Question:

# What is the best blood glucose meter?

## The best blood glucose meter based on size, speed, memory, and whether test strips required users to enter codes before testing is the OneTouch UltraMini. They are $20, and$1.14 per strip.

The Clarke Error Grid Analysis (EGA) was developed in 1987 to quantify clinical accuracy of patient estimates of their current blood glucose as compared to the blood glucose value obtained in their meter. It was then used to quantify the clinical accuracy of blood glucose estimates generated by meters as compared to a reference value. A description of the EGA appeared in Diabetes Care in 1987. Eventually, the EGA became accepted as one of the “gold standards” for determining the accuracy of blood glucose meters. The grid breaks down a scatterplot of a reference glucose meter and an evaluated glucose meter into five regions:
OneTouch Ultra is a blood glucose monitoring device for people with diabetes and is the foundation product for LifeScan's OneTouch Ultra Family of blood glucose monitoring systems. OneTouch Ultra Blood Glucose Meters provide blood glucose test results in 5 seconds, offer alternative test site options, and various memory and flagging features. The results are displayed as plasma values. OneTouch Meters are sold in kits containing a carry case, a lancing device, control solution, sample quantities of lancets, and a replacement cap for use with the sampling device when using alternative site testing. The OneTouch Ultra 2 is similar in design and operation to the OneTouch Ultra Meter, but also offers Before and After Meal Flags, Comments, and a list style memory recall. This meter also provides 7 day, 14 day, and 30-day averages, with the option of averaging Before meal or After Meal records. Other OneTouch Ultra Meters include the OneTouch UltraSmart and the OneTouch UltraMini Meter (known as the OneTouch UltraEasy in Europe). In addition to the original Silver Moon color, LifeScan introduced three additional colors of the OneTouch UltraMini Meter in summer 2007: Pink Glow, Limelight, and Jet Black. OneTouch Meters with data ports can be used in combination with the downloadable OneTouch Diabetes Management Software and a PC to compute averages and trends. The software is available from LifeScan's Web site but an interface cable must be purchased. Current: William C. Weldon, Chairman & CEO
A glucose meter (or glucometer) is a medical device for determining the approximate concentration of glucose in the blood. It is a key element of home blood glucose monitoring (HBGM) by people with diabetes mellitus or hypoglycemia. A small drop of blood, obtained by pricking the skin with a lancet, is placed on a disposable test strip that the meter reads and uses to calculate the blood glucose level. The meter then displays the level in mg/dl or mmol/l. Since approximately 1980, a primary goal of the management of type 1 diabetes and type 2 diabetes mellitus has been achieving closer-to-normal levels of glucose in the blood for as much of the time as possible, guided by HBGM several times a day. The benefits include a reduction in the occurrence rate and severity of long-term complications from hyperglycemia as well as a reduction in the short-term, potentially life-threatening complications of hypoglycemia. There are several key characteristics of glucose meters which may differ from model to model: Table of blood glucose units of measurement by country Country Country Special glucose meters for multi-patient hospital use are now used. These provide more elaborate quality control records. Their data handling capabilities are designed to transfer glucose results into electronic medical records and the laboratory computer systems for billing purposes. The cost of home blood glucose monitoring is substantial due to the cost of the test strips. In 2006, the consumer cost of each glucose strip ranged from about $0.35 to$1.00. Manufacturers often provide meters at no cost to induce use of the profitable test strips. Type 1 diabetics may test as often as 4 to 10 times a day due to the dynamics of insulin adjustment, whereas type 2 typically test less frequently, especially when insulin is not part of treatment. Batches of counterfeit test strips for some meters have been identified, which have been shown to produce inaccurate results. Accuracy of glucose meters is a common topic of clinical concern. Blood glucose meters must meet accuracy standards set by the International Organization for Standardization (ISO). According to ISO 15197 Blood glucose meters must provide results that are within 20% of a laboratory standard 95% of the time (for concentrations about 75 mg/dL, absolute levels are used for lower concentrations). However, a variety of factors can affect the accuracy of a test. Factors affecting accuracy of various meters include calibration of meter, ambient temperature, pressure use to wipe off strip (if applicable), size and quality of blood sample, high levels of certain substances (such as ascorbic acid) in blood, hematocrit, dirt on meter, humidity, and aging of test strips. Models vary in their susceptibility to these factors and in their ability to prevent or warn of inaccurate results with error messages. The Clarke Error Grid has been a common way of analyzing and displaying accuracy of readings related to management consequences. More recently an improved version of the Clarke Error Grid has come into use: It is known as the Consensus Error Grid. Strips that go in blood glucose numbers usually need to be coded so that numbers on the strip match the number that appears on the meter, otherwise, the exact accuracy of the blood glucose meter may out. In 1962, Leland Clark and Champ Lyons at the Medical College of Alabama developed the first glucose enzyme electrode. It relied on a thin layer of glucose oxidase on an oxygen of oxygen consumed by the enzyme. Another early glucose meter was the Ames Reflectance Meter by Anton H. Clemens. It was used in American hospitals in the 1970s. A moving needle indicated the blood glucose after about a minute. Home glucose monitoring was demonstrated to improve glycemic control of type 1 diabetes in the late 1970s, and the first meters were marketed for home use around 1981. The two models initially dominant in North America in the 1980s were the Glucometer, introduced on November 1981 whose trademark is owned by Bayer and the Accu-chek meter (by Roche). Consequently, these brand names have become synonymous with the generic product to many health care professionals. In Britain, a health care professional or a patient may refer to "taking a BM": "Mrs X's BM is 5", etc. BM stands for Boehringer Mannheim, now called Roche, who produced test strips called 'BM-test'. Test strips that changed color and could be read visually, without a meter, were also widely used in the 1980s. They had the added advantage that they could be cut longitudinally to save money. As meter accuracy and insurance coverage improved, they lost popularity. However, a generic version of the BM is marketed under the brand name Glucoflex-R. There is a UK Pharmaceutical company (Ambe Medical Group) who have the executive rights for distribution within the United Kingdom. On May 1, 2009, one manufacturer reduced the price of their test strip to the NHS, by approximately 50% (distributed in the UK by Ambe Medical Group and led by Patrick O'Neill-Ortiz). This should allow the NHS to save money on strips and perhaps loosen the restrictions on supply a little, but there is one catch - the test strip (Glucoflex-R) is read by eye, not by meter. Critics argue this is not as accurate or convenient as meter testing. The manufacturer cites studies that show the product is just as effective despite not giving an answer to one decimal place, something they argue is unnecessary for control of blood sugar. This debate has already happened in Germany where Glucoflex-R is an established strip for type 2 diabetes (test strips are not subsidized by the German government for people with Type 2 Diabetes). As a footnote, another low cost visually read strip is soon to be available on prescription according to sources at the NHS. How the other manufactures and the NHS react to these developments, remains to be seen. Another visual strip is also marketed under the brand name Betachek. At least in North America, hospitals resisted adoption of meter glucose measurements for inpatient diabetes care for over a decade. Managers of laboratories argued that the superior accuracy of a laboratory glucose measurement outweighed the advantage of immediate availability and made meter glucose measurements unacceptable for inpatient diabetes management. Patients with diabetes and their endocrinologists eventually persuaded acceptance. Some health care policymakers still resist the idea that the society would be well advised to pay the consumables (reagents, lancets, etc.) needed. Home glucose testing was adopted for type 2 diabetes more slowly than for type 1, and a large proportion of people with type 2 diabetes have never been instructed in home glucose testing. This has mainly come about because health authorities are reluctant to bear the cost of the test strips and lancets. Development of noninvasive devices may enable continuous monitoring. Research is being done on noninvasive methods for measuring blood glucose, such as using infrared or near-infrared light, electric currents, and ultrasound. One noninvasive glucose meter has been approved by the U.S. FDA: The GlucoWatch G2 Biographer is designed to be worn on the wrist and uses electric fields to draw out body fluid for testing. The device does not replace conventional blood glucose monitoring. One limitation is that the GlucoWatch is not able to cope with perspiration at the measurement site. Sweat must be allowed to dry before measurement can resume. Due to this limitations and others, the product is no longer on the market. The market introduction of noninvasive blood glucose measurement by spectroscopic measurement methods, in the field of near-infrared (NIR), by extracorporal measuring devices, failed so far because at this time, the devices measure tissue sugar in body tissues and not the blood sugar in blood fluid. To determine blood glucose, the measuring beam of infrared light, for example, has to penetrate the tissue for measurement of blood glucose. Throughout the 1990s a company in Hagerstown, Maryland, Futrex, Inc., was deep into finding a universal calibration for their meter, the Dream Beam, which relied on near-infrared technology, however in 1996 the company was raided by the FDA and a lawsuit was filed by the SEC charging Futrex, Inc. and its president Robert Rosenthal with fraud due to the belief that no non-invasive meter could accurately measure blood glucose. The raid was due to an unruly employee however critical time and information was lost throughout the raid and lawsuit, and development was ended on the instrument. It is speculated that within the next decade, meters may be replaced with continuous glucose sensors for many people with diabetes.][ This will likely decrease complications found in people with diabetes by limiting problems associated with hyperglycemia and hypoglycemia. There are currently three CGMS (continuous glucose monitoring system) available. The first is Medtronic's Minimed Paradigm RTS with a sub-cutaneous probe attached to a small transmitter (roughly the size of a quarter) that sends interstitial glucose levels to a small pager sized receiver every five minutes. The DexCom STS System is another available system (2Q 2006). It is a hypodermic probe with a small transmitter. The receiver is about the size of a cell phone and can operate up to five feet from the transmitter. Aside from a two-hour calibration period, monitoring is logged at five-minute intervals for up to 72 hours. The user can set the high and low glucose alarms. The third CGMS available is the FreeStyle Navigator from Abbott Laboratories. There is currently an effort to develop an integrated treatment system with a glucose meter, insulin pump, and wristop controller, as well as an effort to integrate the glucose meter and a cell phone. These glucose meter/cellular phone combinations are under testing and currently cost \$149 USD retail.][ Testing strips are proprietary and available only through the manufacturer (no insurance availability). These "Glugophones" are currently offered in three forms: as a dongle for the iPhone, an add-on pack for LG model UX5000, VX5200, and LX350 cell phones, as well as an add-on pack for the Motorola Razr cell phone. In US, this limits providers to AT&T and Verizon. Similar systems have been tested for a longer time in Finland.][ An Israeli company by the name of Cnoga Medical Ltd. has developed a non-invasive glucometer. Cnoga's technology is based on real-time tissue photography. Tissue image color is processed in real-time providing the temporary color distribution using dynamic range of at least 36-bit color depth representing over 6.8^10 color combination, then by using sophisticated mathematical algorithm.][ Another Israeli company named Integrity Applications has developed a non-invasive glucometer called the GlucoTrack. Integrity's product is based on a combination of ultrasonic, electromagnetic and thermal technologies to measure glucose. Their product is scheduled to be commercially available in the EU in 2012 and about a year later in the US. Recent advances in cellular data communications technology have enabled the development of glucose meters that directly integrate cellular data transmission capability, enabling the user to both transmit glucose data to the medical caregiver and receive direct guidance from the caregiver on the screen of the glucose meter. The first such device, from Telcare, Inc., was exhibited at the 2010 CTIA International Wireless Expo, where it won an E-Tech award. This device is currently undergoing clinical testing in the US and internationally. Many glucose meters employ the oxidation of glucose to gluconolactone catalyzed by glucose oxidase (sometimes known as GOx). Others use a similar reaction catalysed instead by another enzyme, glucose dehydrogenase (GDH). This has the advantage of sensitivity over glucose oxidase but is more susceptible to interfering reactions with other substances. The first-generation devices relied on the same colorimetric reaction that is still used nowadays in glucose test strips for urine. Besides glucose oxidase, the test kit contains a benzidine derivative, which is oxidized to a blue polymer by the hydrogen peroxide formed in the oxidation reaction. The disadvantage of this method was that the test strip had to be developed after a precise interval (the blood had to be washed away), and the meter needed to be calibrated frequently. Most glucometers today use an electrochemical method. Test strips contain a capillary that sucks up a reproducible amount of blood. The glucose in the blood reacts with an enzyme electrode containing glucose oxidase (or dehydrogenase). The enzyme is reoxidized with an excess of a mediator reagant, such as a ferricyanide ion, a ferrocene derivative or osmium bipyridyl complex. The mediator in turn is reoxidised by reaction at the electrode,which generates an electrical current. The total charge passing through the electrode is proportional to the amount of glucose in the blood that has reacted with the enzyme. The coulometric method is a technique where the total amount of charge generated by the glucose oxidation reaction is measured over a period of time. This is analogous to throwing a ball and measuring the distance it has covered so as to determine how hard it was thrown. The amperometric method is used by some meters and measures the electrical current generated at a specific point in time by the glucose reaction. This is analogous to throwing a ball and using the speed at which it is travelling at a point in time to estimate how hard it was thrown. The coulometric method can allow for variable test times, whereas the test time on a meter using the amperometric method is always fixed. Both methods give an estimation of the concentration of glucose in the initial blood sample. The same principle is used in test strips that have been commercialised for the detection of diabetic ketoacidosis (DKA). These test strips use a beta-hydroxybutyrate-dehydrogenase enzyme instead of a glucose oxidising enzyme and have been used to detect and help treat some of the complications that can result from prolonged hyperglycaemia. Blood alcohol sensors using the same approach, but with alcohol dehydrogenase enzymes, have been tried and patented but have not yet been successfully commercially developed. Although the apparent value of immediate measurement of blood glucose might seem to be higher for hypoglycemia than hyperglycemia, meters have been less useful. The primary problems are precision and ratio of false positive and negative results. An imprecision of ±15% is less of a problem for high glucose levels than low. There is little difference in the management of a glucose of 200 mg/dl compared with 260 (i.e., a "true" glucose of 230±15%), but a ±15% error margin at a low glucose concentration brings greater ambiguity with regards to glucose management. The imprecision is compounded by the relative likelihoods of false positives and negatives in populations with diabetes and those without. People with type 1 diabetes usually have glucose levels above normal, often ranging from 40 to 500 mg/dl (2.2 to 28 mmol/l), and when a meter reading of 50 or 70 (2.8 or 3.9 mmol/l) is accompanied by their usual hypoglycemic symptoms, there is little uncertainty about the reading representing a "true positive" and little harm done if it is a "false positive." However, the incidence of hypoglycemia unawareness, hypoglycemia-associated autonomic failure (HAAF) and faulty counterregulatory response to hypoglycemia make the need for greater reliability at low levels particularly urgent in patients with type 1 diabetes mellitus, while this is seldom an issue in the more common form of the disease, type 2 diabetes mellitus. In contrast, people who do not have diabetes may periodically have hypoglycemic symptoms but may also have a much higher rate of false positives to true, and a meter is not accurate enough to base a diagnosis of hypoglycemia upon. A meter can occasionally be useful in the monitoring of severe types of hypoglycemia (e.g., congenital hyperinsulinism) to ensure that the average glucose when fasting remains above 70 mg/dl (3.9 mmol/l).
Accu-Chek is the brand of blood sugar-testing devices (glucose meters) and Insulin Pumps (originally by Distronic) manufactured by Roche Diagnostics, largely for the diabetic market. Accu-Chek Blood Glucose Monitor Kits contain: - a blood glucose meter which measures blood sugar via inserted one-time-use "strips" (Accu-chek Aviva, Accu-chek Compact Plus) or a disposable cassette with 50 tests (Accu-chek Mobile) - a lancet device which fires a sharp needle marginally through the epidermis of the finger in order to allow a small amount of blood to be squeezed onto the strip in the monitor - a user manual - registration cards for the lifetime warranty
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D-Glucose (2R,3S,4R,5R)-2,3,4,5,6-Pentahydroxyhexanal Blood sugar
Dextrose
Corn sugar
D-Glucose
Grape sugar OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O C([C@@H]1[C@H]([C@@H]([C@H]([C@H](O1)O)O)O)O)O InChI=1S/C6H12O6/c7-1-2-3(8)4(9)5(10)6(11)12-2/h2-11H,1H2/t2-,3-,4+,5-,6?/m1/s1
Key: WQZGKKKJIJFFOK-GASJEMHNSA-N  α-D-glucose: 146 °C
β-D-glucose: 150 °C Glucose ( or ; C6H12O6, also known as D-glucose, dextrose, or grape sugar) is a simple monosaccharide found in plants. It is one of the three dietary monosaccharides, along with fructose and galactose, that are absorbed directly into the bloodstream during digestion. An important carbohydrate in biology, cells use it as the primary source of energy and a metabolic intermediate. Glucose is one of the main products of photosynthesis and fuels for cellular respiration. Glucose exists in several different molecular structures, but all of these structures can be divided into two families of mirror-images (stereoisomers). Only one set of these isomers exists in nature, those derived from the "particular chiral form" of glucose, denoted D-glucose, or D-glucose. The chemical D-glucose is sometimes referred to as dextrose, a historical name that derives from dextrorotatory glucose because a solution of D-glucose in water rotates the plane of polarized light to the right (dextro). However, the D- in D-glucose refers to a chiral chemical similarity property in sugars, not the property of rotating light (for example, D-fructose rotates light to the left). For this reason, the D- and L- designations in sugars do not perfectly predict optical rotation, and do not refer to this property. Starch and cellulose are polymers derived from the dehydration of D-glucose. The other stereoisomer, called -glucoseL, is hardly ever found in nature. The name "glucose" comes from the Greek word glukus (), meaning "sweet". The suffix "-ose" denotes a sugar. Why glucose—and not another monosaccharide such as fructose—is so widely used in organisms is not clearly understood. One reason might be that glucose has a lower tendency, relative to other hexose sugars, to react non-specifically with the amino groups of proteins. This reaction (glycation) reduces or destroys the function of many enzymes. The low rate of glycation is due to glucose's preference for the less reactive cyclic isomer. Nevertheless, many of the long-term complications of diabetes (e.g., blindness, renal failure, and peripheral neuropathy) are probably due to the glycation of proteins or lipids. In contrast, enzyme-regulated addition of glucose to proteins by glycosylation is often essential to their function.][ Another reason as to why glucose is the most common sugar is that it is the most conformationally stable among other possibilities. Glucose is a common medical analyte measured in blood samples. Eating or fasting prior to taking a blood sample has an effect on the result. A high fasting glucose blood sugar level may be a sign of prediabetes or diabetes mellitus. Glucose is a ubiquitous fuel in biology. It is used as an energy source in most organisms, from bacteria to humans. Use of glucose may be by either aerobic respiration, anaerobic respiration, or fermentation. Glucose is the human body's key source of energy, through aerobic respiration, providing approximately 3.75 kilocalories (16 kilojoules) of food energy per gram. Breakdown of carbohydrates (e.g. starch) yields mono- and disaccharides, most of which is glucose. Through glycolysis and later in the reactions of the citric acid cycle (TCAC), glucose is oxidized to eventually form 2CO and water, yielding energy sources, mostly in the form of ATP. The insulin reaction, and other mechanisms, regulate the concentration of glucose in the blood. Glucose is a primary source of energy for the brain, and hence its availability influences psychological processes. When glucose is low, psychological processes requiring mental effort (e.g., self-control, effortful decision-making) are impaired. Use of glucose as an energy source in cells is via aerobic or anaerobic respiration. Both of these start with the early steps of the glycolysis metabolic pathway. The first step of this is the phosphorylation of glucose by hexokinase to prepare it for later breakdown to provide energy. The major reason for the immediate phosphorylation of glucose by a hexokinase is to prevent diffusion out of the cell. The phosphorylation adds a charged phosphate group so the glucose 6-phosphate cannot easily cross the cell membrane. Irreversible first steps of a metabolic pathway are common for regulatory purposes. In anaerobic respiration one glucose molecule produces a net gain of two ATP molecules (four ATP molecules are produced during glycolysis but two are required by enzymes used during the process). In aerobic respiration a molecule of glucose is much more profitable in that a net worth of 32 ATP molecules is generated (34 gross with two being required in the process). Click on genes, proteins and metabolites below to link to respective articles. Organisms use glucose as a precursor for the synthesis of several important substances. Starch, cellulose, and glycogen ("animal starch") are common glucose polymers (polysaccharides). Some of these polymers like starch or glycogen serve as energy stores while others like cellulose and chitin (which is made from a derivative of glucose) have structural roles. Oligosaccharides of glucose combined with other sugars serve as important energy stores. These include lactose, the predominant sugar in milk which a glucose-galactose disaccharide and sucrose, another disaccharide of glucose and fructose. Glucose is also added onto certain proteins and lipids in a process called glycosylation. This is often critical for their functioning. The enzymes that join glucose to other molecules usually use phosphorylated glucose to power the formation of the new bond by breaking the glucose-phosphate bond. Other than its direct use as a monomer, glucose can be broken down to synthesize a wide variety of other biomolecules. This is important as glucose serves both as a primary store of energy but also as a source of organic carbon. Glucose can be broken down and converted into lipids. It is also a precursor for the synthesis of other important molecules like vitamin C (ascorbic acid). Though plants and some microbes can create all the compounds they need from glucose given the necessary minerals, all animals and many microbes cannot synthesize some or all of the necessary compounds and thus need to obtain them from an external source such as diet. Glucose is a monosaccharide with formula C6H12O6 or H-(C=O)-(CHOH)5-H, whose five hydroxyl (OH) groups are arranged in a specific way along its six-carbon backbone. In its fleeting open-chain form, the glucose molecule has an open (as opposed to cyclic) and unbranched backbone of six carbon atoms, C-1 through C-6; where C-1 is part of an aldehyde group H(C=O)-, and each of the other five carbons bears one hydroxyl group -OH. The remaining bonds of the backbone carbons are satisfied by hydrogen atoms -H. Therefore glucose is a hexose and an aldose, or an aldohexose. Each of the four carbons C-2 through C-5 is a stereocenter, meaning that its four bonds connect to four different substitutents. (Carbon C-2, for example, connects to -(C=O)H, -OH, -H, and -(CHOH)4H.) In D-glucose, these four parts must be in a specific three-dimensional arrangement. Namely, when the molecule is drawn in the Fischer projection, the hydroxyls on C-2, C-4, and C-5 must be on the right side, while that on C-3 must be on the left side. The positions of those four hydroxyls are exactly reversed in the Fischer diagram of -glucoseL. D- and L-glucose are two of the 16 possible aldohexoses; the other 14 are allose, altrose, mannose, gulose, idose, galactose, and talose, each with two enantiomers, "D-" and "L-". In solutions, the open-chain form of glucose (either "D-" or "L-") exists in equilibrium with several cyclic isomers, each containing a ring of carbons closed by one oxygen atom. In aqueous solution however, more than 99% of glucose molecules, at any given time, exist as pyranose. The open-chain form is limited to about 0.25% and furanose exists in negligible amounts. The terms "glucose" and "D-glucose" are generally used for these cyclic forms as well. The ring arises from the open-chain form by a nucleophilic addition reaction between the aldehyde group -(C=O)H at C-1 and the hydroxyl group -OH at C-4 or C-5, yielding a hemiacetal group -C(OH)H-O-. The reaction between C-1 and C-5 creates a molecule with a six-membered ring, called pyranose, after the cyclic ether pyran, the simplest molecule with the same carbon-oxygen ring. The (much rarer) reaction between C-1 and C-4 creates a molecule with a five-membered ring, called furanose, after the cyclic ether furan. In either case, each carbon in the ring has one hydrogen and one hydroxyl attached, except for the last carbon (C-4 or C-5) where the hydroxyl is replaced by the remainder of the open molecule (which is -(C(CH2OH)HOH)-H or -(CHOH)-H, respectively). The ring-closing reaction makes carbon C-1 chiral, too, since its four bonds lead to -H, to -OH, to carbon C-2, and to the ring oxygen. These four parts of the molecule may be arranged around C-1 (the anomeric carbon) in two distinct ways, designated by the prefixes "α-" and "β-". When a glucopyranose molecule is drawn in the Haworth projection, the designation "α-" means that the hydroxyl group attached to C-1 and the -CH2OH group at C-5 lies on opposite sides of the ring's plane (a trans arrangement), while "β-" means that they are on the same side of the plane (a cis arrangement). Therefore, the open-chain isomer D-glucose gives rise to four distinct cyclic isomers: α-D-glucopyranose, β-D-glucopyranose, α-D-glucofuranose, and β-D-glucofuranose; which are all chiral. α-D-
Glucopyranose β-D-
Glucopyranose α-D-
Glucofuranose β-D-
Glucofuranose The other open-chain isomer L-glucose similarly gives rise to four distinct cyclic forms of L-glucose, each the mirror image of the corresponding D-glucose. The rings are not planar but twisted in three dimensions. The glucopyranose ring (α or β) can assume several non-planar shapes, analogous to the "chair" and "boat" conformations of cyclohexane. Similarly, the glucofuranose ring may assume several shapes, analogous to the "envelope" conformations of cyclopentane. The glucopyranose forms of glucose predominate in solution, and are the only forms observed in the solid state. They are crystalline colorless solids, highly soluble in water and acetic acid, poorly soluble in methanol and ethanol. They melt at (α) and (β), and decompose at higher temperatures into carbon and water. Each glucose isomer is subject to rotational isomerism. Within the cyclic form of glucose, rotation may occur around the O6-C6-C5-O5 torsion angle, termed the ω-angle, to form three staggered rotamer conformations called gauche-gauche (gg), gauche-trans (gt) and trans-gauche (tg). For methyl α-D-glucopyranose at equilibrium the ratio of molecules in each rotamer conformation is reported as 57:38:5 gg:gt:tg. This tendency for the ω-angle to prefer to adopt a gauche conformation is attributed to the gauche effect. All forms of glucose are colorless and easily soluble in water, acetic acid, and several other solvents. They are only sparingly soluble in methanol and ethanol. The open-chain form is thermodynamically unstable, and it spontaneously isomerizes to the cyclic forms. (Although the ring closure reaction could in theory create four- or three-atom rings, these would be highly strained and are not observed.) In solutions at room temperature, the four cyclic isomers interconvert over a time scale of hours, in a process called mutarotation. Starting from any proportions, the mixture converges stable ratio of α:β 36:64. The ratio would be α:β 11:89 if it were not for the influence of the anomeric effect. Mutarotation is considerably slower at temperatures close to 0 °C. Mutarotation consists of a temporary reversal of the ring-forming reaction, resulting in the open-chain form, followed by a re-forming of the ring. The ring closure step may use a different -OH group than the one recreated by the opening step (thus switching between pyranose and furanose forms), and/or the new hemiacetal group created on C-1 may have the same or opposite handedness as the original one (thus switching between the α and β forms). Thus, even though the open-chain form is barely detectable in solution, it is an essential component of the equilibrium. Depending on conditions, three major solid forms of glucose can be crystallised from water solutions: α-glucopyranose, β-glucopyranose, and β-glucopyranose hydrate. Whether in water or in the solid form, D-glucose is dextrorotatory, meaning that it will rotate the direction of polarized light clockwise. The effect is due to the chirality of the molecules, and indeed the mirror-image isomer, L-glucose, is levorotatory (rotates polarized light counterclockwise) by the same amount. The strength of the effect is different for each of the five tautomers. Note that the D- prefix does not refer directly to the optical properties of the compound. It indicates that the C-2 chiral center has the same handedness as that of D-glyceraldehyde (which was so labeled because it is dextrorotatory). The fact that D-glucose is dextrorotatory is a combined effect of its four chiral centers, not just of C-2; and indeed some of the other D-aldohexoses are levorotatory. In plants and some prokaryotes, glucose is a product of photosynthesis. In animals and fungi, glucose results from the breakdown of glycogen, a process known as glycogenolysis. In plants the breakdown substrate is starch. In animals, glucose is synthesized in the liver and kidneys from non-carbohydrate intermediates, such as pyruvate, lactate and glycerol, by a process known as gluconeogenesis. In some deep-sea bacteria, glucose is produced by chemosynthesis. Glucose is produced commercially via the enzymatic hydrolysis of starch. Many crops can be used as the source of starch. Maize, rice, wheat, cassava, corn husk and sago are all used in various parts of the world. In the United States, cornstarch (from maize) is used almost exclusively. Most commercial glucose occurs as a component of invert sugar, an approximately 1:1 mixture of glucose and fructose. In principle, cellulose could be hydrolysed to glucose, but this process is not yet commercially practical. Most dietary carbohydrates contain glucose, either as their only building block, as in starch and glycogen, or together with another monosaccharide, as in sucrose and lactose. In the lumen of the duodenum and small intestine, the glucose oligo- and polysaccharides are broken down to monosaccharides by the pancreatic and intestinal glycosidases. Other polysaccharides cannot be processed by the human intestine and require assistance by intestinal flora if they are to be broken down; the most notable exceptions are sucrose (fructose-glucose) and lactose (galactose-glucose). Glucose is then transported across the apical membrane of the enterocytes by SLC5A1, and later across their basal membrane by SLC2A2. Some of the glucose is converted to lactic acid by astrocytes, which is then utilized as an energy source by brain cells, some of the glucose is used by intestinal cells and red blood cells, while the rest reaches the liver, adipose tissue and muscle cells, where it is absorbed and stored as glycogen (under the influence of insulin). Liver cell glycogen can be converted to glucose and returned to the blood when insulin is low or absent; muscle cell glycogen is not returned to the blood because of a lack of enzymes. In fat cells, glucose is used to power reactions that synthesize some fat types and have other purposes. Glycogen is the body's "glucose energy storage" mechanism, because it is much more "space efficient" and less reactive than glucose itself. Because glucose is a basic necessity of many organisms, a correct understanding of its chemical makeup and structure contributed greatly to a general advancement in organic chemistry. This understanding occurred largely as a result of the investigations of Emil Fischer, a German chemist who received the 1902 Nobel Prize in Chemistry as a result of his findings. The synthesis of glucose established the structure of organic material and consequently formed the first definitive validation of Jacobus Henricus van't Hoff's theories of chemical kinetics and the arrangements of chemical bonds in carbon-bearing molecules. Between 1891 and 1894, Fischer established the stereochemical configuration of all the known sugars and correctly predicted the possible isomers, applying van't Hoff's theory of asymmetrical carbon atoms. M: MET mt, k, c/g/r/p/y/i, f/h/s/l/o/e, a/u, n, m k, cgrp/y/i, f/h/s/l/o/e, au, n, m, epon m (A16/C10), i (k, c/g/r/p/y/i, f/h/s/o/e, a/u, n, m) M: MET mt, k, c/g/r/p/y/i, f/h/s/l/o/e, a/u, n, m k, cgrp/y/i, f/h/s/l/o/e, au, n, m, epon m (A16/C10), i (k, c/g/r/p/y/i, f/h/s/o/e, a/u, n, m) M: MET mt, k, c/g/r/p/y/i, f/h/s/l/o/e, a/u, n, m k, cgrp/y/i, f/h/s/l/o/e, au, n, m, epon m (A16/C10), i (k, c/g/r/p/y/i, f/h/s/o/e, a/u, n, m)
The blood sugar concentration or blood glucose level is the amount of glucose (sugar) present in the blood of a human or animal. The body naturally tightly regulates blood glucose levels as a part of metabolic homeostasis. Glucose is the primary source of energy for the body's cells, and blood lipids (in the form of fats and oils) are primarily a compact energy store. (There are exceptions. For example, because their dietary metabolizable carbohydrates tend to be used by rumen organisms, ruminants tend to be continuously gluconeogenic; consequently their hepatocytes must rely on such primary energy sources as volatile fatty acids, absorbed from the rumen, rather than glucose.) Glucose is transported from the intestines or liver to body cells via the bloodstream, and is made available for cell absorption via the hormone insulin, produced by the body primarily in the pancreas. The mean normal blood glucose level in humans is about 5.5 mM (5.5 mmol/L or 100 mg/dL, i.e. milligrams/deciliter); however, this level fluctuates throughout the day. Glucose levels are usually lowest in the morning, before the first meal of the day (termed "the fasting level"), and rise after meals for an hour or two by a few millimolar. The normal blood glucose level (tested while fasting) for non-diabetics, should be between 70 and 100 milligrams per deciliter (mg/dL). Blood sugar levels for those without diabetes and who are not fasting should be below 125 mg/dL. The blood glucose target range for diabetics, according to the American Diabetes Association, should be 70–130 (mg/dL) before meals, and less than 180 mg/dL after meals (as measured by a blood glucose monitor). Blood sugar levels outside the normal range may be an indicator of a medical condition. A persistently high level is referred to as hyperglycemia; low levels are referred to as hypoglycemia. Diabetes mellitus is characterized by persistent hyperglycemia from any of several causes, and is the most prominent disease related to failure of blood sugar regulation. Intake of alcohol causes an initial surge in blood sugar, and later tends to cause levels to fall. Also, certain drugs can increase or decrease glucose levels. The international standard way of measuring blood glucose levels are in terms of a molar concentration, measured in mmol/L (millimoles per litre; or millimolar, abbreviated mM). In the United States, mass concentration is measured in mg/dL (milligrams per decilitre). Since the molecular weight of glucose C6H12O6 is about 180 g/mol, for the measurement of glucose, the difference between the two scales is a factor of 18, so that 1 mmol/L of glucose is equivalent to 18 mg/dL. Normal value ranges may vary slightly among different laboratories. Many factors affect a person's blood sugar level. A body's homeostatic mechanism, when operating normally, restores the blood sugar level to a narrow range of about 4.4 to 6.1 mmol/L (79.2 to 110 mg/dL) (as measured by a fasting blood glucose test). Healthy non-diabetic values are also stated to be 83-85 mg/dL to avoid complications of chronic hyperglycemia (Bernstein, R.K. 2011. Dr. Bernstein's Diabetes Solution: The Complete Guide to Achieving Normal) Blood Sugars. Despite widely variable intervals between meals or the occasional consumption of meals with a substantial carbohydrate load, human blood glucose levels tend to remain within the normal range. However, shortly after eating, the blood glucose level may rise, in non-diabetics, temporarily up to 7.8 mmol/L (140 mg/dL) or slightly more. The American Diabetes Association recommends a post-meal glucose level of less than 10 mmol/L (180 mg/dL) and a fasting plasma glucose of 5 to 7.2 mmol/L (90–130 mg/dL). The actual amount of glucose in the blood and body fluids is very small. In a healthy adult male of 75 kg with a blood volume of 5 liters, a blood glucose level of 5.5 mmol/L (100 mg/dL) amounts to 5 grams, slightly less than two typical American restaurant sugar packets for coffee or tea. Part of the reason why this amount is so small is that, to maintain an influx of glucose into cells, enzymes modify glucose by adding phosphate or other groups to it. In general, ranges of blood sugar in common domestic ruminants are lower than in many monogastric mammals. However this generalization does not extend to wild ruminants or camelids. For serum glucose in mg/dL, reference ranges of 42 to 75 for cows, 44 to 81 for sheep, and 48 to 76 for goats, but 61 to 124 for cats; 62 to 108 for dogs, 62 to 114 for horses, 66 to 116 for pigs, 75 to 155 for rabbits, and 90 to 140 for llamas have been reported. A 90 percent reference interval for serum glucose of 26 to 181 mg/dL has been reported for captured mountain goats (Oreamnos americanus), where no effects of the pursuit and capture on measured levels were evident. For beluga whales, the 25–75 percent range for serum glucose has been estimated to be 94 to 115 mg/dL. For the white rhinoceros, one study has indicated that the 95 percent range is 28 to 140 mg/dL. For harp seals, a serum glucose range of 4.9 to 12.1 mmol/L [i.e. 88 to 218 mg/dL] has been reported; for hooded seals, a range of 7.5 to 15.7 mmol/L [i.e. about 135 to 283 mg/dL] has been reported. The body's homeostatic mechanism keeps blood glucose levels within a narrow range. It is composed of several interacting systems, of which hormone regulation is the most important. There are two types of mutually antagonistic metabolic hormones affecting blood glucose levels: If blood sugar levels remain too high the body suppresses appetite over the short term. Long-term hyperglycemia causes many of the long-term health problems including heart disease, eye, kidney, and nerve damage. The most common cause of hyperglycemia is diabetes. When diabetes is the cause, physicians typically recommend an anti-diabetic medication as treatment. From the perspective the majority of patients, treatment with an old, well-understood diabetes drug such as metformin will be the safest, most effective, least expensive, most comfortable route to managing the condition. Diet changes and exercise implementation may also be part of a treatment plan for diabetes. If blood sugar levels drop too low, a potentially fatal condition called hypoglycemia develops. Symptoms may include lethargy, impaired mental functioning; irritability; shaking, twitching, weakness in arm and leg muscles; pale complexion; sweating; paranoid or aggressive mentality and loss of consciousness. Mechanisms that restore satisfactory blood glucose levels after extreme hypoglycemia (below 40 mg/dl) must be quick and effective to prevent extremely serious consequences of insufficient glucose: confusion or unsteadiness and, in the extreme (below 15 mg/dl) loss of consciousness and seizures. It is far more dangerous to have too little glucose in the blood than too much, at least temporarily. In healthy individuals, blood glucose-regulating mechanisms are generally quite effective, and symptomatic hypoglycemia is generally found only in diabetics using insulin or other pharmacological treatment] [. Hypoglycemic episodes can vary greatly between persons and from time to time, both in severity and swiftness of onset. For 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. Glucose is measured in whole blood, plasma or serum. Historically, blood glucose values were given in terms of whole blood, but most laboratories now measure and report plasma or serum glucose levels. Because red blood cells (erythrocytes) have a higher concentration of protein (e.g., hemoglobin) than serum, serum has a higher water content and consequently more dissolved glucose than does whole blood. To convert from whole-blood glucose, multiplication by 1.15 has been shown to generally give the serum/plasma level. Collection of blood in clot tubes for serum chemistry analysis permits the metabolism of glucose in the sample by blood cells until separated by centrifugation. Red blood cells, for instance, do not require insulin to intake glucose from the blood. 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. Ambient temperature at which the blood sample is kept prior to centrifuging and separation of plasma/serum also affects glucose levels. At refrigerator temperatures, glucose remains relatively stable for several hours in a blood sample. Loss of glucose can be prevented by using Fluoride tubes (i.e., gray-top) since fluoride inhibits glycolysis. However, these 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 after being centrifuged isolating the serum from cells. To prevent contamination of the sample with intravenous fluids, particular care should be given to drawing blood samples from the arm opposite the one in which an intravenous line is inserted. Alternatively, blood can be drawn from the same arm with an IV line after the IV has been turned off for at least 5 minutes, and the arm has been elevated to drain infused fluids away from the vein. Inattention can lead to large errors, since as little as 10% contamination with a 5% glucose solution (D5W) will elevate glucose in a sample by 500 mg/dL or more. Remember that the actual concentration of glucose in blood is very low, even in the hyperglycemic. Arterial, capillary and venous blood have comparable glucose levels in a fasting individual. Following meals, venous levels are somewhat lower than those in capillary or arterial blood; a common estimate is about 10%. Two major methods have been used to measure glucose. The first, still in use in some places, is a chemical method exploiting the nonspecific reducing property of glucose in a reaction with an indicator substance that changes color when reduced. Since other blood compounds also have reducing properties (e.g., urea, which can be abnormally high in uremic patients), this technique can produce erroneous readings in some situations (5 to 15 mg/dL has been reported). The more recent technique, using enzymes specific to glucose, is less susceptible to this kind of error. The two most common employed enzymes are glucose oxidase and hexokinase. In either case, the chemical system is commonly contained on a test strip which is inserted into a meter, and then has a blood sample applied. Test-strip shapes and their exact chemical composition vary between meter systems and cannot be interchanged. Formerly, some test strips were read (after timing and wiping away the blood sample) by visual comparison against a color chart printed on the vial label. Strips of this type are still used for urine glucose readings, but for blood glucose levels they are obsolete. Their error rates were, in any case, much higher. More precise blood glucose measurements are performed in a medical laboratory, using hexokinase, glucose oxidase or glucose dehydrogenase enzymes. Urine glucose readings, however taken, are much less useful. In properly functioning kidneys, glucose does not appear in urine until the renal threshold for glucose has been exceeded. This is substantially above any normal glucose level, and is evidence of an existing severe hyperglycemic condition. However, as urine is stored in the bladder, any glucose in it might have been produced at any time since the last time the bladder was emptied. Since metabolic conditions change rapidly, as a result of any of several factors, this is delayed news and gives no warning of a developing condition. Blood glucose monitoring is far preferable, both clinically and for home monitoring by patients. Healthy urine glucose levels were first standardized and published in 1965 by Hans Renschler. \begin{alignat}{2} & \mathrm{Glucose} + \mathrm{ATP}\xrightarrow[\mathrm{Phosphorylation}] {\mathrm{Hexokinase} + \mathrm{Mg}^{++}} \textrm{G-6PO}_4 + \mathrm{ADP} \\ & \textrm{G-6PO}_4 + \mathrm{NADP}\xrightarrow[\mathrm{Oxidation}] {\textrm{G-6PD}} \textrm{G-Phosphogluconate} + \mathrm{NADPH} + \mathrm{H}^{+} \\ \end{alignat} The fasting blood glucose level, which is measured after a fast of 8 hours, is the most commonly used indication of overall glucose homeostasis, largely because disturbing events such as food intake are avoided. Conditions affecting glucose levels are shown in the table below. Abnormalities in these test results are due to problems in the multiple control mechanism of glucose regulation. The metabolic response to a carbohydrate challenge is conveniently assessed by a postprandial glucose level drawn 2 hours after a meal or a glucose load. In addition, the glucose tolerance test, consisting of several timed measurements after a standardized amount of oral glucose intake, is used to aid in the diagnosis of diabetes. Error rates for blood glucose measurements systems vary, depending on laboratories, and on the methods used. Colorimetry techniques can be biased by color changes in test strips (from airborne or finger borne contamination, perhaps) or interference (e.g., tinting contaminants) with light source or the light sensor. Electrical techniques are less susceptible to these errors, though not to others. In home use, the most important issue is not accuracy, but trend. Thus if a meter / test strip system is consistently wrong by 10%, there will be little consequence, as long as changes (e.g., due to exercise or medication adjustments) are properly tracked. In the US, home use blood test meters must be approved by the Federal Food and Drug Administration before they can be sold. Finally, there are several influences on blood glucose level aside from food intake. Infection, for instance, tends to change blood glucose levels, as does stress either physical or psychological. Exercise, especially if prolonged or long after the most recent meal, will have an effect as well. In the normal person, maintenance of blood glucose at near constant levels will nevertheless be quite effective.][ In a physiological context, the term is a misnomer because it refers to glucose, yet other sugars besides glucose are always present. Food contains several different types (e.g., fructose (largely from fruits/table sugar/industrial sweeteners), galactose (milk and dairy products), as well as several food additives such as sorbitol, xylose, maltose, etc.). But because these other sugars are largely inert with regard to the metabolic control system (i.e., that controlled by insulin secretion), since glucose is the dominant controlling signal for metabolic regulation, the term has gained currency, and is used by medical staff and lay folk alike. The table above reflects some of the more technical and closely defined terms used in the medical field. M: URI anat/phys/devp/cell noco/acba/cong/tumr, sysi/epon, urte proc/itvp, drug (G4B), blte, urte M: END anat/phys/devp/horm noco (d)/cong/tumr, sysi/epon proc, drug (A10/H1/H2/H3/H5) M: HRT anat/phys/devp noco/cong/tumr, sysi/epon, injr proc, drug (C1A/1B/1C/1D), blte M: DIG anat (t, g, p)/phys/devp/enzy noco/cong/tumr, sysi/epon proc, drug (A2A/2B/3/4/5/6/7/14/16), blte
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OneTouch Ultra is a blood glucose monitoring device for people with diabetes and is the foundation product for LifeScan's OneTouch Ultra Family of blood glucose monitoring systems.

OneTouch Ultra Blood Glucose Meters provide blood glucose test results in 5 seconds, offer alternative test site options, and various memory and flagging features. The results are displayed as plasma values.

A glucose meter (or glucometer) is a medical device for determining the approximate concentration of glucose in the blood. It can also be a strip of glucose paper dipped into a substance and measured to the glucose chart. It be from negative to extreme. It is a key element of home blood glucose monitoring (HBGM) by people with diabetes mellitus or hypoglycemia. A small drop of blood, obtained by pricking the skin with a lancet, is placed on a disposable test strip that the meter reads and uses to calculate the blood glucose level. The meter then displays the level in mg/dl or mmol/l.

Since approximately 1980, a primary goal of the management of type 1 diabetes and type 2 diabetes mellitus has been achieving closer-to-normal levels of glucose in the blood for as much of the time as possible, guided by HBGM several times a day. The benefits include a reduction in the occurrence rate and severity of long-term complications from hyperglycemia as well as a reduction in the short-term, potentially life-threatening complications of hypoglycemia.

A test strip is a band/piece/strip of paper or other material used for biological testing.

Specifically, test strip may refer to:

The blood sugar concentration or blood glucose level is the amount of glucose (sugar) present in the blood of a human or animal. The body naturally tightly regulates blood glucose levels as a part of metabolic homeostasis.

Glucose is the primary source of energy for the body's cells]citation needed[, and blood lipids (in the form of fats and oils) are primarily a compact energy store. (There are exceptions. For example, because their dietary metabolizable carbohydrates tend to be used by rumen organisms, ruminants tend to be continuously gluconeogenic; consequently their hepatocytes must rely on such primary energy sources as volatile fatty acids, absorbed from the rumen, rather than glucose.) Glucose is transported from the intestines or liver to body cells via the bloodstream, and is made available for cell absorption via the hormone insulin, produced by the body primarily in the pancreas.

Glucose

The insulin pump is a medical device used for the administration of insulin in the treatment of diabetes mellitus, also known as continuous subcutaneous insulin infusion therapy. The device includes:

An insulin pump is an alternative to multiple daily injections of insulin by insulin syringe or an insulin pen and allows for intensive insulin therapy when used in conjunction with blood glucose monitoring and carb counting.

The term diabetes mellitus includes several different metabolic disorders that all, if left untreated, result in abnormally high concentrations of a sugar called glucose in the blood. Diabetes mellitus type 1 results when the pancreas no longer produces significant amounts of the hormone insulin, owing to the destruction of the insulin-producing beta cells of the pancreas. Diabetes mellitus type 2, in contrast, results from insulin resistance. The pancreas of a person with type 2 diabetes may be producing normal or even abnormally large amounts of insulin. Other forms of diabetes mellitus, such as the various forms of maturity onset diabetes of the young, may represent some combination of insufficient insulin production and insulin resistance. Some degree of insulin resistance may also be present in a person with type 1 diabetes.

The main goal of diabetes management is to restore carbohydrate metabolism to as close to a normal state as possible. To achieve this goal, individuals with an absolute deficiency of insulin require insulin replacement therapy, which is given through injections or an insulin pump. Insulin resistance, in contrast, can be corrected by dietary modifications and exercise. Other goals of diabetes management are to prevent or treat the many complications that can result from the disease itself and from its treatment.

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