How does glucose monitoring relate to diabetes?

When you finish the blood glucose check, write down your results and review them to see how food, activity and stress affect your blood glucose. Take a close look at your blood glucose record to see if your level is too high or too low several days in a row at about the same time. If the same thing keeps happening, it might be time to change your plan. Work with your doctor or diabetes educator to learn what your results mean for you. This takes time. Ask your doctor or nurse if you should report results out of a certain range at once by phone.

William Lee Dubois

The glucose monitor, commonly called a meter, changed everything. It’s a compass that keeps you on course for controlling your diabetes.

Many people new to diabetes wine about having to “poke” their finger, but I promise you that done right, testing your blood sugar involves little-to-no pain, and it reveals a universe of information about what is going on inside your body.

  • Using a meter shows you if your medications are working right for you.
  • Using a meter shows you how various foods (and drinks!) affect your blood sugar.
  • Using a meter shows you how different levels of exercise affect your diabetes.
  • Using a meter warns you if your diabetes is “advancing.”
Dr. Jack Merendino, MD

This seemingly simple question is actually quite complex, and it’s really at the heart of properly managing diabetes. First, it is important to realize that everyone, even someone with impeccable health habits, will have blood sugar readings that don’t make sense. That’s just the nature of diabetes. So individual numbers are usually not that important. In most cases patterns are what is important, and responding to blood sugar readings in an effective manner is often called “pattern management.” 

I think it is helpful to keep in mind what happens when someone does not have diabetes, and recognize that what you are doing to manage diabetes is designed to get you as close to that non-diabetic situation as possible. In most people who don’t have diabetes, the blood sugar when they first get up is between about 70 and 100. After eating, the sugar level rises at hits its peak somewhere betten 45 and 90 minutes (there are always exceptions, of course). Our technical definition of diabetes is that a random blood sugar level, including one after eating, is not normal if it goes above 200, but in fact most truly normal people don’t go above around 140 or so at their highest, and most people who go much higher either have pre-diabetes or unrecognized diabetes. By 2 hours the blood sugar is falling, and by 3 to 4 hours it will have returned to its baseline of near or under 100. 

Getting a handle on your pattern of blood sugars will involve testing at varying times of the day, including when you are fasting, before and after meals, before bedtime and, occasionally, in the middle of the night. It’s not necessary to do all this testing at once. An easy way to do this is to do two tests a day, preferable before and 2 hours after a meal, and record the results on a grid like those found in the log books that come with most meters. I recommend that people not rely on the time record of the meter, because the meter will assign a before meal or after meal designation to a number based on the time of day, and this will obviously be wrong in many cases. Even though it’s a pain, I think it’s best to write these numbers down on the grid. After a couple of weeks of testing, a pattern will emerge and this pattern will provide important information. For example, if you are very high when you first get up, it may mean that you are going low in the middle of the night and are suffering a rebound (called the “Somogyi” phenomenon) or that changes in other hormones in the early morning hours are driving your sugars up (called the “dawn” phenomenon). These two problems are treated differently, and distinguishing between them may require that you awaken yourself at 2 or 3 a.m. for two or three days to make sure that you are not having unrecognized lows. Numbers that are much higher after a particular meal of the day may mean that you need to change what you are eating for breakfast or dinner or that an adjustment in the dose or timing of your medication may be necessary. 

The bottom line is that having a good understanding of the daily variation in your blood sugar readings is essential to both you are your doctor if you are going to make smart decisions about diabetes care.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.