Blood sugar is the amount of glucose in the blood. Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology. Glucose, transported via the bloodstream, is the primary source of energy for the body's cells.

Blood sugar concentration, or glucose level, is tightly regulated in the human body. Blood sugar regulation is the process by which the levels of Blood sugar, primarily Glucose, are maintained by the body Normally, the blood glucose level is maintained between about 4 and 6 mmol/L. Normal blood glucose level (homoeostasis) is about 90mg/100ml or 5mM. The total measurement of glucose in the circulating blood is therefore about 3. 3 to 7g (assuming an ordinary adult blood volume of 5 liters). Glucose levels rise after meals and are usually lowest in the morning, before the first meal of the day.

Failure to maintain blood glucose in the normal range leads to conditions of persistently high (hyperglycemia) or low (hypoglycemia) blood sugar. Hyperglycemia, hyperglycaemia, or high blood sugar is a condition in which an excessive amount of Glucose circulates in the Blood plasma Hypoglycemia or hypoglycaemia is the medical term for a pathologic state produced by a lower than normal level of Glucose ( sugar) in the blood Diabetes mellitus, characterized by persistent hyperglycemia of several causes, is the most prominent disease related to failure of blood sugar regulation. Diabetes mellitus (ˌdaɪəˈbiːtiːz or /ˌdaɪəˈbiːtəs/ /məˈlaɪtəs/ or /ˈmɛlətəs/ often referred to simply as diabetes ( Ancient Greek: grc

Although it is called "blood sugar," sugars besides glucose are found in the blood, such as fructose and galactose. Fructose (also levulose or laevulose) is a simple reducing Sugar ( Monosaccharide) found in many foods and is one of the three Galactose (Gal (also called brain sugar) is a type of Sugar which is less sweet than Glucose. Only glucose levels are regulated via insulin and glucagon. Insulin is a Hormone with intensive effects on both metabolism and several other body systems (eg vascular compliance Glucagon is an important Hormone involved in Carbohydrate metabolism.

Contents 1 Normal values 2 Regulation 3 Glucose measurement 3.1 Sample type 3.2 Methodology 3.3 Laboratory tests 3.4 Clinical correlation 4 Health effects 5 Low blood sugar 6 Converting glucose units 7 References 8 See also

Normal values

Despite long intervals between meals or the occasional consumption of meals with a substantial carb load, human blood glucose levels normally remain within a remarkably narrow range. In most humans this varies from about 80 mg/dl to perhaps 120 mg/dl (3. 9 to 6. 0 mmol/litre) except shortly after eating when the blood glucose level rises temporarily (up to 140 mg/dl in a non-diabetic). The mole (symbol mol) is a unit of Amount of substance: it is an SI base unit, and almost the only unit to be used to measure this

It is usually a surprise to realize how little glucose is actually maintained in the blood and body fluids. The control mechanism works on very small quantities. In a healthy adult male of 75 kg (165. 35 lb) with a blood volume of 5 litres (1. The pound or pound-mass (abbreviation lb, lbm, or sometimes in the United States #) is a unit of Mass Blood is a specialized Bodily fluid that delivers necessary substances to the body's cells ��such as nutrients and oxygen—and transports Waste products The litre or liter (see spelling differences) is a unit of Volume. 32 gal), a blood glucose level of 100 mg/dl or 5. A gallon is a measure of Volume. It is in current use in the United States and still has limited use in many other English-speaking countries 5 mmol/l corresponds to about 5 g (0. 2 oz or 0. A fluid ounce (abbreviated fl oz, fl oz or oz fl) is a unit of Volume in both the imperial and the US customary systems 002 gal, 1/500 of the total) of glucose in the blood and approximately 45 g (1½ ounces) in the total body water (which obviously includes more than merely blood and will be usually about 60% of the total body weight in men). A gallon is a measure of Volume. It is in current use in the United States and still has limited use in many other English-speaking countries A fluid ounce (abbreviated fl oz, fl oz or oz fl) is a unit of Volume in both the imperial and the US customary systems In medicine body water is all of the Water content of the Human body. Although many people prefer the less-ambiguous term body mass, the term body weight is overwhelmingly used in daily English speech and in biological and medical science contexts A more familiar comparison may help – 5 grams of glucose is about equivalent to a commercial sugar packet (as provided in many restaurants with coffee or tea). CoFFEE is an Open source Software for computer supported collaborative learning (CSCL in a digital classroom Tea refers to the cured agricultural product of the leaves leaf buds and internodes of Camellia sinensis, which have been prepared and cured for the market

Regulation

The homeostatic effect that keeps the blood value of glucose in a remarkably narrow range is the result of many factors, of which hormone regulation is the most important. Homeostasis (from Greek: ὅμος hómos, "equal" and ιστημι istēmi, "to stand" lit

There are two types of mutually antagonistic metabolic hormones affecting blood glucose levels:

• catabolic hormones (such as glucagon, growth hormone, and catecholaminesthyroxine, somatostatin), which increase blood glucose
• and one anabolic hormone (insulin), which decreases blood glucose. Glucagon is an important Hormone involved in Carbohydrate metabolism. Growth hormone ( GH) is a Peptide hormone that stimulates growth and cell reproduction in humans and other animals Insulin is a Hormone with intensive effects on both metabolism and several other body systems (eg vascular compliance aac to aamir & abid glucose level is approx. 85. 5- 134. 5(in research)

Glucose measurement

Sample type

Glucose can be measured in whole blood, serum, or plasma. Blood plasma is the Liquid component of Blood, in which the Blood cells are suspended Blood plasma is the Liquid component of Blood, in which the Blood cells are suspended Historically, blood glucose values were given in terms of whole blood, but most laboratories now measure and report the serum glucose levels. Because RBC (erythrocytes) have a higher concentration of protein (i. Red blood cells are the most common type of Blood cell and the Vertebrate body's principal means of delivering Oxygen to the body tissues via the Blood e. hemoglobin) than serum, serum has a higher water content and consequently more dissolved glucose than does whole blood. To convert from whole-blood glucose, multiply the value by 1. 15 to give the serum/plasma level.

Collection of blood in clot (red-top) tubes for serum chemistry analysis permits the metabolism of glucose in the sample by blood cells until separated by centrifugation. Serum-separating tubes, also known as serum separator tubes or SSTs are used in Medical Clinical chemistry tests requiring Blood serum. Centrifugation is a process that involves the use of the Centrifugal force for the separation of mixtures used in industry and in laboratory settings Higher than normal amounts of white or red blood cell counts can lead to excessive glycolysis in the sample with substantial reduction of glucose level if the sample is not processed quickly. See also Gluconeogenesis, which carries out a process wherein glucose is synthesized rather than catabolized Ambient temperature at which the blood sample is kept prior to centrifugation and separation of Plasma/Serum also affects glucose levels. At refrigerator temperatures, glucose remains relatively stable for several hours in the blood sample. At room temperature (25 °C), a loss of 1 to 2% of glucose per hour should be expected. The loss of glucose levels in aforementioned conditions can be prevented by using Fluoride top (gray-top) as the anticoagulant of choice upon blood collection, as Fluoride inhibits glycolysis. However, this should only be used when blood will be transported from one hospital laboratory to another for glucose measurement. Red-top serum separator tubes also preserve glucose in samples once they have been centrifugated to isolate the serum from cells, this tube would be the most efficient. Particular care should be given to drawing blood samples from the arm opposite the one in which an intravenous line is inserted, to prevent contamination of the sample with intravenous fluids (IV). Intravenous therapy or IV therapy is the giving of Liquid substances directly into a Vein. Alternatively, blood can be drawn from the same arm with an IV line after the IV was turned off for at least 5 minutes and the arm is elevated to drain the infused fluids away from the vein. As little as 10% contamination with 5% dextrose (D5W) will elevate glucose in a sample by 500 mg/dl or more. Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology. Arterial, capillary and venous blood have comparable glucose levels in a fasting individual, whereas after meals venous levels are lower than capillary or arterial blood.

Methodology

There are two different major methods that have been used to measure glucose. The older one is a chemical method that exploits the nonspecific reducing property of glucose in a reaction with an indicator substance that acquires or changes color on its reduction. Since other blood compounds also have reducing properties (e. g. , urea, which can build up in uremic patients), this method can have erroneous measurements up to 5 to 15 mg/dl. This is solved by the Enzymatic methods that are highly specific for glucose. The two most common employed enzymes are glucose oxidase and hexokinase. The glucose oxidase enzyme (GOx ( binds to beta-D-glucose (an Isomer of the six-carbon sugar Glucose) and aids in breaking the sugar down into its Metabolites Variation across species Hexokinases have been found in every organism checked ranging from bacteria, Yeast, and Plants to humans and other Vertebrates

I. CHEMICAL METHODS
A. Oxidation-Reduction Reaction
1. Alkaline Copper Reduction
Folin Wu Method		Blue end-product
Benedict's method	Modification of Folin wu for Qualitative Urine Glucose
Nelson Somoygi Method		Blue end-product
Neocuproine Method	*	Yellow-orange color Neocuproine
Shaeffer Hartmann Somygi	Utilizes the principle of Iodine reaction with Cuprous byproduct. Iodine (ˈaɪədaɪn ˈaɪədɪn or /ˈaɪədiːn/ from ιώδης iodes "violet" is a Chemical element that has the symbol I and Atomic Excess I2 is then titrated with thiosulfate. Thiosulfate (S2O32&minus is an Oxyanion of Sulfur produced by the reaction of Sulfite ions with elemental sulfur
2. Alkaline Ferricyanide Reduction
Hagedorn Jensen		Colorless end product; other reducing substances interfere with reaction
B. Condensation
Ortho-toluidine Method	Utilizes aromatic amines and hot acetic acid Forms Glycosylamine and Schiff's base which is emerald green in color This is the most specific method, but the reagent used is toxic
Anthrone (Phenols) Method	Forms hydroxymethyl furfural in hot acetic acid
II. An aromatic amine is an Amine with an Aromatic Substituent - that is - N[[hydrogen H]]2 - N[[hydrogen H]]- or Nitrogen Acetic acid, also known as ethanoic acid, is an organic chemical compound, giving Vinegar its sour taste Glycosylamine is a biochemical compound consisting of an Amine with a β-N-glycosidic bond to a Carbohydrate. ENZYMATIC METHODS
A. Glucose Oxidase
Saifer Gernstenfield Method		Inhibited by reducing substances like BUA, Bilirubin, Glutathione, Ascorbic Acid
Trinder Method	uses 4-aminophenazone oxidatively coupled with Phenol Subject to less interference by increases serum levels of Creatinine, Uric Acid or Hemoglobin Inhibited by Catalase
Kodak Ektachem	A Dry Chemistry Method Uses Reflectance Spectrophotometry to measure the intensity of color through a lower transparent film
Glucometer	Home monitoring blood glucose assay method Uses a strip impregnated with a Glucose Oxidase reagent
B. Bilirubin (formerly referred to as hematoidin) is the yellow breakdown product of normal Heme Catabolism. Glutathione ( GSH) is a Tripeptide. It contains an unusual Peptide linkage between the amine group of Cysteine and the Carboxyl This article deals with the molecular aspects of ascorbic acid Creatinine is a break-down product of Creatine phosphate in Muscle, and is usually produced at a fairly constant rate by the body (depending on muscle mass Uric acid (or urate) is an Organic compound of Carbon, Nitrogen, Oxygen and Hydrogen with the formula C5H4N4O3 Hemoglobin ( also spelled haemoglobin and abbreviated Hb or Hgb) is the Iron -containing Oxygen -transport Metalloprotein Catalase is a common Enzyme found in nearly all living organisms where it functions to catalyze the decomposition of Hydrogen peroxide to Hexokinase
NADP as cofactor NADPH (reduced product) is measured in 340 nm More specific than Glucose Oxidase method due to G-6PO_4, which inhibits interfering substances except when sample is hemolyzed

Laboratory tests

1. Fasting Blood Sugar or Glucose test (FBS)
2. Urine Glucose test
3. Two-hr Postprandial Blood Sugar Test (2-h PPBS)
4. Oral Glucose Tolerance test (OGTT)
5. Intravenous Glucose Tolerance test (IVGTT)
6. Glycosylated Hemoglobin (HbA_1C)
7. Self-monitoring of Glucose level via Home Kits

Clinical correlation

The fasting blood glucose (FBG) level is the most commonly used indication of overall glucose homeostasis. Nicotinamide adenine dinucleotide phosphate ( NADP+, in older notation triphosphopyridine nucleotide TPN) is used in anabolic reactions such as Lipid Conditions that affect glucose levels are shown in the table below. They reflect abnormalities in the multiple control mechanism of glucose regulation.

The metabolic response to a carbohydrate challenge is conveniently assessed by the postprandial glucose level drawn 2 hours after a meal or a glucose load. In addition, the glucose tolerance test, consisting of serial timed measurements after a standardized amount of oral glucose intake, is used to aid in the diagnosis of diabetes. Diabetes mellitus (ˌdaɪəˈbiːtiːz or /ˌdaɪəˈbiːtəs/ /məˈlaɪtəs/ or /ˈmɛlətəs/ often referred to simply as diabetes ( Ancient Greek: grc

Causes of Abnormal Glucose Levels

Persistent Hyperglycemia	Transient Hyperglycemia	Persistent Hypoglycemia	Transient Hypoglycemia
Reference Range, FBG: 70-110 mg/dl
Diabetes Mellitus	Pheochromocytoma	Insulinoma	Acute Alcohol Ingestion
Adrenal cortical hyperactivity Cushing's Syndrome	Severe Liver Disease	Adrenal cortical insufficiency Addison's Disease	Drugs: salicylates, antituberculosis agents
Hyperthyroidism	Acute stress reaction	Hypopituitarism	Severe Liver disease
Acromegaly	Shock	Galactosemia	Several Glycogen storage diseases
Obesity	Convulsions	Ectopic Insulin production from tumors	Hereditary fructose intolerance

Health effects

If blood sugar levels drop too low, a potentially fatal condition called hypoglycemia develops. A phaeochromocytoma ( pheochromocytoma in the US is a Neuroendocrine tumor of the medulla of the Adrenal glands (originating in the Chromaffin An insulinoma is a Tumour of the Pancreas derived from the Beta cells which while retaining the ability to synthesize and secrete Insulin is autonomous The liver is a vital organ in the human body and is present in Vertebrates and some other animals Addison's disease (also known as chronic Adrenal insufficiency, '''hypocortisolism''' or '''hypocorticism) is a rare Endocrine disorder Salicylic acid (from the Latin word for the willow tree Salix, from whose bark it can be obtained is a Beta hydroxy acid (BHA with the formula Hyperthyroidism is the term for overactive tissue within the Thyroid gland resulting in overproduction and thus an excess of circulating free thyroid hormones Thyroxine Hypopituitarism is the decreased ( hypo) secretion of one or more of the eight Hormones normally produced by the Pituitary gland at the base of the Brain Acromegaly (from Greek akros "extreme" or "extremities" and megalos "large" - extremities enlargement is a Syndrome Galactosemia is a rare genetic metabolic disorder which affects an individual's ability to properly metabolize the sugar Galactose. Glycogen storage disease (synonyms glycogenosis, dextrinosis) is any one of several inborn errors of metabolism that result from Enzyme defects Obesity is a condition in which excess Body fat has accumulated to such an extent that health may be negatively affected An epileptic seizure is caused by excessive and/or hypersynchronous electrical Neuronal activity and is usually self-limiting Hypoglycemia or hypoglycaemia is the medical term for a pathologic state produced by a lower than normal level of Glucose ( sugar) in the blood Symptoms may include lethargy, impaired mental functioning, irritability, and loss of consciousness. Irritability is an excessive response to stimuli. Irritability takes many forms from the Contraction of a Unicellular organism when touched to complex See also Unconscious mind. Unconsciousness, more appropriately referred to as loss of Consciousness or lack of consciousness is

If levels remain too high, appetite is suppressed over the short term. Long-term hyperglycemia causes many of the long-term health problems associated with diabetes, including eye, kidney, and nerve damage. Hyperglycemia, hyperglycaemia, or high blood sugar is a condition in which an excessive amount of Glucose circulates in the Blood plasma Diabetes mellitus (ˌdaɪəˈbiːtiːz or /ˌdaɪəˈbiːtəs/ /məˈlaɪtəs/ or /ˈmɛlətəs/ often referred to simply as diabetes ( Ancient Greek: grc

Low blood sugar

Some people report drowsiness or impaired cognitive function several hours after meals, which they believe is related to a drop in blood sugar, or "low blood sugar". For more information, see:

• idiopathic postprandial syndrome
• hypoglycemia

Mechanisms which restore satisfactory blood glucose levels after hypoglycemia must be quick and effective, because of the immediate serious consequences of insufficient glucose (in the extreme, coma, less immediately dangerous, confusion or unsteadiness, amongst many other effects). Idiopathic postprandial syndrome is a medical term describing a collection of symptoms popularly attributed to Hypoglycemia but without demonstrably low Glucose levels Hypoglycemia or hypoglycaemia is the medical term for a pathologic state produced by a lower than normal level of Glucose ( sugar) in the blood Hypoglycemia or hypoglycaemia is the medical term for a pathologic state produced by a lower than normal level of Glucose ( sugar) in the blood This is because, at least in the short term, it is far more dangerous to have too little glucose in the blood than too much. In healthy individuals these mechanisms are indeed generally efficient, and symptomatic hypoglycemia is generally only found in diabetics using insulin or other pharmacological treatment. Such hypoglycemic episodes vary greatly between persons and from time to time, both in severity and swiftness of onset. In severe cases prompt medical assistance is essential, as damage (to brain and other tissues) and even death will result from sufficiently low blood glucose levels.

Converting glucose units

The U. S. uses mg/dL. The rest of the world, including Canada and Mexico, uses what is referred to as the "World Standard" of mmol/L.

To convert blood glucose readings:

• Divide the mg/dL figure by 18 (or multiply by 0. 055) to get mmol/L.
• Multiply the mmol/L figure by 18 (or divide by 0. 055) to get mg/dL.

References

• John Bernard Henry, M. D. : Clinical diagnosis and Management by Laboratory Methods 20th edition, Saunders, Philadelphia, PA, 2001.
• Ronald A. Sacher and Richard A. McPherson: Widmann's Clinical Interpretation of Laboratory Tests 11th edition, F. A. Davis Company, 2001.

See also

• Current research - Boronic acids in supramolecular chemistry: Saccharide recognition

A boronic acid is an Alkyl or Aryl substituted Boric acid containing a Carbon to Boron Chemical bond belonging to

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