Glucose: From 3 Different Sources
A simple sugar that is naturally present in fruits and is a product of the digestion of starch and sucrose. It is the chief source of energy for the body and is carried to all tissues in the blood. The term blood sugar refers to glucose in the bloodstream.The level of glucose in the blood is normally kept fairly constant by the actions of various hormones, notably insulin, glucagon, adrenaline, corticosteroid hormones, and growth hormone. An abnormally high blood glucose level (known as hyperglycaemia) may cause glucose to be lost into the urine. An abnormally low blood glucose level is called hypoglycaemia.
Glucose, also known as dextrose or grape sugar, is the form of sugar found in honey and in grapes and some other fruits. It is also the form of sugar circulating in the bloodstream, and the form into which all sugars and starches are converted in the small INTESTINE before being absorbed. Glucose is a yellowish-white crystalline substance soluble in water and having the property of turning a ray of polarised light to the right. It is often given to patients orally or, sometimes, intravenously as an easily assimilated form of CARBOHYDRATE. It has the further practical advantage in this context of not being nearly as sweet-tasting as cane sugar and therefore relatively large amounts can be consumed without sickening the patient.
(dextrose) n. a simple sugar containing six carbon atoms (a hexose). Glucose is an important source of energy in the body and the sole source of energy for the brain. Free glucose is not found in many foods (grapes are an exception); however, glucose is one of the constituents of both sucrose and starch, both of which yield glucose after digestion. Glucose is stored in the body in the form of *glycogen. The concentration of glucose in the blood is maintained at around 5 mmol/l by a variety of hormones, principally *insulin and *glucagon. If the blood-glucose concentration falls below this level neurological and other symptoms may result (see hypoglycaemia). Conversely, if the blood-glucose level is raised above its normal level, to 10 mmol/l, the condition of *hyperglycaemia develops. This is a symptom of *diabetes mellitus.
A way of assessing the body’s e?ciency at metabolising GLUCOSE. The test is used in the diagnosis of DIABETES MELLITUS. The patient is starved for up to 16 hours, after which he or she is fed glucose by mouth. The concentrations of glucose in the blood and urine are then measured at half-hour intervals over a period of two hours.... glucose-tolerance test
An ENZYME that performs an essential function in the metabolism of CARBOHYDRATE. A de?ciency in this enzyme – acronym G6PD – results in the breakdown of ERYTHROCYTES (HAEMOLYSIS), usually in the presence of oxidants (see OXIDANT) such as infections or drugs. The de?ciency disorder is a hereditary condition in which the enzyme is absent. The condition, characterised by pallor, rigors and pain in the loin, is divided into African, European (including FAVISM) and Oriental types. Sufferers should avoid substances that trigger haemolysis. Acute episodes are best treated symptomatically.... glucose-6-phosphate dehydrogenase
A deficiency in the enzyme G6PD resulting in a haemolytic anaemia. This haemoglobinopathy contraindicates the use of the 4-aminoquinolines such as primaquine for the radical treatment of benign tertian and ovale tertian malaria.... glucose-6-phosphate-dehydrogenase (g6pd) deficiency
The level of glucose in the blood. Abnormally high blood glucose (sometimes called sugar) levels are an indication of diabetes mellitus. (See also hyperglycaemia; hypoglycaemia.)... blood glucose
a hereditary disorder – an X-linked condition (see sex-linked) – in which the absence of the enzyme glucose-6-phosphate dehydrogenase (G6PD), which functions in carbohydrate metabolism, results in the breakdown of the red blood cells (*haemolysis), usually after exposure to *oxidants, such as drugs, or infections. The breakdown causes acute attacks that are characterized by pallor, loin pain, and rigors. There are several varieties of G6PD deficiency, which is most common in people of African, Middle Eastern, and Mediterranean descent. Treatment involves identifying and avoiding agents that trigger the haemolysis and treating acute attacks symptomatically. See also favism.... glucose-6-phosphate dehydrogenase deficiency
(IFG) see glucose tolerance test.... impaired fasting glucose
(IGT) see glucose tolerance test.... impaired glucose tolerance
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