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Position Paper A1c over Fasting Blood Glucose

The Health Performance Institute has published this position statement on using HbA1c as a screening method for type 2 diabetes.

Summary
We recommend all employers use A1c as part of their annual biometric screening, which will provide a more clear picture of the impact type 2 diabetes has on their employees, their organization and their healthcare costs. Additionally, this information will allow employers to make better decisions regarding health and/or wellness programs.

 

Continue reading to learn why we are taking this position.

The incidence and prevalence of type 2 diabetes continues to rise; these increases put further strain on our healthcare system as they coincide with increased costs for care and related co-morbidities. A recent publication from the Journal of the American Medical Association (JAMA) showed that over a 14-year tracking period, type 2 diabetes was the most expensive condition to have and treat.

In their 2018 publication on Standards of Care, the American Diabetes Association recommends that A1c testing be done when at all possible.

While these recommendations are for healthcare providers, most employers do not have a complete picture of the impact of type 2 diabetes on their organization. This is because fasting plasma glucose (FPG) is most frequently used in annual biometric screenings. FPG lacks sensitivity and specificity in correctly identifying those at-risk or with type 2 diabetes – particularly in comparison to A1c testing. This results in less accurate identification of type 2 diabetics, pre-diabetics and those at risk.

It is our position that all groups providing health insurance to their employees include A1c testing in their annual screenings.

Preference for A1c over Fasting Plasma Glucose

From the Classification and Diagnosis of Diabetes section in the Standards of Medical Care in Diabetes:

“If chronic hyperglycemia sufficient to cause diabetes-specific complications is the hallmark of diabetes, common sense would dictate that laboratory measures that capture long-term glycemic exposure should provide a better marker for the presence and severity of the disease than single measures of glucose concentration. Observational studies that have assessed glycemia with measures that capture longer-term exposure (i.e., A1C) or with single or longitudinal measurements of glucose levels have consistently demonstrated a strong correlation between retinopathy and A1C (24–26) but a less consistent relationship with fasting glucose levels (27).”

Links to references 24, 25, 26 and 27 in the text noted above.

The key here is the last part of the last sentence – “a less consistent relationship with fasting glucose levels.”

Let’s break this quote down.

The first sentence essentially says this: If chronically elevated blood sugar is sufficient to cause diabetes-specific complications, then it would make sense that lab tests measuring long-term blood sugar levels would be a better indicator of risk as opposed to a single measure of fasting blood sugar (or FPG). This is what we see when A1c is used versus FPG – a stronger association with A1c and diabetes risk when compared to fasting blood sugar. This is what the “less consistent” part of the sentence means.

Type 2 diabetes is a condition of chronically elevated blood sugar due to insulin resistance. Even in those with type 2 diabetes, randomly measured blood sugar varies. The key to understanding the extent of blood sugar control in any one person is to get a better picture of overall blood sugar control, not a single fasting measure. A1c, a 90-day measure of overall blood sugar control, provides this, FPG does not.

The “less consistent” results with FPG translate directly to employer reports, providing a less than ideal assessment on the impact of type 2 diabetes on the organization. Implementing the A1c test during the annual biometric screening will remedy this situation.

Therefore, it is our position that all groups providing health insurance to their employees include A1c in the annual screeing.

 

Notes
  1. Standards of Care – 2018 from the American Diabetes Association
  2. Are there any limitations in using A1c? Yes! But they are minimal, easily controlled for and far outweigh the limitations in fasting plasma glucose testing. See Chapter 2 – Classification and Diagnosis of Diabetes in the Standards of Care publication.

For additional information on this position statement, please contact us.

Should you have other questions or need any additional assistance, please contact us.

Thank you,

Brian Sekula, PhD
President / CEO
The Health Performance Institute

For inquiries, email us or call us at 713-494-6871.