Tuesday, October 16, 2007
Glucose is the major energy source for the human body. When the total daily energy intake exceeds daily expenditure, the excess is converted to fat and stored in adipose tissue. When daily energy needs are not met by sufficient calorie intake, glucose is produced from the berakdown of carbohydate stores and from non-carbohydrate sources (eg. gluconeogenic amino acids, lactate and glycerol) the glucose level in blood is kept within a fairly narrow range through a variety of influences. Feeding and fasting cause variation in the blood glucose levels..
Glucose measurement is performed for the diagnosis and follow-up of carbohydate metabolism abnormalities (eg. diabetes mellitus, hypoglycemia) and other conditions (such as cerebrospinal fluid glucose in suspected meningitis).
Glucose levels in the body increase due to:
- Diabetes Mellitus including: Hemochromatosis, Cushing's syndrome, Acromegaly and gigantism
- Increased circulating epinephrine: Adrenal injection, pheochromocytoma, stress (emotions, burns, shock)
- Acute pancreatitis
- Chronic pancreatitis
- Wernicke's encephalopathy
- CNS lesions
- Effects of drugs
Glucose levels in the body decrease due to:
- Pancreatic disorders: islet cell tumors
- glucagon deficiency
- carcinoma of adrenal gland
- carcinomaof stomach
- fibrosarcoma
- Hepatic Disease: Poisoning, hepatitis, cirrhosis, primary/ metastatic
- Endocrine Disorder: Hypopituitarism and Addison's disease, hypothyroidism
- functional disturbances: post gastrectomy. gastroenterostomy, antonomic nervous system disorder
- Pediatric Anomalies:
-prematurity,infant of diabetic mother, ketotic hypoglycemia, Zetterstrom's syndrome, idiopathic leucine sensitivity, spontaneous hypoglycaemia in infants
- Enzyme diseases:
-Von Gerke's disease, galactosemia, maple syrup urine disease, fructose intolerance
The Analyser used for the glucose measurement is the Beckman Coulter LX20 PRO analyser, besides this test, the analyser can also be used to measure various electrolytes (eg. sodium, potassium) and some liver enzymes (GGT, ALT,AST etc)
The samples usually collected for the glucose test are serum, plasma, urine or cerebrospinal fluid.
Principle of Analysis
The analyser determines the glucose concentration by using a glucose reagent in conjunction with calibration standards done by the med tech. when the reagent is input into the machine.
The Analyser measures the oxygen consumption rate of the sample.
10 microlitre of sample is injected into the reaction cup containing the glucose oxidase solution. The ratio used is one part sample to 76 part reagent. The peak of the oxygen consumption is directly proportional to the concentration of glucose in the sample.
The machine then prints out the readout when the test has finished.
Thanks,
Randall
TG02
Can u name some drugs that will cause an increase in glucose level? Thanks =) see u..btw randall u didn't put ur name
Eugene Wong
TG02
Drug groups that raise glucose levels include:
-Corticosteroids
-Diazoxide (used to treat low glucose levels)
-Diuretics
-Epinephrine and Adrenaline
-Estrogens
-Phenobarbital
-phenytoin
-Beta-blockers (eg. propanolol)
hope that answers your question
Thanks
Randall
Quote from your entry: "When the total daily energy intake exceeds daily expenditure, the excess is converted to fat and stored in adipose tissue."
Thought glucose is converted to glycogen first??
What is the sample used? Plain blood centrifuged serum?
Is there anything the patient have to do before going for the test? i.e. Fast for some time before taking the blood?
Douglas
the sample used for the test is a plain tube.
patients have to usually fast for 12 hours before coming for the test.
Plain blood is used? I thought for fasting glucose a fluoride tube must be used? The Sodium fluoride in the grey top tube will reduce the rate of glucose metabolism so as to reduce/prevent false negative results, right? At least, thats what they do in my lab leh. Any idea why you guys don't used fluoride tube?
Sharifah
TG01
Thanks Sharifah
Randall
Sharifah
For glucose reference ranges,
each running time has a different range, eg. the fasting tube, the 1st hour and 2nd hour.
hope that answers your question
randall
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