The glucose tolerance test is the best way to diagnose prediabetes or gestational diabetes because it shows how your body is reacting to sugar.It will be done at your doctor's office, and it can warn you of the onset of diabetes, or detect borderline diabetes (prediabetes).
Obstetricians use it to check for the presence of gestational diabetes, which only happens during pregnancy. It is also called the oral glucose tolerance test or OGTT.
It measures hyperglycemia (too much sugar in the blood) but it cannot be used to diagnose hypoglycemia (too little sugar in the blood) even if a fasting blood sugar is unusually low. There is really no test doctors can use right now to diagnose hypoglycemia, making it harder to pin down.
Preparing For the Glucose Tolerance Test
It is very important to eat just as you normally would in the days before the test, and to keep your activity level the same, too. Eating an unusually large meal the day before, or not eating normal meals can affect the results, making them inaccurate.
And if there is any illness going on, that will mess up the test too. You'll need to let your doctor know all the medications you are on, because some of them may affect the results of the test as well.
Other things that might make the test a false positive for diabetes are stress, trauma, heart attack or stroke, and anything that would affect your pancreas, such as pancreatitis. For that reason the American Diabetic Association recommends doctors do the GTT twice if it comes up positive, just to be sure it is giving accurate results.
What To Expect The Day of the Test
You must fast the night before the test and not eat breakfast that morning. No juice, nothing but water. You should have been fasting for 8 hours before the test begins. At your doctor visit, the nurse will give you a fingerstick blood test, which might hurt on the fingertip for a second.
The reading will be recorded. Then you will be given an 8-ounce cup of syrupy liquid to drink, and you should finish it within a 5-minute window. You'll wait for an hour, and then they'll give you another fingerstick blood test.
After a second hour of waiting you'll get a third fingerstick test. Some doctors continue for a third hour and do another fingerstick test, but the second one will tell them what they need to know.
What Do the Numbers Mean?
A normal fasting blood sugar should be below 110. If it is between 110 and 125 you will be considered a borderline diabetic or prediabetic. A fasting number above 125 gives you a diagnosis of diabetes if it is consistent over at least two fasting readings.
Assuming your fasting number is normal, if after 2 hours your blood sugar has dropped below 140 you do not have insulin resistance. If the number is between 140 and 200, you have impaired glucose tolerance. That means insulin resistance or prediabetes. If you are a woman that number may mean you have polycystic ovarian syndrome, which presents as prediabetes, and it would be a good idea to check this with your gynecologist.
Testing for for gestational diabetes is a little different, and the test might only take one hour instead of two or three. If you have gestational diabetes, your doctor will simply suggest ways to lower your blood sugar over the rest of your pregnancy. You will be treated as a higher risk pregnancy and your blood sugar will be watched closely. Most of the time blood sugars return to normal after delivery.
For the regular GTT, if the fingerstick test two hours after taking the glucose drink is above 200, you will receive a diagnosis of diabetes. Many times a doctor will ask for another oral glucose tolerance test to verify the diagnosis, especially if there are other things going on that make him or her suspect the test is not accurate, or if it is borderline.
You will be given suggestions for things to do to lower your blood sugar, such as limiting sugary and processed carbohydrates, starting an exercise program and losing a few pounds. Even small changes can make a difference in the numbers.
Some doctors like to start patients right away on metformin before they've even begun to try the diet and exercise route. Maybe they have little faith in patients changing their habits, and it's easier to just start the pills. And some of us have such high numbers already that we need treatment right away to bring the blood sugar down quickly.
The glucose tolerance test is a reliable first diagnostic tool for smoking out prediabetes, and that's great because those lifestyle changes can begin before you become diabetic. That's a great gift if you can recognize it and use it wisely.
Obstetricians use it to check for the presence of gestational diabetes, which only happens during pregnancy. It is also called the oral glucose tolerance test or OGTT.
It measures hyperglycemia (too much sugar in the blood) but it cannot be used to diagnose hypoglycemia (too little sugar in the blood) even if a fasting blood sugar is unusually low. There is really no test doctors can use right now to diagnose hypoglycemia, making it harder to pin down.
Preparing For the Glucose Tolerance Test
It is very important to eat just as you normally would in the days before the test, and to keep your activity level the same, too. Eating an unusually large meal the day before, or not eating normal meals can affect the results, making them inaccurate.
And if there is any illness going on, that will mess up the test too. You'll need to let your doctor know all the medications you are on, because some of them may affect the results of the test as well.
Other things that might make the test a false positive for diabetes are stress, trauma, heart attack or stroke, and anything that would affect your pancreas, such as pancreatitis. For that reason the American Diabetic Association recommends doctors do the GTT twice if it comes up positive, just to be sure it is giving accurate results.
What To Expect The Day of the Test
You must fast the night before the test and not eat breakfast that morning. No juice, nothing but water. You should have been fasting for 8 hours before the test begins. At your doctor visit, the nurse will give you a fingerstick blood test, which might hurt on the fingertip for a second.
The reading will be recorded. Then you will be given an 8-ounce cup of syrupy liquid to drink, and you should finish it within a 5-minute window. You'll wait for an hour, and then they'll give you another fingerstick blood test.
After a second hour of waiting you'll get a third fingerstick test. Some doctors continue for a third hour and do another fingerstick test, but the second one will tell them what they need to know.
What Do the Numbers Mean?
A normal fasting blood sugar should be below 110. If it is between 110 and 125 you will be considered a borderline diabetic or prediabetic. A fasting number above 125 gives you a diagnosis of diabetes if it is consistent over at least two fasting readings.
Assuming your fasting number is normal, if after 2 hours your blood sugar has dropped below 140 you do not have insulin resistance. If the number is between 140 and 200, you have impaired glucose tolerance. That means insulin resistance or prediabetes. If you are a woman that number may mean you have polycystic ovarian syndrome, which presents as prediabetes, and it would be a good idea to check this with your gynecologist.
Testing for for gestational diabetes is a little different, and the test might only take one hour instead of two or three. If you have gestational diabetes, your doctor will simply suggest ways to lower your blood sugar over the rest of your pregnancy. You will be treated as a higher risk pregnancy and your blood sugar will be watched closely. Most of the time blood sugars return to normal after delivery.
For the regular GTT, if the fingerstick test two hours after taking the glucose drink is above 200, you will receive a diagnosis of diabetes. Many times a doctor will ask for another oral glucose tolerance test to verify the diagnosis, especially if there are other things going on that make him or her suspect the test is not accurate, or if it is borderline.
You will be given suggestions for things to do to lower your blood sugar, such as limiting sugary and processed carbohydrates, starting an exercise program and losing a few pounds. Even small changes can make a difference in the numbers.
Some doctors like to start patients right away on metformin before they've even begun to try the diet and exercise route. Maybe they have little faith in patients changing their habits, and it's easier to just start the pills. And some of us have such high numbers already that we need treatment right away to bring the blood sugar down quickly.
The glucose tolerance test is a reliable first diagnostic tool for smoking out prediabetes, and that's great because those lifestyle changes can begin before you become diabetic. That's a great gift if you can recognize it and use it wisely.
0 comments:
Post a Comment