The Effect of Glycemic Index on Plasma Glucose and Lactate Levels during Incremental Exercise

Consumption of low glycemic index (GI) foods before submaximal endurance exercise may be beneficial to performance. To test whether this may also be true for high intensity exercise. 10 trained cyclists began an incremental exercise test to exhaustion 65 min after consuming equal carbohydrate portions of glucose (HGI), pasta (LGI), and a noncarbohydrate control (PL). Time to fatigue did not differ significantly (p = 0.05) between treatments. Plasma glucose concentration was significantly lower after LGI vs. HGI from 15 to 45 min of rest postprandial. During exercise, plasma glucose concentration was significantly lower after HGI vs. LGI from 200 W until exhaustion. Plasma lactate concentration following HGI was significantly higher than PL from 30 min of rest postprandial through to the end of the 200-W workload. Plasma lactate concentration following LGI was significantly lower than after HGI from 45 min of rest postprandial through to the end of the 100-W workload. At higher exercise intensities, there was no significant difference in plasma lactate levels between treatments. These findings suggest that a high GI carbohydrate meal (1 g/kg body wt) 65 min prior to exercise decreases plasma glucose and increases plasma lactate levels compared to a low GI meal, but not enough to be detrimental to incremental exercise performance.

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Glucose lactate interrelations in sheep.

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1978.235.5.e487 ◽

1978 ◽

Vol 235 (5) ◽

pp. E487

Author(s):

P E Reilly ◽

L G Chandrasena

Keyword(s):

Plasma Glucose ◽

Glucose Concentration ◽

Lactate Concentration ◽

Lactate Production ◽

Plasma Glucose Concentration ◽

Constant Infusion ◽

Dilution Method ◽

Entry Rate ◽

Net Production ◽

Arterial Plasma

The constant-infusion, isotope-dilution method was used to investigate the interrelationships between the glucose and lactate pools of six trained sheep deprived of food overnight. Arterial plasma lactate concentration was a linear function of the net lactate entry rate as was the net production of glucose from lactate, which suggests that the net rate of formation of glucose from lactate is dependent on the availability of lactate. Similarly the arterial plasma glucose concentration was correlated with the net entry rate of glucose as was the net production rate of lactate from glucose, suggesting that the net rate of lactate production from glucose is a function of arterial plasma glucose concentration. The demonstration of these two interrelations between glucose and lactate in normal sheep suggests that, in the absence of external factors producing hormonal or other changes that could cause perturbations of carbohydrate homeostasis, the net rates of conversion of glucose to lactate and of lactate to glucose may be largely determined by the arterial concentrations of glucose and lactate, respectively.

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Carbohydrate stores in chickens infected with Eimeria tenella

Parasitology ◽

10.1017/s0031182000041068 ◽

1970 ◽

Vol 61 (2) ◽

pp. 245-251 ◽

Cited By ~ 15

Author(s):

B. M. Freeman

Keyword(s):

Plasma Glucose ◽

Lactate Concentration ◽

Muscular Activity ◽

Eimeria Tenella ◽

Transient Increase ◽

Hepatic Glycogen ◽

Plasma Lactate ◽

Voluntary Muscle ◽

Plasma Lactate Concentration ◽

Glycogen Stores

Changes in plasma glucose and lactate and glycogen stores of cardiac and voluntary muscle have been determined during the course of an infection by Eimeria tenella.No hyperglycaemia resulted nor was there any significant change in the stores of hepatic glycogen during the period of observation.There was a significant reduction in the plasma lactate concentration on the 1st and 2nd days after infection.There was a transient increase in the stores of cardiac glycogen on the 5th day after infection.Glycogen stores of voluntary muscle were significantly reduced on the 5th and 6th days after infection. It is thought that this depletion resulted from a reduction in muscular activity rather than from an impairment of glycogenesis.

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Clinical evaluation of a novel subcutaneous lactate monitor

Journal of Clinical Monitoring and Computing ◽

10.1007/s10877-021-00685-1 ◽

2021 ◽

Author(s):

Nitsan Dror ◽

John Weidling ◽

Sean White ◽

Francesca Ortenzio ◽

Samir Shreim ◽

...

Keyword(s):

Minimally Invasive ◽

Delay Time ◽

Lactate Concentration ◽

Medical Attention ◽

Plasma Lactate ◽

Indirect Measure ◽

Exercise Challenge ◽

Plasma Lactate Concentration ◽

Lactate Levels ◽

Clinical Conditions

AbstractLactate levels are commonly used as an indirect measure to assess metabolic stress in clinical conditions like sepsis. Dynamic lactate measurements are recommended to assess and guide treatment in patients with shock and other critical care conditions. A minimally invasive, continuous lactate monitor has potential to improve clinical decisions and patient care. The purpose of the study was to evaluate continuous lactate measurements of a novel enzymatic Continuous Lactate Monitor (CLM) developed in our laboratory. Lactate levels were monitored during incremental cycling exercise challenges as a tool for hyperlactatemia. Six healthy individuals 18–45 y/o (4 males, 2 females) participated in the study. CLM devices were inserted subcutaneously in the postero-lateral trunk below the renal angle, one hour before the exercise challenge. Each exercise challenge consisted of a 3 to 12-min warm up period, followed by up to 7, 4-min incremental workload bouts separated by rest intervals. Continuous lactate measurements obtained from CLM were compared with commercial lactate analyzer (Abbott iSTAT) measurements of venous blood (plasma) drawn from the antecubital vein. Blood was drawn at up to 25 time points spanning the duration of before exercise, during exercise, and up to 120 min post exercise. Area under the curve (AUC), and delay time were calculated to compare the CLM readings with plasma lactate concentration. Average plasma lactate concentration increased from 1.02 to 16.21 mM. Ratio of AUC derived from CLM to plasma lactate was 1.025 (0.990–1.058). Average dynamic delay time of CLM to venous plasma lactate was 5.22 min (2.87–10.35). Insertion sites examined 48 h after CLM removal did not show signs of side effects and none required medical attention upon examination. The newly developed CLM has shown to be a promising tool to continuously measure lactate concentration in a minimally invasive fashion. Results indicate the CLM can provide needed trends in lactate over time. Such a device may be used in the future to improve treatment in clinical conditions such as sepsis.

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Glucose and lactate kinetics in burn shock.

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1977.232.4.e415 ◽

1977 ◽

Vol 232 (4) ◽

pp. E415 ◽

Cited By ~ 2

Author(s):

R R Wolfe ◽

H I Miller ◽

J J Spitzer

Keyword(s):

Plasma Glucose ◽

Control Level ◽

Lactate Concentration ◽

Constant Infusion ◽

Burn Shock ◽

Plasma Lactate ◽

Lactate Kinetics ◽

Plasma Lactate Concentration ◽

Substrate Kinetics

We studied the glucose and lactate kinetics during burn shock by means of the primed constant infusion of [6-3H]glucose and Na-L-(+)-[U-14C]lactate. We found an early postburn hyperglycemia that was due to an increased rate of appearance (Ra) of glucose. Later, the ability of the tissues to extract glucose became impaired, and the plasma glucose concentration increased even more in spite of the return of Ra of glucose to the control level. The Ra of lactate rose rapidly postburn, whereas the rate of disappearance (Rd) of lactate stayed at the control level for 30 min. Consequently, plasma lactate rose approximately 350%. After 30 min, Rd of lactate increased to the same level as Ra; and Ra, Rd, plasma lactate concentration, and the percent of glucose derived from lactate remained elevated for the duration of the experiment. These results indicate an important role of lactate in burn shock metabolism and substrate kinetics.

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Glucose and lactate kinetics and interrelations in an antarctic bird (emperor penguin)

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1982.242.5.r458 ◽

1982 ◽

Vol 242 (5) ◽

pp. R458-R464 ◽

Cited By ~ 2

Author(s):

R. Groscolas ◽

A. Rodriguez

Keyword(s):

Body Mass ◽

Transit Time ◽

Plasma Glucose ◽

Glucose Concentration ◽

Lactate Concentration ◽

Plasma Glucose Concentration ◽

Emperor Penguin ◽

Replacement Rate ◽

Lactate Kinetics ◽

Mean Glucose

The isotope single-injection method was used to investigate the glucose and lactate kinetics and the interrelationships between the glucose and lactate pools in fasting emperor penguins. In these remarkably fast-resistant birds, mean lactate concentration, replacement rate, pool, space, and transit time were 1.5 mmol.1-1,53 mumol.min-1.kg-1, 900 mumol.kg-1, 60% of body mass, and 17 min, respectively. Mean glucose concentration, replacement rate, pool, space, and transit time were 20 mmol.1-1, 23 mumol.min-1.kg-1, 4,300 mumol.kg-1, 24% of body mass, and 196 min, respectively. Maximum conversions of lactate into glucose and of glucose into lactate were 29 +/- 2.9% and 75.5 +/- 4.2%, respectively, which indicates that lactate is an effective gluconeogenic precursor and a major fate of glucose metabolism in fasting penguins. The lactate replacement rate and incorporation into glucose were related to the plasma lactate concentration, which suggests that the rate of formation of glucose from lactate is dependent on the availability of lactate. The glucose replacement rate and reduction into lactate were related with the plasma glucose concentration, suggesting that the rate of lactate formation from glucose is dependent on the plasma glucose concentration. These data suggest that in the fasting emperor penguin glucose and lactate availability is capable of regulating the rate at which these substrates are utilized and interconverted. To our knowledge, this is the first evidence for such regulatory capacities in birds.

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Relation of fasting plasma glucose concentration to plasma insulin and glucagon concentrations. Studies in latent diabetics and women who have produced large-for-dates babies

Diabetes ◽

10.2337/diabetes.26.3.166 ◽

1977 ◽

Vol 26 (3) ◽

pp. 166-171 ◽

Cited By ~ 5

Author(s):

R. C. Turner ◽

E. Harris ◽

S. R. Bloom ◽

C. Uren

Keyword(s):

Plasma Glucose ◽

Fasting Plasma Glucose ◽

Glucose Concentration ◽

Plasma Insulin ◽

Plasma Glucose Concentration ◽

Fasting Plasma ◽

Fasting Plasma Glucose Concentration

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Relationship between hepatic glucose production and fasting plasma glucose concentration in patients with NIDDM

Diabetes ◽

10.2337/diabetes.43.12.1440 ◽

1994 ◽

Vol 43 (12) ◽

pp. 1440-1444 ◽

Cited By ~ 19

Author(s):

C. Y. Jeng ◽

W. H. Sheu ◽

M. M. Fuh ◽

Y. D. Chen ◽

G. M. Reaven

Keyword(s):

Plasma Glucose ◽

Fasting Plasma Glucose ◽

Glucose Concentration ◽

Hepatic Glucose Production ◽

Glucose Production ◽

Plasma Glucose Concentration ◽

Fasting Plasma ◽

Hepatic Glucose ◽

Fasting Plasma Glucose Concentration

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Direct Chemical Measurement of the λ of the Lumped Constant of the [14C]Deoxyglucose Method in Rat Brain: Effects of Arterial Plasma Glucose Level on the Distribution Spaces of [14C]Deoxyglucose and Glucose and on λ

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1989.48 ◽

1989 ◽

Vol 9 (3) ◽

pp. 304-314 ◽

Cited By ~ 34

Author(s):

Kentaro Mori ◽

Nancy Cruz ◽

Gerald Dienel ◽

Thomas Nelson ◽

Louis Sokoloff

Keyword(s):

Plasma Glucose ◽

Glucose Concentration ◽

Severe Hypoglycemia ◽

Plasma Glucose Concentration ◽

Operational Equation ◽

Chemical Measurements ◽

Lumped Constant ◽

Dg Method ◽

Arterial Plasma ◽

Distribution Spaces

The lumped constant in the operational equation of the 2-[14C]deoxyglucose (DG) method contains the factor λ that represents the ratio of the steady-state tissue distribution spaces for [14C]DG and glucose. The lumped constant has been shown to vary with arterial plasma glucose concentration. Predictions based mainly on theoretical grounds have suggested that disproportionate changes in the distribution spaces for [14C]DG and glucose and in the value of λ are responsible for these variations in the lumped constant. The influence of arterial plasma glucose concentration on the distribution spaces for DG and glucose and on λ were, therefore, determined in the present studies by direct chemical measurements. The brain was maintained in steady states of delivery and metabolism of DG and glucose by programmed intravenous infusions of both hexoses designed to produce and maintain constant arterial concentrations. Hexose concentrations were assayed in acid extracts of arterial plasma and freeze-blown brain. Graded hyperglycemia up to 28 m M produced progressive decreases in the distribution spaces of both hexoses from their normoglycemic values (e.g., ∼ – 20% for glucose and – 50% for DG at 28 m M). In contrast, graded hypoglycemia progressively reduced the distribution space for glucose and increased the space for [14C]DG. The values for λ were comparatively stable in normoglycemic and hyperglycemic conditions but rose sharply (e.g., as much as 9–10-fold at 2 m M) in severe hypoglycemia.

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Comparative Study of Fasting Plasma Glucose Concentration and Glucose Challenge Test for Screening Gestational Diabetes Mellitus

Journal of SAFOG with DVD ◽

10.5005/jp-journals-10006-1275 ◽

2014 ◽

Vol 6 (2) ◽

pp. 75-78

Author(s):

Sujaya Sham ◽

B Poornima R Bhat ◽

Aruna Kamath

Keyword(s):

Diabetes Mellitus ◽

Plasma Glucose ◽

Fasting Plasma Glucose ◽

Glucose Concentration ◽

Challenge Test ◽

Plasma Glucose Concentration ◽

Fasting Plasma ◽

Glucose Challenge Test ◽

Glucose Challenge ◽

Fasting Plasma Glucose Concentration

ABSTRACT Background To compare the sensitivity and specificity of fasting plasma glucose (FPG) with that of standard glucose challenge test (GCT). Materials and methods Eighty-nine eligible pregnant women underwent GCT between 24th and 28th gestational week, followed by a diagnostic 3 hours 100 gm oral glucose tolerance test within 1 week. Out patient clinic in Father Muller Medical College Hospital, Mangalore. Data was analyzed for significance by chi-square test. Results Fasting plasma glucose concentration at a threshold value of 90 mg/dl and GCT at recommended standard threshold of 140 mg/dl yielded sensitivities of 66.7% and 100% respectively and specificities of 87.3% and 46.5% respectively. Reducing the threshold value of FPG to 80 mg/dl increased the sensitivity of test to 91.7% with specificity of 54.9% which was comparable to standard GCT, in our study. Conclusion Measuring FPG concentration using a cut-off of. 80 mg/dl is an easier, tolerable and more cost effective procedure than GCT for detecting more severe cases of GDM, i.e. the diabetes mellitus group. In resource poor settings with population belonging to average risk or high risk category, FPG at a cut-off of 90 mg/dl can be used to screen GDM. How to cite this article Sham S, Bhat BPR, Kamath A. Comparative Study of Fasting Plasma Glucose Concentration and Glucose Challenge Test for Screening Gestational Diabetes Mellitus. J South Asian Feder Obst Gynae 2014;6(2):75-78.

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