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Diabetes Monitoring


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Getting to Know Your Blood Glucose Numbers

Nina Ghamrawi, MS, RD, CDE
December 23, 2021

When start monitoring your blood sugar (glucose), you may have a lot of questions about the numbers. This article will explain the monitoring timing and go over monitoring goals with you.

Home Monitoring

For people with Diabetes, there are a few different targets depending on whether you’ve eaten or not, and also whether you have pre-diabetes, or type 1 or 2. But first, some definitions to know about timing:

  • Fasting glucose is defined as 8 or more hours without food or drink
  • Pre-meal glucose is a glucose reading that is taken before your first bite of food and before meal-time medication, usually approximately 4-5 hours after your last meal.
  • Post-meal glucose is typically defined as glucose that is checked 1.5-2.5 hours after the first bite of a meal
  • Bedtime glucose, for some is more aptly similar to a post-meal glucose, and for others, bedtime is more similar to a pre-meal glucose range, depending on your schedule or routine for eating and sleeping.

For Type 1 and Type 2 Diabetes:

  • Fasting glucose goal: 70-130mg/dL
  • Pre-meal glucose goal: 70-130mg/dL
  • Post-meal glucose goal: 100-180mg/dL

For Pre-Diabetes:

There are no standard glucose goals for patients in the pre-diabetes rang, except to maintain numbers below those ranges for Type 1 and Type 2 Diabetes. Generally speaking, your A1C should be maintained at or below 6.4% to maintain a pre-diabetes diagnosis. At an A1C of 6.5% or higher, a patient will be classified as having Diabetes.

To learn more about when to check your blood sugar and find the monitoring schedule that fits you the most, please read this article and discuss with your dietitian in the care team.

A1C Testing Recommendations

  • Check your A1C in a lab at least two times a year if you are meeting treatment goals, and you have stable glucose (not very widely variable)
  • Check your A1C every 3 months if your medications or lifestyle habits have changed or if you are not meeting goals

A1C reflects average glucose over approximately 3 months. It is useful to get a snapshot. It will only tell us your average, but doesn’t tell us how controlled you are. For example, you might have a narrow glucose range, 150-200, so your average is 175, or you may have a very wide range, between 50-450, also maintaining an average of 175. Check your glucose often and follow a schedule to keep blood sugars steady.

Although the average glucose is acceptable, plenty of research shows that wide fluctuations in glucose tend to lead to higher risks of complications, and higher risks of low glucose.

So while checking your A1C is still recommended to get an average, checking your glucose regularly at its peaks and also its valleys using your home glucose monitor is still crucial to reducing your risk of Diabetes complications.

What A1C is Right for Me?

Blood glucose targets are individualized based on:

  • duration of diabetes
  • age/life expectancy
  • other conditions a person may have
  • cardiovascular disease or diabetes complications
  • hypoglycemia unawareness
  • individual patient considerations

Generally, if you are older, taking medications that may cause low glucose, such as sulfonylureas or insulin, or have a history of heart attack, cardiovascular disease, or stroke, then a slightly higher target may be more appropriate. Talk to your provider about what target range is most appropriate for your situation, and ask our Diabetes Educators for guidance.

Reference: American Diabetes Association; 6. Glycemic Targets: Standards of Medical Care in Diabetes—2021. Diabetes Care 1 January 2021; 44 (Supplement_1): S73–S84.