HbA1c Diagnostic Technique Proposed For Diabetes

A panel of diabetes experts has recently made recommendations for the improved testing and diagnosing of the disease. It’s estimated that over six million Americans suffering from diabetes don’t know they have it, making the panel’s recommendations an important step in better identifying the presence of this under-diagnosed condition.

In the United States, approximately 21 million people suffer from diabetes, making nearly one-third undiagnosed (the 6 million mentioned above). And for those that are diagnosed, the “average lag between onset and diagnosis is 7 years.” This means that many diagnosed individuals are already in developed or severe stages of conditions like retinopathy, and are at high risk for diabetic-associated conditions like cardiovascular disease. While diabetes appears in different forms (varying degrees of severity in both type 1 and type 2 diabetes), it’s become evident that improvements are necessary in both awareness and diagnostic techniques.

The panel that made the following recommendations consisted of “experts in the area of diagnosis, monitoring and management of diabetes.” The underlying novel concept implemented by the panel was the use of hemoglobin A1c (HbA1c) as a diagnostic tool that measures blood glucose levels.

Before making specific recommendations, the panel considered the various benefits for using HbA1c over other blood glucose tests. They are as follows:

a) HbA1c does not require patients to be fasting;

b) HbA1c reflects longerterm glycemia than does plasma glucose;

c) HbA1c laboratory methods are now well standardized and reliable;

d) errors caused by non-glycemic factors affecting HbA1c such as hemoglobinopathies are infrequent and can be minimized by confirming the diagnosis of diabetes with a plasma glucose (PG)-specific test.”

The two current blood glocuse tests,fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT), both require approximately eight hours of fasting before administration. Also, HbA1c does not falter due to short-term lifestyle changes, whereas “a few days or weeks of dieting or increased exercise in preparation for a doctor visit can significantly affect FPG and OGTT.”

The panel makes three specific diagnostic recommendations as to the use of HbA1C. The first states that “Screening standards should be established that prompt further testing and closer followup.” These include conditions being met such as HbA1c>6% during diagnosis. The second recommendation, which aims to establish a definitive definition of the presence of diabetes, states that “HbA1c ≥ 6.5 – 6.9%, confirmed by a PG-specific test (FPG or OGTT), should establish the diagnosis of diabetes.” The third and final recommendation, which also aims to establish a definition of diabetes presence, states that “HbA1c ≥7%, confirmed by another HbA1c or a PG-specific test (FPG or OGTT) should establish the diagnosis of diabetes.”

The suggested greater efficiency and safety of using HbA1c as a diagnostic tool for diabetes makes the recommendations of this study potentially profound. If doctors can begin to implement HbA1c, either in conjunction with FPG or OGTT, or confidently by itself, many undiagnosed diabetics may find out the possibly fatal condition they are living with. Six million people in America alone living with diabetes and not knowing it is tragic, but can be changed through greater awareness of the diesease, and better diagnostic techniques.

Source: Defeat Diabetes Foundation: Saudek, Christopher. Davidson, Mayer. et al. Journal of Clinical Endocrinology & Metabolism. “A New Look at Screening and Diagnosing Diabetes Mellitus.” May 2008.