I have type 1 diabetes and practice as an outpatient diabetes educator and pump trainer.  I have worn an insulin pump since 1998.  I have worn a CGM occasionally to become familiar with the technology.  Until last week, I was familiar with the Medtronic personal CGM and this week I have been wearing the Dexcom. 

The only disadvantage I see with the Dexcom over the Medtronic system is that the Dexcom does not communicate data through my pump so I have to carry the remote around.  Honestly though, that is not a big deal.  I find the Dexcom much more 'user friendly' and independent studies have found it more accurate.  That is worth carrying around a remote to me!  In addition, you can calibrate the Dexcom any time of the day, not just when BG is 'stable'.  (When is BG ever stable????)

I wanted to share a few things I have learned wearing the CGM for the past 5.5 days so far and get your input from yourself or your patients experiences.  

My last A1C was in 6.4%-6.7% range.  My blood sugars are not out of control.  But wearing the CGM has opened my eyes to the wide variations in blood sugar that I have from hour to hour of the day.  For example, after meals my blood sugar may go over 200mg/dL then immediately begin its decline back to goal range.  I know that the brief rise and then fall is not too bad but if I am doing this 3 times a day everyday of the week then what effect are these high BGs having on my organs?  This is disturbing to me.  When I look at the trend graph on the CGM it is like looking at a roller coaster ride.  (Weeeeeee-NOT!) 

So this morning I tried an experiment.  I checked my blood sugar and it was 76mg/dL.  I bolused for breakfast knowing that I was going to eat in the next 15 minutes.  And I did.  After that meal my blood sugar went to the highest of 125mg/dL then came back down to goal over the next 2-3 hours.  I was thrilled.  I am considering purchasing the system and working to get off the roller coaster!  

Other areas I want to work on are high fat meals and exercise.

Right now I sometimes use a dual-wave bolus for high fat meals and give part of the bolus at the time of the meal and the rest over a course of 2-4 hours.  But I don't always do that because it is not always necessary.  Two weekends ago I ate mexican food.  My blood sugar was fine 2 hours later and I went to bed.  When I woke up the next morning my BG was in the 300 range!  I had not used the dual-wave bolus that night because I didn't think the meal was that high in fat.  And I didn't know my BG was high until hours later when I checked it in the morning.  That is disturbing.  

The other night I did not use the dual-wave feature after eating a piece of key lime pie (boxed) that had about 15g fat per piece (I know, I know, not a usual occurance).  Anyway, my blood sugar was fine 2 hours later but then high (over 250mg/dL) most of the night after the insulin wore off and the pie finally began digesting.  The reason I knew this is because the CGM beeped at me until I got it back down.  So the CGM saved my having to go until my morning check to figure out that my BG was high but I am looking forward to experimenting with the post-meal hump in blood sugar on the CGM curve to figure out the best course of action when eating high fat meals using the dual-wave feature so that the BG doesn't go high like that at all!

I also want to work on exercise.  Right now I usually eat a snack to bring my BG up to about 170mg/dL before a one hour aerobic workout knowing that it will drop into range afterward.  I want to work on a different strategy.  Maybe lowering my basal rate hours prior to the workout or something.  I don't know.  I plan to ask other athletes how they manage it.  

Although my A1C is not bad I have a feeling it could be better.  And I am excited to work on it!

Please share your thoughts and experiences with the CGM.

Which system do you prefer and why?  What have you learned using the system?  Etc?

Micki, thank you so very much for sharing your experience with the 2 CGM products.  Please keep us posted as you experiment further. I am also glad to hear that you found the DEXCom CGM to be more advantageous. That is what I thought, but I always value observations of users of the devices.  You should publish an article about your experiences

Thanks for sharing Mikki.  Did it take you a lot to be convinced that it would be worth "wearing" all the equipment to get a better handle on your glucose levels?

I too am a Type 1 pumper and have worn both the Dexcom (about 1.5 yrs) and currently use the Medtronic CGM (about 1.5 yrs).  I switched to the Medtronic and have found it to not be quite as accurate however I kept loosing my Dexcom because I just couldn't wear another device.  I kept leaving it somewhere and forgetting where it was!  (needs a clapper option!)  I can only fit so many things (pump, CGM, cellphone) in my bra and the Dexcom is a bit large with the cover on it.  I don't find the Medtronic CGM accuracy issue significant enough to overcome the frequent loss of availabiltiy of CGM I had with Dexcom.  It's just my personal issue but to me it became about six of one and half a dozen of the other.  I also found the irritation of the increase # of button pushes for the Animas pump that I used when I used the Dexcom was another driving reason I went back to Medtronic.  I will say I liked the faster delivery of boluses with the Animas however.  And I know the bolus coverage accuracy ends up being better with Animas because of that.  I don't bolus until I've got the food in front of me cause if I do it 15 minutes prior I end up getting distracted and eat later then have lows!  We are all different and have to find what works best for each of us. 

I too have found the ability to review waveforms on an ongoing basis very enlightening.  I wish everyone could do it.  I remember when my endo looked at the first set of reports I brought in I was prepared to be read the riot act cause I thought those variations were horrible, never having seen them before.  He actually said I was doing pretty good.  I find them most useful when I look at the recent weeks/months averages, it's easy to see where the basal rates need tweaking and I can do so in very specific timeframes.  I personally find my control levels change periodically dispite consistant lifestyle.  My thyoid function seems to fluctuate and other things fluctuate.  I seem to need to adjust things several times a year sometimes.  I can catch the need to update insulin dosages a lot faster when I'm coming down with something and Bg is rising.  I haven't really seen too many reports on type 2's but I suspect they don't look as bad.  The more I learned about variations I realized we Type 1's will have them.  We certainly want to minimize and it's just about impossible without a pump and CGM. 

I use the suspend feature on my pump to help with low BG TX and the use ability to reduce percentage of basal temporatily for increased activity. This requires less food/glucose intake and reduces calories on someone dealing with weight issues.  This is easier to do with CGM.

One other point I would like to make, the sleep interuption with CGM.  I just recently have gone a few weeks without mine while waiting for sensors (apparently insurance over the holiday issues) and then the subsequent loss of function of my transmitter requiring a replacement.  I was really suprised how much I enjoyed not waking up to alarms in the middle of the night.  I have my parameters set pretty tight and enjoy the control levels from that. I also found that I am so sleepy when I am awakened by an alarm that it's dangerous to respond with button pushing when your're half asleep!  I've made a few of those mistakes in the past.  So I have decided to just turn it off at night!.  That just works better for me.  My nighttime BG control is pretty stable after about 3 yrs of using CGM so I feel comfortable doing that. 

I have considered getting a CGM for many years.  But frankly I did not like the Medtronic system.  It seemed clunky and a pain, too much information, too many alarms, too much calibration, etc.  I went to a webinar last year at this time and saw the independent research showing that Dexcom was more accurate.  But since it didn't 'talk' to my pump (Medtronic) that was a barrier for me.  And I assumed my insurance company would prefer the system that talked to my pump.  All that, plus my A1C is good!  So I didn't pursue it.  A couple of events recently prompted me.  I recently started dating a man who is very supportive of my health and diabetes managment.  He has really been a motivating factor for me.  He figures if there is a device that will help me manage my diabetes and get better control then what am I waiting for???  And then last week the Dexcom rep that I met at that webinar last year contacted me to wear the Dexcom as a trial. The rep told me that about 30-40% of their users wear the Medtronic pump.   It was the perfect storm!  When she trained me on the Dexcom I was thrilled with the differences from Medtronic.  

1.  Dexcom ENCOURAGES you to calibrate when BGs are fluctuating.  Medtronic wants you to calibrate when BGs are stable (when is that again???).  So I can calibrate really whenever and not run the risk of the sensor giving me a 'calibrate now' alarm in the middle of the night b/c I have missed a scheduled calibration.  

2.  The Dexcom sensor itself has a smaller insertion wire (its actually a different technology than the Medtronic) about the width of 2 human hairs.  So the 'wound' is not as severe.

3.  The transmitter is not as 'clunky'.  It seems to be sleeker and attach to my body better.  The Medtronic system has to be taped down to avoid it being bumped and moved a lot.   In fact, the first time I wore it I didn't have it taped.  I opened my door to get closer to a drive up ATM and as I was leaving I happende to glance down (thank goodness) and noticed the transmitter had come off and was laying on the ground of the bank parking lot!  Yikes!

4.  The Dexcom transmitter is warranted for 1 yr.  The Medtronic is warranted for 6 months.

5.  The research shows the Dexcom is more accurate than the Medtronic...meaning less 'false alarms' at any time of the day (especially in the middle of the night!!!).

6.  The Dexcom is approved for 7 day use.  The Medtronic is approved for 3 day use.  

7.  Although the remote is a seperate 'thing' to wear or carry I don't think I'm gonna mind.  I have 2 clips on order.  One of them is called the spiband wrist/ankle pocket that I think I will be able to wear on my upper arm or ankle and just slip the remote in there.  http://store.spibelt.com/category-s/66.htm

I love my medtronic pump and think they are a great company and I am not here to knock the Medtronic system.  I just stating my experience.  I understand your issues with Dexcom Sonia and I am grateful that you have found the system that works best for you.  Isn't it great that we have options?  Your experience with getting that stablility overnight is encouraging to me.    

I am very grateful that I have found a system that will work for me and look forward to getting off the roller coaster ride.  

Micki, I am excited for you and if you're like me you'll wonder how you ever got along without CGM in short time.  My control was reasonable before I started but it is so much better now.  There will always be imperfections but it's still a huge step forward in diabetes control.  I am grateful to have it and yes, options are the best.  We are all different, but we are more alike than we realize!  I think both Animas and Medtronic are good companies and either is better than nothing.  I remember testing my blood sugar with urine in a test tube after all.  And I was a teenager so you know that didn't happen very often! 

Yes the transmitter and sensor with the Dexcom is also better.  But I personally wear my 3 day Medtronic sensor for two cycles since I never had problems with the seven day Dexcom.  I have not had problems doing that but of course would not promote doing that to pts.  I still secured my Dexcom transmitter but yes the Medtronic transmitter is "floppier".  There is a little increased pain with insertion of the Medtronic sensor but I personally didn't find it terribly off putting. 

I'm kinda like one of my younger female patients who wouldn't consider a pump until she saw the Omnipod because she didn't like "the tubing".  I sorta couldn't understand that cause I loved my pump, but to each his own.  At least she ended up trying a pump!  My issues in choosing Medtronic over Animas/Dexcom probably boil down to body image and bulk of an extra piece of equipment just like her.  Ahh vanity. 

Hi,

I have DM-1 for 15 yrs and worn a pump for 10. I have tried the dexcom but the reason I went for the medtronic (the lastest system that is the size of a quarter) is b/c of the fact it can beam info to my pump and I don't have a second device to tote around.

As far as accuracy, I tried the Dexcom for a week and thought it was fine although, there were a couple of instances when it didn't catch a low, but I have had the same thing happen with the medtronic system. I wore the older verson of the CGMS from medtronic and chose not to get it b/c it was way too big and bulky so I am glad they came out with something smaller. I do remember the sensor insertion being very easy with dexcom and painless... which is unfortunately not always the case with the medtronic. I didn't realize the needle gauge was larger so that is probably why.

Recently, I received a letter from medtronic stating that we should turn off the feature that beams bs reading from the meter to the pump when using the CGMS b/c the CGMS will use that bs that may not be "stable" enough to calibrate causing data to be off somewhat. However, I have not always found that to be true. As long as I calibrate a NEW sensor when I haven't eaten, given correction or exercised in the past 4 hrs it seems to work out pretty well. The best time for me to calibrate is first thing in the morning. So I may insert the sensor the night before but turn on the sensor in the morning. I know it says to wear the sensor 3 days but I always wear mine 7 and have not noticed any problem in doing so.

I have learned that I should bolus 15-20 min IN ADVANCE of eating or drinking coffee. If I am above 100 I add minutes, or try to, the 15-20 min I am already planning to wait to eat after bolusing. For high fat meals I do dual square wave bolus with a 70/30 split for 1.5 hrs.

Other things I have learned:

* I need to set my low snooze at 80 to better detect lows

* I really ride a roller coaster sometimes but I have made adjustments that help..

* It seems like it takes a lot longer from bs to come down from high then I realized

* I have adjusted my ICR and sensitivity factor and night time basal rates since I started wearing this thing full time about 8 weeks ago. It really helps me to be more aware of what's going on and I actually like wearing it now and feel lost without it!

Has anyone heard of and used Super Bolus and if so can you tell me your experience with it? It is a method of giving a larger bolus for high GI foods upfront and cutting back on basals for the the next 2 hrs to prevent crashing later. I read about it in the Pumping Insulin book by Walsh and Roberts, 4th edition, P. 56-57.

In the interest of trying to protect prime pumping real estate, where are some areas I can wear the medtronic system? I currently use hip and abdomen... has anyone tried thigh area?

Thanks!

One more thing to share....

I absolutely hate the alarms in the middle of the night too but I don't know what to do about it... I recently had an alarm go off and in trying to turn it off (in my sleep!) I suspended my pump and woke up pretty high!!! My parameters are set pretty tight too...

In general continuous glucose sensing is such an eye opener.  Patient's experience when using the DexCom has been that an actual 30 min premeal dose of Novolog was needed to smoothe off peaks of mealtime highs and keep them around 150.  It is a nice tool for those who choose to use insulin injections yet or never were able to get a pump, or never wanted one.  The other finding that has helped is exactly how much fix is needed for hypoglycemia.  While the body craves both hands feeding carb at warp speed, the 15 grams, wait, retest really works for levels 50 or above. 

I think that Continuous Glucose Monitoring systems are the greatest advance in helping people with Diabetes Self Management. Thank you all for sharing your personal experiences.

Hello ladies,

I'm sorry to come to this CGM party so late, but I've been off the site for awhile.  I've had Type 1 diabetes for 42 years, been on a pump for 31 years and have worn all three sensors, and worked for Medtronic and was a clinical scientific liaison for Abbott's Navigator which I REALLY to this day, still miss.  I worn Medtronic's sensor continuously for four year and was a patient in their FDA study, the Star 1 trial.  Then I worn Navigator for 18 months, and now I'm on the Dex Com.  I actually simultaneously wore the three sensors and pushed by gluocose up by not bolusing and then corrected and watched it drop to see which sensor would pick up the changes the quickest and the Navigator was by far, the most accurate and timely.  But, alas, it is no longer available to those of us in the US.  I could consider moving to Europe for that reason alone.

One BIG difference with the Medtronic and the Dex Cox is that there is tylenol interference with the Dex Com--that's why I went on this one last, because I was routinely taking tylenol arthritis.  If you're on tylenol the Dex Com sensor will artifically raise your gluscose by 200 or more mg/dl.  VERY important to let patients know this.  I've now switched to aspirin for periodic arthritis pain.

The Dex Com is a 26 gauge, the Navigator was a 25 gauge needle and the Medtronic current sensor is a 22 gauge needle, so yes, bigger.  Medtronic's new sensor which is approved in Europe but not here yet is significantly smaller, 25 gauge and supposedly much more comfortable to wear.

The technology is just incredibly helpful, albeit annoying at times.  One of the things I learned is:

STRESS has a major impact on my blood glucose.  I actually got to the point that if I had a difficult conversation with someone, I'd bolus with a normal blood glucose because I learned that if I didn't my glucose would be high, two hours later.

I also learned that I needed a bolus 20 to 30 minutes before the meal to have normal glucoses after the meal.  But if I did this and didn't change anything else, I could be low 2.5 hours after that bolus.  Jill Abelseth, MD who is out of Albany Medical Center and was my physician (and I live on Long Island) during the Star 1 Trial noticed that all of her patients were doing better with dual wave boluses, even those of us without gastroparesis, and not eating a lot of high fat meals.  Using the dual wave, also decreased my hypoglycemia 2.5 hours after the bolus.  Jill asked us to start by doing 50% of the bolus up front and the other 40% over 1 hour and this worked very well for those of us without gastroparesis.  IF however, I had a high glucose going into the meal and needed a correction, I did that with a 70% up front and 30% over 2 hours.  I still use that formula for correcting highs and recommend it to all my patients.  It's more like landing a plane.  You come down slower but you avoid the hypo that so often can follow correcting a high where you get slammed down and then counter-regulate and bounce back up.

I also would put in the Medtronic sensor the night before I needed it and unconnected to the transmitter, let it "wet', and then attach it to the transmitter the next am after charging the transmitter.  This worked great!  I routinely used those sensors for 6 days or more without any difficulty whatsoever.

I really like the dex com insertion which is almost painless, and love the increased flexibility with calibrations but still feel that the less fluctuation at the time of the calibration, the closer my sensor readings are to the actual finger stick glucose.

I now wear an OmniPod and love it because of my access to "virgin territory".  Having worn a pump for 32 years and a sensor for over 7 years, I have a lot of scarred tissue--nothing that you can see externally, but areas that don't absorb insulin sufficiently well.  So the OmniPod has been great for me because I can use the newly acquired 'back fat' that being older has endowed me with--it's a no hands insertion so this works, which it never would it I needed to manually insert the canula.  The simplicity of the OmniPod design is fantastic and it's all good.  There are also two new patch pumps coming soon to a teather near us--Roche's, originally MedINGo's Solo, and the Asante Pearl.

So, more, smaller, thinner pumps, smaller needled sensors, all good.  I often think of how fortunate I am to have been diagnosed with diabetes in the late 1960s and not the 1920's or 50s.  42 years, lots of insertions but no complications, and in 8 more years, Joslin's going to give me a medal for having survived it all!

Donna, Micki -

Thanks so much for sharing your insights about your personal experiences with managing your glucose with your CGM. I know I find your insights really valuable and truly wish there was way more dialog about practical real life management....I'd like to see a consensus conference with some of you sitting around the table!

It's important for us to listen to a common thread you both and Christine noted...that's timing of rapid acting in relationship to food consumption (I now call it "ain't so rapid, rapid-acting insulin" (but best we've got at the moment)). Due to findings from studies on the true action curve (albeit with quite a bit of intra and inter-person variation) we need to get away from our early message about taking this insulin right before you eat. In taking to people who are using CGM this is one of the most common learnings.

And to Donna, you should know that I now use your expression "virgin territory" with every OmniPod training I do. I heard you say at the AADE Insulet/OmniPod program last year and it resonated. Thanks for the teaching pearl!

Thanks,
Hope Warshaw, MMSc, RD, CDE, BC-ADM
Nutrition Section editor, PRESENTdiabetes.com

Donna,

When you say "if I did this and didn't change anything else" in regard to the bolus 20-30 min prior to the meal you would have a low 2.5 hrs later, what did you change?  Are you talking about the dual0wave bolus over 1.5 to 2 hrs?  

Thanks for sharing your experience.

I am now wearing my new Dexcom and I love it!

2 days ago I ate a high fat, high carb meal (confession).  I don't do that often but occasionally it happens.  My blood sugar was 119mg/dL prior to the meal and I bolused 20 min prior to eating.  According to the CGM my blood sugar did not go over 130mg/dL after that meal and 2 hrs post meal it was 107!  I had no low that night either.  Now if I can just remember to bolus 20 min prior to eating!

Lastnight I did a cardio workout for 1 hr.  I put on a temporary basal rate prior to the workout to run at 40% of total basal and had a small snack 15g carb with only a partial bolus.  During the exercise my blood sugar rose slightly in the beginning but then leveled off around 98!  I couldn't believe it!  And no low after exercise or lastnight.  I am thrilled.  I know this may not happen every time but I am hopeful that with practice I can work it out.  

Practice, practice, practice!

I truly wish more of my patients were on this link.  Thanks to you all for being so forthcoming.