Influence of mild exercise at the lactate threshold on glucose effectiveness

1999 ◽  
Vol 87 (6) ◽  
pp. 2305-2310 ◽  
Author(s):  
Makoto Sakamoto ◽  
Yasuki Higaki ◽  
Yuichiro Nishida ◽  
Akira Kiyonaga ◽  
Munehiro Shindo ◽  
...  
Keyword(s):  
Blood Flow ◽  
Lactate Threshold ◽  
Lactate Production ◽  
Area Under The Curve ◽  
Young Male ◽  
Threshold Level ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Intravenous Glucose ◽  
Glucose Effectiveness

The effect of a single bout of mild exercise on glucose effectiveness (SG) and insulin sensitivity (SI) was studied in six young male subjects by using a minimal model. An intravenous glucose tolerance test was performed under two conditions as follows: 1) 25 min after a bout of exercise on a cycle ergometer at the lactate threshold level for 60 min (Ex) and 2) without any prior exercise (Con). Leg blood flow (LBF) was also measured by strain-gauge plethysmography simultaneously with blood sampling. SI did not significantly change after exercise (18.1 ± 1.5 vs. 17.7 ± 1.9 × 10−5 min/pM), whereas SG significantly increased (0.016 ± 0.002 vs. 0.025 ± 0.002 min−1, P < 0.01). The increased blood flow after exercise remained high during the time period for measurement of the glucose disappearance constant and may be a determinant of SG. The incremental lactate area under the curve until insulin loading was also significantly higher in Ex than in Con (2.6 ± 0.9 vs. −3.5 ± 1.5 mM/min, P < 0.05). These results suggest that increased SG after mild exercise may be due, at least in part, to increased LBF and lactate production under a hyperglycemic state.

Effects of a single bout of exercise on glucose effectiveness

1996 ◽  
Vol 80 (3) ◽  
pp. 754-759 ◽  
Author(s):  
Y. Higaki ◽  
T. Kagawa ◽  
J. Fujitani ◽  
A. Kiyonaga ◽  
M. Shindo ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Exercise Bout ◽  
Threshold Level ◽  
Tolerance Test ◽  
Cycle Ergometer ◽  
Intravenous Glucose Tolerance Test ◽  
Exhaustive Exercise ◽  
Intravenous Glucose ◽  
Glucose Effectiveness ◽  
Single Bout

The effects of a single bout of exercise on glucose effectiveness (SG) and insulin sensitivity (SI) in 22 sedentary subjects were estimated with a minimal model approach. The intravenous glucose tolerance test (IVGTT) was performed 1) 11 h after an exercise bout on a cycle ergometer at the lactate threshold level (mild exercise) for 60 min, 2) 11 h after an exercise bout at the 4 mM lactate level (hard exercise) for 36 +/- 1 min, 3) 11 h after an exhaustive-exercise bout (exhaustive exercise) for 96 +/- 7 min, or 4) without any prior exercise (control). Only the exhaustive exercise increased the glucose disappearance constant (2.69 +/- 0.28 vs. 2.05 +/- 0.13%/min; P < 0.05) and SI (15.0 +/- 2.0 vs. 10.3 +/- 0.9 x 10(-5) min/pM: P < 0.05) in comparison with the control condition. The SG and SG at zero insulin (GEZI) were not affected by any exercise condition. However, a marked individual difference in GEZI emerged after the exhaustive exercise and could be divided into two subgroups: one decreased in GEZI (0.014 +/- 0.001 vs. 0.007 +/- 0.001 min-1) and the other increased in GEZI (0.014 +/- 0.001 vs. 0.021 +/- 0.003 min-1). The former subgroup was accompanied by elevated levels of plasma creatine kinase (100 +/- 16 vs. 598 +/- 315 IU/l; P < 0.05) and myoglobin (Mb; 46 +/- 4 vs. 126 +/- 47 ng/ml; P < 0.05), whereas the latter subgroup showed no significant change in creatinine kinase (99 +/- 10 vs. 128 +/- 9 IU/l; P = 0.05) and Mb (50 +/- 7 vs. 51 +/- 4 ng/ml; P = 0.05). In both subgroups, SI was similarly increased after the exhaustive exercise. These results thus suggest that a single bout of exercise that results in muscle damage or changes in muscle permeability, as reflected in the increased creatine kinase and Mb levels, decreases GEZI, whereas exhaustive exercise without such alterations increases GEZI.

scholarly journals Interrelationships of growth hormone AluI polymorphism, insulinresistance, milk production and reproductive performance in Holstein-Friesian cos

2008 ◽  
Vol 53 (No. 11) ◽  
pp. 604-616 ◽  
Author(s):  
O. Balogh ◽  
O. Szepes ◽  
K. Kovacs ◽  
M. Kulcsar ◽  
J. Reiczigel ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Insulin Sensitivity ◽  
Glucose Tolerance Test ◽  
Area Under The Curve ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Intravenous Glucose ◽  
Intravenous Glucose Tolerance ◽  
Holstein Friesian ◽  
Friesian Cows

Healthy multiparous Holstein-Friesian cows (<I>n</I> = 22, parity: 2–4) from a large-scale dairy herd in Hungary were subjected to an intravenous glucose tolerance test 10–15 days after calving. <I>Alu</I>I genotype of growth hormone, several plasma metabolites and metabolic hormones were determined, and current and previous lactation yields were recorded. We also used the Revised Quantitative Insulin Sensitivity Check Index (RQUICKI) and its modified version (RQUICKI<sub>BHB</sub>) for the estimation of peripheral insulin sensitivity. The majority of cows (<I>n</I> = 18) was leucine homozygous (LL), four were heterozygous (LV) and there were no valine homozygous (VV) animals in the population. Current average milk production was not different between <I>Alu</I>I genotypes, but LV cows tended to have higher 305-day previous lactation yields (<I>P</I> = 0.13). <I>Alu</I>I polymorphism was not associated with any of the calculated glucose and leptin parameters of the intravenous glucose tolerance test (<I>P</I> > 0.58). Heterozygous cows were prone to higher basal insulin levels (<I>P</I> = 0.064), longer time to reach half of the maximal and basal insulin concentrations (<I>P</I> = 0.035 and <I>P</I> = 0.054, respectively) and larger insulin area under the curve (<I>P</I> = 0.032). Both RQUICKI and RQUICKIBHB estimated decreased insulin sensitivity in LV compared to LL cows (<I>P</I> = 0.055 and <I>P</I> = 0.044, respectively). Higher plasma NEFA and BHB levels accounted for slower glucose disappearance and lower insulin release and insulin clearance rate (<I>P</I> < 0.05). Average yield was inversely related to glucose area under the curve (<I>P</I> = 0.040) and time to reach baseline concentration (<I>P</I> = 0.005). Plasma cortisol lowered glucose clearance rate (<I>P</I> = 0.040) and prolonged time to reach basal levels (<I>P</I> = 0.006). More weight loss was associated with higher glucose peak and prolonged glucose disappearance time (<I>P</I> = 0.055 and <I>P</I> = 0.024, respectively). All cows became cyclic and showed signs of estrus during the study period. There were no differences between leucine homozygous and heterozygous animals in the onset of ovarian activity and in the time of first observed estrus (<I>P</I> > 0.540). We conclude that Holstein-Friesian cows heterozygous for <I>Alu</I>I polymorphism of the growth hormone gene may be more likely to develop insulin resistance during early lactation than leucine homozygous cows. Decreased insulin sensitivity could be part of a homeorhetic adaptation process that supports nutrient partioning for the use of the mammary gland and may allow LV cows to reach higher yields throughout lactation.

Intravenous glucose tolerance test—derived glucose effectiveness in strength-trained humans

Metabolism ◽  
1998 ◽  
Vol 47 (7) ◽  
pp. 874-877 ◽  
Author(s):  
Junzo Fujitani ◽  
Yasuki Higaki ◽  
Toshiko Kagawa ◽  
Makoto Sakamoto ◽  
Akira Kiyonaga ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Intravenous Glucose ◽  
Glucose Effectiveness ◽  
Intravenous Glucose Tolerance

Insufficient islet compensation to insulin resistance vs. reduced glucose effectiveness in glucose-intolerant mice

2002 ◽  
Vol 283 (4) ◽  
pp. E738-E744 ◽  
Author(s):  
Bo Ahrén ◽  
Giovanni Pacini
Keyword(s):  
Insulin Secretion ◽  
Glucose Intolerance ◽  
High Fat Diet ◽  
Control Diet ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
High Fat ◽  
Intravenous Glucose ◽  
Glucose Effectiveness ◽  
Time Points

This study evaluated the relative contribution of insulin-dependent mechanisms vs. mechanisms independent on dynamic insulin for glucose intolerance induced by high-fat diet. C57BL/6J mice underwent a frequently sampled intravenous glucose tolerance test (1 g/kg glucose) at 1 wk and 1, 3, and 10 mo after initiation of a high-fat diet (58% fat; control diet 11% fat) to measure glucose effectiveness (SG) and disposition index (DI), i.e., insulin sensitivity (SI) times early or total insulin secretion. Glucose disappearance (KG) and SI were reduced in high-fat-fed mice at all time points. Total (50 min) insulin secretion was sufficiently increased at all time points to compensate for the reduced SI, as judged by normal DI50 min. In contrast, early (10 min) insulin secretion was not sufficiently increased; DI10 min was reduced after 1, 3, and 10 mo. SG was reduced after 1 wk; the reduction persisted throughout the study period. Thus glucose intolerance induced by high-fat diet is, in early phases, solely explained by reduced glucose effectiveness, whereas insufficient early insulin secretion is of importance after long-term feeding.

scholarly journals A Convenient LC-MS Method for Assessment of Glucose Kinetics In Vivo with d-[13C6]Glucose as a Tracer

2009 ◽  
Vol 55 (3) ◽  
pp. 527-532 ◽  
Author(s):  
Haoyue Zhang ◽  
Robert D Stevens ◽  
Sarah P Young ◽  
Richard Surwit ◽  
Anastasia Georgiades ◽  
...  
Keyword(s):  
Solid Phase ◽  
Low Cost ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Ionization Mass ◽  
Intravenous Glucose ◽  
Glucose Effectiveness ◽  
Novel Approach ◽  
Glucose Derivative

Abstract Background: The isotope-labeled intravenous glucose tolerance test (IVGTT) combined with computer modeling is widely used to derive parameters related to glucose metabolism in vivo. Most of these methods involve use of either 2H2-labeled or 13C1-labeled d-glucose as a tracer with GC-MS to measure the isotope enrichment. These methods are challenging, both technologically and economically. We have developed a novel approach that is suitable for labeled-IVGTT studies involving a large cohort of individuals. Methods: The tracer, d-[13C6]glucose, is a low-cost alternative with the significant advantage that the sixth isotope of natural glucose has virtually zero natural abundance, which facilitates isotopomer analysis with &lt;1% labeled glucose in the infusate. After deproteinization of plasma samples collected at various times, glucose is converted to a stable derivative, purified by solid-phase extraction (SPE), and analyzed by HPLC–electrospray ionization mass spectrometry to accumulate the isotope-abundance data for the A+2, A+3, and A+6 ions of the glucose derivative. A 2-pool modeling program was used to derive standard kinetic parameters. Results: With labeled-IVGTT data from 10 healthy male individuals, the values for insulin sensitivity, glucose effectiveness, and the plasma clearance rate estimated with the 2-pool minimal model compared well with values obtained via traditional methods. Conclusions: The relative simplicity and robustness of the new method permit the preparation and analysis of up to 48 samples/day, a throughput equivalent to 2 complete IVGTT experiments, and this method is readily adaptable to existing 96 well–format purification and analytical systems.

scholarly journals Minimal model SGoverestimation and SIunderestimation: improved accuracy by a Bayesian two-compartment model

1999 ◽  
Vol 277 (3) ◽  
pp. E481-E488 ◽  
Author(s):  
Claudio Cobelli ◽  
Andrea Caumo ◽  
Matteo Omenetto
Keyword(s):  
Insulin Sensitivity ◽  
Minimal Model ◽  
Compartment Model ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Glucose Kinetics ◽  
Intravenous Glucose ◽  
Glucose Effectiveness ◽  
Normal Humans ◽  
Improved Accuracy

The intravenous glucose tolerance test (IVGTT) single-compartment minimal model (1CMM) method has recently been shown to overestimate glucose effectiveness and underestimate insulin sensitivity. Undermodeling, i.e., use of single- instead of two-compartment description of glucose kinetics, has been advocated to explain these limitations. We describe a new two-compartment minimal model (2CMM) into which we incorporate certain available knowledge on glucose kinetics. 2CMM is numerically identified using a Bayesian approach. Twenty-two standard IVGTT (0.30 g/kg) in normal humans were analyzed. In six subjects, the clamp-based index of insulin sensitivity ([Formula: see text]) was also measured. 2CMM glucose effectiveness ([Formula: see text]) and insulin sensitivity ([Formula: see text]) were, respectively, 60% lower ( P < 0.0001) and 35% higher ( P < 0.0001) than the corresponding 1CMM [Formula: see text] and[Formula: see text] indexes: 2.81 ± 0.29 (SE) vs.[Formula: see text] = 4.27 ± 0.33 ml ⋅ min−1 ⋅ kg−1and [Formula: see text] = 11.67 ± 1.71 vs.[Formula: see text] = 8.68 ± 1.62 102ml ⋅ min−1 ⋅ kg−1per μU/ml. [Formula: see text] was not different from[Formula: see text] = 12.61 ± 2.13 102ml ⋅ min−1 ⋅ kg−1per μU/ml (nonsignificant), whereas [Formula: see text]was 60% lower ( P < 0.02). In conclusion, a new 2CMM has been presented that improves the accuracy of glucose effectiveness and insulin sensitivity estimates of the classic 1CMM from a standard IVGTT in normal humans.

Reliability of error estimates from the minimal model: implications for measurements in physiological studies

1994 ◽  
Vol 266 (2) ◽  
pp. E279-E286 ◽  
Author(s):  
R. L. Prigeon ◽  
S. E. Kahn ◽  
D. Porte
Keyword(s):  
Monte Carlo ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Sensitivity Index ◽  
True Error ◽  
Intravenous Glucose ◽  
Glucose Effectiveness ◽  
Intravenous Glucose Tolerance ◽  
The Mean

MINMOD provides an estimate of the error in the insulin sensitivity index (SI) and glucose effectiveness at basal insulin (Sg) as the fractional standard deviation (FSD). The validity of the FSD estimate has not been assessed in a large number of human studies, nor has a comparison of the accuracies achievable using the two different intravenous glucose tolerance test (IVGTT) protocols (glucose only and tolbutamide protocol) been performed. To address these two issues, we obtained the FSD value and performed Monte Carlo simulations for 237 IVGTT studies. The FSD underestimated the true error as determined as the coefficient of variation from Monte Carlo simulation (COV-MC) with the ratio of COV-MC to FSD being 3.07 +/- 0.20 (mean +/- SE) for SI using the tolbutamide protocol. Additionally, the mean COV-MC for glucose-only protocol was approximately two to three times that for the tolbutamide protocol for both SI and Sg. We conclude that FSD underestimates the true error in SI and Sg. Additionally, more accurate results are obtained from the tolbutamide protocol than with the glucose-only protocol.

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