Estimated Average Glucose

Estimated Average Glucose (eAG) is a vital biomarker offering insights into average blood glucose levels over time. Defined as a calculated estimation derived from Hemoglobin A1c (HbA1c) levels, eAG serves as a pivotal tool for individuals with diabetes, healthcare providers, and those looking to optimize their health.  

By delving into what eAG represents, its correlation with HbA1c, and practical applications in clinical settings, this article aims to aid individuals to navigate the complexities of diabetes management effectively.

What is Estimated Average Glucose (eAG)?

Definition and Significance of Estimated Average Glucose (eAG)

Estimated Average Glucose (eAG) is a calculated estimate of an individual's average blood glucose levels over a specific period, typically spanning three months. eAG provides a convenient and easily interpretable metric for assessing glycemic control. 

Calculation Method of EAG: How to Convert HbA1c to eAG

Estimated Average Glucose (eAG) is calculated using a mathematical formula based on the correlation between Hemoglobin A1c (HbA1c) levels and average blood glucose concentrations. The formula utilizes established conversion equations to derive an estimated average glucose level in units of milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L) from the HbA1c percentage. 

A commonly used formula is (28.7 x HbA1c) - 46.7 for conversion from HbA1c to eAG in mg/dL.  [3.]

Correlation with Average Blood Glucose Levels

Estimated Average Glucose (eAG) is derived from the correlation between Hemoglobin A1c (HbA1c) levels and average blood glucose concentrations. HbA1c reflects the percentage of hemoglobin that has become glycated, or bound to glucose molecules, over the lifespan of red blood cells. As blood glucose levels rise, more hemoglobin becomes glycated, resulting in a higher HbA1c percentage. 

For every percent increase in HbA1c, the estimated average glucose rises 29 mg/dL.  [3.]

What is Hemoglobin A1c with eAG?

Hemoglobin A1c (HbA1c) is a form of hemoglobin in the blood that becomes glycated, or bound to glucose molecules, over time. The percentage of HbA1c in the blood directly correlates with average blood glucose concentrations over the past two to three months. 

This correlation serves as the basis for calculating Estimated Average Glucose (eAG), which provides a practical estimation of average blood glucose levels in units of milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). 

While HbA1c provides a percentage value indicating average blood glucose levels over the past two to three months, eAG offers a practical estimation of average glucose levels in units of mg/dL or mmol/L. 

Together, these metrics provide complementary information, allowing individuals and healthcare providers to monitor glycemic control from different perspectives. This combined approach enhances the interpretation of results and facilitates informed decision-making regarding diabetes management strategies tailored to each individual's unique needs and circumstances.

What Causes High Glucose Levels?

Consistently elevated glucose levels over time can lead to a cascade of metabolic disturbances including the development of insulin resistance and ultimately, diabetes mellitus. 

Chronically high glucose levels are most often associated with poor dietary habits, sedentary lifestyle, or underlying metabolic disorders.  Other potential causes include endocrine disorders such as Cushing's syndrome, thyroid problems, PCOS, or acromegaly, which can disrupt glucose metabolism. 

Chronically high glucose places excessive demands on the body's insulin-producing pancreatic beta cells. In response to prolonged hyperglycemia, the pancreas secretes higher amounts of insulin to help cells absorb glucose. 

However, over time, cells become less responsive to insulin's actions, leading to insulin resistance. This reduced sensitivity of cells to insulin necessitates even higher insulin levels to maintain normal glucose levels, placing further strain on pancreatic function. 

Eventually the beta cells may become exhausted, resulting in decreased insulin production and impaired glucose regulation. Insulin resistance coupled with inadequate insulin secretion culminates in persistent hyperglycemia, a hallmark feature of type 2 diabetes mellitus.

Consequently, individuals with chronically high glucose levels are at increased risk of developing insulin resistance, diabetes, and its associated complications.

What is a Good eAG Level?

Target Range Recommended by Healthcare Providers

Healthcare providers recommend specific target ranges for Estimated Average Glucose (eAG) to guide both diabetic and non-diabetic individuals in maintaining optimal glycemic control. 

For diabetic individuals, target eAG levels typically correspond to Hemoglobin A1c (HbA1c) percentages within recommended ranges, generally 7% or lower for most adults. This corresponds to an EAG of 154 mg/dL with a range from 123 to 185 mg/dL.

For non-diabetic individuals, target eAG levels may vary based on factors such as age, health status, and individualized goals for maintaining metabolic health. Generally, non-diabetic individuals are advised to aim for eAG levels within a range considered normal for their age and health status, which may fall between 70 to 110 mg/dL or 3.9 to 6.1 mmol/L. 

A normal eAG is less than 114 mg/dL which correlates with a HbA1c of 5.6%.  eAG levels between 114-137 mg/dL correlate with an HbA1c of 5.6%-6.4%, which is considered prediabetes. 

An HbA1c at or above 6.5% corresponds with the diagnosis of diabetes and an eAG level of 140 mg/dL.  [2.]

Test Procedure

The eAG blood test, primarily derived from Hemoglobin A1c (HbA1c) measurements, involves a straightforward procedure and typically requires minimal preparation. 

During the test, a healthcare professional collects a blood sample, usually via venipuncture, from a vein in the arm. Prior to the procedure, individuals are generally advised to fast for at least 8 hours to obtain accurate results, although specific fasting requirements may vary depending on the healthcare provider's instructions. Once the blood sample is collected, it is sent to a laboratory for analysis. 

Results are typically available within a few days, allowing individuals and healthcare providers to assess glycemic control and make informed decisions regarding diabetes management strategies.

Managing eAG Levels

Diet and lifestyle measures are extremely effective in managing glucose levels and supporting healthy eAG levels over time in nondiabetic patients as well as  in the majority of patients diagnosed with type 2 Diabetes.  

Strategies to Lower Glucose Levels Naturally [8., 9., 10.]

• Incorporate fiber-rich foods into the diet such as fruits, vegetables, whole grains, and legumes to slow down glucose absorption.
• Engage in regular physical activity like brisk walking, cycling, or strength training to improve insulin sensitivity and glucose uptake.
• Stay hydrated, manage stress levels, get adequate sleep, and avoid tobacco and excessive alcohol consumption for better glucose regulation.

Dietary and Lifestyle Recommendations for Healthy Glucose Levels [6., 7., 8., 9., 10.]

• Follow a balanced and nutritious diet emphasizing portion control, carbohydrate counting, and consumption of low-glycemic index foods.
• Include nutrient-dense options like lean proteins, healthy fats, non-starchy vegetables, and whole grains to stabilize blood sugar levels.
• Reduce intake of sugary beverages, processed foods, refined carbohydrates, and saturated fats to support glycemic control.
• Maintain a healthy weight through portion control, regular physical activity, and lifestyle modifications.
• Quit smoking and manage stress through relaxation techniques or mindfulness practices to promote overall metabolic health and stress management.