Saturday, September 30, 2006

Dogfight in the Emerging CGMS Market?

"Dogfight" in CGMS. According to a Reuters September 29th article by Julie Steenhuysen, this is what some analysts who monitor the Diabetes medical device market are saying about CGMS. I don't mind a good dogfight in CGMS; the more competition, the better for we type 1 diabetics, and type 2 as well: we really need these tools and the insurance industry needs to understand that; right now, they just don't get the message; their bottom line is: money, money, and more money. The more players in the market, and the more studies conducted that show the benefits of CGMS, the quicker the insurance companies will respond.

Dogfight over Features

The president of Abbott's diabetes unit, Ed Fiorentino, says:

"Better accuracy and longer-wearing sensors -- five days with the Abbott product vs. three days with the Medtronic and DexCom devices -- will give Abbott an edge."

Mr. Fiorentino may be right on when it comes to accuracy, though with DexCom I'm doing pretty well with accuracy compared to my somewhat accurate fingersticks. As far as sensor life goes, 3-days wear time is so far a minimum for me with DexCom. On the accuracy and non-calibration requirement (if you choose to use the Navigagor off-label), Abbott leapfrogs ahead of DexCom, if what abbott claims is true about completed studies and studies almost completed. DexCom had better get cooking on some new features, and stay away from the vaporware type of announcements we've seen with other companies, it's coming, it's coming, really, it is...

So we've got DexCom, MiniMed, Navigator, and now J&J jumping into the CGMS market. I am psyched!!!

DexCom Charger Replacement and New Sensors

Got my new charger today after my latest accident with my CGMS gadgetry. It's not listed on the DexCom on-line store, but the charger costs $25, plus $5 for shipping, which is the going rate for these things.

I do try to be careful; my wife accuses me of 'sucking all of the fun out of a room', because I'm constantly pointing out accidents waiting to happen, which I'm sure all of you parents out there can relate to. Most of the time I see the accident before it happens; I just have to hold my tongue of course, since my kids need to learn from their behaviors. Now I need to learn from my behavior and stop plugging things in where people can trip over them.

Anyway, I'm off on a tangent here; I also got my second box of sensors, so to date, with two months of DexCom usage, I'm out of pocket about $350. Oops, make that around $400, if you include shipping.

I'm trying to calculate out-of-pocket expenses for next year so that I can at least re-coup some cost from my medical savings account. Might change if I decide to switch CGMS, we'll see ...

Thursday, September 28, 2006

How long do YOUR DexCom batteries last?

Okay, I've got to get over this obsession with looking at the DexCom receiver all of the time. It's either the constant looking at the receiver that's draining the batteries, or my receiver batteries just doesn't hold a charge. My DexCom rep told me initially that her batteries lasted five days between charges, but my batteries seem to last a paltry day-and-a-half, MAX. Seems like I'm charging it too much. Maybe I should take it off of belt clip and just hide it in my pocket, that way I'll be less tempted to look at the darn thing.

Had a scare last night- because it always seems like I'm charging it, I plugged it in by the dinner table, with the cord running behind me to the receptacle. One of my daughters, helpful and polite that she is, got up to get me a drink of water, and, you guessed it: she tripped over the cord. Luckily, she wasn't hurt; can't say the same for the Dex charger however. It had an odd looking, sickly, angled position on the wall receptacle. Oh S..., another accident. First I drown the receiver, now I've broken the charger.

I carefully pulled it out of the wall socket, and one of the plug prongs drops to the floor. Groan. Fortunately, I used my pliers to insert the plug prong back into the charger, and it seems to charge the Dex, but now I'm afraid to unplug it from the receptacle.

I wonder how much a replacement charger costs? It's not listed for sale on their web site.

Hmmm, what other DexCom component can I break? There's not much left ...

Tuesday, September 26, 2006

The Ups and Downs of CGMS

What a day for ups and downs! This morning I headed to the gym for my daily workout, pushed it a little harder than normal, but decided to skip the normal temp basal adjustment, since I've been getting by without it for the moderate workouts. Boy, did I pay for that! I've hit below 70 four times today. Fortunately, Dex warned me with the Dex low alarm before my BGs got too out of hand.

Coupled with skipping the temp bolus, I had whole-wheat raisin bran, and a cup of Soy milk, for a total of 50 grams of carbs. Dex showed me that my BGs shot way, way, up, and I over-corrected since I normally need more insulin when I go up into the 300s. I'm really trying hard to minimize those peaks, using delayed boluses and limiting myself to no more than 50 grams of carbs at a sitting, but those high glycemic foods don't want to cooperate. Thinking more and more about Symilin, ... sigh.

Sunday, September 24, 2006

DexCom Noisy Night Readings and a Hairy Conundrum

I've noticed that I am a noisy person at a night (and no, that doesn't mean that I snore, although my wife will argue that point). With the current DexCom sensor site, I've been having night readings jump all over the place. Below is an example of what a noisy night is; stark contrast between night and day. I tend to toss and turn a lot at night, and I sleep on either my right or left side, and I've located the sensor on my right side. Apparently I am disturbing the sensor so much that I'm generating all of this noise. I haven't had this problem with previous placements.

I'll have to find sites that don't see as much action during the night, which means I'll have to locate the sensor in the stomach area. I don't have a lot of bare areas on my stomach, which means I'll either have to place the sensor pod over the the stomach hair, which makes for a fun time when I remove the pod (ouch), or I'll have to shave the area. Hmmm, maybe some of those bare-chested Baywatch models are going to get some competition!

Saturday, September 23, 2006

Creating My Own Glycemic Index

I have a love/hate relationship with my carbs. I love them for their taste, that satisfying, luxurious, feeling I get after ingesting them, and I hate what they do to my sugars.

I used the DexCom software to chart my response to one of my favorite carbs, a Dunkin' Donuts blueberry muffin for breakfast (73g CHO). The GI value is listed as medium for this food, but the DexCom software shows me shooting up well into the 300s, even with a combo/square wave bolus, taken 15 minutes prior to eating the muffin. Is Symlin in my future if I want to enjoy a muffin? Next time I'll go for half a muffin!

I was in a rush for lunch, as usual, so I enjoyed a Smart Ones Fiesta Chicken; not bad tasting, and quick (47 grams CHO). For dinner, we sometimes celebrate Friday night with pizza; this time I opted for a gyro (55g CHO). Total carbs for the day- 175 grams. Wouldn't it be something if the software had an expert system component that could suggest basal rates, carb/ins ratios, correction factors, and insulin sensitivity factors?

Sensor Probe Size

So, how big is the sensor probe that goes under your skin? In case you're concerned about the size, here is a side by side comparison of a 0.5 mm pencil lead, a Paradigm Silhouette insertion needle, a 31 gauge, 5/16" (8mm) syringe needle, and the the sensor probe. The vertical part of the probe goes under your skin, and the horizontal part is attached to the 'sensor pod' that holds the transmitter and the sensor part that connects to the transmitter. You feel a slight pinch as you would with an infusion set insertion, but the probe feels comfortable under the skin, at least for me.

Friday, September 22, 2006

Get More Life Out of a DexCom Shower Cover, and Yet Another Use for Saran Wrap

Thanks to the tip from a fellow CGMS user:  she suggested that I try wearing a DexCom shower cover for 3 days, instead of just one day. Two days worked for her, but my friend noted that since I'm a male, I will probably spend less time in the shower , so 3 days might just work.

So ..., the results are in, drumroll please... Yes I was able to get 3 showers out of one cover, so now my shower cover costs are reduced from 60 cents a shower to 20 cents a shower , or if I take one shower a day, just six dollars a month. A small price to pay for not getting the Sensor wet so I can get good readings after a shower.

Thanks for the tip: Any CGMS users out there with money-saving tips, please send them my way.

By the way, my friend is going to try that wonderful product with 10,000 uses... Saran Wrap!

Thursday, September 21, 2006

DexCom Single Day Glucose Trend Screen Shot

Okay, here we have another type of screen shot that the DexCom software will give you. You can choose to have up to 7 days displayed, but that's too much data to display here, so I just chose one day. The blue circles are sensor BGs, and the red stars are uploaded values from the ultra meter. Those values are used to calibrate the DexCom, and to check to make sure it's tracking along with the ultra BG values. The largest delta is between the first red star to the right, over from the mg/dl Y-axis. The delta is 17 points, which I consider acceptable.

What I can't explain, is the drop in BG from 3:11 am to 3:21 am. The graph shows that I dropped 59 points in 10 minutes, an obvious hiccup. I do a lot of tossing and turning at night, and the sensor is installed on my side, I'm wondering if I somehow disturbed it and the transmitter in such a manner as to cause this glitch.

Anyhow, you can determine from the graph when my meals occured, how high my post-prandial spikes went, how much time I spent between the lower and upper limits of 80 and 200, respectively, and that I need to tune-up my basal rates.

DexCom Modal Day Screen Shot Sample

Here is a sample modal screen shot of my BGs over Monday, Tuesday, and Wednesday. It's hard to see, but see if you can guess when I had my meals.

Sensor Site After 10 Days, and a New, Flaky Sensor

Ok, so I was somewhat concerned about leaving the sensor in the site for 10 days, given that you're only supposed to do it for 3, and a trial is underway to get FDA approval for 7, but I tried it anyway, risk taker that I am. I will probably end up using them for 7 - 10 days, but no longer. I know some others that are using the same sensor past 10 days, but I'm not going that far.

Anyway, the site looked beautiful: no irritation, only a very slight, almost undetectable, faint hint of redness. The puncture site was almost invisible: except for the tape residue, I would not have known that a sensor was ever there. Looked a lot better than some of my infusion sites after 3 days. I put some Aquaphor over the area to moisturize the skin, inserted a new sensor, and am on my way, probably 7 days this time, although I've had a couple of sensors stop working after 2 days.

Another tip about starting a new sensor session: start it in the MORNING, not the evening, so you can deal with the inaccuracies while you're awake, and not trying to sleep. The new sensor was flaky for a few hours, and woke me up with 2 low alarms, whereas the ultra read 101, and 105.

Dex Software Has Arrived!

DexCom delivered the software via priority overnight yesterday. I installed it last night, uploaded my data (the last 7 days are supported), and played around with it a little.

I'm thinking I'm going to get some valuable data out of this software, although the GUI (Graphical User Interface), looks outdated; but hey, I had to complain about something. I emailed the patient files to work, and I'll see if I can open them with the DexCom software installed at work. Would be nice if I could email the data to my doc, but of course Harvard Vanguard has this nifty little system for email that does not allow for attachments. I'm sure the I.T. police are responsible for that one, wouldn't want to allow some sneaky virus to get in there and shut down their system. I'll just do it the old fashioned way, print out the reports and then FAX them in. I'm sure my endo will be delighted to receive them. I'll probably mark up the data to explain what a 'shower spike' is, amongst other things.

I plan to post some screen shots here in the future, but first, more playing around with the software. It looks exactly like the software that my DexCom rep had, as it allows multiple patient entries, similarly to other meter software packages. It seems as if all of the diabetes software packages have these quirky looking somewhat outdated GUIs, but I'd rather have the data than some slick GUI where the most important simple features don't seem to work (a.k.a. Microsoft).

Wednesday, September 20, 2006

CGMS Sensor Life

DexCom says to use a sensor no longer than 3 days, and that they're working on getting FDA approval for a 7-day sensor. I've been browsing the internet to find out what others are experiencing for sensor life. One CGMS user I know seems to get a couple of weeks out of one sensor. That seemed a little extreme to me, and when I mentioned it to my DexCom rep, she said that 2 weeks was way to long to leave a sensor in.

I decided to see how long I could go with one sensor, and to date, my current sensor has been in for 10 days. I'm sure I could go longer, but I'm going to pull the plug on it tonight. The sensor seems to get more accurate after a couple of days, and the past few days, this sensor has been right on target, except of course, for rapidly changing BGs.

Went to the eye doctor for my annual dialated pupil exam last night, and got some good news; no sign of any retinopathy or other damage. I'm concerned about that, as my sister has severe diabetic retinopathy, as did my father. After the eye exam, I played softball in our backyard with my 3 girls: boy did I look like a real geek with those wrap-around glasses on, or so my daughters tell me.

So far it has been about 4 weeks on the DexCom CGMS, and I'm finally getting used to it, and also getting used to the fact that I don't need to look at all of the time! Still no word from DexCom on when they're sending me my software. They said I would get an email when it shipped, but nothing yet.

BTW, tried to wear the shower cover for an extra day on the suggestion of a CGMS user friend, and it worked! She suggested that since I was male, I might try to get three days out of a cover. I'll give that a shot, too.

On another blog technical note, I've been trying to post to other OC blogs, but since I switched to the *beta* template, I'm not allowed to. Once again, I pay the price for being an early adopter .

Sunday, September 17, 2006

Update on fingerstick frequency: Less sticks!

I'm doing less fingersticks now that I'm becoming more comfortable with CGMS. I don't think I'm going to go below 8 sticks a day, assuming this would be a typical day. I would add a couple on top of this for additional calibration requirements and other variables:

Stick 1: calibration in the morning/Pre-Prandial prior to breakfast
Stick 2: Post-Prandial Breakfast
Stick 3: Pre-Prandial Lunch
Stick 4: Post-Prandial Lunch
Stick 5: Pre-Prandial Dinner
Stick 7: Post-Prandial Dinner
Stick 8: Bed Time BG

This is my fingerstick frequency over the last few days, averaging to a little more than 8 per day:

DATENumber of Fingersticks
Tuesday, September 128
Wednesday, September 137
Thursday, September 1411
Friday, September 1511
Saturday, September 166

Friday, September 15, 2006

How much are annual out-of-pocket costs for CGMS?

How much does it cost me for annual out-of-pocket expenses for CGMS? Here is what I estimate CGMS will cost me in the next year, provided I can get 7 days out of one sensor. Note that the figures vary by individual; some folks don't use shower covers, and some may get more or less wear-time on a sensor. Question for the insurance companies: How much does it cost for an ER hospital visit to treat one episode of extreme hypoglycemia? $5000, $10,000? Do the math: CGMS pays for itself if only ONE ER visit is eliminated.

ItemAnnual Cost
DexCom STS Receiver$550
DexCom Transmitter, 2/yr$500
Sensors, 1/wk$1976
Shower Covers, 1/day$225
Total Annual Costs$3001

Wednesday, September 13, 2006

DexCom software now in their on-line store!

Finally, the DexCom Software is listed in their on-line store, and I should be getting it in a couple of days. It will be nice to look at 7 days worth of data at once, instead of having to take pictures of the receiver to analyze the data! I’m looking forward to working with my endo; I won't be able to send the reports via email as their system doesn't accept attachments, but at least I will be able to print out and FAX the reports to her.

Here are some of the software features they list on the link, in addition to saving files and printing reports:

  • View Glucose Trend Information (up to 7 days)

  • Display up to 7 days of Glucose data

  • View Modal Day Information (up to 7 days)where up to 7 days of your glucose data can be displayed at once

  • Zoom in on Glucose Trend Graphs (down to 4 hours)

  • You can zoom in up to 4 hour display for more detailed glucose trend in Glucose Trend Graphs
I'm REALLY looking forward to trying this out!

Sunday, September 10, 2006

How often do you do a fingerstick test when you're on the DexCom?

I see this question occasionally. Since it's only my 3rd week on the sytstem, I find that I am testing more frequently than before I went on CGMS, because (1) I make mistakes, and (2) I also need to get more comfortable with Continuous Glucose Monitoring- sometimes the DexCom can be off up to 40 points from the fingerstick test (I've had successive fingersticks off 40 points from eachother, too, on different hands, go figure that one out), so you MUST do a confirmatory test before you make treatment decisions. CGMS does not replace fingerstick tests, although I have read about some users that are doing this. I do not get that comfort level from CGMS. Here is a sample of my fingerstick frequency over the last 10 days. I'm hoping to cut this figure in half after a couple of months or so:

DATENumber of Fingersticks
Thursday, August 3115
Friday, September 110
Saturday, September 213
Sunday, September 314
Monday, September 416
Tuesday, September 513
Wednesday, September 612
Thursday, September 713
Friday, September 817
Saturday, September 917

Thursday, September 07, 2006

DexCom is BACK!

It was great to receive my NEW DexCom receiver in the mail, I almost felt naked without the trend data the past couple of days. Nice job, DexCom with the one day service delivery, got a new one as I have in the past with pumps that needed to be replaced.

I've switched sides today; the new sensor is on my left instead of my right side, but no noticeable differences: DexCom is still tracking my fingerstick tests rather well.

Interestingly enough, I'm reminded of how inaccurate fingerstick meters are: when I calibrated the DexCom this morning (with 2 successive fingersticks), the Ultra read 181 on one finger of my left hand, and 207 on one finger of the right hand, a 26 point difference! I've also experienced 40 POINT DIFFERENCES from successive fingerstick tests on fingers of different hands. Kind of makes you wonder about folks complaining about a 20 point difference between a CGMS reading and their fingerstick reading from their trusty blood glucose meter. It's important to remember that cheap home test meters don't have the accuracy of lab instruments, and that when it comes to CGMS, trend analysis is key, in addition to the single point value given by the CGMS and the blood glucose meter.

Wednesday, September 06, 2006

Dexcom takes a lickin' and Doesn't keep on tickin'

Nice way to end Labor Day *NOT*:

My 8 year-old daugther convinced me to jump into the frigid water on
the last day of the pool being open; of course I wasn't planning to
swim, and my trusty Dexcom receiver went in with me.

You guessed it, the Dexcom receiver is toast. I thought about trying to dry it out, but the holes are sealed with epoxy, so there's no way to get at it without drilling through the epoxy and getting the screws out. Would probably have voided the warranty anyway.

Fortunately, DexCom has a one time only replacement policy, so I saved $550 bucks. They're shipped it out yesterday, and it will arrive today. Now that's GOOD customer service! - CU finds genetic clues to children's diabetes risk

So it looks like what we families with type 1 diabetes have long suspected is true: There is a genetic link, gene x, that increases the likelihood of a person developing type 1 diabetes. With the strong type 1 history of family (my sister, and I have it, my dad had it but is now deceased) it really makes me think about getting my own 3 children tested. The dilemma is, even if they have the gene marker and have an 80% chance of developing type 1, there is no way to prevent it. There is work underway to develop a vaccine, but until that time, the question is whether or not to do gene/antibody testing on my children. I'm already keeping a close eye on them to look for signs; I was 39 when I developed type 1, and my father and sister both developed it at 19. I'm praying for a vaccine soon, as type 1 could develop in my children anytime. - CU finds genetic clues to children's diabetes risk: "CU finds genetic clues to children's diabetes risk

By Karen Augé
Denver Post Staff Writer

University of Colorado researchers have discovered new genetic markers to identify children at high risk of developing diabetes.
In a 13-year study, following 30,000 newborn babies, researchers at the Barbara Davis Center for Juvenile Diabetes found genetic differences that increase three to four times the chances that a child will develop Type 1 diabetes, in which the body cannot produce insulin.
The researchers did not identify the exact gene - which they are calling gene X. "

Monday, September 04, 2006

False lows during overnight Basal Testing: Day 14

This overnight basal test was to confirm a previous test run to confirm my overnight profile. The test was successful, with two annoying exeptions:

Dexcom STS woke me up with a low alarm (DexCom alarm set to 80) at 5 am (ultra = 136). I re-calibrated, went back to sleep, and an hour later, received another low alarm (ultra = 132). The low alarms occurred even though DexCom was showing my BG trend was essentially flat during the evening, hovering around 100 +/- 15. As can be seen from the following nine-hour trend screen. Note the false noise dipping below the dashed line in the middle of the screen(the low alarms), circled in red. I have no idea what caused this. This particular sensor is on day 8 Ignore the 228 BG reading, that's the dawn phenomenon I'm now working to correct:

Normally I wouldn't mind a false low at this hour since I'm an early riser during the week, but hey, it's labor day weekend and I wanted to sleep in a little later.

Anyway, I re-calibrated a second time, and DexCom is now tracking my dawn phenomenon quite well. I consider the test successful since it confirmed my new overnight basal rate, although I did wake up a couple of times. I have my low alarm set at 80, perhaps I need to consider setting it to 70 if this pattern is too frequent, although these are the first false lows I've encountered overnight. Back to some more experimenting!

Sunday, September 03, 2006

The Beep of the Sensor, the Thrill of Control - New York Times

This article appeared in the August 29, 2006 edition of the New York Times, by Mr. Dan Hurley. Mr. Hurley, a diabetic for 30 years, recounted several episodes of severe hypoglycemia, including a recent episode, in which he almost didn't wake up. The article focuses mainly on the advantages of catching lows. Here's a snippet from the article and the link to it:

The Beep of the Sensor, the Thrill of Control - New York Times: "The main problem was that the sensor was simply not as accurate as a blood-glucose tester. MiniMed’s studies show the sensor’s accuracy can be off by as much as 18 percent. Another sensor, just approved by the F.D.A. and made by DexCom, is said by some researchers to be a bit more accurate, as is a third device, from Abbot, which has not yet been approved. But none are as accurate as a standard blood-sugar test."

Saturday, September 02, 2006

Overnight Basal Testing Made Easier

I've always had a tough time with the overnight basal test. Fasting and then waking up at various times during the night to test my BGs were definitely some of my least favorite things to do.

So, enter the Dexcom, with the promise of NOT having to disturb a good nights rest for several nights. I mean, getting the overnight basal rate down correctly one night is a challenge, and then they want you to do it AGAIN.

I've rarely been successfuly at it, and never knew what really happened with my BGs overnight.

After visiting my endo on Wednesday, she suggested a small change per the standard recommendation of reducing my overnight rate by 0.1 u/h starting at 9 pm, in order to avoid the lows that Dex had caught for a couple of nights. I did just that, and had mostly flat BG curve in the evening, awaking with a 150, which was still within the 30 point spread outlined in Pumping Insulin (4th Ed.).

Now I'll try to confirm it with another test, that is if I can avoid that tempting late night snack ;>