If your blood glucose (BG) levels are something you are interested in understanding better, you have come to the right place. BG is the amount of glucose or sugar in the blood, and BG rises and falls as you eat, fast, exercise, stress, and sleep. Glucose is released into the blood stream by your digestive system or from your stores so that it can be burned by your cells to generate energy. If it’s not needed or can’t be burned, then it must be stored. Insulin is what signals the cells to accept glucose from the blood stream. If your body isn’t producing enough insulin or if your cells have grown resistant to insulin, your BG will remain high, and sustained high levels of BG are damaging to your body.
How high is too high?
The first way you will probably test your BG is through a blood lab test ordered by your practitioner. BG measurements that may be on your lab report include your fasting glucose, which is the level of glucose detected in your blood after fasting for eight hours. A value of >100 is flagged on lab reports as high because after 8 hours, your cells should have absorbed BG down to <=99. A fasting BG level of >=126 is considered diabetic.
What does A1c mean?
Another measurement of BG that might be on your lab report is hemoglobin A1c, which is an approximate average of your BG over a 3-month period. Glucose binds to your hemoglobin proportionately to your BG levels over time. A1c levels between 5.7 and 6.4, inclusive, are flagged on lab reports as pre-diabetic indicating average BG of 117 to 137. A1c >=6.5 is flagged as diabetic.
It’s an average, so an average BG of 120 means that your BG was below 120 part of the time and above 120 part of the time, but A1c won’t tell you how high or how low your BG was, or how long it stayed at any particular level. You can see why your practitioner and you should be concerned if your fasting BG is >100 and your average BG is >120 because that means your BG must also be higher for sustained periods of time for the average to be that high.
How do I measure my blood glucose?
So, how do you find out how high and low your BG is ranging, what’s causing the spikes, and how long the spikes are lasting without doing a blood lab test? The most common measurement device is a glucometer which can be purchased for home use. It requires measurement strips which you insert into the meter and then a finger prick for placing a drop of blood on a strip each time you want to measure your BG. Pricking your finger and squeezing a drop of blood does generate some discomfort, and it requires some getting used to. I quickly learned what depth to set the lancing device to for each finger to get the minimum amount of blood needed, and I now know which fingers and which parts of the fingertip tend to be more sensitive to pricks. I have more info on glucometers in this post on gadgets.
How might you use the BG data?
Checking your BG after eating different foods or doing different activities can be valuable to understand better how the foods and activities are affecting your BG. Everyone’s metabolism is different, so you may be surprised by some of the readings. I found, for example, that higher glycemic fruits such as an orange or apple that I’d have as an afternoon snack would spike my BG. Combining the fruit with some moderate exercise would help tame the spike, or switching to lower glycemic fruits like berries helped me keep my BG lower.
What is a CGM?
If you’re finding that the data you’re getting from your glucometer is helpful but the frequent finger pricks are getting to be too much, then you may consider a continuous glucose monitor or CGM. This is a relatively new technology that is becoming more mainstream. Initially only available by prescription for those diagnosed with diabetes, CGMs are now available to non-diabetics who want to understand their BG 24×7.
CGMs work by applying a sensor about the size of a stack of 3 quarters to your arm or abdomen. A thread-like detector embedded in your skin’s interstitial fluid will approximate your BG and send the data continuously to your smartphone or measuring device. You can log what you eat and activities you do and then scrutinize the effects of these on your BG while studying a line graph of your BG measurements. You can then try different experiments in changing your diet, your eating patterns, and/or your activities to identify what changes may or may not improve your BG. I have more info on CGMs in this post on gadgets.
Because everyone’s metabolism is different, you may be intrigued about the patterns you discover and the opportunities that emerge. For example, when I was first diagnosed as pre-diabetic, I switched to lower, more complex carbohydrate foods for breakfast, as many do and you may be considering, to lower the glycemic load. I noticed an improvement in my BG levels, but I wanted a bigger improvement. Experimenting with other breakfast options, I found that my metabolism seems to agree best when I went grain-free. And it tastes great! I also experimented with intermittent fasting (IF), or time-restricted feeding, and monitoring my BG with the CGM during my feeding window helped me to time my meals when I was feeding during a smaller window.
