Frustration on using the Dexcom CG Monitor

My daughter, age 24, just started wearing the Dexcom CG Monitor 3 days ago and she is frustrated over the numbers (she understands how the sensory unit operates; she is a nutritional science major) and is flummox when it's time to eat and take Humalog. She is to take Humalog if her #'s are at 90 or above. Her readings varies so she feels uncertain when and how much of insulin she should take. I think the word that best describes her state of mind is extreme frustration and wanting to quit wearing it (& this is her first session)! Would love ways of providing support to her and easing her mind when she looks at her numbers. She still uses her glucometer at least twice a day or more if necessary, but the purpose of the Dexcom was to limit the amount of times she would have to prick her fingers.

does your daughter have a good endo?
i think not

I am not a Dexcom professional but I do use a Dexcom CGM (although I am still new at it myself).

A CGM is not a replacement for blood glucose testing. It is meant for seeing your glucose trends. Where you've been and where you are heading and possibly how fast you are getting there. It is a great tool for learning how your lifestyle is impacting your glucose levels, and will help you to gain tighter control. You should never treat/medicate based off of your CGM numbers. Always test your blood sugar and treat/medicate from that number only.

The reason for this is because the CGM does not read blood sugar. It gets its readings from other fluids and these are close but not the same as blood glucose. So the CGM is good for seeing trends and learning how to better control your glucose, but not for exact blood sugar readings.

Is she frustrated with the numbers being different from the meter? Or is she frustrated about her real glucose numbers?

This "use Humalog above 90" rule sounds really odd to me. Usually insulin is calculated for the amount of carbohydrates you are about to eat. The approach to just eat and then afterwards react to the rising glucose with corrections will boldly fail. Like Shoshana I would recommend a visit to a good endo - and a book like "Think Like a Pancreas" by our TuMember Gary Scheiner.

She has a great endo who is very supportive! She is eats a 45- 60 carbs per meal per her endo and nutritionists taking Humalog if her BGL are 90 and above. When she was pricking her fingers before all meals she would use that BGL to determine if she needed Humalog, now she does it off the numbers on the sensory.

I second what Tamra says. There are members on here that use their Dexcom to determine their insulin dose. Dexcom is pretty clear in all their literature that you need to do fingersticks to treat your diabetes. The CGM is for trends.

Is your daughter a type one or two?

No disrespect intended, but this way of managing BG is from the Dark Ages of diabetes! I’d get another endo if I were your daughter…

If my daughter is on the lowish side before a meal, let’s say in the 60’s, she’ll still need to bolus for her meal. She’ll just takes her insulin at the start of the meal rather than 30 minutes before the meal. Even if you start a meal on the low side, you’re still going to spike significantly (and dangerously) if you don’t bolus for the meal. There’s some sort of confusion going on here. Surely the endo did not mean to say not to bolus AT ALL if she were 90 and above.

I agree with the above on the humalog dosing. Humalog is to cover her carbs. What is her basal insulin. I think even a good CDE could help,her a lot.

She takes Lantus twice a day (am 16 units, pm 13 units) & 8 units of Humalog as needed before eating a meal. She takes her Humalog right before eating and Lantus after eating in the morning and then at bedtime. Her frustration stems from our understanding that she would not need to prick her fingers as much as she did before wearing the Dexcom. Perhaps it was our misunderstanding....

The “set” dosing of 8 units, regardless of meal is perplexing. One usually counts the amount of carbs, then doses based on that. For example, my daughter takes 1 unit for every 15 carbs at lunch. So when I pack her a 60 carb lunch, she’ll inject 4 units. She does indeed do less finger sticks once her CGM is calibrated and working well, after 24 hours. However, 2 finger sticks are required per day to calibrate the CGM. She averages about 3-4 finger sticks even with the CGM.

My daughter is just doing as she was told by her endo. As I said before, her carbs per meal is at a min 45 to a max of 60 carbs. She was just diagnosed in late October and her endo is always adjusting her insulin. I told her to send her endo a message and question all that "we" have discussed via this blog /site.

I really appreicate everyones thoughts, concerns & advice!

Mom, Is your daughter on TuDiabetes? Please ask her to join or ask her to look at these postings with you. We can help her out. I love my Dexcom, but I'm not on a pump...yet. I'm on pens. Please let her know that we are like her with frustrations, questions and sometimes odd advice from our doctors.


My daughter does read these responses and we discuss them together. I have asked her to join, but she seems hesitate right now. She does see all of these post and we are very appreciative of everyone's suggestions too!

please join us in the chat room where we can talk freely & hopefully help you
i think you will be glad you did
hugs to you both

Hi Mom, first off let me say, take a deep breath it's going to be o.k. Learning how to manage diabetes is a tough job no matter the age but it is doable as evidenced by so many people here at TUDiabetes. I was also diagnosed at age 24, I'm 41 now, and I was very overwhelmed and frustrated also. I originally visited a family doc who had me dosing similarly to your daughter. It wasn't hard to do, but it didn't work. Insulin and food have a very sensitive relationship, it's a massive balancing act and it's different for every single person. Like many others I would suggest you discuss precise dosing for carbs with your endo and if she/he doesn't agree I would find a new endo.

I started on the dexcom last September (after having the minimed version for 4 years). I love my dex. I find it to be incredibly accurate. However, when I firsts started I probably did more finger sticks than before I had a cgm. The reason was I wanted to know how well the dex worked and if I could TRUST it's readings to dose or eat. After being on it for 6 months I test my blood much less than I used to and I believe what dex is telling me most of the time. Using a cgm takes some getting used to, and you always have to remember that it was designed for giving you the "wide angle" picture of diabetes. It was never FDA approved to replace finger sticks (however many of us dex users have done just that). No diabetic will ever be able to forgo finger sticks, it's just the nature of the beast, but Dexcom will lessen the number of times you must do so each day.

I normally test around 3 times per day - upon waking up - to calibrate with a steady number, around dinner time - also to calibrate and at bedtime - just to be safe. I also test anytime I am suspicious of the Dex # or anytime I feel funky. Sometimes dex can be a little slow to catch the lows. Hope some of this helps and please tell you daughter to join us. Lots of great info here for old and new diabetics alike.