Post by Jana on Sept 29, 2004 15:54:46 GMT -5
Insulin resistance is a silent condition that increases the chances of developing diabetes and heart disease. Learning about insulin resistance is the first step you can take toward making lifestyle changes that will help you prevent diabetes and other health problems.
What does insulin do?
After you eat, the food is broken down into glucose, the simple sugar that is the main source of energy for the body's cells. But your cells cannot use glucose without insulin, a hormone produced by the pancreas. Insulin helps the cells take in glucose and convert it to energy. When the pancreas does not make enough insulin or the body is unable to use the insulin that is present, the cells cannot use glucose. Excess glucose builds up in the bloodstream, setting the stage for diabetes.
Being obese or overweight affects the way insulin works in your body. Extra fat tissue can make your body resistant to the action of insulin, but exercise helps insulin work well.
How are insulin resistance, pre-diabetes, and type 2 diabetes linked?
If you have insulin resistance, your muscle, fat, and liver cells do not use insulin properly. The pancreas tries to keep up with the demand for insulin by producing more. Eventually, the pancreas cannot keep up with the body's need for insulin, and excess glucose builds up in the bloodstream. Many people with insulin resistance have high levels of blood glucose and high levels of insulin circulating in their blood at the same time.
People with blood glucose levels that are higher than normal but not yet in the diabetic range have "pre-diabetes." Doctors sometimes call this condition impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), depending on the test used to diagnose it. In a cross-section of U.S. adults aged 40 to 74 tested during the period 1988 to 1994, 33.8 percent had IFG, 15.4 percent had IGT, and 40.1 percent had pre-diabetes (IGT or IFG or both). Applying these percentages to the 2000 U.S. population, about 35 million adults aged 40 to 74 would have IFG, 16 million would have IGT, and 41 million would have pre-diabetes.
If you have pre-diabetes, you have a higher risk of developing type 2 diabetes, formerly called adult-onset diabetes or noninsulin-dependent diabetes. Studies have shown that most people with pre-diabetes go on to develop type 2 diabetes within 10 years, unless they lose 5 to 7 percent of their body weight--which is about 10 to 15 pounds for someone who weighs 200 pounds--by making modest changes in their diet and level of physical activity. People with pre-diabetes also have a higher risk of heart disease.
Type 2 diabetes is sometimes defined as the form of diabetes that develops when the body does not respond properly to insulin, as opposed to type 1 diabetes, in which the pancreas makes no insulin at all. At first, the pancreas keeps up with the added demand by producing more insulin. In time, however, it loses the ability to secrete enough insulin in response to meals.
Insulin resistance can also occur in people who have type 1 diabetes, especially if they are overweight.
What causes insulin resistance?
Because insulin resistance tends to run in families, we know that genes are partly responsible. Excess weight also contributes to insulin resistance because too much fat interferes with muscles' ability to use insulin. Lack of exercise further reduces muscles' ability to use insulin.
Many people with insulin resistance and high blood glucose have excess weight around the waist, high LDL (bad) blood cholesterol levels, low HDL (good) cholesterol levels, high levels of triglycerides (another fat in the blood), and high blood pressure, all conditions that also put the heart at risk. This combination of problems is referred to as the metabolic syndrome, or the insulin resistance syndrome (formerly called Syndrome X).
What are the symptoms of insulin resistance and pre-diabetes?
Insulin resistance and pre-diabetes usually have no symptoms. You may have one or both conditions for several years without noticing anything. If you have a severe form of insulin resistance, you may get dark patches of skin, usually on the back of your neck. Sometimes people get a dark ring around their neck. Other possible sites for these dark patches include elbows, knees, knuckles, and armpits. This condition is called acanthosis nigricans.
If you have a mild or moderate form of insulin resistance, blood tests may show normal or high blood glucose and high levels of insulin at the same time.
Do you have insulin resistance or pre-diabetes?
Anyone 45 years or older should consider getting tested for diabetes. If you are overweight and aged 45 or older, it is strongly recommended that you get tested. You should consider getting tested if you are younger than 45, overweight, and have one or more of the following risk factors:
family history of diabetes
low HDL cholesterol and high triglycerides
high blood pressure
history of gestational diabetes (diabetes during pregnancy) or gave birth to a baby weighing more than 9 pounds
minority group background (African American, American Indian, Hispanic American/Latino, or Asian American/Pacific Islander)
Diabetes and pre-diabetes can be detected with one of the following tests:
A fasting glucose test measures your blood glucose after you have gone overnight without eating. This test is most reliable when done in the morning. Fasting glucose levels of 100 to 125 mg/dL are above normal but not high enough to be called diabetes. This condition is called pre-diabetes or impaired fasting glucose, and it suggests that you have probably had insulin resistance for some time. IFG is considered a pre-diabetic state, meaning that you are more likely to develop diabetes but do not have it yet.
A glucose tolerance test measures your blood glucose after an overnight fast and 2 hours after you drink a sweet liquid provided by the doctor or laboratory. If your blood glucose falls between 140 and 199 mg/dL 2 hours after drinking the liquid, your glucose tolerance is above normal but not high enough for diabetes. This condition, also a form of pre-diabetes, is called impaired glucose tolerance and, like IFG, it points toward a history of insulin resistance and a risk for developing diabetes.
These tests give only indirect evidence of insulin resistance. The test that most accurately measures insulin resistance is too complicated and expensive to use as a screening tool in most doctors' offices. The test, called the euglycemic clamp, is a research tool that helps scientists learn more about sugar metabolism problems. Insulin resistance can also be assessed with measurement of fasting insulin. If conventional tests show that you have IFG or IGT, your doctor may suggest changes in diet and exercise to reduce your risk of developing diabetes.
If your blood glucose is higher than normal but lower than the diabetes range, have your blood glucose checked in 1 to 2 years.
What does insulin do?
After you eat, the food is broken down into glucose, the simple sugar that is the main source of energy for the body's cells. But your cells cannot use glucose without insulin, a hormone produced by the pancreas. Insulin helps the cells take in glucose and convert it to energy. When the pancreas does not make enough insulin or the body is unable to use the insulin that is present, the cells cannot use glucose. Excess glucose builds up in the bloodstream, setting the stage for diabetes.
Being obese or overweight affects the way insulin works in your body. Extra fat tissue can make your body resistant to the action of insulin, but exercise helps insulin work well.
How are insulin resistance, pre-diabetes, and type 2 diabetes linked?
If you have insulin resistance, your muscle, fat, and liver cells do not use insulin properly. The pancreas tries to keep up with the demand for insulin by producing more. Eventually, the pancreas cannot keep up with the body's need for insulin, and excess glucose builds up in the bloodstream. Many people with insulin resistance have high levels of blood glucose and high levels of insulin circulating in their blood at the same time.
People with blood glucose levels that are higher than normal but not yet in the diabetic range have "pre-diabetes." Doctors sometimes call this condition impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), depending on the test used to diagnose it. In a cross-section of U.S. adults aged 40 to 74 tested during the period 1988 to 1994, 33.8 percent had IFG, 15.4 percent had IGT, and 40.1 percent had pre-diabetes (IGT or IFG or both). Applying these percentages to the 2000 U.S. population, about 35 million adults aged 40 to 74 would have IFG, 16 million would have IGT, and 41 million would have pre-diabetes.
If you have pre-diabetes, you have a higher risk of developing type 2 diabetes, formerly called adult-onset diabetes or noninsulin-dependent diabetes. Studies have shown that most people with pre-diabetes go on to develop type 2 diabetes within 10 years, unless they lose 5 to 7 percent of their body weight--which is about 10 to 15 pounds for someone who weighs 200 pounds--by making modest changes in their diet and level of physical activity. People with pre-diabetes also have a higher risk of heart disease.
Type 2 diabetes is sometimes defined as the form of diabetes that develops when the body does not respond properly to insulin, as opposed to type 1 diabetes, in which the pancreas makes no insulin at all. At first, the pancreas keeps up with the added demand by producing more insulin. In time, however, it loses the ability to secrete enough insulin in response to meals.
Insulin resistance can also occur in people who have type 1 diabetes, especially if they are overweight.
What causes insulin resistance?
Because insulin resistance tends to run in families, we know that genes are partly responsible. Excess weight also contributes to insulin resistance because too much fat interferes with muscles' ability to use insulin. Lack of exercise further reduces muscles' ability to use insulin.
Many people with insulin resistance and high blood glucose have excess weight around the waist, high LDL (bad) blood cholesterol levels, low HDL (good) cholesterol levels, high levels of triglycerides (another fat in the blood), and high blood pressure, all conditions that also put the heart at risk. This combination of problems is referred to as the metabolic syndrome, or the insulin resistance syndrome (formerly called Syndrome X).
What are the symptoms of insulin resistance and pre-diabetes?
Insulin resistance and pre-diabetes usually have no symptoms. You may have one or both conditions for several years without noticing anything. If you have a severe form of insulin resistance, you may get dark patches of skin, usually on the back of your neck. Sometimes people get a dark ring around their neck. Other possible sites for these dark patches include elbows, knees, knuckles, and armpits. This condition is called acanthosis nigricans.
If you have a mild or moderate form of insulin resistance, blood tests may show normal or high blood glucose and high levels of insulin at the same time.
Do you have insulin resistance or pre-diabetes?
Anyone 45 years or older should consider getting tested for diabetes. If you are overweight and aged 45 or older, it is strongly recommended that you get tested. You should consider getting tested if you are younger than 45, overweight, and have one or more of the following risk factors:
family history of diabetes
low HDL cholesterol and high triglycerides
high blood pressure
history of gestational diabetes (diabetes during pregnancy) or gave birth to a baby weighing more than 9 pounds
minority group background (African American, American Indian, Hispanic American/Latino, or Asian American/Pacific Islander)
Diabetes and pre-diabetes can be detected with one of the following tests:
A fasting glucose test measures your blood glucose after you have gone overnight without eating. This test is most reliable when done in the morning. Fasting glucose levels of 100 to 125 mg/dL are above normal but not high enough to be called diabetes. This condition is called pre-diabetes or impaired fasting glucose, and it suggests that you have probably had insulin resistance for some time. IFG is considered a pre-diabetic state, meaning that you are more likely to develop diabetes but do not have it yet.
A glucose tolerance test measures your blood glucose after an overnight fast and 2 hours after you drink a sweet liquid provided by the doctor or laboratory. If your blood glucose falls between 140 and 199 mg/dL 2 hours after drinking the liquid, your glucose tolerance is above normal but not high enough for diabetes. This condition, also a form of pre-diabetes, is called impaired glucose tolerance and, like IFG, it points toward a history of insulin resistance and a risk for developing diabetes.
These tests give only indirect evidence of insulin resistance. The test that most accurately measures insulin resistance is too complicated and expensive to use as a screening tool in most doctors' offices. The test, called the euglycemic clamp, is a research tool that helps scientists learn more about sugar metabolism problems. Insulin resistance can also be assessed with measurement of fasting insulin. If conventional tests show that you have IFG or IGT, your doctor may suggest changes in diet and exercise to reduce your risk of developing diabetes.
If your blood glucose is higher than normal but lower than the diabetes range, have your blood glucose checked in 1 to 2 years.