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Chapter 2: Section 1 - Glucose Monitoring

  • Updated

It is essential to know where you’re starting so you can determine what sort of changes you may need to make to move you toward your goal. Lab values along with a manual blood glucose meter (BGM) and/or continuous glucose monitor (CGM) are all tools that can help you to get a sense of your current blood sugar values.

 

These will also serve as important benchmarks to assess your progress throughout this journey.

 

Lab Values and Target Ranges

 

  • Fasting Blood Glucose - This is a measure of your blood sugar after an overnight fast (at least 8+ hours fasting).

    • Diabetes - >126 mg/dL

    • Pre-Diabetes - >100-125 mg/dL

    • Optimal Target - 70-90 mg/dL

       

  • Hemoglobin A1c* - This is a measure of your average glucose values over the past three months.

    • Diabetes - >6.5%

    • Pre-Diabetes - 5.7-6.4%

    • No diabetes/pre-diabetes diagnosis - <5.7%

       

    *Work with your diabetes management team to determine what your specific A1c target is.

     

  • Glucose Tolerance Test - During this test, your blood glucose is monitored both before and 2 hours after drinking a glucose-containing beverage.

    • Diabetes - >200 mg/dL

    • Pre-Diabetes - 140-199 mg/dL

    • No diabetes/pre-diabetes diagnosis - <140 mg/dL

       

  • Fasting Insulin*

    • Target is 2-8 mIU/mL

       

    *Fasting insulin targets can vary pretty considerably. The above target range is the optimal goal, but in general, any reduction in your fasting insulin value would be considered an improvement.

     

  • Lipid Panel

    • HDL - >60 mg/dL

    • Triglycerides - <150 mg/dL although research suggests <90 mg/dL is optimal

    • HDL:TG Ratio - <2, although <1 is considered optimal

       

       

Blood Glucose Monitor versus Continuous Glucose Monitor

 

Both a blood glucose monitor (BGM) and a continuous glucose monitor (CGM) can be important parts of monitoring your blood sugar levels. However, they do work in different ways, and understanding those differences is an important part of any blood sugar optimization program.

 

A BGM works by measuring the glucose in your blood and, as such, requires you to prick your finger with a lancet and then put a drop of blood on a test strip in the BGM. This measurement will tell you what your blood glucose is in that moment, and if you want to see your glucose at any other time of the day, you’ll need to prick your finger again.

 

In comparison, a CGM measures your glucose data continuously, meaning you’ll see your glucose pattern for the entire period you’re wearing the CGM. A CGM doesn’t require you to prick your finger each time you want to see your glucose data. It also works differently from a BGM because it is inserted into your interstitial fluid (don’t let that scare you - it’s painless!), meaning that it measures your glucose values in the fluid between your cells rather than in your bloodstream.

 

Given that a BGM and CGM are measuring glucose from different areas of your body, it’s not expected that they match up perfectly, even if you compare readings at the same time. The glucose in your interstitial fluid ‘lags’ behind the glucose in your bloodstream, meaning that if your glucose is trending up (such as after a meal), the CGM will read lower than a BGM and vice versa.

 

 

If you need to calibrate your CGM using a BGM, the best time to do it based on that lag time is when you’re fasting in the morning. For more information on calibrating a CGM using a BGM, check out this article.

 

 

BGM Targets

 

Your diabetes management team may give you individualized values to aim for, however, some typical targets are:

 

  • Fasting Glucose - Being without food for at least 8 hours (generally when you first wake up in the morning before eating or drinking anything).

    • If you have a diagnosis of diabetes, working towards a target of <120 mg/dL may be appropriate here.

    • If you are currently in the pre-diabetes range, aiming for <100 mg/dL may be more appropriate.

  • Testing in Pairs - Testing both before and after a meal. This can be a helpful way to see how you respond to that particular meal, although a CGM will give you a much more complete picture in this regard.

    • If you have a diagnosis of diabetes, you may be told to aim for 80-130 mg/dL prior to the meal with a goal of being under 180 mg/dL two hours after the start of that meal.

    • If you have pre-diabetes, you may be told to aim for being back to your starting point two hours after the start of the meal.

     

     

CGM Targets

 

When it comes to monitoring glucose via a CGM, there are a few different areas to focus on, and with all of the values listed below, the goal is to work on continuing to optimize your own values over time. Depending on your unique situation, your NutriSense nutrition coach may offer slightly different targets to aim for. For example, if you have a diagnosis of diabetes and your fasting glucose is already around 120 mg/dL, maybe a more appropriate goal to strive for would be <110 mg/dL.

 

These are the primary areas that you’re looking at:

 

  • Baseline Values:

    • Fasting Glucose - Being without food for at least 8 hours (generally when you first wake up in the morning before eating or drinking anything).

    • Mean/Median - This is an estimate of your 24-hour average.

      • With Diabetes - <140 mg/dL

      • Without Diabetes - <105 mg/dL

    • Sleeping Average - This is your average value during sleep. This is calculated based on how you have the fasting window set in the app (Settings > System > Fasting).

  • Postprandial Glucose - These are your ‘after eating’ max glucose values

    • With Diabetes - <180 mg/dL. If you are easily maintaining this target, your team may suggest aiming for a more strict target like <160 mg/dL to continue to reduce risk factors associated with diabetes.

    • Without Diabetes <140 mg/dL

    • Along with simply looking at how high your glucose goes after eating a meal, the NutriSense app also offers a “Meal Glucose Card” to help take your postprandial glucose knowledge to the next level. This meal card looks at the max value mentioned above, but it also looks at three additional metrics, such as:

      • Exposure (or Area Under the Curve - AUC) - This is a measure of both how high your glucose rises and how long it stays elevated after a meal. This can be used as a proxy for your insulin response to that particular meal. In general, lower is typically better.

      • Stability (or delta) - This measures how much your glucose “shifts” after eating a meal. The goal is to aim for a smaller shift regardless of your starting point. If you have a diabetes diagnosis, you’ll be aiming for <50 whereas if you don’t have a diabetes diagnosis, <30 will be your optimal target.

      • Recovery (or 2-hour delta) - This measures how quickly you return back to your pre-meal values. The general goal for most people is to be back to their baseline value within two to three hours after eating that meal.

       

       

  • Glycemic Variability - This refers to your swings or fluctuations in glucose. This is assessed by looking at standard deviation.

Next: Hypoglycemia

 

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