Steady state glucose kinetics and their relation to plasma glucose concentration in the premature and full term neonatal piglet

1981 ◽  
Vol 59 (10) ◽  
pp. 1069-1072 ◽  
Author(s):  
P. A. Flecknell ◽  
R. Wootton ◽  
Muriel John ◽  
J. P. Royston

Steady state glucose kinetics were measured in 19 premature and 16 full-term piglets. Bodyweight, plasma glucose concentration, total body glucose turnover rate, and glucose pool size were not significantly different between the two groups. This suggests that the premature piglet is capable of maintaining glucose homeostasis during the first 24 h of life. Although there appeared to be a correlation between glucose turnover and plasma glucose concentration, analysis of covariance showed that it was spurious, suggesting that glucose utilization proceeds independently of the glucose concentration in plasma.Glucose turnover rate in the premature piglet is closely comparable with that reported in the premature human infant. These findings encourage the use of the neonatal piglet as an animal model for the study of the problems of the neonatal human.

1992 ◽  
Vol 12 (3) ◽  
pp. 448-455 ◽  
Author(s):  
Graeme F. Mason ◽  
Kevin L. Behar ◽  
Douglas L. Rothman ◽  
Robert G. Shulman

The concentration of intracerebral glucose as a function of plasma glucose concentration was measured in rats by 13C NMR spectroscopy. Measurements were made in 20–60 min periods during the infusion of [1-13C]d-glucose, when intracerebral and plasma glucose levels were at steady state. Intracerebral glucose was found to vary from 0.7 to 19 μmol g−1 wet weight as the steady-state plasma glucose concentration was varied from 3 to 62 m M. A symmetric Michaelis–Menten model was fit to the brain and plasma glucose data with and without an unsaturable component, yielding the transport parameters Km, Vmax, and Kd. If it is assumed that all transport is saturable ( Kd = 0), then Km = 13.9 ± 2.7 m M and Vmax/ Vgly = 5.8 ± 0.8, where Vgly is the rate of brain glucose consumption. If an unsaturable component of transport is included, the transport parameters are Km = 9.2 ± 4.7 m M, Vmax/ Vgly = 5.3 ± 1.5, and Kd/ Vgly = 0.0088 ± 0.0075 ml μmol−1. It was not possible to distinguish between the cases of Kd = 0 and Kd > 0, because the goodness of fit was similar for both. However, the results in both cases indicate that the unidirectional rate of glucose influx exceeds the glycolytic rate in the basal state by 2.4-fold and as a result should not be rate limiting for normal glucose utilization.


PEDIATRICS ◽  
1979 ◽  
Vol 63 (3) ◽  
pp. 389-396 ◽  
Author(s):  
Richard M. Cowett ◽  
William Oh ◽  
Arnold Pollak ◽  
Robert Schwartz ◽  
Barbara S. Stonestreet

Tolerance for glucose was studied in 35 well, appropriate for gestational age, low birth weight (LBW) infants (mean birth weight, 1,216 gm; mean gestational age, 30 weeks) between 3 and 38 days of age. Infants were given a graded dose of glucose at 8.1, 11.2, or 14.0 mg/kg/min for three hours by continuous peripheral intravenous infusion. Plasma glucose and insulin, and timed urine glucose and volume were measured. A steady state of plasma glucose concentration was noted by one hour at all infusion rates. In the nine infants receiving 8.1 mg/kg/min, plasma glucose and insulin were similar to the baseline values during the steady state, and none of these infants evidenced glucosuria. In the 16 infants receiving 11.2 mg/kg/min, the plasma glucose concentration significantly increased (140 to 166 mg/dl) during the steady state but the plasma insulin levels were not significantly different compared to baseline. Half of these infants developed hyperglycemia (plasma glucose 150 mg/dl) and glucosuria. Ten infants receiving 14.0 mg/kg/min developed a significantly higher plasma glucose and plasma insulin response in colmparison to those infants who received 8.1 and 11.2 mg/kg/min, and all evidenced hyperglycemia and glucosuria. Glucosuria did not exceed 6.4 mg/kg/hr (0.1 mg/kg/min) so that glucose disposal (retention) exceeded 99% of intake, and an osmotic diuresis was not noted in those infants who had glucosuria. Our data suggested that in well LBW infants, a three-hour infusion of glucose up to 14.0 mg/kg/min (approximately 80 kcal/kg/day) did not produce an osmotic diuresis, but in the highest infusion group (14 mg/kg/min), hyperglycemia did occur. The effect of hyperglycemia in the neonate is unknown and needs to be investigated.


1994 ◽  
Vol 267 (5) ◽  
pp. R1226-R1234 ◽  
Author(s):  
T. G. West ◽  
C. J. Brauner ◽  
P. W. Hochachka

The involvement of circulatory glucose in the energy provision of skeletal muscle and heart of swimming carp was examined. Plasma glucose concentration varied from 3 to 17 mM among individual carp, and estimates of glucose turnover rate (RT) were positively correlated with plasma glucose level in resting fish (range 1.6-6.3 mumol.min-1.kg-1) and in swimming fish (range 4.2-10.7 mumol.min-1.kg-1). Carp that were exercised at 80% of their critical swimming speed displayed a twofold higher RT at any given plasma glucose concentration. Metabolic clearance rate also doubled in swimming carp (1.0 +/- 0.1 ml.min-1.kg-1) relative to resting controls (0.5 +/- 0.1 ml.min-1.kg-1). Indexes of muscle glucose utilization (GUI), determined with 2-deoxy-D-[14C]glucose, indicated that glucose utilization in red muscle was not dependent on plasma glucose concentration; however, glucose utilization in this muscle mass was threefold higher in swimming fish than in resting control fish. On the basis of whole body aerobic scope measurements in carp, it was estimated that circulatory glucose potentially comprised 25-30% of the total fuel oxidation in the active red muscle mass. GUI in heart was positively correlated with plasma glucose concentration, and it is possible that glucose availability had considerable influence on the pattern of myocardial substrate oxidation in resting and active carp. Carp are somewhat more reliant than rainbow trout on glucose for locomotor energetics, correlating with species differences in swimming capability and with the greater capacity of omnivorous carp to tolerate dietary glucose.


1992 ◽  
Vol 263 (5) ◽  
pp. E844-E849 ◽  
Author(s):  
K. A. Yunis ◽  
W. Oh ◽  
S. Kalhan ◽  
R. M. Cowett

To evaluate the mechanism(s) of the observed increase in plasma glucose concentration following the administration of an intravenous fat emulsion to the neonate, we measured glucose kinetics in eight low-birth-weight neonates by the prime constant rate infusion technique with D-[6,6-2H2]glucose at a rate of 0.22 +/- 0.01 mumol.kg-1 x min-1 (39.4 +/- 1.3 micrograms.kg-1 x min-1) while the neonates received 32 +/- 5 mumol.kg-1 x min-1 glucose (6.3 +/- 1.1 mg.kg-1 x min-1) plus an amino acid mixture (parenteral alimentation) alone and in combination with an intravenous fat emulsion (Intralipid). Following the latter combination, there were significant increases in plasma glucose concentration [4.07 +/- 0.11 (73 +/- 2 mg/dl) to 5.00 +/- 0.22 mmol/l (90 +/- 4 mg/dl); P < 0.01] and in plasma insulin concentration [72 +/- 14 (10 +/- 2 microU/ml) to 172 +/- 36 pmol/l (24 +/- 5 microU/ml); P < 0.05]. The parenteral alimentation and intravenous fat effusion combination did not affect the glucose production rate: 0.15 +/- 0.05 mumol.kg-1 x min-1 (0.03 +/- 0.01 mg.kg-1 x min-1) during the parenteral alimentation alone and 0.16 +/- 0.05 mumol.kg-1 x min-1 (0.03 +/- 0.01 mg.kg-1 x min-1) when parenteral alimentation was combined with an intravenous fat emulsion. We conclude that the increased plasma glucose concentration seen in association with administration of parenteral alimentation combined with an intravenous fat emulsion to the premature neonate is not due to enhanced glucose production but could be the result of alterations in glucose utilization.


1989 ◽  
Vol 9 (3) ◽  
pp. 304-314 ◽  
Author(s):  
Kentaro Mori ◽  
Nancy Cruz ◽  
Gerald Dienel ◽  
Thomas Nelson ◽  
Louis Sokoloff

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.


2014 ◽  
Vol 6 (2) ◽  
pp. 75-78
Author(s):  
Sujaya Sham ◽  
B Poornima R Bhat ◽  
Aruna Kamath

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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