Diabetes: How blood sugar levels affect your body

A commonly used diabetes test may not spot the disease as well as an older test does, a new study suggests. The researchers said the newer test -- called hemoglobin A1C -- didn't catch three-quarters of the diabetes diagnoses found by the older test -- called an oral glucose tolerance test. "Diabetes is a global epidemic. Since the incorporation of A1C [as a test for diagnosis] in 2010, it's been relied on more and more for its convenience because patients don't have to fast. But it's not a perfect test," said study author Dr. Maria Mercedes Chang Villacreses. She is an endocrinology fellow at the City of Hope National Medical Center in Los Angeles.

The oral glucose tolerance test "is more cumbersome to do, but it gives more of an idea of the physiology of the patient, she added. "If you have a patient where you have risk factors for diabetes or you have a high suspicion of diabetes, you should go ahead and do the [glucose tolerance test]. If you rely only on A1C, you may miss an opportunity to intervene earlier," she said. That's important because good diabetes management can help prevent complications of the disease.

However, not everyone shares her concern about using the A1C test.

Dr. Joel Zonszein, director of the clinical diabetes center at Montefiore Medical Center in New York City, pointed out that the "A1C has been approved for the diagnosis and management of diabetes. It's a very practical test, but it's not perfect. A random A1C test gives us enough information to diagnose diabetes. It's a good tool."

He said the tests available to diagnose and manage diabetes all have their pros and cons. "It's not which is better. They each give us different information," he explained.

There are three types of blood tests that can be used to look for diabetes -- the A1C, a fasting blood test or a random blood test, according to the US National Institute for Diabetes and Digestive and Kidney Diseases (NIDDK).

The A1C allows doctors to get an idea of what your blood sugar levels are over a period of two to three months. Random and fasting blood tests show your doctor what your blood sugar level is at one point in time.

Fasting isn't required for either the A1C or the random blood test.

The oral glucose tolerance test is typically used for diagnosing diabetes in pregnancy (gestational diabetes), NIDDK said. The test requires you to fast for at least eight hours.

Then your blood sugar level is measured when you get to the doctor's office. You then drink a sugary liquid and wait. Your blood sugar will be checked again, often multiple times. The test can take between one hour and three hours.

"A glucose tolerance test is costly and very inconvenient for patients," said Zonszein. He said the test is used in pregnancy and for research studies.

The current study looked at 9,000 people over the age of 20. The study participants had both an A1C and an oral glucose intolerance test done.

The researchers said that the A1C test missed the diagnosis of diabetes in 73 per cent of cases that were found by the glucose intolerance test.

    HealthDay

Diabetes: How blood sugar levels affect your body

A commonly used diabetes test may not spot the disease as well as an older test does, a new study suggests. The researchers said the newer test -- called hemoglobin A1C -- didnt catch three-quarters of the diabetes diagnoses found by the older test -- called an oral glucose tolerance test. Diabetes is a global epidemic. Since the incorporation of A1C [as a test for diagnosis] in 2010, its been relied on more and more for its convenience because patients dont have to fast. But its not a perfect test, said study author Dr. Maria Mercedes Chang Villacreses. She is an endocrinology fellow at the City of Hope National Medical Center in Los Angeles. The oral glucose tolerance test is more cumbersome to do, but it gives more of an idea of the physiology of the patient, she added. If you have a patient where you have risk factors for diabetes or you have a high suspicion of diabetes, you should go ahead and do the [glucose tolerance test]. If you rely only on A1C, you may miss an opportunity to intervene earlier, she said. Thats important because good diabetes management can help prevent complications of the disease. However, not everyone shares her concern about using the A1C test. Dr. Joel Zonszein, director of the clinical diabetes center at Montefiore Medical Center in New York City, pointed out that the A1C has been approved for the diagnosis and management of diabetes. Its a very practical test, but its not perfect. A random A1C test gives us enough information to diagnose diabetes. Its a good tool. He said the tests available to diagnose and manage diabetes all have their pros and cons. Its not which is better. They each give us different information, he explained. There are three types of blood tests that can be used to look for diabetes -- the A1C, a fasting blood test or a random blood test, according to the US National Institute for Diabetes and Digestive and Kidney Diseases (NIDDK). The A1C allows doctors to get an idea of what your blood sugar levels are over a period of two to three months. Random and fasting blood tests show your doctor what your blood sugar level is at one point in time. Fasting isnt required for either the A1C or the random blood test. The oral glucose tolerance test is typically used for diagnosing diabetes in pregnancy (gestational diabetes), NIDDK said. The test requires you to fast for at least eight hours. Then your blood sugar level is measured when you get to the doctors office. You then drink a sugary liquid and wait. Your blood sugar will be checked again, often multiple times. The test can take between one hour and three hours. A glucose tolerance test is costly and very inconvenient for patients, said Zonszein. He said the test is used in pregnancy and for research studies. The current study looked at 9,000 people over the age of 20. The study participants had both an A1C and an oral glucose intolerance test done. The researchers said that the A1C test missed the diagnosis of diabetes in 73 per cent of cases that were found by the glucose intolerance test. HealthDay