WINSTON-SALEM, N.C., June 8 The "gold standard" diabetes test, Hemoglobin A1c (A1C), explains much less about the risk of cardiovascular complications in patients with diabetes than originally thought, according to an article in the June 9 issue of the Journal of the American Medical Association (JAMA). The article entitled, "Beyond HbA1c: Need for Additional Markers of Risk for Diabetic Microvascular Complications," was co-authored by Irl Hirsch, M.D., of the University of Washington Medical School (Seattle, WA) and Michael Brownlee, M.D., of the Albert Einstein College of Medicine (New York, NY).
The authors contend that the A1C test and duration of diabetes (glycemic exposure) explain only 11% of the risk of microvascular complications in the Diabetes Control and Complications Trial (DCCT), a major landmark study in diabetes care. They then suggest that fluctuations of blood glucose levels ("glycemic variability" or "glucose peaks and valleys") may be a significant factor in explaining the remaining 89% of microvascular complication risk. As the A1C test represents an average of glucose levels over a two to three-month period, it provides no information on glucose fluctuations.
The 1,5-anhydroglucitol test (GlycoMark) and/or continuous glucose monitoring (CGM) are advocated as clinical monitoring tools which provide a "definitive examination of the impact of glycemic variability on clinical endpoints." New therapeutic approaches which address glycemic variability are also recommended. These include faster prandial insulins, pramlintide, and incretins.
According to co-author Irl Hirsch, "A1C is helpful in tracking broad glucose targets, but it provides virtually no information on glycemic variability. 1,5-anhydroglucitol is a simple blood test which provides an index of postprandial hyperglycemia and glycemic variability over the past 2-3 weeks and can be used in routine clinical practice."
Hirsch and Brownlee conclude the article by indicating that "it is important for physicians to realize that much remains to be done in identifying important factors contributing to microvascular complications risk which are not captured by A1C. The future identification of these factors will have important implications for devising additional markers and for designing better treatment methods."
Diabetes and Microvascular Complications
Microvascular complications of diabetes are conditions resulting from prolonged excess levels of glucose in the small blood vessels supplying certain body tissues. There are 3 primary microvascular complications related to diabetes: retinopathy (eye disease), neuropathy (nerve disease), and nephropathy (kidney disease). More than a third of people with diabetes will develop at least one microvascular complication.
GlycoMark is an FDA-cleared blood test that reveals repeated episodes of postprandial hyperglycemia/glycemic variability by tracking postprandial glucose levels as they related to blood levels of the molecule 1,5-anhydroglucitol (1,5-AG). Multiple published studies indicate that 1,5-AG detects hyperglycemia not detected by the hemoglobin A1C test. A recent study conducted as part of the international A1C-Derived Average Glucose (ADAG) study showed that 1,5-AG accurately reflects blood glucose fluctuations significantly better than the A1C test. The ADAG study was sponsored by the American Diabetes Association (ADA), the European Association for the Study of Diabetes (EASD), and the International Diabetes Federation (IDF).
GlycoMark is being used in clinical practices nationwide and is available at major reference laboratories including Quest Diagnostics, LabCorp, Esoterix, Mayo Medical Laboratories, and ARUP Laboratories. The test is also available at most major contract research organizations for pharmaceutical research studies. Additional information on GlycoMark can be obtained at www.glycomark.com.
SOURCE GlycoMark, Inc.