standard error, P = 0.016) over baseline within 30 min in all subjects combined. When CCK concentrations at 5 min after soup and 5 min after yogurt were averaged, the women's mean averaged concentration was 5.58 pmol/L (+/- 1.994, t = 2.80, P = 0.0073) higher than the men's. The elevated levels persisted but did not rise further upon consumption of the yogurt shake. Hunger ratings declined and fullness ratings increased after eating, although patterns of ratings did not match exactly patterns of CCK release. CONCLUSIONS: A large quantity of tomato soup stimulates significant CCK release; therefore, some of the satiating effects of soup preloads could have been mediated by an elevation in endogenous CCK.     

Medium-chain triacylglycerols enhance release of cholecystokinin in chicks.

Whether medium-chain triacylglycerols (MCT) affect the plasma concentration of cholecystokinin (CCK) and crop-emptying rate in chicks was investigated after 0, 30, 60, 90, 120 or 180 min of diet intubation. Triacylglycerol sources used were corn oil [containing long-chain triacylglycerols (LCT)], glyceryl tricaprate and glyceryl tricaprylate at a level of 200 g/kg diet. Plasma CCK concentration was significantly enhanced in chicks given the two MCT treatments, but not in those given the LCT treatment, after 30 min feeding relative to the initial level. At all time points, chicks fed the diet containing LCT had significantly lower plasma CCK concentrations than those fed MCT, and chicks fed glyceryl tricaprate had higher concentrations than those fed glyceryl tricaprylate. Dietary MCT sources significantly delayed diet passage from the crop compared with dietary LCT. These results indicate that MCT are more potent stimulators of CCK secretion in chicks than LCT.     

Endocrine and lipid responses to chronic androstenediol-herbal supplementation in 30 to 58 year old men

OBJECTIVE: The effectiveness of an androgenic nutritional supplement designed to enhance serum testosterone concentrations and prevent the formation of dihydrotestosterone and estrogen was investigated in healthy 3 to 58 year old men. DESIGN: Subjects were randomly assigned to consume a nutritional supplement (AND-HB) containing 300-mg androstenediol, 480-mg saw palmetto, 450-mg indole-3-carbinol, 300-mg chrysin, 1,500 mg gamma-linolenic acid and 1.350-mg Tribulus terrestris per day (n = 28), or placebo (n = 27) for 28 days. Subjects were stratified into age groups to represent the fourth (30 year olds, n = 20), fifth (40 year olds, n = 20) and sixth (50 year olds, n = 16) decades of life. MEASUREMENTS: Serum free testosterone, total testosterone, androstenedione, dihydrotestosterone, estradiol, prostate specific antigen and lipid concentrations were measured before supplementation and weekly for four weeks. RESULTS: Basal serum total testosterone, estradiol, and prostate specific antigen (PSA) concentrations were not different between age groups. Basal serum free testosterone concentrations were higher (p < 0.05) in the 30- (70.5 +/- 3.6 pmol/L) than in the 50 year olds (50.8 +/- 4.5 pmol/L). Basal serum androstenedione and dihydrotestosterone (DHT) concentrations were significantly higher in the 30- (for androstenedione and DHT, respectively, 10.4 +/- 0.6 nmol/L and 2198.2 +/- 166.5 pmol/L) than in the 40- (6.8 +/- 0.5 nmol/L and 1736.8 +/- 152.0 pmol/L) or 50 year olds (6.0 +/- 0.7 nmol/L and 1983.7 +/- 147.8 pmol/L). Basal serum hormone concentrations did not differ between the treatment groups. Serum concentrations of total testosterone and PSA were unchanged by supplementation. Ingestion of AND-HB resulted in increased (p < 0.05) serum androstenedione (174%), free testosterone (37%), DHT (57%) and estradiol (86%) throughout the four weeks. There was no relationship between the increases in serum free testosterone, androstenedione, DHT, or estradiol and age (r2 = 0.08, 0.03, 0.05 and 0.02, respectively). Serum HDL-C concentrations were reduced (p < 0.05) by 0.14 mmol/L in AND-HB. CONCLUSIONS: These data indicate that ingestion of androstenediol combined with herbal products does not prevent the formation of estradiol and dihydrotestosterone.     

Medium-chain, triglyceride-containing lipid emulsions increase human neutrophil beta2 integrin expression, adhesion, and degranulation

BACKGROUND: To test the hypothesis that lipid emulsions with different triglyceride structures have distinct immunomodulatory properties, we analyzed human neutrophil adhesion and degranulation after lipid incubation. METHODS: Neutrophils, isolated from the blood of 10 healthy volunteers, were incubated in medium or physiologic (2.5 mmol/L) emulsions containing long-chain (LCT), medium-chain (MCT), mixed LCT/MCT, or structured (SL) triglycerides. Expression of adhesion molecules and degranulation markers was evaluated by flow cytometry. Also, functional adhesion was investigated by means of a flow cytometric assay using fluorescent beads coated with the integrin ligand intercellular adhesion molecule (ICAM)-1. RESULTS: Although LCT and SL had no effect, LCT/MCT significantly increased expression of the beta2 integrins lymphocyte-function-associated antigen 1 (+18%), macrophage antigen 1 (+387%), p150,95 (+82%), and (alphaDbeta2 (+230%). Degranulation marker expression for azurophilic (CD63, +210%) and specific granules (CD66b, +370%) also significantly increased, whereas L-selectin (CD62L, -70%) decreased. The effects of LCT/MCT were mimicked by the MCT emulsion. ICAM-1 adhesion (% beads bound) was increased by LCT/MCT (34% +/- 4%), whereas LCT (19% +/-3%) and SL (20% +/- 2%) had no effect compared with medium (17% +/- 3%). CONCLUSIONS: LCT/MCT and MCT, contrary to LCT and SL emulsions, increased neutrophil beta2 integrin expression, adhesion, and degranulation. Apart from other emulsion constituents, triglyceride chain length might therefore be a key feature in the interaction of lipid emulsions and the phagocyte immune system.     

Effect of 2 Liquid Nutritional Supplements for Diabetes Patients on Postprandial Glucose,Insulin Secretion,and Insulin Sensitivity in Healthy Individuals

Aim: To compare the effect of 2 liquid nutritional supplements (Enterex Diabetic and Glucerna SR) designed for the patient with diabetes mellitus on postprandial glucose, insulin secretion, and insulin sensitivity in healthy individuals. Patients and Methods: A randomized, double‐blind, crossover clinical trial was carried out in 14 healthy, young (average age 21.7 ± 2.8 years) volunteers. Each individual received a single administration of 232 kcal in 232 mL of Enterex Diabetic or in 237 mL of Glucerna SR. Three days later, the intervention was crossed using the opposite supplement. At the beginning of each administration and later at 30, 60, 90, and 120 minutes, glucose and insulin concentrations were measured. Triglyceride concentrations were measured at the beginning and at 120 minutes. Area under the curve of glucose and insulin was calculated. First‐phase and total insulin secretion, as well as insulin sensitivity, were assessed. Results: Glucose concentration at 120 minutes was significantly lower after the administration of Enterex Diabetic in comparison with Glucerna SR (4.3 ± 0.6 vs 4.7 ± 0.4 mmol/L; P = .012). Enterex Diabetic compared with Glucerna SR showed a greater change of the glucose concentration from 0 to 120 minutes (–0.7 ± 0.6 vs –0.0± 0.4 mmol/L; P = .002). Administration of Enterex Diabetic decreased insulin concentrations at 120 minutes (60 ± 18 vs 48 ± 19 pmol/L; P = .013). Administration of Glucerna SR increased triglyceride concentration at 120 minutes (1.0 ± 0.3 vs 1.1 ± 0.4 mmol/L; P = .026). Conclusion: A single administration of Enterex Diabetic in healthy individuals decreased glucose and insulin concentrations at 120 minutes without any modification in triglyceride levels.     

Thermogenesis from intravenous medium-chain triglycerides

Eighteen hospitalized patients dependent on total parenteral nutrition (TPN) were randomly enrolled into a prospective study comparing intravenous long-chain triglycerides (LCT) with a physical mixture of 75% medium-chain triglycerides (MCT) and 25% LCT. The TPN was given continuously as amino acids and glucose over 5 days with the respective lipid emulsion given intermittently during each day for 10 hr. Indirect calorimetry was measured on each patient before the lipid emulsion was administered in the morning and again 10 hr later near the end of the lipid infusion, on days 1, 3, and 5. Resting energy expenditure, VO2, VCO2, and calculated fat oxidation were shown to increase during MCT infusion but not during LCT administration, (resting energy expenditure 899 +/- 37 to 1085 +/- 40, compared with 978 +/- 23 to 976 +/- 39, kcal/m2 body surface area [BSA]/day, respectively, p less than 0.0002; VO2: 129.9 +/- 5.2 to 157.2 +/- 5.9, compared with 140.9 +/- 3.6 to 141.2 +/- 5.9 ml O2/min/m2 BSA, respectively, p less than 0.0005; and VCO2: 110.7 +/- 4.4 to 127.5 +/- 4.3, compared with 118.3 +/- 2.8 to 118.0 +/- 5.3, ml CO2/min/m2 BSA, respectively, p less than 0.0076; calculated fat oxidation 10.7 +/- 1.5 to 19.3 +/- 2.4, compared with 20.0 +/- 2.7 to 20.0 +/- 3.6, kcal/m2 BSA/hr, respectively, p less than 0.014). Respiratory quotient tended to fall with lipid infusion but did not change statistically. Body temperatures were unaltered by either fat infusion. It is concluded that TPN consisting of MCT causes an increased thermogenesis, most likely through increased fat oxidation, reflective of MCT's property as an obligate fuel. The increased thermogenesis occurs without an increase in body temperature.     

American ginseng improves glycemia in individuals with normal glucose tolerance: effect of dose and time escalation

OBJECTIVE: We studied the effect of escalating the dose and administration time of American ginseng (AG, Panax quinquefolius L.) in nondiabetic individuals to achieve further improvements in glucose tolerance seen previously when 3 g of AG was taken 40 minutes before a 25 g glucose challenge. METHODS: Ten nondiabetic individuals (6M:4F; mean +/- STD: age = 41 +/- 13 years, BMI = 24.8 +/- 3.5 kg/m2, FBG = 4.5 +/- 0.1 mmol L(-1)) on 12 separate occasions, randomly received 0 (placebo), 3, 6 or 9 g of ground AG root at 40, 80, or 120 minutes before a 25 g oral glucose challenge. Capillary blood glucose was measured prior to ingestion of AG or placebo capsules and at 0, 15, 30, 45, 60 and 90 minutes from start of challenge. RESULTS: Compared with the placebo, 3, 6 and 9 g of AG reduced (p<0.05) postprandial incremental glucose at 30, 45 and 60 minutes; also, 3 and 9 g of AG did so at 90 minutes. At 60 minutes, 9 g of AG reduced incremental postprandial glucose relative to 3 g of AG (p<0.05). All AG doses reduced (p<0.05) area under the incremental glucose curve (3 g, 26.6%; 6 g, 29.3%; 9 g, 38.5%). AG taken at different times did not have an additional influence on postprandial glycemia. CONCLUSIONS: In nondiabetic individuals, 3, 6 or 9 g of AG taken 40, 80 or 120 minutes before a glucose challenge similarly improved glucose tolerance.     

Gastric motility function in critically ill patients tolerant vs intolerant to gastric nutrition

BACKGROUND: Administration of gastric enteral nutrition (EN) in the intensive care unit (ICU) is commonly impeded by high gastric residual volumes (GRV). This study evaluated gastric emptying in patients with limited GRV (tolerant group) vs volumes > or =150 mL (intolerant group) and whether prokinetic therapy improves gastric motility in intolerant patients. METHODS: To assess gastric motility, mechanically ventilated patients received acetaminophen 975 mg, and peak plasma concentration (Cmax), concentration at 60 minutes (C(60)), time to Cmax (Tmax), and area under the concentration-time curve from 0 to 60 minutes (AUC(0-60)) were determined. This evaluation was repeated in intolerant patients after 24 hours of either erythromycin 250 mg or metoclopramide 10 mg therapy, both administered intravenously every 6 hours. RESULTS: Ten tolerant and 20 intolerant patients were studied. Tolerant patients had significantly greater Cmax (14.12 +/- 7.25 vs 9.28 +/- 5.22 mg/L; p < .05), C(60) (9.62 +/- 4.65 vs 6.08 +/- 4.00 mg/L; p < .001), and AUC(0-60) (10.01 +/- 5.97 vs 3.93 +/- 2.84 mg/h/L; p < .01) and shortened Tmax (0.81 +/- 0.61 vs 1.98 +/- 1.26 hours; p < .001) compared with intolerant patients. After prokinetic therapy, Cmax (15.26 +/- 8.85 mg/L), C(60) (11.96 +/- 5.99 mg/L), and AUC(0-60) (10.90 +/- 6.57 mg/h/L) increased and Tmax (1.07 +/- 1.01 hours) decreased in the intolerant group to values similar to the tolerant group. CONCLUSIONS: ICU patients with elevated GRV during gastric EN have delayed gastric motility. Initiating prokinetic therapy accelerates gastric emptying to resemble that of ICU patients tolerating EN.