Effects of hyperglycemia on glucose metabolism before and after oral glucose ingestion in normal men.

The plasma glucose excursion may influence the metabolic responses after oral glucose ingestion. Although previous studies addressed the effects of hyperglycemia in conditions of hyperinsulinemia, it has not been evaluated whether the route of glucose administration (oral vs. intravenous) plays a role. Our aim was to determine the effects of moderately controlled hyperglycemia on glucose metabolism before and after oral glucose ingestion. Eight normal men underwent two oral glucose clamps at 6 and 10 mmol/l plasma glucose. Glucose turnover and cycling rates were measured by infusion of [2H7]glucose. The oral glucose load was labeled by D-[6,6-2H2]glucose to monitor exogenous glucose appearance, and respiratory exchanges were measured by indirect calorimetry. Sixty percent of the oral glucose load appeared in the systemic circulation during both the 6 and 10 mmol/l plasma glucose tests, although less endogenous glucose appeared during the 10 mmol/l tests before glucose ingestion (P < 0.05). This inhibitory effect of hyperglycemia was not detectable after oral glucose ingestion, although glucose utilization was increased (+28%, P < 0.05) due to increased nonoxidative glucose disposal [10 vs. 6 mmol/l: +20%, not significant (NS) before oral glucose ingestion; +40%, P < 0.05 after oral glucose ingestion]. Glucose cycling rates were increased by hyperglycemia (+13% before oral glucose ingestion, P < 0.001; +31% after oral glucose ingestion, P < 0.05) and oral glucose ingestion during both the 6 (+10%, P < 0.05) and 10 mmol/l (+26%, P < 0.005) tests. A moderate hyperglycemia inhibits endogenous glucose production and contributes to glucose tolerance by enhancing nonoxidative glucose disposal. Hyperglycemia and oral glucose ingestion both stimulate glucose cycling.

Induction of the 72 kDa heat shock protein by glucose ingestion in black pregnant women

Obese Black women are at increased risk for development of gestational diabetes mellitus and have worse perinatal outcomes than do obese women of other ethnicities. Since hsp72 has been associated with the regulation of obesity-induced insulin resistance, we evaluated associations between glucose ingestion, hsp72 release and insulin production in Black pregnant women. Specifically, the effect of a 50-g glucose challenge test (GCT) on heat shock protein and insulin levels in the circulation 1 h later was evaluated. Hsp27 and hsp60 levels remained unchanged. In contrast, serum levels of hsp72 markedly increased after glucose ingestion (p = 0.0054). Further analysis revealed that this increase was limited to women who were not obese (body mass index <30). Insulin levels pre-GCT were positively correlated with body mass index (p = 0.0189). Median insulin concentrations also increased post GCT in non-obese women but remained almost unchanged in obese women. Post-GCT serum hsp72 concentrations were inversely correlated with post GCT insulin concentrations (p = 0.0111). These observations suggest that glucose intake during gestation in Black women rapidly leads to an elevation in circulating hsp72 only in non-obese Black women. The release of hsp72 may regulate the extent of insulin production in response to a glucose challenge and, thereby, protect the mother and/or fetus from development of hyperglycemia, hyperinsulinemia, and/or immune system alterations. © 2013 Cell Stress Society International.

GLUT2 and the incretin receptors are involved in glucose-induced incretin secretion.

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are incretins secreted in response to oral glucose ingestion by intestinal L and K cells, respectively. The molecular mechanisms responsible for intestinal cell glucose sensing are unknown but could be related to those described for beta-cells, brain and hepatoportal sensors. We determined the role of GLUT2, GLP-1 or GIP receptors in glucose-induced incretins secretion, in the corresponding knockout mice. GLP-1 secretion was reduced in all mutant mice, while GIP secretion did not require GLUT2. Intestinal GLP-1 content was reduced only in GIP and GLUT2 receptors knockout mice suggesting that this impairment could contribute to the phenotype. Intestinal GIP content was similar in all mice studied. Furthermore, the impaired incretins secretion was associated with a reduced glucose-stimulated insulin secretion and an impaired glucose tolerance in all mice. In conclusion, both incretins secretion depends on mechanisms involving their own receptors and GLP-1 further requires GLUT2.

Sélection des substrats lors de l’exercice prolongé avec ingestion de glucides : études par traçage au 13C

Les principaux substrats oxydés à l’exercice, soit les glucides, les lipides et les pro- téines ne contribuent pas tous au même niveau à la fourniture d’énergie lors de l’effort prolongé. De plus, le glucose peut provenir de différentes sources endogènes (muscle, foie) et exogènes. Plusieurs facteurs peuvent influencer leur contribution respective incluant : la masse musculaire impliquée et l’entraînement préalable, le sexe, l’état nutritionnel et les conditions environnementales. L’utilisation d’isotopes stables, tels que le carbone 13 (13C), combinée à la calorimétrie indirecte respiratoire corrigée pour l’excrétion d’urée dans l’urine et la sueur, permet de différencier les substrats endogènes et exogènes et d’évaluer la contribution de leur oxydation à la fourniture d’énergie. Ces méthodes d’investigation permettant d’apprécier la sélection des substrats lors de l’exercice prolongé avec ingestion de glucose ont permis d’effectuer les comparaisons qui ont fait l’objet des trois études de cette thèse. Dans la première étude, la sélection des substrats au cours d’un effort prolongé effectué avec les membres inférieurs ou les membres supérieurs a été comparée avec et sans ingestion de glucose. Une différence modeste fut observée entre la sélection des substrats selon le mode d’exercice avec l’ingestion d’eau, celle-ci favorisant légèrement l’oxydation des glucides lors de l’effort avec les membres supérieurs. La quantité de glucose exogène oxydée était plus faible lors de l’exercice avec les membres supérieurs qu’avec les membres supérieurs, mais sa contribution plus importante, conséquence d’une dépense énergétique plus faible. Dans la deuxième étude, on a comparé la sélection des substrats chez des sujets mas- culins et féminins et les effets d’une alimentation enrichie en glucides ou de l’ingestion de glucose, au cours d’un exercice prolongé d’une durée de deux heures. On reconnaît généralement que, pour une même puissance relative, les femmes utilisent moins de glucides et davantage de lipides que les hommes. Les effets séparés d’une alimentation riche en glucides ou de l’ingestion de glucose pendant l’exercice sur la sélection des substrats furent pourtant similaires chez les deux sexes. L’effet combiné des deux procédures de supplémentation est toutefois plus important chez la femme que chez l’homme, soutenant l’hypothèse qu’un léger déficit en glucides soit présent chez les femmes. Dans la troisième étude, l’oxydation des substrats et particulièrement celle d’amidon exogène au cours d’une marche prolongée à une faible puissance de travail a été décrite. Les individus qui pratiquent des activités physiques prolongées à des intensités faibles (< 40 %VO2max) sont encouragés à ingérer des glucides et de l’eau pendant l’effort, mais la contribution de leur oxydation à la fourniture d’énergie est relativement peu connue. Nous avons montré que, contrairement aux observations précédemment effectuées à jeun sans ingestion de glucides pendant l’effort, les glucides (incluant de source exogène) peuvent fournir une très grande partie de l’énergie lorsqu’ils sont ingérés à des intervalles réguliers au cours de l’exercice prolongé. Dans l’ensemble, les résultats des études expérimentales présentées dans cette thèse montrent que les glucides ingérés peuvent fournir une grande proportion de l’énergie pendant l’exercice prolongé. Toutefois, le mode d’exercice, le sexe et la puissance de travail mènent à des variations qui sont en grande partie liées à une dépense énergétique variable selon les conditions et les groupes d’individus ayant des caractéristiques différentes.

Mobilisation of enterocyte fat stores by oral glucose in humans

Background and aims: When a high fat oral load is followed several hours later by further ingestion of nutrients, there is an early postprandial peak in plasma triacylglycerol (TG). The aim of this study was to investigate the location and release of lipid from within the gastrointestinal tract. Methods: Ten healthy patients undergoing oesopho-gastro-duodenoscopy (OGD) were recruited. At t=0, all patients consumed a 50 g fat emulsion and at t=5 hours they consumed either water or a 38 g glucose solution. OGD was performed at t=6 hours and jejunal biopsy samples were evaluated for fat storage. A subgroup of five subjects then underwent a parallel metabolic study in which postprandial lipid and hormone measurements were taken during an identical two meal protocol. Results: Following oral fat at t=0, samples from patients that had subsequently ingested glucose exhibited significantly less staining for lipid within the mucosa and submucosa of the jejunum than was evident in patients that had consumed only water (p=0.028). There was also less lipid storage within the cytoplasm of enterocytes (p=0.005) following oral glucose. During the metabolic study, oral glucose consumed five hours after oral fat resulted in a postprandial peak in plasma TG, chylomicron-TG, and apolipoprotein B48 concentration compared with oral water. Conclusion: After a fat load, fat is retained within the jejunal tissue and released into plasma following glucose ingestion, resulting in a peak in chylomicron-TG which has been implicated in the pathogenesis of atherosclerosis.

Preterm birth and risk factors for chronic disease : Helsinki Study of Very Low Birth Weight Adults

Background: The improved prognosis of early preterm birth has created a generation of surviving very low birth weight (< 1500 g, VLBW) infants whose health risks in adulthood are poorly known. Of every 1000 live-born infants in Finland, about 8 are born at VLBW. Variation in birth weight, even within the normal range, relates to considerable variation in the risk for several common adult disorders, including cardiovascular disease and osteoporosis. Small preterm infants frequently exhibit severe postnatal or prenatal growth retardation, or both. Much reason for concern thus exists, regarding adverse health effects in surviving small preterm infants later lives. We studied young adults, aiming at exploring whether VLBW birth and postnatal events after such a birth are associated with higher levels of risk factors for cardiovascular disease or osteoporosis. Subjects and Methods: A follow-up study for VLBW infants began in 1978; by the end of 1985, 335 VLBW survivors at Helsinki University Central Hospital participated in the follow-up. Their gestational ages ranged from 24 to 35 weeks, mean 29.2 and standard deviation 2.2 weeks. In 2004, we invited for a clinic visit 255 subjects, aged 18 to 27, who still lived in the greater Helsinki area. From the same birth hospitals, we also invited 314 term-born controls of similar age and sex. These two study groups underwent measurements of body size and composition, function of brachial arterial endothelium (flow-mediated dilatation, FMD) and carotid artery intima-media thickness (cIMT) by ultrasound. In addition, we measured plasma lipid concentrations, ambulatory blood pressure, fasting insulin, glucose tolerance and, by dual-energy x-ray densitometry, bone-mineral density. Results: 172 control and 166 VLBW participants underwent lipid measurements and a glucose tolerance test. VLBW adults fasting insulin (adjusted for body mass index) was 12.6% (95% confidence interval, 0.8 to 25.8) higher than that of the controls. The glucose and insulin concentrations 120 minutes after 75 g glucose ingestion showed similar differences (N=332) (I). VLBW adults had 3.9 mmHg (1.3 to 6.4) higher office systolic blood pressure, 3.5 mmHg (1.7 to 5.2) higher office diastolic blood pressure (I), and, when adjusted for body mass index and height, 3.1 mmHg (0.5 to 5.5) higher 24-hour mean systolic blood pressure (N=238) (II). VLBW birth was associated neither with HDL- or total cholesterol nor triglyceride concentrations (N=332) (I), nor was it associated with a low FMD or a high cIMT (N=160) (III). VLBW adults had 0.51-unit (0.28 to 0.75) lower lumbar spine Z scores and 0.56-unit (0.34 to 0.78) lower femoral neck Z scores (N=283). Adjustments for size attenuated the differences, but only partially (IV). Conclusions: These results imply that those born at VLBW, although mostly healthy as young adults, already bear several risk factors for chronic adult disease. The significantly higher fasting insulin level in adults with VLBW suggests increased insulin resistance. The higher blood pressure in young adults born at VLBW may indicate they later are at risk for hypertension, although their unaffected endothelial function may be evidence for some form of protection from cardiovascular disease. Lower bone mineral density around the age of peak bone mass may suggest increased risk for later osteoporotic fractures. Because cardiovascular disease and osteoporosis are frequent, and their prevention is relatively cheap and safe, one should focus on prevention now. When initiated early, preventive measures are likely to have sufficient time to be effective in preventing or postponing the onset of chronic disease.

Preterm birth and risk factors for chronic disease : Helsinki Study of Very Low Birth Weight Adults

Background: The improved prognosis of early preterm birth has created a generation of surviving very low birth weight (PIENEMPI KUIN 1500 g, VLBW) infants whose health risks in adulthood are poorly known. Of every 1000 live-born infants in Finland, about 8 are born at VLBW. Variation in birth weight, even within the normal range, relates to considerable variation in the risk for several common adult disorders, including cardiovascular disease and osteoporosis. Small preterm infants frequently exhibit severe postnatal or prenatal growth retardation, or both. Much reason for concern thus exists, regarding adverse health effects in surviving small preterm infants later lives. We studied young adults, aiming at exploring whether VLBW birth and postnatal events after such a birth are associated with higher levels of risk factors for cardiovascular disease or osteoporosis. Subjects and Methods: A follow-up study for VLBW infants began in 1978; by the end of 1985, 335 VLBW survivors at Helsinki University Central Hospital participated in the follow-up. Their gestational ages ranged from 24 to 35 weeks, mean 29.2 and standard deviation 2.2 weeks. In 2004, we invited for a clinic visit 255 subjects, aged 18 to 27, who still lived in the greater Helsinki area. From the same birth hospitals, we also invited 314 term-born controls of similar age and sex. These two study groups underwent measurements of body size and composition, function of brachial arterial endothelium (flow-mediated dilatation, FMD) and carotid artery intima-media thickness (cIMT) by ultrasound. In addition, we measured plasma lipid concentrations, ambulatory blood pressure, fasting insulin, glucose tolerance and, by dual-energy x-ray densitometry, bone-mineral density. Results: 172 control and 166 VLBW participants underwent lipid measurements and a glucose tolerance test. VLBW adults fasting insulin (adjusted for body mass index) was 12.6% (95% confidence interval, 0.8 to 25.8) higher than that of the controls. The glucose and insulin concentrations 120 minutes after 75 g glucose ingestion showed similar differences (N=332) (I). VLBW adults had 3.9 mmHg (1.3 to 6.4) higher office systolic blood pressure, 3.5 mmHg (1.7 to 5.2) higher office diastolic blood pressure (I), and, when adjusted for body mass index and height, 3.1 mmHg (0.5 to 5.5) higher 24-hour mean systolic blood pressure (N=238) (II). VLBW birth was associated neither with HDL- or total cholesterol nor triglyceride concentrations (N=332) (I), nor was it associated with a low FMD or a high cIMT (N=160) (III). VLBW adults had 0.51-unit (0.28 to 0.75) lower lumbar spine Z scores and 0.56-unit (0.34 to 0.78) lower femoral neck Z scores (N=283). Adjustments for size attenuated the differences, but only partially (IV). Conclusions: These results imply that those born at VLBW, although mostly healthy as young adults, already bear several risk factors for chronic adult disease. The significantly higher fasting insulin level in adults with VLBW suggests increased insulin resistance. The higher blood pressure in young adults born at VLBW may indicate they later are at risk for hypertension, although their unaffected endothelial function may be evidence for some form of protection from cardiovascular disease. Lower bone mineral density around the age of peak bone mass may suggest increased risk for later osteoporotic fractures. Because cardiovascular disease and osteoporosis are frequent, and their prevention is relatively cheap and safe, one should focus on prevention now. When initiated early, preventive measures are likely to have sufficient time to be effective in preventing or postponing the onset of chronic disease.

Effect of carbohydrate overfeeding on whole body macronutrient metabolism and expression of lipogenic enzymes in adipose tissue of lean and overweight humans

OBJECTIVE: Lipids stored in adipose tissue can originate from dietary lipids or from de novo lipogenesis (DNL) from carbohydrates. Whether DNL is abnormal in adipose tissue of overweight individuals remains unknown. The present study was undertaken to assess the effect of carbohydrate overfeeding on glucose-induced whole body DNL and adipose tissue lipogenic gene expression in lean and overweight humans. DESIGN: Prospective, cross-over study. SUBJECTS AND METHODS: A total of 11 lean (five male, six female, mean BMI 21.0+/-0.5 kg/m(2)) and eight overweight (four males, four females, mean BMI 30.1+/-0.6 kg/m(2)) volunteers were studied on two occasions. On one occasion, they received an isoenergetic diet containing 50% carbohydrate for 4 days prior to testing; on the other, they received a hyperenergetic diet (175% energy requirements) containing 71% carbohydrates. After each period of 4 days of controlled diet, they were studied over 6 h after having received 3.25 g glucose/kg fat free mass. Whole body glucose oxidation and net DNL were monitored by means of indirect calorimetry. An adipose tissue biopsy was obtained at the end of this 6-h period and the levels of SREBP-1c, acetyl CoA carboxylase, and fatty acid synthase mRNA were measured by real-time PCR. RESULTS: After isocaloric feeding, whole body net DNL amounted to 35+/-9 mg/kg fat free mass/5 h in lean subjects and to 49+/-3 mg/kg fat free mass/5 h in overweight subjects over the 5 h following glucose ingestion. These figures increased (P<0.001) to 156+/-21 mg/kg fat free mass/5 h in lean and 64+/-11 mg/kg fat free mass/5 h (P<0.05 vs lean) in overweight subjects after carbohydrate overfeeding. Whole body DNL after overfeeding was lower (P<0.001) and glycogen synthesis was higher (P<0.001) in overweight than in normal subjects. Adipose tissue SREBP-1c mRNA increased by 25% in overweight and by 43% in lean subjects (P<0.05) after carbohydrate overfeeding, whereas fatty acid synthase mRNA increased by 66 and 84% (P<0.05). CONCLUSION: Whole body net DNL is not increased during carbohydrate overfeeding in overweight individuals. Stimulation of adipose lipogenic enzymes is also not higher in overweight subjects. Carbohydrate overfeeding does not stimulate whole body net DNL nor expression of lipogenic enzymes in adipose tissue to a larger extent in overweight than lean subjects.

Efecto de la glicemia materna en la monitoría electrónica fetal

Introducción: Después del ingreso de la monitoría fetal electrónica como estudio de bienestar fetal, se ha considerado por décadas que un aporte de carbohidratos a la gestante antes de la realización de la monitoría fetal influye en el reporte pero existen estudios que consideran que los niveles de glicemia materna no afecta la variabilidad de la monitoría fetal. Metodología: Se realizó un estudio de corte transversal, para evaluar el efecto de la glicemia materna en la monitoría fetal electrónica comparando los valores de glicemia materna con su resultado, según la categorización del ACOG. Las principales variables fueron las horas de ayuno, valores de glicemia, variabilidad de la monitoría fetal y presencia de aceleraciones. Resultados: Se incluyeron un total de 60 pacientes, que ingresaron al servicio de obstetricia y ginecología del Hospital Universitario Mayor Méderi en el periodo de estudio. No se encontraron diferencias estadísticamente significativas entre los resultados de monitoría fetal y los valores de glicemia materna. Ninguna paciente presentó monitoría categoría III (según categorización de la ACOG). Discusión Se requieren estudios analíticos más amplios para evaluar el papel de la glicemia en el resultado de la monitoría, pero el presente estudio sugiere que no existe relación entre la glicemia materna y el resultado de la monitoría fetal electrónica en la categorización del Colegio Americano De Ginecología Y Obstetricia (ACOG).

Sincronização dos ritmos de atividade motora e temperatura central à disponibilidade de glicose em ratos

Food is essential for the survival of all animals. Its temporal availability is an important enviromental cue for the behavioral and physiological organization throughout the 24 hours of day in different species. Rats and mice, for example, show increased locomotion in the hours before food availability when it is presented in a recurrent manner, a behavior named foodanticipatory activity. Several lines of evidence indicate that this anticipation is mediated by a circadian oscillator. In this work, based on the hypothesis that pre- or post-ingestive humoral signals are involved in the entrainment process, we tested whether the daily intake of glucose is sufficient to induce anticipatory activity in rats. The rhythms of motor activity and central temperature were recorded in animals undergoing 10 days of temporal glucose (solution at 50%) or chow restriction in light-dark (LD) and constant darkness (DD). Animals under temporal glucose restriction increase motor activity and and central temperature in the hours preceding glucose availability and such aticipation is extremely similar to that observed in animals under temporal chow restriction. Glucose ingestion is, therefore, a sufficient temporal cue to induce anticipation in rats. It is possible that the increase in plasma glucose after food ingestion constitutes one of the signals involved in the behavioral entrainment process to food availability

HYPERANDROGENISM DUE TO 3-BETA-HYDROXYSTEROID DEHYDROGENASE-DEFICIENCY WITH ACCESSORY ADRENOCORTICAL TISSUE - A HORMONAL AND METABOLIC EVALUATION

1. Adrenal ectopic tissue has been detected in the paragonadal region of normal women. In patients with congenital adrenal hyperplasia due to 21-hydroxylase (21-OH) deficiency, the manifestation of hyperplasia of paragonadal accessory adrenal tissue has been usually reported to occur in males. Probably, this is the first report of a female with 3beta-hydroxysteroid dehydrogenase (3beta-HSD) deficiency with ectopic adrenal tissue in ovaries. However, the occurrence of hyperplasia of adrenal rests among women with classical congenital adrenal hyperplasia may not be rare, especially among patients with a late diagnosis.2. We report a woman with 3beta-HSD deficiency whose definitive diagnosis was made late at 41 years of age immediately before surgery for the removal of a uterine myoma. During surgery, exploration of the abdominal cavity revealed the presence of bilateral accessory adrenal tissue in the ovaries and in the para-aortic region. The patient had extremely high levels of ACTH (137 pmol/l), DHEA (901.0 nmol/l), DHEA-S (55.9 mumol/l), androstenedione (70.2 nmol/l), testosterone (23.0 nmol/l) and 17alpha-hydroxypregnenolone (234.4 nmol/l) suggesting 3beta-HSD deficiency.3. In view of these elevated androgen levels, with an absolute predominance of DHEA and DHEA-S, we evaluated the effect of this hormonal profile on carbohydrate tolerance and insulin response to glucose ingestion.4. The patient presented normal glucose tolerance but her insulin response was lower than that of 14 normal women (area under the curve, 3beta-HSD = 17,680 vs 50,034 pmol/l for the control group over a period of 3 h after glucose ingestion).5. These results support recent data suggesting that patients with increased serum DHEA and DHEA-S levels do not present resistance to insulin.

Impact of lipoprotein lipase gene polymorphism, S447X, on postprandial triacylglycerol and glucose response to sequential meal ingestion

Lipoprotein lipase (LPL) is a key rate-limiting enzyme for the hydrolysis of triacylglycerol (TAG) in chylomicrons and very low-density lipoprotein. Given that postprandial assessment of lipoprotein metabolism may provide a more physiological perspective of disturbances in lipoprotein homeostasis compared to assessment in the fasting state, we have investigated the influence of two commonly studied LPL polymorphisms (rs320, HindIII; rs328, S447X) on postprandial lipaemia, in 261 participants using a standard sequential meal challenge. S447 homozygotes had lower fasting HDL-C (p = 0.015) and a trend for higher fasting TAG (p = 0.057) concentrations relative to the 447X allele carriers. In the postprandial state, there was an association of the S447X polymorphism with postprandial TAG and glucose, where S447 homozygotes had 12% higher TAG area under the curve (AUC) (p = 0.037), 8.4% higher glucose-AUC (p = 0.006) and 22% higher glucose-incremental area under the curve (IAUC) (p = 0.042). A significant gene–gender interaction was observed for fasting TAG (p = 0.004), TAG-AUC (Pinteraction = 0.004) and TAG-IAUC (Pinteraction = 0.016), where associations were only evident in men. In conclusion, our study provides novel findings of an effect of LPL S447X polymorphism on the postprandial glucose and gender-specific impact of the polymorphism on fasting and postprandial TAG concentrations in response to sequential meal challenge in healthy participants

Thermoregulatory responses to ice-slush beverage ingestion and exercise in the heat

We compared the effects of an ice-slush beverage (ISB) and a cool liquid beverage (CLB) on cycling performance, changes in rectal temperature (T (re)) and stress responses in hot, humid conditions. Ten trained male cyclists/triathletes completed two exercise trials (75 min cycling at similar to 60% peak power output + 50 min seated recovery + 75% peak power output x 30 min performance trial) on separate occasions in 34A degrees C, 60% relative humidity. During the recovery phase before the performance trial, the athletes consumed either the ISB (mean +/- A SD -0.8 +/- A 0.1A degrees C) or the CLB (18.4 +/- A 0.5A degrees C). Performance time was not significantly different after consuming the ISB compared with the CLB (29.42 +/- A 2.07 min for ISB vs. 29.98 +/- A 3.07 min for CLB, P = 0.263). T (re) (37.0 +/- A 0.3A degrees C for ISB vs. 37.4 +/- A 0.2A degrees C for CLB, P = 0.001) and physiological strain index (0.2 +/- A 0.6 for ISB vs. 1.1 +/- A 0.9 for CLB, P = 0.009) were lower at the end of recovery and before the performance trial after ingestion of the ISB compared with the CLB. Mean thermal sensation was lower (P < 0.001) during recovery with the ISB compared with the CLB. Changes in plasma volume and the concentrations of blood variables (i.e., glucose, lactate, electrolytes, cortisol and catecholamines) were similar between the two trials. In conclusion, ingestion of ISB did not significantly alter exercise performance even though it significantly reduced pre-exercise T (re) compared with CLB. Irrespective of exercise performance outcomes, ingestion of ISB during recovery from exercise in hot humid environments is a practical and effective method for cooling athletes following exercise in hot environments.