Which test is considered a more reliable method of monitoring long term diabetes control?
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Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Show
There are many types of sugar. Some sugars are simple, and others are complex. Table sugar (sucrose) is made of two simpler sugars called glucose and fructose. Milk sugar (lactose) is made of glucose and a simple sugar called galactose. The carbohydrates in starches, such as bread, pasta, rice, and similar foods, are long chains of different simple sugar molecules. Sucrose, lactose, carbohydrates, and other complex sugars must be broken down into simple sugars by enzymes in the digestive tract before the body can absorb them. Once the body absorbs simple sugars, it usually converts them all into glucose, which is an important source of fuel for the body. Glucose is the sugar that is transported through the bloodstream and taken up by cells. The body can also make glucose from fats and proteins. Blood "sugar" really means blood glucose. The levels of glucose in the blood vary normally throughout the day. They rise after a meal and return to pre-meal levels within about 2 hours after eating. Once the levels of glucose in the blood return to pre-meal levels, insulin production decreases. The variation in blood glucose levels is usually within a narrow range, about 70 to 110 milligrams per deciliter (mg/dL), or 3.9 to 6.1 millimoles per liter (mmol/L) of blood in healthy people. If people eat a large amount of carbohydrates, the levels may increase more. People older than 65 years tend to have slightly higher levels, especially after eating. Prediabetes is a condition in which blood glucose levels are too high to be considered normal but not high enough to be labeled diabetes. People have prediabetes if their fasting blood glucose level is between 100 mg/dL (5.6 mmol/L) and 125 mg/dL (6.9 mmol/L) or if their blood glucose level 2 hours after a glucose tolerance test is between 140 mg/dL (7.8 mmol/L) and 199 mg/dL (11.0 mmol/L). Prediabetes carries a higher risk of future diabetes as well as heart disease. Decreasing body weight by 5 to 10% through diet and exercise can significantly reduce the risk of developing diabetes. In type 1 diabetes (formerly called insulin-dependent diabetes or juvenile-onset diabetes), the body's immune system attacks the insulin-producing cells of the pancreas, and more than 90% of them are permanently destroyed. The pancreas, therefore, produces little or no insulin. Only about 5 to 10% of all people with diabetes have type 1 disease. Most people who have type 1 diabetes develop the disease before age 30, although it can develop later in life. Scientists believe that an environmental factor—possibly a viral infection or a nutritional factor during childhood or early adulthood—causes the immune system to destroy the insulin-producing cells of the pancreas. A genetic predisposition makes some people more susceptible to an environmental factor. In type 2 diabetes (formerly called non–insulin-dependent diabetes or adult-onset diabetes), the pancreas often continues to produce insulin, sometimes even at higher-than-normal levels, especially early in the disease. However, the body develops resistance to the effects of insulin, so there is not enough insulin to meet the body’s needs. As type 2 diabetes progresses, the insulin-producing ability of the pancreas decreases. Type 2 diabetes was once rare in children and adolescents but has become more common. However, it usually begins in people older than 30 and becomes progressively more common with age. About 26% of people older than 65 have type 2 diabetes. People of African, Asian American, American Indian, Alaskan native, and Spanish or Latin American ancestry are at increased risk of developing type 2 diabetes. Type 2 diabetes tends to run in families. Certain disorders and medications can affect the way the body uses insulin and can lead to type 2 diabetes. Examples of common states (conditions) that result in impaired insulin use are The two types of diabetes can have very similar symptoms if the blood glucose is significantly elevated. The symptoms of high blood glucose levels include
Other symptoms of diabetes include
In people with type 1 diabetes, the symptoms often begin abruptly and dramatically. A serious condition called diabetic ketoacidosis Diabetic Ketoacidosis Diabetic ketoacidosis is an acute complication of diabetes that occurs mostly in type 1 diabetes mellitus. Symptoms of diabetic ketoacidosis include nausea, vomiting, abdominal pain, and a characteristic... read more , a complication in which the body produces excess acid, may quickly develop. In addition to the usual diabetes symptoms of excessive thirst and urination, the initial symptoms of diabetic ketoacidosis also include nausea, vomiting, fatigue, and—particularly in children—abdominal pain. Breathing tends to become deep and rapid as the body attempts to correct the blood’s acidity (see Acidosis Acidosis Acidosis is caused by an overproduction of acid that builds up in the blood or an excessive loss of bicarbonate from the blood (metabolic acidosis) or by a buildup of carbon dioxide in the blood... read more ), and the breath smells fruity and like nail polish remover. Without treatment, diabetic ketoacidosis can progress to coma and death, sometimes very quickly. After type 1 diabetes has begun, some people have a long but temporary phase of near-normal glucose levels (honeymoon phase) due to partial recovery of insulin secretion. People with type 2 diabetes may not have any symptoms for years or decades before they are diagnosed. Symptoms may be subtle. Increased urination and thirst are mild at first and gradually worsen over weeks or months. Eventually, people feel extremely fatigued, are likely to develop blurred vision, and may become dehydrated. Because people with type 2 diabetes produce some insulin, ketoacidosis Diabetic Ketoacidosis Diabetic ketoacidosis is an acute complication of diabetes that occurs mostly in type 1 diabetes mellitus. Symptoms of diabetic ketoacidosis include nausea, vomiting, abdominal pain, and a characteristic... read more does not usually develop even when type 2 diabetes is untreated for a long time. Rarely, the blood glucose levels become extremely high (even exceeding 1,000 mg/dL [55.5 mmol/L]). Such high levels often happen as the result of some superimposed stress, such as an infection or medication use. When the blood glucose levels get very high, people may develop severe dehydration Dehydration Dehydration is a deficiency of water in the body. Vomiting, diarrhea, excessive sweating, burns, kidney failure, and use of diuretics may cause dehydration. People feel thirsty, and as dehydration... read more , which may lead to mental confusion, drowsiness, and seizures, a condition called hyperosmolar hyperglycemic state Hyperosmolar Hyperglycemic State (HHS) Hyperosmolar hyperglycemic state is a complication of diabetes mellitus that most often occurs in type 2 diabetes. Symptoms of hyperosmolar hyperglycemic state include extreme dehydration and... read more . Many people with type 2 diabetes are diagnosed by routine blood glucose testing before they develop such severely high blood glucose levels. High blood glucose levels also cause disturbances in the body's immune system, so people with diabetes mellitus are particularly susceptible to bacterial and fungal infections.
Doctors check blood glucose levels in people who have symptoms of diabetes, such as increased thirst, urination, or hunger. Additionally, doctors may check blood glucose levels in people who have disorders that can be complications of diabetes, such as frequent infections, foot ulcers, and yeast infections. To accurately evaluate blood glucose levels, doctors usually use a blood sample taken after people have fasted overnight. Diabetes can be diagnosed if fasting blood glucose levels are 126 mg/dL (7.0 mmol/L) or higher. However, it is possible to use blood samples taken after people have eaten. Some elevation of blood glucose levels after eating is normal, but even after a meal the levels should not be very high. Diabetes can be diagnosed if a random (not done after fasting) blood glucose level is higher than 200 mg/dL (11.1 mmol/L). Doctors can also measure the level of a protein, hemoglobin A1C (also called glycosylated or glycolated hemoglobin), in the blood, which reflects the person's long-term trends in blood glucose levels rather than rapid changes. Hemoglobin is the red, oxygen-carrying substance in red blood cells. When blood is exposed to high blood glucose levels over a period of time, glucose attaches to the hemoglobin and forms glycosylated hemoglobin. The hemoglobin A1C level blood test is reported as the percentage of hemoglobin that is A1C . Measurements of hemoglobin A1C can be used to diagnose diabetes when testing is done by a certified laboratory (not by instruments used at home or in a doctor's office). People with a hemoglobin A1C level of 6.5% or more have diabetes. If the level is between 5.7 and 6.4, they have prediabetes and are at risk of developing diabetes. In this test, people fast, have a blood sample taken to determine the fasting blood glucose level, and then drink a special solution containing a large, standard amount of glucose. More blood samples are then taken over the next 2 to 3 hours and are tested to determine whether the glucose in the blood rises to abnormally high levels. Blood glucose levels are often checked during a routine physical examination. Checking the levels of glucose in the blood regularly is particularly important in older people because diabetes is so common in later life. People may have diabetes, particularly type 2 diabetes, and not know it. Doctors do not do routine tests to screen for type 1 diabetes even in people at high risk of type 1 diabetes (such as siblings or children of people who have type 1 diabetes). However, it is important to do screening tests in people at risk of type 2 diabetes, including those who
People with these risk factors should be screened for diabetes at least once every three years. Diabetes risk can also be estimated using a risk calculators from the American Diabetes Association. Doctors may measure fasting blood glucose levels and hemoglobin A1C level, or do an oral glucose tolerance test. If the test results are on the border between normal and abnormal, doctors do the screening tests more often, at least once a year.
Diet, exercise, and education are the cornerstones of treatment of diabetes and often the first recommendations for people with mild diabetes. Weight loss is important for people who are overweight. People who continue to have elevated blood glucose levels despite lifestyle changes, or have very high blood glucose levels and people with type 1 diabetes (no matter their blood glucose levels) also require medication. Because complications are less likely to develop if people with diabetes strictly control their blood glucose levels, the goal of diabetes treatment is to keep blood glucose levels as close to the normal range as possible. It is helpful for people with diabetes to carry or wear medical identification (such as a bracelet or tag) to alert health care practitioners to the presence of diabetes. This information allows health care practitioners to start life-saving treatment quickly, especially in the case of injury or change in mental status. People with diabetes benefit greatly from learning about the disorder, understanding how diet and exercise affect their blood glucose levels, and knowing how to avoid complications. A nurse trained in diabetes education can provide information about managing diet, exercising, monitoring blood glucose levels, and taking medication. Diet management is very important in people with either type of diabetes mellitus. Doctors recommend a healthy, balanced diet and efforts to maintain a healthy weight. People with diabetes can benefit from meeting with a dietitian or a diabetes educator to develop an optimal eating plan. Such a plan includes
People with type 1 diabetes and certain people with type 2 diabetes may use carbohydrate counting or the carbohydrate exchange system to match their insulin dose to the carbohydrate content of their meal. "Counting" the amount of carbohydrate in a meal is used to calculate the amount of insulin the person takes before eating. However, the carbohydrate-to-insulin ratio (the amount of insulin taken for each gram of carbohydrate in the meal) varies for each person, and people with diabetes need to work closely with a dietician who has experience in working with people with diabetes to master the technique. Some experts have advised use of the glycemic index (a measure of the impact of an ingested carbohydrate-containing food on the blood glucose level) to delineate between rapid and slowly metabolized carbohydrates, although there is little evidence to support this approach. Exercise, in appropriate amounts (at least 150 minutes a week spread out over at least three days), can also help people control their weight and improve blood glucose levels. Because blood glucose levels go down during exercise, people must be alert for symptoms of hypoglycemia. Some people need to eat a small snack during prolonged exercise, decrease their insulin dose, or both. Poor eyesight may make it hard for people to read glucose meters and dose scales on insulin syringes. People with arthritis or Parkinson disease or who have had a stroke may have problems manipulating the syringe. In addition to learning about diabetes itself, people with multiple medical disorders may have to learn how to fit management of diabetes in with their management of other disorders. Learning about how to avoid complications, such as dehydration, skin breakdown, and circulation problems, and to manage factors that can contribute to complications of diabetes, such as high blood pressure and high cholesterol levels, is especially important. Such problems become more common as people age, whether they have diabetes or not. Many older people have difficulty following a healthy, balanced diet that can control blood glucose levels and weight. Changing long-held food preferences and dietary habits may be hard. Some people have other disorders that can be affected by diet and may not understand how to integrate the dietary recommendations for their various disorders. Some people cannot control what they eat because someone else is cooking for them—at home or in a nursing home or other institution. When people with diabetes do not do their own cooking, the people who shop and prepare meals for them must also understand the diet that is needed. These people and their caregivers usually benefit from meeting with a dietitian to develop a healthy, feasible eating plan. Some people may have a difficult time adding exercise to their daily life, particularly if they have not been active in the past or if they have a disorder that limits their movement, such as arthritis. However, they may be able to add exercise to their usual routine. For example, people can walk instead of drive or climb the stairs instead of take the elevator. Taking the medications used to treat diabetes, particularly insulin, may be difficult for some people. For those with vision problems or other problems that make accurately filling a syringe difficult, a caregiver can prepare the syringes ahead of time and store them in the refrigerator. People whose insulin dose is stable may purchase prefilled syringes. Prefilled insulin pen devices may be easier for people with physical limitations. Some of these devices have large numbers and easy-to-turn dials. Poor vision, limited manual dexterity due to arthritis, tremor, or stroke, or other physical limitations may make monitoring blood glucose levels more difficult for some people. However, special monitors are available. Some have large numerical displays that are easier to read. Some provide audible instructions and results. Some monitors read blood glucose levels through the skin and do not require a blood sample. People can consult a diabetes educator to determine which meter is most appropriate. Monitoring blood glucose levels is an essential part of diabetes care. Routine blood glucose monitoring provides the information needed to make necessary adjustments in medications, diet, and exercise regimens. It is potentially harmful to wait until there are symptoms of low or high blood glucose levels to check blood glucose. Experts recommend that people keep their blood glucose levels
Hemoglobin A1C levels should be less than 7%. Some people use a continuous glucose monitor (CGM), an external device that is attached to the body and continuously records blood glucose levels. When this type of device is used, doctors use a different measurement to determine how well blood glucose levels are being controlled. They use a value called time in range. Time in range is the percentage of time over a specific period that the blood glucose level is at the person's goal level. The usual range is 70 to 180 mg/mL (3.9 to 9.9 mmol/L). Some other goals are keeping systolic blood pressure less than 140 mm Hg and diastolic blood pressure less than 90 mm Hg. For people with diabetes who have heart disease or are at high risk for heart disease, the blood pressure goal is less than 130/80 mm Hg. Many things cause blood glucose levels to change:
The blood glucose levels may jump after people eat foods they did not realize were high in carbohydrates. Emotional stress, an infection, and many medications tend to increase blood glucose levels. Blood glucose levels increase in many people in the early morning hours because of the normal release of hormones (growth hormone and cortisol), a reaction called the dawn phenomenon. Blood glucose may shoot too high if the body releases certain hormones in response to low blood glucose levels (Somogyi effect). Exercise may cause the levels of glucose in the blood to fall low. Blood glucose levels can be measured easily at home or anywhere. A fingerstick glucose test is most often used to monitor blood glucose. Most blood glucose monitoring devices (glucose meters) use a drop of blood obtained by pricking the tip of the finger with a small lancet. The lancet holds a tiny needle that can be poked into the finger or placed in a spring-loaded device that easily and quickly pierces the skin. Most people find that the pricking causes only minimal discomfort. Then, a drop of blood is placed on a reagent strip. The strip contains chemicals that undergo changes depending on the glucose level. The glucose meter reads the changes in the test strip and reports the result on a digital display. Some devices allow the blood sample to be obtained from other sites, such as the palm, forearm, upper arm, thigh, or calf. Home glucose meters are smaller than a deck of cards. Continuous glucose monitoring (CGM) systems use a small glucose sensor placed under the skin. The sensor measures blood glucose levels every few minutes. There are two types of CGMs, with different purposes:
Professional CGMs collect continuous blood glucose information over a period of time (72 hours to up to 14 days). Health care providers use this information to make treatment recommendations. Professional CGMs do not provide data to the person with diabetes. Personal CGMs are used by the person and provide real-time blood glucose data on a small portable monitor or on a connected smart phone. Alarms on the CGM system can be set to sound when blood glucose levels drop too low or climb too high, so the device can help people quickly identify worrisome changes in blood glucose. CGM systems are particularly helpful in certain circumstances, such as in people with type 1 diabetes who have frequent, rapid changes in blood glucose (particularly when the glucose levels sometimes go very low), which are difficult to identify with fingerstick testing. CGM systems allow people to measure the period of time that their blood glucose stays within a certain range, and doctors use this measurement to set goals for treatment and adjust insulin dose. Keeping a record of blood glucose levels and reporting them to their doctor or nurse helps doctors and nurses provide advice in adjusting the dose of insulin or the oral antihyperglycemic medication. Many people can learn to adjust the insulin dose on their own as necessary. Some people who have mild or early type 2 diabetes that is well-controlled with one or two medications may be able to monitor their fingerstick glucose levels relatively infrequently. Doctors can monitor treatment using a blood test called hemoglobin A1C. When the blood glucose levels are high, changes occur in hemoglobin, the protein that carries oxygen in the blood. These changes are in direct proportion to the blood glucose levels over an extended period. The higher the hemoglobin A1C level, the higher the person's glucose levels have been. Thus, unlike the blood glucose measurement, which reveals the level at a particular moment, the hemoglobin A1C measurement demonstrates whether the blood glucose levels have been controlled over the previous few months. People with diabetes aim for a hemoglobin A1C level of less than 7%. Achieving this level is sometimes difficult, but the lower the hemoglobin A1C level, the less likely people are to have complications. Doctors may recommend a slightly higher or lower target for certain people depending on their particular health situation. However, levels above 9% show poor control, and levels above 12% show very poor control. Most doctors who specialize in diabetes care recommend that hemoglobin A1C be measured every 3 to 6 months. Although urine can also be tested for the presence of glucose, checking urine is not a good way to monitor or adjust treatment. Urine testing can be misleading because the amount of glucose in the urine may not reflect the current level of glucose in the blood. Blood glucose levels can get very low or reasonably high without any change in the glucose levels in the urine. People with type 1 diabetes may have more frequent swings in blood glucose levels because insulin production is completely absent. Infection, delayed movement of food through the stomach, and other hormonal disorders may also contribute to blood glucose swings. In all people who have difficulty controlling blood glucose, doctors look for other disorders that might be causing the problem and also give people additional education on how to monitor diabetes and take their medications. No treatments prevent the onset of type 1 diabetes mellitus. Some medications may induce remission of early type 1 diabetes in some people, possibly because they prevent the immune system from destroying the cells of the pancreas. However, these changes are temporary, and the medications cause side effects that limit their use. Type 2 diabetes can be prevented with lifestyle changes. People who are overweight and lose as little as 7 percent of their body weight and who increase physical activity (for example, walking 30 minutes per day) can decrease their risk of diabetes mellitus by more than 50%. Metformin, a medication that is used to treat diabetes, may reduce the risk of diabetes in people with impaired glucose regulation. The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of the resources.
What is the most reliable test for diabetes?The A1C test is also the primary test used for diabetes management. An A1C test is a blood test that reflects your average blood glucose levels over the past 3 months. The A1C test is sometimes called the hemoglobin A1C, HbA1c, glycated hemoglobin, or glycohemoglobin test.
What test is most effective in evaluating the effectiveness of long term diabetes management?Besides daily blood sugar monitoring, your provider will likely recommend regular A1C testing to measure your average blood sugar level for the past 2 to 3 months. Compared with repeated daily blood sugar tests, A1C testing shows better how well your diabetes treatment plan is working overall.
Which is the best measurement for assessing long term control of the diabetic patient?A1C, in the setting of a normal hematological profile and in the nonpregnant population, reflects mean glycemia over the previous 8–12 weeks. Its periodic monitoring is widely used and considered, along with self-monitoring of blood glucose (SMBG), the primary technique to assess DM control.
What is the most common test for blood sugar monitoring?A1c test. Blood testing allows a doctor to determine the levels of blood sugar in the body. The A1C test is one of the most common because its results estimate blood sugar levels over time, and you don't have to fast before the test. The A1C test is also known as the glycated hemoglobin test.
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