PDF – Click to open
Ctrl click to download (3megs)
DIABETES: A Worldwide Epidemic
Article By Shannon Rose
Read full article at http://www.clpmag.com/issues/articles/2010-01_01.asp
As all forms of diabetes continue to increase in incidence, testing options also expand.
Approximately 23.6 million children and adults in the United States—almost 8% of the population—suffer from diabetes, according to the 2007 National Diabetes Fact Sheet.
Of these, approximately 5.7 million go undiagnosed, and 57 million people are estimated to be prediabetic. In addition, 1.6 million new cases are diagnosed every year in individuals 20 years and older, according to the fact sheet compiled by the Centers for Disease Control (CDC), National Institutes of Health (NIH), and the American Diabetes Association (ADA), among others. The World Health Organization (WHO) estimates that approximately 300 million individuals worldwide will be living with diabetes by the year 2025.
In all three forms of the metabolic disorder—type 1 and 2 diabetes, and gestational diabetes—the body is unable to effectively control its glucose levels. More than 90% of diabetics suffer from type 2 diabetes, in which either the pancreas does not produce enough insulin, or the body does not utilize the insulin it has to effectively control glucose levels. In individuals with type 1 diabetes, the body attacks the pancreas to such a degree that it does not produce insulin at all.
The high prevalence of the condition and its complications make diabetes a significant public health issue. The consequences caused by uncontrolled blood sugar in persons with diabetes are severe, and they include heart disease and stroke, high blood pressure, blindness, diseases of the nervous system, amputations, and dental disease.
According to the fact sheet, costs of the disease in the United States are estimated at $218 billion, including $18 billion for those with undiagnosed diabetes and $623 each for the 180,000 pregnant women with gestational diabetes. In 2006, the condition was the seventh leading cause of death in the nation.
“It’s not that diabetes is difficult to diagnose,” says Randy Byrd, vice president and chief technical officer at Bionostics Inc, Devens, Mass. “The problem is that many people are undiagnosed. The challenge for labs is the ability to access patients to perform the testing which provides diagnosis.”
Changing the Gold Standard
Until recently, the gold standard for diagnosis of diabetes was the measurement of glucose levels, with increased glucose concentration in urine or blood indicating diabetes.
The two main tests are the direct measurement of glucose levels in the blood during an overnight fast—the fasting plasma glucose test (FPG)—and a test that measures blood glucose levels four to five times over a 3-hour period—the oral glucose tolerance test (OGTT). While the WHO advocates the OGTT, the ADA advocates the FPG.
However, at the ADA’s annual meeting in June, a committee of international experts recommended the A1C assay test as a new diagnostic tool, except for gestational diabetes. The A1C test, also known as glycated hemoglobin or HbA1c, is a blood test that measures a person’s average blood glucose control over the preceding 2 to 3 months. The excess glucose produced by diabetics glycates with—or sticks to—hemoglobin, which carries oxygen from the lungs to the body’s cells.
The A1C test measures the percentage of this glycated hemoglobin in the blood, which is a reflection of average blood glucose control. The test is not new, but has been used for the past 30 years to determine how well a patient controls diabetes, rather than as a diagnostic tool.
The report could instigate a change in the way diabetes is diagnosed, the ADA said. The international committee concluded that an A1C level of 6.5% indicates that a person has diabetes, while values between 6% and 6.5% are likely to be at highest risk for developing diabetes.
“The A1C test is a more stable, reliable diagnostic tool than the OGTT or the FPG,” says Ranka Milojkovic, HPLC product manager at Tosoh Bioscience Inc, San Francisco. “There are problems with reproducibility and accuracy with the tests that measure glucose.”
Advances in Instrumentation—the Next Generation
According to Milojkovic, lack of standardization kept the A1C test from being recommended as a diagnostic tool. Advances in instrumentation and standardization have eliminated the major roadblocks to the use of the test for diagnosis. Currently, it is mainly performed in hospital and reference laboratories, using either high-performance liquid chromatography (HPLC), often considered the gold standard, or immunoassay methods.
Launched in December 2008, Tosoh’s G8 HPLC Analyzer is the next generation of Tosoh’s industry-leading HPLC testing systems. Designed from a user perspective and using ion-exchange technology, the G8 HPLC Analyzer enhances overall safety and convenience of operation.
The system, which is certified by the National Glycohemoglobin Standardization Program, features stable A1C results in 1.6 minutes through in vitro diagnostic measurement of HbA1c in blood specimens. It has a compact footprint of 21 x 20 x 19 inches and automated daily maintenance.
“We are always thinking of our customer,” Milojkovic says. “Labs are under pressure as there is greater demand to run more samples in less time, and we wanted to address that and design a high-speed analyzer with high resolution. There is no faster HbA1c assay out there.”
Forty flags, or machine parameters, allow the system to print out only those results that the user needs to analyze.
“This reduces review time for patient results,” Milojkovic says.
The throughput for 50 tests takes 1 hour and 20 minutes, while 100 tests can be performed in 2 hours and 40 minutes. There are two loaders available: the standard 90-sample loader, which has a walkaway time of 2 hours and 24 minutes, and the 290-sample loader, which has a walkaway time of 7 hours and 44 minutes (basically one shift for a lab technician).
“The technician can load it in the morning and leave it for the whole day,” Milojkovic says.
To continue reading, see complete article by Shannon Rose at http://www.clpmag.com/issues/articles/2010-01_01.asp
“DIABETES: A Worldwide Epidemic” CLP Article Discusses Tosoh G8 HPLC Analyzer
