The glucose tolerance test as a laboratory tool with clinical implications 7 even with time for recovery, glucose homeostasis can be altered by ongoing wound healing and pain. Irrespective of age, the obese rats had a normal blood glucose tolerance when glucose or tolbutamide load was given intravenously, whereas the glucose ingestion oral glucose tolerance test ogtt caused a marked glucose intolerance that became more pronounced with the duration of the syndrome. The glucose tolerance test as a laboratory tool with. Glucose is the substrate for many energyproducing cellular functions. A healthcare provider will take a fasting lab draw of blood to test your fasting glucose level first. Flunarizine and distilled water were given orally for 5 days to the test t and control c groups of 6 normal albino rats respectively n 6. Copper deficiency was associated with impaired glucose tolerance characterized by increased blood glucose and decreased insulin levels only in copper. Glucose tolerance, assessed as the glucose fractional disappearance rate between 3 and 11 minutes after the glucose injection, was similar in the clipped and sham groups 0. An ogtt is used clinically to diagnose impaired glucose tolerance and as a standardized test of carbohydrate metabolism and insulin secretion. Evaluating the glucose tolerance test in mice american.
The pregnant women must also undergo this test for diagnosis of gestational diabetes. Abnormal oral glucose tolerance in genetically obese fa. Oral glucose tolerance test the serum glucose level, after oral administration of glucose in normal control and treated rats are given in table 1. In vitro antioxidant, hypoglycemic and oral glucose. To understand the contribution of insulin sensitivity and the relative. The test is usually used to test for diabetes, insulin resistance, impaired beta cell function, and sometimes reactive hypoglycemia and acromegaly, or rarer disorders of carbohydrate metabolism. A blood sample is then drawn to determine whether you are metabolizing glucose as you should be. The most common glucose tolerance test is the oral glucose tolerance test ogtt. Following an overnight fast 16 h, rats received an oral gavage of 20% dextrose 2 gkg and blood samples were collected for measurement of blood glucose time 0, 15, 30, 45, 60, and 120 min plasma insulin and the gut hormones glp1. The glucose tolerance of the rats was assessed by the oral glucose tolerance test ogtt. The test is a more substantial indicator of diabetes than finger prick testing. This test was performed during the last week of the experiment after 12 h of fasting and began when the first blood sample was taken from a cut at the tip of the tail time 0.
Exendin4 improves the oral glucose tolerance in diabetic. Finally, in models of bariatric surgery, the improvement in glucose tolerance between rats with gi surgery or control operations is only 2040%. Use of the oral glucose tolerance test to assess insulin. The blue line represents the diabetic group and the red line represents the normal group. The glucose tolerance test gtt, also referred to as the oral glucose tolerance test ogtt, is a method which can help to diagnose instances of diabetes mellitus or insulin resistance. The oral glucose tolerance test ogtt, also known as the glucose tolerance test, gauges the bodys ability to metabolize sugar glucose and clear it from the bloodstream. The mice are subjected to a sevenweek hfd challenge using a western diet. Plasma glucose and insulin concentrations during the intraperitoneal glucose tolerance test ipgtt. Assessing the shape of the glucose curve during an oral. In a person without diabetes, the glucose levels rise and then fall quickly.
Carbohydrates provide the body with glucose, the most important monosaccharide in the blood. An oral glucose tolerance test ogtt, in which the mice are challenged with a bolus of glucose and blood glucose and insulin levels are measured across a two hour time course is performed one week prior to the initiation of the hfd challenge. The normal rate of glucose clearing depends on the amount of glucose ingested. Youll get the oral glucose tolerance test at your doctors office, a clinic, a hospital, or a lab. The test is based on oral administration of glucose and subsequently following plasma glucose and insulin levels over time.
The glucose tolerance test is a medical test in which glucose is given and blood samples taken afterward to determine how quickly it is cleared from the blood. Oral glucose tolerance test ogtt in normal control and. The oral glucose tolerance test ogtt, insulin release test irt and insulin tolerance test itt were performed to measure the glycometabolism of the diabetic rats at the end of the treatment. Meal feeding improves oral glucose tolerance in male rats. Get your dr to do a fasting insulin test plus a glucose tolerance test and use the homa ir formula to work out the score.
The test detect how quickly glucose is metabolized from the bloodstream for use by cells as energy source. The oral glucose tolerance test ogtt has often been used to evaluate apparent insulin release and insulin resistance in various clinical settings. For this purpose, the animals were fasted for about 16 h prior to the time the test commenced. The effect was more pronounced when the test was done in rats fed the extract on the day of the test compared with tests done in rats which were not fed the extract on the same day. Antidiabetic and antihypercholesterolemic effects of. Auc glucose e and auc insulin f were calculated using the trapezoidal rule. The total area under the insulin curve during glucose tolerance tests was. Metabolic syndrome markers in wistar rats of different.
Glucose tolerance testgtt test normal range, procedure. For example, insulin levels in shrob rats must be raised to levels that would result. Initially a single day oral glucose tolerance test was conducted and the effective dose 1. Blood glucose concentration was evaluated at 0, 30, 60, 90 and 120 minutes after treatment in both cases. Effect of fructose or sucrose feeding with different. The genetically obese fafa rat is glucose intolerant when tested in a conscious state after the spontaneous ingestion of a glucose solution. Oral glucose tolerance test of different extracts of musa species was conducted in nondiabetic rats. The most common glucose tolerance test is the oral glucose tolerance test. In gtt, the patient is given a glucose solution and blood samples are drawn afterword at intervals to measure how well the body cells are able to absorb glucose. Recent national and international randomized controlled trials have shown that diabetes can be delayed or prevented among persons with igt.
During week 5 the fructose portion of the copperdeficient diet was replaced 20 rats by starch 10 rats or glucose 10 rats. The glucose tolerance test gtt is the most sensitive test for detecting borderline diabetes mellitus. This test helps in the diagnosis of type 1 and type 2 diabetes. Although the nih mouse metabolic phenotyping center consortium has provided a standard operating procedure for performing glucose tests in mice ayala et al. Effect of various hormones on the rate of decline of the blood sugar in the modified glucose insulin tolerance test. The test requires you to drink a syrupy solution after a period of fasting. The current article describes the generation and metabolic characterization of highfat dietfed mice as a model of dietinduced insulin resistance and obesity. The purpose of the present study was to identify parameters that determine the shape of the plasma glucose course measured at 0, 30, 60, 90, and 120 min during an ogtt. Interpretation of glucose tolerance test gtt labmonk. There are several variations to the glucose tolerance test used in different conditions but, the most common one of them is the oral glucose tolerance test or ogtt. Chronic administration showed an improvement in the oral glucose tolerance curve. Second, glucose tolerance was not improved in response to parenteral glucose despite significant, albeit smaller, differences in body weight between the mf and al rats. Ileal interposition improves glucose tolerance in low dose.
To evaluate the effect of flunarizine on blood glucose levels in normal albino rats through oral glucose tolerance test ogtt materials and methods. The aim of the experiment is to interpretation of glucose tolerance test gtt. The isoflavone sissotrin and the flavonol derivative, isoquercitrin, were selected for the oral glucose tolerance test. The simultaneous assessment of quantitative indexes of insulin secretion and action in a single individual is important when quantifying their relative role in the evolution of glucose tolerance in different physiopathological states. A twohour, 75gram oral glucose tolerance test ogtt is used to test for diabetes. The opposing effects of the flavonoids isoquercitrin and.
Your blood sugar level can give your doctor important clues about your health, and an oral glucose tolerance test ogtt shows how well your body handles sugar from foods it. The glucose tolerance test provides the ability of the body cells to absorb glucose, or sugar after ingestion. The changes of blood glucose concentration during oral glucose tolerance test in gk rats the aucs of the glucose response in gk rats are shown in fig. Interpretation is based on venous plasma glucose results before and 2 hours after a 75 g oral glucose load. Oral glucose tolerance test in two groups of n3 rats. The classic oral glucose tolerance test measures blood glucose levels five times over a period of three hours. The recommended preparation for and administration of the ogtt are important to ensure that test results are not affected. Oral glucose tolerance test minimal model indexes of. During the 9th week, an oral glucose tolerance test was performed.
Impairment of glucose tolerance in copperdeficient rats. The oral glucose tolerance test ogtt is currently the gold standard for the diagnosis of diabetes. Effect of flunarizine on blood glucose levels in normal. Igt is defined on the basis of an abnormal oral glucose tolerance test ogtt.
Study of in vivo glucose metabolism in highfat dietfed. Available methods quantify these indexes in relatively nonphysiological conditions, e. Pdf oral glucose tolerance test ogtt in normal control. Subsequently, a zero time baseline blood sample was drawn and designated 0 min glucose level.
It further features detailed protocols to perform the oral glucose tolerance test and the insulin tolerance test, monitoring wholebody alterations of glucose metabolism in vivo. Oral glucose tolerance test ogtt in nondiabetic rats 21,22. Measurement of glucose is useful in the diagnosis and monitoring of carbohydrate metabolism disorders. The oral glucose tolerance test ogtt and mixed meal tolerance test mmt are widely used in clinical metabolic research and diabetes drug development. Oral glucose tolerance test ogtt was performed at the end of the 14week experimental period. Use of anesthesia dramatically alters the oral glucose. The standard twohour oral glucose tolerance test in the diagnosis of diabetes mellitus in subjects without fasting hyperglycemia. Persons without diabetes but with an ogtt 2hour value of 140199 mgdl are considered to have igt. Some physicians simply take a baseline blood sample followed by a sample two hours after drinking the glucose solution. Laboratory procedure manual centers for disease control.
For highly insulin resistant individuals, insulin must be elevated to very high levels. Body weight bw and blood glucose bg were tested daily and oral glucose tolerance ogt on day. However, because insulin sensitivity and insulin release are interdependent, to what extent they can be predicted from an ogtt is unclear. In the experiment, different levels of fructose crystalline fructose 99. Neither the reference drug metformin nor the test drugs me and ae showed any hypoglycaemic effect in normal rats as evident by basal to 0 min. Objective the oral glucose tolerance test ogtt is used to define the status of glucose tolerance based on the plasma glucose level at 120 min. Oral glucose tolerance and mixed meal tolerance tests.
The oral glucose tolerance test ogtt is a widely used experimental procedure for metabolic studies in mice. There were no significant differences between the acute fructose and sucroseadministered groups, whereas the aucs of fructoseadministered groups tended to be smaller than those of the. Oral glucose tolerance test uses, procedure and results. Niacin improves adiponectin secretion, glucose tolerance. Glucose tolerance means ability of the body to utilize glucose in the circulation.
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