A1C Also known as glycohemoglobin, glycated hemoglobin or glycosylated hemoglobin, A1C is primarily used to monitor the glucose control of people with type 1 and type 2 diabetes. A1C represents the average blood glucose level over a period of 2-3 months. A1C values are directly proportional to the concentration of glucose in the blood over the full lifespan of the red blood cells (90-120 days). Compared to daily blood sugar measurements - which can be greatly affected by recent dietary intake - A1C is a more accurate, long-term measure of diabetes control. Diabetes Diabetes is a disease in which the body does not produce or properly use insulin. There are 4 major types of diabetes that can cause serious complications and even death if not properly controlled. Type 1 diabetes - formerly known as insulin dependent diabetes (IDDM) or juvenile onset diabetes is caused by the body's inability to produce insulin. 5-10% of Americans diagnosed with diabetes have type 1. Type 2 diabetes - formerly known as non-insulin dependent diabetes (NIDDM) or adult onset diabetes results from inefficient usage of insulin by the body. The majority of Americans with diabetes have type 2. Gestational diabetes - this form of diabetes is developed during pregnancy and occurs more frequently in overweight women and those of African American or Hispanic descent and American Indians. Pre-diabetes - is diagnosed when a person's glucose levels are elevated but not high enough to be considered to be type 2 diabetes.

ADA Guidelines

The American Diabetes Association (ADA) clinical practice recommendations call for intensive management of type 1 and 2 diabetes to control hyperglycemia and minimize the risk of complications. The ADA also identifies A1C as the best test to find out if a patient's blood sugar is under control over time.

According to the ADA, the target A1C value is <7%. Patients with values >8% require reevaluation. However, according to the ADA, only one-third of patients with diabetes between 65 and 74 years of age keep their A1C levels in a healthy range.

The Link: Diabetes and Cardiovascular Disease

There is a direct association between diabetes, hyperlipidemia, hypertension, and obesity that leads to an increased incidence of coronary artery disease (CAD). Here's a look at some of the sobering statistics:

• Eighty percent of patients with diabetes are obese
  • Obesity also contributes to hyperlipidemia in diabetic patients
• People with diabetes have a two to four fold higher risk for having cardiovascular events than people without diabetes
• Up to one half of type 2 diabetics have coronary heart disease (CHD)
  • Individuals with diabetes are recognized as having coronary event risks comparable to individuals with established CHD.
• In men and women between ages 35 and 64, diabetes mellitus increases the risk of congestive heart failure by 4 and 8 times, respectively
• Mortality after acute myocardial infarction (heart attack) is 1.2 to 2 times higher for diabetes patients

Patients with diabetes and established cardiovascular disease form a unique and challenging patient population with a higher morbidity and mortality compared to those without these two diseases. Managing these patients appropriately requires a thorough knowledge of the clinical outcomes associated with diabetes and heart disease and effective strategies for secondary prevention of heart disease in the presence of diabetes.

Benefits of Periodic Testing

Depending on the type of diabetes or how well controlled it is, the ADA recommends testing 2-4 times a year.

Studies have shown that point-of-care A1C testing with devices like the Cholestech GDX System can increase patient compliance and may lead to an overall reduction of complications associated with diabetes. Physicians who get A1C results while patients are still in their office are twice as likely to intensify or modify treatment and achieve reductions in A1C by as much as 1% on average¹. For every 1% reduction in A1C, type 2 diabetes patients can reduce their risk of microvascular complications, myocardial infarction, and death by 37%, 14%, and 21%, respectively².

¹ Ferencsi A et al. Endocr Pract 2001; 7:85-8
² Stratton IM et al. BMJ 2000; 321:405-12