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Results for “Glucose Tolerance Test”

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At least 19 recordsLinked to original sources

PubMed1978

Effect of estrogen treatment for one year on carbohydrate and lipid metabolism in women with normal and abnormal glucose tolerance test results. Glucose, insulin, growth hormone, triglycerides, and Premarin.

A prospective study of the effects of a conjugated estrogen (Premarin, 1.25 mg.) was performed in 36 women over a 1 year period. Each subject received a 3 hour oral glucose tolerance test before starting the medication and another after 1 year of use. The blood glucose levels were similar at five times during the two tests except for a significant elevation of the 1 hour value at the 1 year test. There were no changes in the plasma insulin, growth hormone, or fasting triglyceride levels. These results suggest that the cyclic administration of this estrogen does not alter lipid or carbohydrate metabolism.

Blood Glucose↗

PubMedDate not supplied

Comparison of the metabolic response to a glucose tolerance test and a standardized test meal and the response to serial test meals in normal healthy subjects.

The plasma glucose and insulin response to a standardized meal test breakfast was compared with the time-honored glucose tolerance test in the same normal healthy subjects. The amplitude of glycemic excursion and between-subject variation was less with the more physiologic standardized test meal than with that seen with the glucose tolerance test. The glucose tolerance test's prime function is to amplify any glucose intolerance, thus aiding diagnosis, whereas a standardized meal gives a more clinically relevant metabolic status. The administration of serial test meals during the same day in a smaller group of normal subjects indicated, as seen previously with repeated glucose tolerance tests, a diminishing carbohydrate tolerance during the day.

Adult↗

PubMed1978

Fallibility of the intravenous glucose tolerance test as a measure of endogenous glucose turnover.

We have used hepatectomized, nephrectomized dogs receiving a constant infusion of unlabeled glucose as well as conscious, unrestrained guinea pigs in order to investigate the calculation of basal glucose kinetics from intravenous glucose tolerance tests (IVGTT). In the dogs, we were not able to determine the known rate of appearance (Ra) or disappearance (Rd) of glucose within 50% of the actual value by means of IVGTT. In the guinea pigs, we found that Ra calculated from IVGTT was 250% higher than Ra determined by means of the validated technique of the primed-constant infusion of 6-3H-glucose in tracer quantities. When live Escherichia coli were infused into the guinea pigs, the isotope-tracer technique revealed a 100% increase in Ra yet Ra appeared to be decreased by 80% when calculated by means of IVGTT. We concluded that basal glucose kinetics cannot be determined reliably from IVGTT, and that in certain pathologic conditions the direction of change in Ra and Rd from the basal state may be incorrectly predicted.

Animals↗

PubMed1979

[Intravenous glucose tolerance test].

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Glucose↗

PubMed1979

Thyroid hormone levels during glucose tolerance test in euthyroid subjects.

Twelve normal, healthy, clinically and biochemically proven euthyroid volunteer subjects (age 19-35) were administered a standard glucose tolerance test (100 g glucose orally) and thyroxine (T4), triiodothyronine (T3) and reverse triiodothyronine (rT3) levels were determined by specific radioimmunoassays to determine the acute effect of glucose and insulin on peripheral monodeiodination of thyroxine. The fasting levels of T4, T3, rT3 and free thyroxine were 82.4 nmol/l, 1.7 nmol/l, 0.52 nmol/l, and 0.22 nmol/l, respectively, and these levels were unchanged during the 3 hours post-glucose load. The rise and fall of glucose and insulin levels were typical of the standard responses normally observed in the glucose tolerance test. The variations in insulin and glucose levels were not correlated with thyroid hormone concentrations at any interval during the test. It is therefore concluded that dietary glucose does not acutely cause shifts in peripheral monodeiodination of thyroxine in healthy euthyroid subjects.

Adult↗

PubMed1978

An interpretation of the intravenous glucose tolerance test in the light of recent findings on the kinetics of glucose and insulin in man.

1. A theoretical investigation of the intravenous glucose tolerance test has been carried out based on recent findings on the kinetics in man of insulin production, distribution, disposal and action, and of glucose turnover and distribution. 2. A good fit to published data on four groups of subjects required a scheme that includes two extravascular glucose spaces and separate venous, arterial and capillary volumes. The fit to the data was little affected by variations within the physiological range of venous and arterial volumes, cardiac output, glycosuria and the properties of the less-accessible glucose pool. 3. The only variables needed to account for the differences between the groups were kinsulin (a measure of the mean sensitivity of insulin-dependent tissues to insulin action) and the readily accessible glucose space. 4. Three published schemes for insulin kinetics were used. They were all consistent with the data and gave very similar relative values for kinsulin in the four groups. 5. It is shown that a rigorous interpretation of the test requires a knowledge of the hepatic response to the glucose load during the test. These effects are not well characterized in pathological states, e.g. diabetes and injury. Consequently conclusions about insulin resistance in these states drawn only from the test are doubtful.

Blood Glucose↗

PubMed1975

Influence of treatment with diet alone on oral glucose-tolerance test and plasma sugar and insulin levels in patients with maturity-onset diabetes mellitus.

Oral glucose-tolerance test (O.G.T.T.) plasma sugar and insulin levels were measured in 118 newly diagnosed maturity-onset diabetic patients before and after treatment with diet alone for periods of 2 and 6 months. The results of glucose-tolerance tests carried out during treatment could be predicted from the initial test and the weight reduction between the tests. This prediction was not improved by the addition of further variables, including age, obesity, and plasma-insulin levels during the first test. The change in O.C.T.T. plasma-insulin between the first and second tests was predicted by the result of the initial tests, the improvement of glucose tolerance between the two tests, and the degree of weight reduction. 95% of the group achieved some improvement of glucose tolerance after 2 months of dietary treatment, and 59% of the group achieved adequate diabetic control by this time. It is concluded that treatment with diet alone should be the first-line management for patients with newly diagnosed maturity-onset diabetes mellitus.

Adult↗

PubMedDate not supplied

[Variation in serum nonesterified fatty acids during glucose tolerance test in undernourished patients with anorexia nervosa and in obese patients].

Intravenous glucose tolerance tests (0,33 g glucose per kg body weight) are performed in 11 self starved women suffering from anorexia nervosa, 10 obese and 8 normal women. They have no genetic or chemical diabetes and belong to the same age group. Plasma concentrations of immuno-reactive insuline (IRI) and non esterified fatty acids (NEFA) are determined during these tests. The basal concentrations of NEFA are very high in the obese patients. In the starved women the elevation of the basal plasma NEFA concentration is less striking and statistically not significant. The plasma level of NEFA is reduced in all subjects by hyperinsulinism secondary to hyperglycemia. This drop in NEFA concentration is significantly reduced in the obese patients and markedly inhibited in the starved women. This observation points toward an increased resistance to the antilipolytic action of insulin in anorexia nervosa because, in these patients, the glucose load determines a normal increase in plasma IRI but the fall in plasma NEFA concentration is severely impaired.

Adolescent↗

PubMed1979

Gycosuria as an indication for glucose tolerance testing during pregnancy.

The indications for and results of all glucose tolerance tests (GTTs) performed at the Antenatal Clinic, Groote Schuur Hospital, Cape Town, over a period of 1 year, and the indications for a GTT in the first 80 newly diagnosed diabetics over a 4-year period are analysed. Out of 558 GTTs, only 17 tentative diagnoses of 'gestational diabetes' were made. The most rewarding single indication for a GTT was repeated glycosuria, which was an indication in 61 out of the 80 newly diagnosed diabetics. A combination of two indications in the same patient was related to twice as many abnormal GTTs as a single indication, while reported previous diabetes or hyperglycaemia certainly merited confirmation. Reasons for repeating GTTs are discussed, as well as the management of 'borderline' and 'potential' diabetics. It is emphasized that 'diabetes' or 'hyperglycaemia' diagnosed during pregnancy is not equivalent to a definite diagnosis of diabetes in the non-pregnant state.

Female↗

PubMed1979

Glycosylated hemoglobin assay and oral glucose tolerance test compared for detection of diabetes mellitus.

We compared the oral glucose tolerance test (I) as evaluated by six commonly used scoring methods and total glycohemoglobin assay (II) with respect to their value in the diagnosis of diabetes mellitus. Depending on the evaluation method used for I, 16.7 to 64.3% of those subjects diagnosed as diabetic or borderline by this test were judged to be normal by II. The best agreement was between II and the Unger evaluation method. High-density-lipoprotein cholesterol, which showed an inverse correlation with II, was decreased in subjects judged to be diabetic by the Unger method. We conclude that the utilization of II measurement as a screening method for diabetes mellitus is consistent with a conservative approach to the diagnosis of diabetes.

Adult↗

PubMedDate not supplied

[Diagnostic and prognostic value of the glucose tolerance test in doubtful cases].

Many-year observation over the changes in glucose tolerance test of different type in 964 women, aged from 17 to 57 years, on free diet and free regimen, was carried out. The changes in glucose tolerance were the more unfavourable--the greater were its deviations during the initial examination. The doubtful tolerance changes, diagnosed by hyperglycemia on fasting stomach, with the normal blood glucose level one and two hours after glucose load, were identical to the normal tolerance changes, serving as a variant of the latter.

Adolescent↗

PubMed1977

The glucose tolerance test.

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Glucose Tolerance Test↗

PubMed1979

Glucose tolerance tests in women with small-for-date fetuses and newborns.

Peroral glucose tolerance tests were performed in women with small-for-date fetuses and in controls with healthy fetuses in the 38th week of pregnancy, 2 days and 6 weeks after delivery. 2 h after the load of 50 g of glucose, the blood glucose level remained significantly higher in pregnant women with small-for-date fetuses. The other parameters followed did not exhibit any difference from the control group. Since this deviation disappeared very rapidly after delivery it may be supposed that it is caused by hormonal and other influences of the atypical conceptus and not by a primary derangement of maternal metabolism or by a disparate responsiveness of the maternal organism to pregnancy.

Blood Glucose↗

PubMed2026

Metabolomic Responses to Oral Glucose Tolerance Test and Hyperinsulinemic-euglycemic Clamp in CKD.

BACKGROUND: The oral glucose tolerance test (OGTT) captures integrated physiological responses involving intestinal glucose absorption, incretin signaling, and endogenous insulin secretion, whereas the hyperinsulinemic-euglycemic clamp (clamp) isolates insulin-mediated glucose uptake. Comparing plasma metabolomic responses to these two challenges may identify processes specific to intestinal nutrient delivery and how they vary in CKD. METHODS: Targeted plasma metabolomics was performed in 59 adults without diabetes (39 with CKD [eGFR <60 mL/min/1.73 m2] and 20 controls) from the Study of Glucose and Insulin in Renal Disease (SUGAR). Each participant underwent a 75-g OGTT and clamp approximately one week apart. Eighty-eight plasma metabolites were quantified at fasting and during each challenge. Metabolite levels were log-transformed and normalized using Systematic Error Removal Using Random Forest (SERRF). Metabolites were classified using adjusted regression slopes relating OGTT and clamp responses. RESULTS: The mean (SD) age and eGFR were 64 (13) years and 54 (26) mL/min/1.73 m2, respectively, and 41% were female. In the overall cohort, OGTT and clamp induced broad plasma metabolic changes, with 63 (72%) and 76 (86%) metabolites significantly altered from fasting, respectively. Seventy-three metabolites (83%) demonstrated a significant relationship between OGTT and clamp responses. Of these, 22 (25%) exhibited true concordance and 51 (58%) demonstrated similar directional changes but differed in magnitude. A total of 15 (17%) metabolites were discordant or non-corresponding, of which only three were discordant. The non-corresponding metabolites were enriched in amino acid metabolism. Eleven metabolites (13%) demonstrated differential responses between OGTT and clamp by CKD status, involving amino acid and glucose metabolism pathways. CONCLUSIONS: Metabolomic responses to OGTT and clamp were largely directionally concordant but differed in magnitude, with attenuation during OGTT. Discordant metabolites were rare, while non-corresponding metabolites were confined to amino acid pathways. CKD modified OGTT-clamp correspondence for metabolites involved in amino acid and glycolytic metabolism.

Journal Article↗

PubMed1979

Study of glucose tolerance and the dynamic property of insulin secretion. Analysis of intravenous glucose tolerance test with the aid of a control theory.

The dynamic property of insulin secretion in relation to glucose tolerance was investigated quantitatively during iv glucose tolerance tests in 237 cases. The following results were obtained; 1) Glucose clearance constant (k-value) was not constant but variable with time and should be expressed as a function of time, K(t). In normal glucose tolerance, K(t) became greater with time. 2) Glucose-induced insulin secretion was expressed as the function of a proportional plus derivative response to glucose concentration. A weighting function of derivative response, reflecting the insulin secretion per unit of rate of change in blood glucose concentration, was calculated from blood glucose concentration (input) and insulin concentration (output) by the deconvolution method. It was clearly shown that the gain in weighting function was small and the response was slow even in the individual whose glucose tolerance was slightly impaired. 3) The greater the weighting function, the larger the change in K(t).

Blood Glucose↗

PubMed2026

Association of Post-Oral Glucose Tolerance Test Hypoglycaemia With Clinical Features, Incident Diabetes and Mortality in the Di@bet.es Cohort.

AIMS: To investigate the association of post-oral glucose tolerance test (OGTT) hypoglycaemia with clinical features, incident diabetes and mortality. MATERIALS AND METHODS: This population-based cohort study included 2924 adults (median age 49 years, 1680 women) without known diabetes who underwent a 75-g OGTT as part of the Di@bet.es Study. Metabolic, demographic and lifestyle variables were collected. Serum glucose and insulin concentrations at 0, 30 and 120 min during the OGTT were obtained, allowing insulin resistance estimation using the HOMA-IR and the Matsuda Index. Participants were grouped according to serum glucose at 120 min: < 70 mg/dL (post-OGTT hypoglycaemia), 70 to < 140 mg/dL (normal result), 140 to < 200 mg/dL, and ≥ 200 mg/dL. The incidence of diabetes (median follow-up, 7.5 years) and mortality (median follow-up, 14.5 years) were assessed. RESULTS: Participants with post-OGTT hypoglycaemia (n = 327, 11.1%) were younger, leaner, less insulin resistant and more frequently active smokers. Despite having the lowest serum glucose at 0, 30 and 120 min, and the lowest serum insulin at 0 and 120 min, these participants tended to have the highest serum insulin concentrations at 30 min. Participants with post-OGTT hypoglycaemia had the lowest incidence of diabetes and mortality, although these associations were attenuated after adjusting for confounders (such as age, sex, body mass index and physical activity) and when compared specifically with the normal result group. CONCLUSIONS: Post-OGTT hypoglycaemia is more frequent in smokers, younger individuals, and those with a favourable metabolic profile. Post-OGTT hypoglycaemia acts as a marker of protection for incident diabetes and mortality. Preserved early insulin secretion together with good insulin sensitivity could explain post-OGTT hypoglycaemia.

Humans↗

PubMed1979

Oral glucose-tolerance tests and the diagnosis of diabetes: results of a prospective study based on the Whitehall survey.

Men who participated in the Whitehall survey and were found to be glucose intolerant have been studied 6--8 years later, together with a control group of men with normal screening blood-sugar levels. Ophthalmoscopically visible microvascular retinal disease was confined to men diagnosed as probably diabetic after the survey because their 2 h blood-sugar level (after a 50 g oral glucose load) in the survey examination or during a subsequent standard oral glucose-tolerance test was greater than or equal to 200 mg/dl (11.1 mmol/l). The lowest blood-sugar in a "diabetic" subsequently found to have retinopathy was 229 mg/dl. Men with lesser degrees of glucose intolerance, including 34 who had "worsened to diabetes", did not have visible retinovascular disease at follow-up. If diabetes implies a risk of specific microvascular complications in the medium term, then the findings in this study support proposals for the revision of diagnostic criteria based on glucose-tolerance tests.

Aged↗

PubMed1977

The effects of long-term therapy with oral hypoglycemic agents on the oral glucose tolerance test dynamics in male chemical diabetics.

The effect of fixed doses of oral hypoglycemic agents and placebo (diet alone) on the blood glucose, serum insulin, triglyceride, and cholesterol responses during oral glucose tolerance tests done annually for up to four years' follow-up was studied, in a double-blind manner, in five groups of mild male chemical diabetics. The drugs used were chlorpropamide (100 mg. O.D.), tolbutamide (500 mg. b.i.d.), phenformin (50 mg. O.D.), acetohexamide (250 mg. O.D.), and placebo. Each subject was given an individualized diet aimed at attaining and maintaining ideal weight. Comparison by chi-square analysis between the placebo group and each of the drug groups showed (a) no significant differences with regard to the number of subjects with normal glucose tolerance in each of the tests and (b) no change in the insulin secretion dynamics. Comparison between the initial test and each of the subsequent tests within each group showed (a) a greater number of subjects with normal glucose tolerance in the first follow-up test in the chlorpropamide group only, (b) no change in the insulin secretion dynamics except in the chlorpropamide group, where there was an increased insulin/glucose ratio in the first follow-up test, and (c) no change in the fasting serum triglyceride and cholesterol levels.

Acetohexamide↗