CGM Continues to Elicit Strong Opinions

Continuous glucose management is a technology still in its infancy and people have stronge feelings about it. As always, discussion is beneficial to the diabetes community.

Aug 28, 2009

In our last issue, we published a letter from reader Sheila Payne, who wrote that we had been far too positive about continuous glucose monitoring (CGM) in our June/July article Get the Facts on Continuous Glucose Monitoring. But her opinion provoked a stack of letters from people who believe that the benefits of CGM substantially outweigh its negatives.  To let you in on the debate, we are reprinting Ms. Payne's thought-provoking letter here, followed by two equally thoughtful responses from readers.

Note: These letters were written by Diabetes Health readers who are not medical professionals. This article neither advises a particular course of action nor endorses continuous glucose monitoring as the best solution for you. We deeply appreciate our readers' personal contributions, but urge you to contact your CGM company with any questions or concerns about your own CGM.

Sheila Payne wrote:
I read your article about CGMs and felt that you left out three-quarters of the facts. You basically only gave the positives. You touched on the "fact" that CGM is expensive and requires a "commitment," but that was far too light.

My son has tried two different CGMs, and the result was the same in both cases. The first one he tried was the Medtronic Real-Time System. I bought the new pump, and he tried it for eight weeks. I begged them to take it back. I will say that Medtronic tried to work out the bugs with him, but there were just too many issues. The second attempt was DexCom. The issues were the same.

The CGM companies want you to calibrate twice a day at least, but you can't calibrate if you have just eaten, have dropped or risen more than 40 points in 20 minutes, have just exercised, or have active insulin on board. Type 1 people have very little time when one of these issues is not in play. Also, you don't want to calibrate too close to the last calibration.

My son's CGM would be off as many as 100 points at times. If you try to recalibrate when it is that far off, it shuts down and you have to begin the whole start-up process again. That can be quite involved-especially when it shuts off in the middle of the night. Unfortunately, my son's CGM was least reliable at night. According to the Medtronic helpline person, that was because my son was sleeping on it. Well, most people don't sleep standing up. After a few nights with the CGM, however, my son and I were doing a little sleeping standing up-because it kept us busy even during the night.

The CGM gave lots of false alarms. The monitor would lose contact with the pump. The sites did not usually last longer than two days before they would start having trouble. Once a site did last six days, but it was not problem-free. My son thought the sites were uncomfortable, and there was pain involved in the insertion. If the CGM had worked, the pain would have been worth it, but it didn't work. The sites for the CGM do not heal as well as the sites for the insulin pump. It is hard to have enough sites for both the pump and the CGM when the healing process is longer for the CGM. My son was doing more finger sticks than ever, and his A1c went up.

I have been told that many people have had great success with CGMs-by magazine articles, doctors, and the companies that make them. But I have never met a real person who uses one and feels any differently than we do. At this point, my son will not even consider trying another one.

As Paul Harvey use to say-"That is the rest of the story."  I feel that these are important facts, and they should have been included in your article.


Don Muchow wrote:

Sheila Payne's letter about her son's bad experiences with CGMs left me feeling that the balance of opinion about their effectiveness has once again been knocked out of whack.  True, the technology is in its early stages, and some people, like Ms. Payne, have had negative experiences.  But my own experience has been relatively positive, and I would encourage others who are using, or are contemplating using, CGMs to consider both their positives and their negatives equally.

I feel compelled to correct some errors in Ms. Payne's letter.  First, it's not true that you can't calibrate after you have exercised or when you have active insulin on board.  Even if the manufacturer's literature says that- which I doubt-my experience has been that the devices will calibrate as long as the "sugar curve" is flat.  As far as "not calibrating too close to the last calibration," yes, the manufacturer says that it's possible to over-calibrate the device.  But in practice, it's almost impossible to do.

I use a Medtronic, the same CGM that Ms. Payne tested.  The device has never shut down in the middle of the night unless it was out of enzyme or low on power.  And it has been as reliable at night as during the day.  In fact, mine has warned me about lows that I would otherwise have slept through! 

As far as the device shutting down-yes, it is possible to get a "weak signal" if you are overweight and the sensor and transmitter are on opposite sides of your body, if you are in a building with wireless security devices, if you are in the shower and the device is on the counter, if the device has become partially dislodged, etc.  But the system won't shut down unless the sensor has been off or out of range for quite a long time. In practice, this has happened to me exactly once in the last year-and-a-half.  If my computer crashed only that often, I'd be pretty darn happy.

The manufacturer makes no guarantee that the sensors will work past three days, and they tell you that CGM is not a substitute for metering.  That's true.  My personal experience has been, however, that the sensors are good for about five days, which isn't bad.  After that, several things can go wrong. The device can get stuck on one reading despite glucose actually going up, and readings can vary wildly up and down or be artificially high or low.  But that's why they say to change the sensor, and that's why we have glucose meters!

The point of calibrating, in fact, is to remove transient inaccuracies/false readings via a weighted regression of data.  The vendors tell you not to calibrate when your sugar is rapidly changing because there is too much change in the slope of the curve, and a linear regression on such a curve is inherently inaccurate.  You can, however, calibrate if your sugar "curve" is flat and high or flat and low. Given that you have to calibrate only twice a day, it's not that inconvenient to find a time when your sugar is flat. In fact, the CGM system has helped flatten my sugar curve because I now tend to do "micro-bolus" corrections more often.

As far as irritation at the site and the size of the sensor, I agree.  The introducer needle is large and somewhat painful.  But I've seen worse. Things I don't like: the fact that sometimes the sensor doesn't go in all the way and I have to push the needle; the fact that you can puncture a blood vessel; the fact that insurance is just starting to cover the devices; and the fact that the dressings don't really stick after a 10K run.  But you know... that's life.

I truly, truly sympathize with Ms. Payne's frustration.  It took me quite a while to get used to my CGM system.  But she seems to imply that only manufacturers or magazines paid by them have anything positive to say about CGM. As the saying goes, one exception breaks the rule. I've used the Medtronic system for a year-and-a-half with no major issues, and I suspect that there are many more exceptions like me.


Hillary Liber wrote:

I agree that there is a lot more to CGM use and management than one article can reveal, and I empathize with the problems that Sheila and her son had while learning to use a CGM.  However, I would like to share with you a bit more of "the rest of the story."

I have had a Minimed CGM for over one year, and I have done three trials with various Dexcom devices.  There is no question that these devices are far from perfect and that the technology has a long way to go before it becomes more user-friendly.  Even in its current incarnation, however, a CGM is still a very useful device.  It just takes a LOT of hard work and time, and there is a LONG learning curve.

What I Get from CGM

Almost from the moment of my diagnosis, I have had what used to be called "brittle diabetes." My blood sugars would fluctuate wildly, even when I was a "perfectly compliant" patient-eating and exercising in a consistent fashion from day to day, taking ten finger sticks and almost as many injections daily, etc. Even after completely mastering the Minimed Paradigm pump, utilizing its special features, and going through the two-week adjusting process every six months, I was still roaming wildly between 30 and 450.  

Out of curiosity (and desperation), I got involved with several studies of the Dexcom CGM. I could see the value of the device, but could also see that it was a LOT of work.  I decided to begin the (one-year-long) fight with insurance to procure a CGM, and I ended up with the Minimed Paradigm CGM device in June 2008.

At that time, I had a very reasonable A1c of 6.3%.  That was a false comfort, however, because I was having serious (below 45) lows almost daily. These extreme lows compensated for my extreme highs, so that my average looked artificially good.

Furthermore, I was having to test up to 15 times each day. I was afraid to do anything (drive, exercise, walk a few blocks from home, or travel by myself) without being certain that I was high enough (which generally meant too high!). More often than anyone would like, I was becoming so low that I could not treat myself.  Although I was always fortunate enough to have someone with me at those times, I was terrified that one day I would be alone and would die from hypoglycemia, as two of my friends have died in the past few years.

After working on getting rid of the lows for the first six months of CGM, my A1c jumped to 7.2%. But now I felt safe, and I even traveled cross-country on my own!  Since then, I've been working on getting rid of the highs, and my recent A1c was 6.5%. I feel very much "on the road" to stability.  This is the WORTH of CGM to me.

What It Took For Me To Learn CGM

I knew from my trial experiences that CGM is not easy to use and that it would not be a panacea for all my diabetes problems.  All I wanted was to feel safe when on my own.  But even that was a difficult goal to achieve.

Just as when a patient is diagnosed, when there are major changes in health or lifestyle, or when any new device or treatment is introduced, there is a "learning curve" to CGM.  I must admit that the learning curve for CGM is very long.  But there ARE ways to utilize the "system" to make it easier. I would like to share my insights and experiences with those struggling to make CGM work.

1) Use the 24-hour helpline. I never used Dexcom's helpline, but Minimed's service is spectacular.  Don't hesitate to call with even the silliest question-and definitely call when there is a serious question.

2) Don't accept the first technician you reach on the phone if that person is not helpful to you.  Ask to speak to a supervisor, or just hang up and call again.  There are many VERY competent representatives, many of whom have diabetes and wear the CGM for their own health management. There are even others who wear it just so that they can help us!  They understand ALL the problems and are both sympathetic and wise.  There is undoubtedly someone on call who has experienced the same problem you are having. If you ask around enough, you will get help.

3) Don't accept scripted answers.  One day I called six times.  When I reached the fifth person and he asked me what insulin I was using (after he looked at the record at my insistence), I said, "The same insulin I was using when I called a half-hour ago. Obviously you are not an experienced user and are reading from a script. I'd like to speak to your supervisor." 

4) Trust your instincts. If it doesn't sound right to you, there's a good chance it's not.  At this point, one year out, I know a lot more about CGM than many of the people whom I call for help.  If I feel that a representative does not have the ability to help me, I tell the person so (nicely).  And if he or she won't get me another person, I hang up and call back.

5) DEMAND to receive what you are entitled to, including a replacement sensor.  If a sensor does not read within the first 24 hours, has not given accurate readings, or has failed before the guaranteed time of use (for Minimed, it's 72 hours; I think it's seven days for Dexcom), insist on getting a replacement sensor. If a service person refuses to do this, ask for a supervisor and politely but firmly state your case.  You pay good money (or your insurance company does) for this device and its equipment, so be sure that you get what you paid for.  You will be sent a new sensor within a couple of days, as well as a canister and prepaid envelope in which to return the bad sensor. (Never throw away a sensor if you feel it did not work properly.)

Now, as to Sheila's son's specific problems.

A) Calibration times:  If you follow all the rules that you get on the phone, you can NEVER calibrate-Sheila is right-on with that. (I was told even more rules than Sheila shared because I called so many times and got so many different people.) However, I finally connected with someone who treated me as the intelligent user that I am and explained how the calibration process works for Minimed specifically.  

When you go to your sensor status screen, you will see a reading that says ISIG: a number of at least 2.00.  Before entering any calibration, look at the ISIG.  If you do not follow the ISIG parameters, you will get a CAL ERROR message, so don't enter a number until you check the ISIG.

To use the ISIG, first check your BG. Then divide that number by 10. The ISIG can be anywhere from ½ of that number to twice that number in order to calibrate. Ideally, your ISIG will be 10 when your BG is 100. However, with a BG of 100, the ISIG can vary from 5.0 to 20.00, and you can still calibrate.

You NEED to learn this computation to use a Minimed CGM. All the rest of the rules they give you are just guidelines. THIS is the real rule! I have consistently broken all the other rules Sheila mentioned and have even calibrated while a bolus was in progress, but only because I used the ISIG rule.

For those who are not math geniuses, here's an example of how to do it: Check your BG (250). Divide that number by 10 (25).  The ISIG can be ½ of that number (12.50) through twice that number (50) in order to calibrate.

B) Start up rules: These rules are the ones that you should be following. You MUST wait at least one minute (I usually wait longer to be safe) between each step.  Here's what I do:

Remove the transmitter and sensor. 

Turn off the sensor feature on the pump. (Press "Sensor," "Settings," "Edit Settings," and "Off.")

Clean the transmitter with alcohol to remove adhesive, sweat, dirt, etc. 

Insert the transmitter in the charger.  Make sure it starts blinking.

The rest of this process is best begun first thing in the morning after a drink of water.  You need water to make this work, and you need time to make it work.  If you start too late in the day, you may still be struggling at bed time.

Insert the NEW sensor with the inserter, at the correct angle and while standing.  Be sure it is held down well before you move one inch! I usually hold it down with easily removable paper tape until I attach the transmitter and put on the IV 3000.

Charge the transmitter UNTIL the charger light stops blinking: not just 10 minutes as they often say, but until the light stops-usually ½ hour, maybe longer.  

Remove the transmitter from the charger. Watch to be sure that the transmitter light blinks (six times on mine).

Wait one to two minutes after the transmitter stops blinking. Then, and only then, attach the transmitter to the sensor.  Be sure they attach firmly and click. Press on the sensor and the transmitter and be sure that the transmitter blinks again.

When you are sure that you are "well connected," tape down the sensor and transmitter with IV-3000. I sometimes use two patches to be sure it's down tight and won't move when I exercise, sleep, etc. This is very important, I have found, especially if you don't want it to stop reading and then have to re-start.

Wait another one to two minutes.  Then start the sensor.

Drink a LOT of water from the beginning (when you disconnect) through the first day of start up.  The more fluid you have in your body, the faster that the sensor will "wet" and start reading accurately.

Turn the sensor feature on your pump back to "ON" and try not to hold your breath.  At this point, it may take anywhere from one to six hours for it to really get started.  Your ISIG will fluctuate until the sensor is ready, and it may give you any number of alarms (sensor error, weak signal, bad sensor). Just turn the alarm off.  Even if you get a "bad sensor" alarm, just disarm it and restart.

Call Minimed for help if necessary, but don't remove the sensor. Never remove a sensor (unless it's supposed to be done) until a Minimed rep tells you to do so and tells you that they will replace it.

When you get the "Meter BG Now," check the ISIG and do a finger stick. If they coincide (see item B above), then enter the BG. If not, turn off the alarm and wait until the two readings coincide according to the mathematical formula.  

C) Start-up times: I was told that it takes two hours from insertion of the sensor to first calibration. Yeah, right! Just as everyone's diabetes is different, so is everyone's response to any device.  I find that it takes a long time for my body to provide the amount of fluid to a sensor for proper calibration-sometimes six hours.  That's why I ALWAYS start this process first thing in the morning. I don't want to be up all night!

If it has been two hours since insertion and you have not had a BG that can be entered to match the ISIG, call Minimed and put them on alert.  Even though it might take four to six hours, you should get it into their records that there might be a problem later in the day. (Remember Rules 1 to 5 above. If someone doesn't understand what you are talking about or makes you answer 20 questions before listening to you, ask to speak to someone else.  Your TIME is VALUABLE!)

D) Alarms: Because there is a lag time of 10 to 30 minutes (yeah, I know they say 15, but we know better!) between your finger stick and your CGM, set your alarms accordingly.  To start, most people set their high at 200 and their low at 80, but that might not be appropriate for you.  For me, having my low at 80 assures me that I won't drop below 45 or 50 when the CGM begins to alarm.  As you get more experienced with the CGM, you can chose alarm points more appropriate for you personally. Then you will have fewer false alarms.

E) Night Alarms:  I am a notoriously light and restless sleeper, but what I really care about at night is that I don't get too low. Consequently, I leave that alarm functioning 24/7.  However, I do turn off my "high" alarm (or set it at a much higher number) when sleeping.  Also, I attach the pump to my nightclothes so that it always remains on the same side of my body as the sensor.

As Sheila's son experienced, when your body gets between pump and sensor, it often gets a weak signal. I have found that it is OK to sleep on the sensor as long as you are also sleeping on the pump-so just keep them together!  Also, check the tape before you go to sleep. If it's loose, put on another adhesive patch. They are expensive, but they make a world of difference. (If you have problems with the adhesive on the IV300, try another one. That's the only one that I can use, so I mention it often!)

F) Weak Signal: Whenever you disconnect your pump to shower, swim, etc., be sure you turn off the sensor feature. Then when you reconnect, turn on the sensor feature and click "Sensor," "Start Sensor," and "Reconnect Old Sensor."  It may or may not ask for a new calibration, but at least you will avoid the entire start-up process.

G) Site problems:  Well, isn't this the perennial problem of every type 1 diabetic? I have very fragile, easily bruised, allergic, and derma-graphic skin. This means that I am a poster child for site problems. And besides the insulin site and the CGM site, I take three or four injections a day.  I don't have any good answers for anyone with site problems.  Obviously, we need to find ways to use less conventional sites.  But as someone who cannot fasten her bra behind her back, I have a hard time using sites that I can't see.  And many sites that other people use are unavailable to me because they bruise too easily or react allergically.

I have only one piece of advice on site issues: antibiotic ointment (Neosporin, bacitracin, or store brand).  As soon as I remove a sensor or infusion set, I apply the ointment to the site.  And after every shower, I apply the ointment to my entire site area and make sure to cover every "dot" of a past site in sight! Although it doesn't get rid of the reaction problem, at least the sites heal more quickly for reuse.  One other thing that works for me is to dedicate a certain area for each "activity": insertion, sensor, and injection.  That way, I know what is causing a problem and what is healing.

H) Finger Sticks: Yes, there are days when I do more finger sticks with a CGM than without it. For me, however, it is worth it.  I haven't passed out once since I got my CGM, and I'm even getting my highs under control. Two weeks ago I printed out my daily sensor overlay, and I had NO BGs below 55 and only one erratic high excursion. All my little graphs were in my target zone! Having a CGM is about better control. But good things come to those who WORK and wait for results patiently.

I)  Changes in A1c: The last problem Sheila Payne raised was about A1c's.  As I mentioned above, an A1c is an average. You may get a better average between your 40s and 400s than between your 70s and 200s, but you will be MUCH healthier in the long run if you control those highs and lows.

Finally, I want to say this to Sheila Payne's son, and to everyone struggling with managing diabetes. With or without a CGM, this is a CRUMMY disease! I want to strangle every person who responds to learning that I'm diabetic with a comment like "At least it's not cancer" or whatever other disease they dread. People who do not have diabetes do not have a clue about how difficult it is to live with this disease.

I'm sure that there are some people who find it easy to manage their diabetes. However, I have learned from talking to people at conferences, seminars, and doctors' offices that most of us struggle all the time, or at least most of the time.  We'd love to believe that all the work we do and all the suffering we have will make us "all better" one day. But as of this writing, there is no cure for diabetes.  We will have it for the rest of our lives.  So don't tell us it's no big deal. It's a great big deal.

Therefore, Sheila and son-bravo to you both.  Bravo to you for trying. Bravo to you for your successes. And bravo to you for enduring your failures. I pray that you have greater ease in the future and that one day we can all celebrate the end of this disease together, for ourselves, our kids, and future generations!

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Categories: A1c Test, Blood Sugar, CGMs, Community, Diabetes, Diabetes, Health, Health Care, Insulin, Insulin Pumps, Losing weight, Low Blood Sugar, Meters, Pre-Diabetes, Research, Type 1 Issues, Type 2 Issues

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Posted by Anonymous on 3 September 2009

I was sorry to hear about Sheila's experience and was also somewhat relieved, as I felt similarly about the CGM. I had been using a Dexcom 7 and experienced more trouble and stress than I did accurate readings or true alerts. Yes, there was quite a learning curve and I kept at it (through many many calls and replacement sensors) and was finally told it really doesn't work well for rapid glucose rises or rapid drops. I was given the Dexcom 7 Plus which supposedly has corrected this issue, and I am currently trying it out and hope that it does work for me.

Posted by Anonymous on 4 September 2009

I'm so glad to read your thoughtful letter here! The picture of diabetes we get is so often the rosy one -- "just follow the regime and, with hard work, your success is guaranteed" say the articles, complete with glossy pictures. I have been diabetic for 30 years (since I was 12) and my bloods range, like Hilary's, all over the place. My experience with the sensor is much like hers. It takes a tremendous amount of work, it is often 10-30 minutes behind and is sometimes wrong. It is tremendously nice to here from someone whosae experience validates my own. Bravo hilary!

Posted by Seymour on 4 September 2009

Having read the three letters as shown, I can only wonder how the companies can sell CGMs. Anything as complicated as this should be administered by specially trained health care professionals.

I am type 1 and do not have any sensation of high or low BG. My wife says that she can tell, but she misses what my finger sticks tell me about 20% of the time. I test myself every 3 hours at night and eat regular schedule same carb/calorie count meals.

I am interested in aquiring a CGM, but do not think that I would be able to operate it properly. I am a degreed mechanical engineer with extensive experience in instrumentation and control systems. The manufacturers of this devices can and should concentrate on making units that are simplier to operate - and a little less expensive would also help.

I am thru moaning and groaning now. Thanks for listening.

Posted by dandbcollier on 5 September 2009

The response by Hillary is fantastic! Thank you so much for taking the time to write all of that. You wrote in a way that was so matter-of-fact yet also sympathetic to both sides of the argument. Bravo to YOU!

I had a very similar experience to Sheila, but Hillary's suggestions are making me consider giving it another shot. We'll see; I just felt like the CGM was giving me only additional pain and frustration without any additional information.

I used a pump for 3 years, and I really liked it...until I finally got sick of it and took a "pump vacation." I've been on that vacation for 6 months, and it's been great; maybe I'll just stay on injections. I have a lot of guilt about not using the "best" technology that's out there, but that probably shouldn't be the case. There are a lot of pros and cons to each side, and all that "best" means is whatever works for an individual.

Posted by Anonymous on 5 September 2009

I am Type 2 and use a Medtronic Mini-med. I think the company is profit oriented and offers equipment that needs FAR more work before having been placed on the market. I am glad my insurance company won't pay for this device as it has saved me some real problems according to what I have been reading. I "hear" the same comments/problems in the letters, but each person seems to deal with the problems differently, that's all.

Posted by Anonymous on 6 September 2009

I have been a Type 1 diabetic since 1989 at the age of ll. I am also using the Pump through medtronic. I have the CGM that works with the pump. I started using the CMG in order to lower my A1C from 6.8% to 5.8%. I needed to do this because of a pregnancy. The first 6 weeks pregnancy are the most cirtical. If your sugars are high or low you will harm or destroy the fetus. Many women do not know they are pregnant until 4 to 5 weeks along. I was able to keep my sugars in tight control. Tight control with blood sugar is very important during pregnancy.

You have to be patient when using the CGM. Sometimes you will have cal errors or weak signals, but you will be able to have more control or your sugars. The only real problem I have the CGM is my insurance company will not cover the sensors. I tired to get the sensors covered during my pregnancy, but at that time the CGM was new technology. I am able to by the 10 pack with a doctor's prescription. I am also able to make my sensors last longer to save money. So do not let the CGM hold you back from better control. I feel more normal with the CGM. I am able to exercise without worry of low sugars. I am able to sleep without worry low sugars at night. I am able to drive my car safely. I would recommend CGM to teens, young adults, women who want to get pregnant, and adults of all ages. Young children may have some issues with CGM, but please try CGM when children are older.

When A1c is lower than 7%, there will be less chance for complications later in life. High A1c's can lead to blindness, amputations, and death. In order to lead a long and healthy life you must keep your A1c less than 7%. The first insulin treated diabetic lived into to early 70's. She did not have CGM, but she took very good care of herself. Doctor's Banting and Best saved her life and all diabetics from early death. You have to make a choice to live a long and healthy life.

Posted by cjensen61 on 7 September 2009

First off, to Sheila, Don, and Hilary, thank you to each of you for your comments. I have felt exactly like both Sheila AND Hilary. How can that be? Well, let me explain. I started on the CGM (RealTime by Medtronic) about 9 months ago. I had many of the problems that Sheila described her son having had. I would call the people at Minimed and they would try to talk me through problems, but I essentially had to have many sensors replaced at the beginning of the experience while I was learning how to get through some of the initial problems. I did go to the class put on by someone who has been using a Real Time CGM for over 2 years. She is a diabetes educator for Minimed. One of the most helpful things sge suggested for those who cannot seem to get the sensor to "wet" well is to insert it at night and then begin using the sensor the next morning. BRAVO and MANY THANKS to her for a wonderful suggestion that has worked very well for this user. If you continue to have problems with your sensors wetting in good time, try inserting the sensor at night and not hooking up the transmitter until morning. By morning, the sensor is definitely "wet" enough to work well!
Every other suggestion that Hilary gave is worth its weight in gold. I have implemented many of the things she has talked about just as she has. I am also one who is considered extremely brittle, so trying to get my diabetes under good control has left me feeling bewildered over the 38 years I have had this disease. At oen point along the way (with the CGM), my insurance was fighting me and I was feeling completely overwhelmed. Then I went to an appointment with my ophthalmologist and had my annual eye exam. He told me that he didn't know what I was doing, but I had better keep it up to maintain my eye health. Just 2 years prior to that, I had had laser treatment for proliferative retinopathy in my right eye. To hear those words come out of his mouth, I felt inspired. I was inspired that somebody could tell me I was doing the right thing for once! And it actually shows! My endocrinologist and I keep fighting for increased coverage by my insurance company (with the help of letters from the ophthalmologist as well) and I have a new lease on life. Sure, using a CGM is darn hard work. Sure, the technology has a long way to go to be where it really needs to be. But darn it all, I finally have relief from reactions that I never felt coming and I can drive without constantly worrying that I might have a low blood sugar and cause an accident somewhere to someone. The peace of mind that it gives me in incomprehensible to the person who hasn't had a CGM and been in the kinds of situations I have described. I only wish the technology would have come sooner so I could have used in during my 3 pregancies with my kids.
To anyone who might be considering the CGM, please don't go into the long process of learning about every single aspect of it with naivete. Become as informed as you possible can and realize that there will be some frustrations concerning this technology. But they are working on improvements as we speak. Realize that stopping the progression of complications is what we are all working on and that our lives depend on it. Every single solitary thing we can do to help ourselves is worth it. Don't give up and don't let the frustrations be all that you see. There are positives and I am here to prove that to you. My HbA1c went from 8.1 to 6.7 in just 3 months from using this technology. This alone speaks volumes!!!!

Posted by angivan on 8 September 2009

Sorry to say I've had the same problems with the Minimed CGMS. Sensor errors, Cal errors when I calibrate (before meals as directed), and terrible swings in results vs. actual. I've been using the trend numbers to make adjustments to my pump regimen. I just had an A1C test and it was 7.8 - I haven't been that high for at least 10 years, usually I'm around 6.5. Not sure what the solution is, but I do accept that we are guinea pigs for this first generation of devices in the public arena...I can only hope the next generation will be a significant improvement!

Posted by jeanniemol1 on 2 February 2010

I've been a Type 1 for 25 years & a minimed pump user since 2002 & been using the cgm for about a month. Thanks to all for the tips (especially Hillary). I still get alot of weak signal errors when the pump & cgm are less than 6 inches from each other. I noticed after the weak signals it takes hours to get back to monitoring again. I know there's alot of trial and error with this, but I'm sure it will alll be beneficial in the long run!

Posted by Anonymous on 6 February 2010

I have to agree with Sheila Payne on the calibration issue, as it was the deal breaker for my daughter's use of the Paradigm CGMS. After spending $1,000 on the system and training on the device w/ Medtronic, it came down to the huge problem of calibration. My daughter is a college athlete and unlike a person that might work out a set time each day, her day consists of multiple workouts at different times of the day. Since you can't calibrate a specific number of hours after eating or exercise (never mind the other calibration restrictions) when would a user such as my daughter be able to fit this into their schedule? Don't get me wrong. I think it's a great device for someone with a predictable schedule. But I wish I had known more about the stringent calibration demands before I invested the $$ as well as the high hopes.

Posted by Anonymous on 26 June 2011

After having read through everyone's comments about the use of CGM, I want to share my story. I have had diabetes for about 40 years and have been a medtronic pump user for the last 16 years. I started using CGM about 2 years ago with my 522 insulin pump. I was educated by Medtronic staff and thought they did a wonderful job in exposing me to the realistic expectations of CGM as well as exposing me to the proper installation and calibration of the device. Admittedly, I initially struggled with the process of calibration and attempting to identify ideal times to calibrate. However, my lifestyle is so variable I really felt I had to make a committment to figuring out the CGM. After using it for about a month, the alarms were a bit much and so started the 24 hour helpline assistance. I have to say that they are remarkable people with a degree of dedication that is admirable. Every helpful hint that I received, I used and gave them feedback.
So, here it goes: Calibration is intermittently difficult depending on what is going on with your eating and bolusing and your knowledge and ability to adjust basal rates for things like exercise and illness (using temp basal rate is wonderful for reducing rapid fire bg fluctuation from exercise for example). I will share with everyone that my initial experience with CGM was to download the pump and get advice on basal and bolus adjustments to mitigate rapid bg fluctuation. My endo has repeatedly emphasized to me that A1C is not the only information that predicts risk for complications, it's bg fluctuation that tells the rest of the story.

BG stabiltiy is really about 90 to 120 mins away from your last bolus or food intake, more bg stability occurs the further you are out from food or bolus....stabiltiy can mean doing a calibration at fast, pre-lunch or 2-3 hours post lunch, pre-dinner or 2-3 hours post dinner and pre or 2-hours post bedtime snack. Also, if waiting that amount of time is difficult, then perhaps attempting to calibrate at 60 to 90 mins post meal or bolus would work if the content of food intake was of the slower acting type...a mixed meal instead of a bowl of Captain Crunch, for ex. I have found that calibration is really easy if you accomplish it on your own time instead of waiting to be reminded by the cal reminder alarm or the "meter BG now" alarm. The only "meter bg now" alarm that you have to wait for is that initial one with start up, all other calibrations can occur at a time where you think you have bg stability, it is significantly easier to deal with calibration and bg stability when you call the shots. Also remember, with the Medtronic system, the calibration clock runs in 12 hour intervals once you get up and running, so that means if you calibrate at 6am with a fast, the alarm won't sound again until 6pm unless you have the cal reminder precurser alarm set (this alarm is a pain in the neck and I would argue, totally unneccessary if you prescribe to my rule of thumb that calibration is so much easier if you call the shots and rethink your bg in terms of stabiltiy rather than numeric value. After my initial bout of alarm frustration, I am finding that CGM is actually quite easy to use. The biggest reward for me is in having the abiltiy to know where I'm trending. I think that us long timers and even those of us with diabetes for only a short period of time, we have all been taught to check on the meter whenever you think something odd is going on, whenever you feel strange, etc, etc.. However, that one number in time does not give us much info at all. With CGM, now we are getting so much more, to look at my CGM and to be able to see the 3 and 6 hour graph gives me so much more information than one fingerstick in time. I do make better decisions and feel significatly better about exercising vigorously for 2 or 3 hours at a time, about driving alone for 3 or 4 hours, about chaperoning a field trip where i have to be constantly on the ball, or even about staying focused in a job where stress is commonplace rather than the exception. I absolutley love my CGM and don't know what I would do without it. But it does take some getting used to, just like it did with diagnosis, just like it did when you were told to count your carbs etc....the psychological re-education about bg is where I think many people have difficulty with this system. It is not supposed to be something that yells at you and then you respond by dropping what you are doing and succumbing to it's demands. It's meant to help you, and I maintain that it will at the point in time that you realize it for what it is and to not expect it to be what it isn' is not a blood glucose meter with it's inherent exactness, it is something to give you exposure to a fluid movement of sugar within your body. Fingerstick bgs tell you what your brain is being exposed to, CGM glucose tells us what our tissues are being washed in, there is a delay but also we can now see where that bg is trending, either up or down. Calibration IS the key to accuracy with sensing, but still does not take away the lag time associated with rapidly fluctuating bgs. Never attempt to assess accuracy issues during bg, rather than compare what your sensor is sensing post meal, compare what the sensor is sensing at that point in time where you think your bg is more stable, when you are most likely to be doing a calibration. The initial goal for me was to reduce bg fluctuation by adjusting basal rates and ratios. After that, the wonderful thing about CGM is feeling so much safer, so much less burden and worry than what I had before and so much more flexibility.
The crux of success for me was when I decided that this device was going to help me and that I was going to make a committment to make it work for me. One other comment I have is that sensing accuracy with the newest Medtronic system is decidedly a bit "quicker" as far as catch up time during bg fluctuation, but also, the ability to have the pump calculate for you when you might be expected to go low is a wonderful new feature that my old pump did not have.
I love the CGM and feel badly that only a few people in this forum have apparently experienced the same level of sucess and freedom that I have. I obviously think that it can be accomplished, but I also feel that it takes knowledgeable help and a familiarity with rethinking the concept of meter vs. sensor and how to think about your sensor information and how to use it appropriately. It can be done, as I have done it, even after experiencing some of the frustrations that I saw in this forum. It can be done without giving up your life as you know it as well. Best of luck to all who read this, I will make it a point to frequent this site agian to see any response, good or bad! Kind Regards, C.

Posted by Anonymous on 5 May 2012

Second month on CGM....I am over 55 currently working in a retail the
Previous positive posts I'm finding the trending data allows me to focus on my WORK at
Work instead of my meter! Being able to glance at the 3 hour graph before I start lifting
Packages or moving materials is a such a benifit...I've also been able to pick up overtime
House on off shifts - something I could not safely do prior to using CGM...thanks for the
Isis info Hillary - my educator had not the way that's HOURS not house...
stupid spell it should be obvious I'm not a technition but I'm still able to
Master enough CGM operation to justify the hassels....

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