LifeAfterDx--Diabetes Uncensored

A internet journal from one of the first T1 Diabetics to use continuous glucose monitoring. Copyright 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016

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Location: New Mexico, United States

Hi! I’m William “Lee” Dubois (called either Wil or Lee, depending what part of the internet you’re on). I’m a diabetes columnist and the author of four books about diabetes that have collectively won 16 national and international book awards. (Hey, if you can’t brag about yourself on your own blog, where can you??) I have the great good fortune to pen the edgy Dear Abby-style advice column every Saturday at Diabetes Mine; write the Diabetes Simplified column for dLife; and am one of the ShareCare diabetes experts. My work also appears in Diabetic Living and Diabetes Self-Management magazines. In addition to writing, I’ve spent the last half-dozen years running the diabetes education program for a rural non-profit clinic in the mountains of New Mexico. Don’t worry, I’ll get some rest after the cure. LifeAfterDx is my personal home base, where I get to say what and how I feel about diabetes and… you know… life, free from the red pens of editors (all of whom I adore, of course!).

Friday, November 27, 2009

In defense of the f-word

So I’ve been getting a lot of flak about my language recently. Not about my in-person language, which could be a lot better. And not about my language in my blog, where cursing seems more socially acceptable; but in my books. Well, specifically in one book: The Born-Again Diabetic.

The fact that I dared to use the f-word in a hard-cover book has ruffled a lot of feathers. Apparently, in some circles, this is regarded as a mortal sin. In fact, one entire department of the University of New Mexico has banned my book because of its use of “problematic language.” This is balanced by a more enlightened department who uses it as a textbook for the class “Perspectives in Diabetes,” where I’m told it gets rave reviews from the students.

Ironically, all of this fuss about my use of the f-word might lead you to believe that I’ve used it on every page, like some sort of drunk late night comedian or a radio shock-jock. So here is the trivia question: does anyone know how many times the f-word is used in The Born-again Diabetic?

Four times. Yep. All this fuss over fuck, fuck, fuck, fuck. Who would have thought that the use of 16 letters in a book of over 50,000 words would cause such a crisis? (Well, OK, it also appears in the glossary once, and twice more when quoting someone else; but I only used it in the text four times.)

Let us look at this logically, clinically. Who swears? Sailors. Soldiers. Lumberjacks. What do they have in common? They are bands of people who face danger together. Is it any surprise that diabetics, especially Type-1s, would also talk like soldiers? Diabetes is trench warfare--dirty, gritty, hand-to-hand combat. People who do not live and suffer with it will never understand it.

So this swearing is all good and fine when chatting with our fellow fighters, and on the wild-and-wooly internet. But why swear in a hard cover book? Do my critics think that I am really that careless of a writer? Now that does insult me! In person, and on my blog, I may be careless in my choice of words. But this is not true of my book writing. Each and every word is carefully chosen and carefully placed, for either strategic or tactical reasons. And that includes my four uses of the f-word. Re-read the book. Or if you have never read it because you are afraid that 16 letters will corrupt your mind, I urge you to read me before you judge me. I believe it was Mozart who said “I am a vulgar man, but I assure you, my music is not!” I did not use the f-word for no reason. Every where it appears there is a good reason for it to be there.

Carefully used profanity accomplishes three things in The Born-Again Diabetic: it gives the book instant creditability with patients who are sick of people in neatly pressed white coats telling them how to live; it sets the work apart from academic and medical texts; and lastly it gives non-diabetic readers a taste of our world. I use swearing in my book writing like a surgeon uses a scalpel. I was very conscious, very aware, of each and every cut.

Never once did I use the f-word lightly. I knew what I was doing. It is a vulgar word, but a powerful one that packs a heavy punch when used correctly, and, more importantly, when used lightly.

The punch I delivered with a mere four words out of 50,000 proves the point.

Thursday, November 26, 2009

Happy Thanksgiving, everyone!

Wednesday, November 25, 2009

Kilmer Kindness, Act 2

So last Thanksgiving, Val Kilmer bought me a turkey. This year he did not, thank God.

Not that it wasn’t a great turkey, and not that I didn’t enjoy eating it, but I just felt there were others whose need was so much greater than my own. So it was that whole joy-mixed-with-guilt-thing that I don’t deal with all too well.

Mr. K, however, got a lot of un-deserved grief for his trouble, from closed minded individuals who said things like “well, he only did that because he’s running for governor.”

Well, here it is T-day again, and I’m pretty sure he’s not running for governor, and yet my conference room is full of turkeys. And stuffing. And rolls. And potatoes. And onions. And pies. And…

Well you get the idea.

Mr. K bought complete Thanksgiving meals for 25 of our most needy families. More correctly, he bought 25 complete Thanksgiving meals for the clinic’s 25 most needy. I’m betting a few church parish halls and community centers are full of boxes of food and rows of turkeys too.

Between patients I slipped back to the conference room to check out this year’s boxes, and while I was there a woman and the cutest little rag-a-muffin you’ve ever seen came in. I wanted to photograph her, but for one-million-and-one legal reasons I could not, would not, did not. So I will paint you a picture of her with words instead.

She’s small in height, in bone structure, and in muscle mass. She’s probably six or seven year’s old, but looks four or five. Not having enough food most of the year will do that to you. Yes, we are in the U.S.A., and yes, I see this everyday. She’s not fully malnourished--but she’s a skinny little thing--the wind would probably blow her down the highway like a tumble weed.

Her clothes are dirty and torn, her hair is long and tangled, her shoes are too big, and her face really needs washing. She does not have a jacket. But the ear-to-ear smile on her face and the joy in her eyes when she sees the boxes of food are perfect.

This smile has been brought to you by Val Kilmer.

So thanks Mr. K.

Thanks from the clinic. Thanks from the people of our villages.

And thanks from a dirty little rag-a-muffin with the perfect smile.

Monday, November 23, 2009

Victory at Sea

“So,” Nurse Eve said as she stepped into my car for pre-dawn commute to the clinic, “I see you single-handedly brought Presbyterian to its knees.”


“Weren’t you thrilled to get the letter?”

What letter? She-who-gets-the-mail has been down with Swine Flu.

Luckily, Eve had brought her copy of the letter along in her purse, and read it out-loud to me. Letters from Pres always start the same: “Our goal is to improve the health of individuals, families, and communities.” Funny, I thought your goal was to improve the health of your shareholder’s bank accounts. “Informing you about changes in your health plan’s benefits is one way we reach this goal.” Oh really?

“You just received a letter from us that informed you about the coverage of Durable Medical Equipment (DME). We are very sorry for any confusion or concern about your benefit this may have caused.”

Then they wave a white flag. They actually backed off. Like a corporation settling a lawsuit without admitting guilt, they go on to say they don’t have to cover our DME, but will as a “Value Added Service until further notice.”

Wow. It’s over. Just like that. We won. Who’d thunk it?

So my pump is safe. At least for now. Chalk one up for the home team. That’s very good news for me, but I already had a bigger fish to fry (hence the “sea” part of the head line for this post). Things that effect me personally stress me out, and annoy me greatly. But my fangs come out and I really get pissed-off when insurance companies screw with my patients. And Lovelace Health Plan had just screwed with my most precious patient.

I’ve only mentioned her in passing, but my youngest patient just turned three years old. We dx’d her with her Type-1 Diabetes this summer. I can’t help but love her, not only is she my littlest sister, but she’s been under my care since day one; so I’ve really bonded with her. All 32 pounds of her.

We have even developed a number of rituals. I originally got her on-board with the concept of testing blood sugar by doing it together, me always first. Now every time she comes into my office she says “we gots to check your blood sugar, Doctor Lee.” So we get out my meter and check my blood sugar. Then we check hers. She is particularly delighted when mine is higher than hers.

Anyway, since day two she’s been using the NovoPen Jr., a blue-with-green-flowers metal half-unit pen that uses Penfils. Last month, when her mother went to refill the script the pharmacy informed her that Lovelace was denying the medication as off-formulary. What at first I assumed to be an administrative mistake quickly became something much more sinister.

Lovelace “corrected” its formulary. No more pens. Unless you are blind. All diabetics must go back to vials and syringes. I went through the roof.

Forty-eight hours later I had begged, bribed, bargained, and bamboozled my way through mountains of red tape and won my little patient a permanent formulary exemption.

That just left everyone else in the state screwed. I’ve been back-and-forth between pumps and pens as my insurance has risen and fallen like the tide; but I’ve never been forced back to pens and syringes. The thought appalls me.

The more I thought about it, the more pissed off I got. Now, most of my insured patients have Pres, rather than Lovelace. But I had an eerie feeling that there might be some sort of collaboration going on behind the scenes (in fact, on Friday a friend who works for a private practice told me she was having problems getting pens for both Pres and Blue Cross patients; but I haven’t experienced this… yet).

My uninsured patients get pens from Patient Assistance Programs. How ironic. If you are indigent and don’t have insurance you get state of the art. If you work your ass off and pay through the nose for your insurance you get state of 1932 instead. Lovely.

I mulled over my options, my mind first going to the five-guys-with-machine-guns-and-a-wall that I think is the best solution for insurance companies. Then I envisioned press conferences with crying children, marches, and mass mailings of syringes in protest. In the end I did what I do best. I wrote.

My mother told me, “you know you won’t win this fight, right?”

Sometimes it isn’t about whether you win or lose, but how you fight that matters. I couldn’t just take this one lying down.

Of course, where I work you can’t just put something on clinic letterhead and drop it in the mail, not at least without risking your own head. I snuck in to my medical boss’s office first thing in the morning before he got in, left a copy of the letter on his desk and scurried away before he could catch me.

Later in the day he called me in. “Your letter is brilliant,” he told me with a very serious expression, “ and I really admire your restraint.”


“Yes, you actually wrote three whole pages without using the word ‘fuck’ even once.” Then he broke out into an ear-to-ear smile and laughed.

I guess my reputation is worse than I thought.

Later I got my administrative boss’s approval too. The letter went to the three top-dogs at Lovelace here in New Mexico. It also went to the Public Regulatory Commission’s Insurance Division. Maybe later it goes to the press. We’ll see. It depends on what happens. My battle flag is hoisted, I’ve fired a shot across their bow. The ball is in their court now.

Here is the full text of my broad-side:

Ladies and Gentlemen—

I am writing to express my grave concerns about the negative impact on the health outcomes of diabetes patients in our state brought about by a recent decision of Lovelace Health Plan.

When the mother of one of our pediatric diabetic patients attempted to
refill her daughter’s insulin pen cartridges recently, the pharmacy informed her that the claim was denied as an off-formulary medication.

When I called Lovelace, assuming that there must have been some kind of mistake, I was informed that the carrier would no longer cover insulin pens of any kind, and that those of us in the field would be required to migrate our diabetes patients back to the archaic vial and syringe method of insulin delivery.

Needless to say, I was shocked. Insulin pens are the global standard of care in evidence-based diabetes treatment. Scientific studies have shown that the use of pens over vials and syringes reduces dosing errors, increases efficacy, increases patient compliance and satisfaction, and saves significant amounts of money in overall health care dollars.

Additionally, I can tell you that from my own clinical experience, it is far easier to “start” diabetic patients on insulin using pens. The syringe carries a symbolic fear factor, largely due to the inter-generational nature of diabetes in our state. Patients remember their grandparents taking “shots” followed by poor outcomes.

Due to this inter-generational fear of “the needle,” syringes significantly increase patient resistance to starting insulin, our most effective glucose-lowering agent. Additionally, syringes take a much greater period of time for patient training than pens do, increase the risk of medicine errors, and greatly reduce patient compliance—especially when injections are required in public places.

Simply put, syringes scare patients. Pens do not. And, I feel, it is cruel to force patients who are doing well on a given therapy to revert to a more primitive, more challenging, and demonstrably more dangerous technology. Beyond cruel, it is simply bad medicine.

While it is true that in many patients, using syringes over pens can save a small amount of money in prescription costs
only, Baldrishman, et al, at Ohio State University demonstrated in a five year study that overall health care costs are dramatically reduced in patients using pens over syringes (Clinical Therapeutics, Aug. 2007). A review of third-party managed care data by Lee, et al, confirms this cost savings (Clinical Therapy 2006; 28).

et al, looked at patient satisfaction, safety and efficacy outcomes, and cost savings in pens vs. syringes in insulin “starts” in hospital environments, and found that patients started on pens where much more likely to continue therapy on discharge. The researchers stated that “A substantial cost savings was projected for patients in the insulin pen group…” (American Journal of Health-System Pharmacy, Oct. 2008).

In the journal
Diabetes Care (Jan. 1999) Lteif and Schwenk found that at low doses, pens are more accurate in their delivery than syringes are; showing that forcing pediatric patients, who are already disportionately more sensitive to small amounts of insulin, to use syringes, places them at higher risk. Possibly to the point of medical liability.

et al, looked specifically at patients over the age of 60 in a randomized cross-over trial to study the safety, efficacy, and acceptability of pens and found pens “safe, efficacious and highly accepted…” (Diabetes Research and Clinical Practice, Volume 28, Issue 3).

Charles Shaefer, MD, FACP, FCCP, writing in the journal
Insulin (July 2009) reminds us that Rubin and Peyrot summarized the situation well in Diabetes Care. 2008; 31, saying “physicians, patients, and payors (emphasis added) should recognize that making it easier for patients to take better care of their diabetes is not a trivial benefit. Burden of treatment is a significant barrier to improved self-care, and reducing this barrier could make an important contribution to improved diabetes outcomes.”

While I understand that for a typical insulin user, forcing the use of syringes and vials saves about 20%, or $2.50 per day
in pharmacy costs alone for a 90 kilo patient, I question the value of such a short term gain when our best scientific evidence indicates that this approach significantly impacts both dosing errors and compliance: either one of which will assure more expensive tertiary intervention in the future.

Of course, in any patient injecting less than 30u per day, there is no savings what-so-ever, as the excess volume of the vial must be disposed of at the end of thirty-days; a problem resolved with the lower-volume pens.

I hope that Lovelace will reconsider the mandate to abandon insulin pens. It is both bad for patient health and well being; and in the long-run it will not create a savings for Lovelace. At best, it may only gain Lovelace “profit” in the very short term, and at a very great price in patient suffering.

Respectfully, but with grave concern for patient health, I await your prompt response.

Saturday, November 21, 2009

How sharp does a blade need to be?

My father carried a Swiss Army knife all his life. It had several blades of various sizes, flat and Phillip’s head screwdrivers, tweezers, a plastic tooth pick, bottle opener, and miniature scissors.

A pretty amazing piece of technology, all things considered.

I don’t carry a Swiss Army knife. I find them too bulky to carry in the pocket. But a blade is a handy thing to have around, which is why men started carrying pocket knives once walking around with a sword went out of fashion.

After trying a number of different things over the years, I finally settled on the Husky Box Cutter. It’s the type of thing you find at Home Depot, and a tool more common to construction workers than diabetes educators. It is a flat, folding knife with a belt clip that uses replaceable razor blades. I clip it to the top of my right pants-pocket and I most often use it to open blood glucose meter boxes.

Beyond being light and flat, I really like the fact that I always have a sharp blade without having to go through the whole grinding on a whetstone rigmarole. My mother, a Girl Scout Troop Leader, was always telling me that dull blades are more dangerous than sharp ones. You apparently need more elbow grease to use a dull blade than a sharp one, hence you are more likely to slip and injure yourself.

So why am I writing about blades? Because last night as I drifted off to sleep it occurred to me that CGM sensors are like knife blades; and that the Guardian was a Swiss Army knife with a dull blade while the Dexcom is a box cutter with a razor sharp blade.

Which tool is better to have?

Well, that depends on what you want (or need) to do with it, doesn’t it? If all you need to do is cut, then by all means get the box cutter. On the other hand, a box cutter makes a poor screwdriver, can’t open a bottle, and will never work like scissors.

As I near the end of my recently extended (thanks Secret Santa!) Dexcom trial, I am more and more impressed with how sharp the sensor is. It is dead on. Always. It is fast and responsive. Wearing the two CGMs, I feel more and more like the Guardian is a lumbering, but comfortable, ocean liner. The Dex is a speed boat.

So, despite what I said recently about sticking with the Guardian, am I contemplating a switch? Mmmmmmmmmm…. maybe so. The jury is still out, or is out again. I thought I’d made up my mind to stay with the Girl I brought to the dance, but…

Over the last ten days, every time I take a fingerstick, the Dex is closer. Scary-closer. I haven’t been able to screw up its calibration, even when intentionally trying to do so. That is great for diabetics everywhere, no so much so for me, as now I need to re-write my chapter on CGM calibration. Damn. Oh well, in the long run this makes my life easier too. The Dex is also heaps better when the you-know-what hits the fan, which often happens with me as I have no common sense when it comes to the temptation of carbs.

At first I was convinced I needed a Swiss Army knife, even if it had a dull blade. But do you know what? I mainly use knives to cut with. Why shouldn’t I have the sharpest blade? The truth is, although I like all of the advanced features of the Guardian, I don’t really use them. I mainly wear it for protection from hypos, which my treacherous body does not feel or warn me of.

Guardian lets you pull some pretty amazing data off of the monitor. Dex does not. But she does have some pretty amazing software that can answer every question you have plus twenty more you didn’t even think to ask.

I still dither about the lack of predictive alarms, but the flow of highly accurate, responsive blood sugar information may trump this worry. Right now, the Dex often alerts me to trouble before the Guardian’s predictive alarms do.

I’m also falling for her big blue eyes. That large, easy to read screen is something a guy could really get used to. Pressing a button for info isn’t really that bad, and is probably the only physical exercise I get. Changing the alarm thresholds is simple, given the Reader’s Digest Style menus on the Dex, but I know I’ll forget some night and lose sleep with nuisance alarms or forget to change back in the morning and run around high half the day.

So… I have not made up my mind. Not yet. I’ve got another sensor coming. I’m going to try it monotherapy: I’m going to give my Guardian a week off and see what life is like just living with Dex.

I carry a box cutter because I need a blade far more often than I need a screwdriver. Or a bottle opener. Or tweezers.

Maybe it is OK to view CGM the same way.

Sunday, November 15, 2009

A better sensor?

So I’m in the middle of a brief affair. More than a one night stand, but less than a relationship of any sort. Kinda of like a wild weekend with a Swedish Stewardess who is going to be flying home on Monday.

Yep. I’m test-driving the Dexcom Seven Plus CGM.

And it’s about fucking time.

As a reminder to all of you, I was standing on the beach when the very first CGMs crawled out of the primordial soup onto dry land. I was there from the very beginning of the Continuous Glucose Monitoring revolution. I’ve worn every model of CGM ever made, except Dexcom. I was never able to get my paws on one, and never had the resources to just go out and buy one. Until now. I was finally able to score a loaner and one single solitary seven-day sensor.

But like the two-timing fink I am, I’m still carrying-on with my Med-T Girl at the same time. It is a lot of gear with two sensors, two monitors, and my insulin pump to boot. But it is very interesting. I guess all men like to have two women fighting over them.

I’ve got a lot to say about the Dex, but I hesitated to say anything at all because a brief affair isn’t really enough time to get to know this girl. She might be really sweet, or she might be a total bitch. I’m not really sure what her inner-woman is yet.

So please bear in mind that my observations in this post aren’t from a properly long review period. Technology honeymoons are tough. Sometimes you love a new device at first, then it sours on you over time. Other times, you come to love a machine that you nearly kicked to the curve, even to the point you can’t do without it.

Also my observations are based on one single sensor. It is impossible to know if its performance is typical or atypical.

And I also realize that I’m accustomed to my Med-T Guardian, having worn it 24-7-365 for … well, forever. It is very easy to get into habits and assume that what you are used to is the right way.

OK, so I guess I’ve qualified my statements ad-nauseam, and at this point and need to cut to the chase. The Dex Seven day sensor is an awesome girl married to a complete dolt. I’m very, very, very impressed with the performance of the sensor, and very, very, very unimpressed with the device it talks to.

The monitor is worse than junk. It is a complete piece of crap. It is large, bizarrely shaped, and strictly right-handed. It has to be plugged into a wall to be recharged; and a single charge does not last the life of a single sensor. If you run out of juice in the field you are just plain screwed. By comparison, Guardians use a single universally available AAA battery that will last several sensors.

The belt case for the Dex can only be called a joke. I gave up on it and carried the monitor in my pocket.

On the plus side, the screen is large, bright, and easy to read. The menus are simple, logical, and (kudos!) plain English. Learning to run the device is easy-peasie. In a negative, strictly personal, pet-peeve of mine, I’m bugged that I have to turn the damn thing on. Can you imagine if nurses in Intensive Care Units had to turn on heart monitors to see if the patient’s hearts are still beating?

Anything that monitors my body for life-threatening trouble should be always-on to be glanced at. Remember the red L.E.D. digital wrist watches in the late 70’s? They were waaaaay cool, but they are not around anymore. Why? ‘Cause you had to press a button to see what time it was, something that you did not have to do since the invention of the wrist watch. Who has time for that?

I like to be able to glace at my CGM to see where I’m at. Of course other’s can see it too. Rio likes to check out my “trace” and Deb has been known to steal a glance at my CGM now and then. I was even standing at the nurse’s station about a week ago and Eve cast a glance at me and said, “nice line.”


“Nice line.” She pointed at my waist, “on your CGM.” I was having a great low-carb day and my six-hour trace looked like a dead man’s.

That is one of several things I don’t like about Med-T’s combined pump and CGM. It turns off. Presumably they were nervous about the faster battery drain of leaving the screen on leaving someone pumpless. As if we are too stupid to carry a AAA battery, or find one before we go DKA.

So for some Dex-details, starting at the start: insertion. The Dex sensor comes in a large bag and looks like some sort of terrifying dental tool. It is a disposable, one-shot insertion device. I don’t like the size of the thing, but damn, does it work great! It is a four step or so process that sound and looks worse than it is. The manual somehow doesn’t really get across how it works and left me afraid I’d screw up my one-and-only sensor. But like many things it life, in practice it was really pretty simple. It generates less trash than the Abbott Navigator, but more than the Med-T with its re-usable Sen-setter.

Disclaimer: I find the Sen-setter to be a piece of crap and I put in my Med-T sensors by hand, simply not an option with the Abbott and Dex, which must be put in with the one-shot inserters.

The Dex sensor needle is much, much, much smaller in diameter. Insertion was virtually painless. It is similar in length to the Med-T, so it anchors nicely into your flesh. The Abbott system inserts rather shallowly, increasing the risk of it not staying in place with vigorous activity.

The transmitter is not rechargeable (boooo, hisssss) and expensive to replace. They do guarantee it for a year, but this approach pisses me off. Med-T did this on both the first and second generation CGM devices, and then stopped making the sealed transmitter/battery components; turning my first CGM into a $2,700 paperweight within 18 months of buying it in cash.

The Dex transmitter is small, and snaps into the sensor base using a built-in plastic crow bar. Even though the transmitter is actually smaller than the Med-T transmitter, the skin landscape required for the sensor site is actually larger due to the shape of the transmitter cradle and the size of the sticky-patch that holds it on your skin. I needed two overlapping IV3000s to secure the site, while I only need a single one to secure my Med-T Guardian site.

Now comparing the Dex’s monitor only to Med-T (as Abbott’s Navigator seems to be disappearing from the Planet—not officially dropped as a product, but very low profile right now); one of the largest differences is in the shape of the screen. The Med-T uses a rectangle and the Dex uses a square. This makes a much larger difference than you’d expect; but it is impossible to say which is better. The same data displayed on the two different screens looks very different. Depending on your point of view, the square either exaggerates excursions or the rectangle minimizes the appearance of change.

To illustrate this Mercator Projection Effect I created a fake blood glucose trace. The “data” is the same. The left-to-right size is the same. On the bottom one I stretched the up-and-down diminution to show you how the same information looks different on the different shapes of screens.

I think you could adjust to either. I always leave my Guardian on at the six hour screen; an option I would not have should I switch to Dexcom, it does not stay on, and ALWAYS reverts to the three-hour screen when you press a button. I choose the 6-hour screen on my Guardian as the 3-hour Med-T screen always shows a straight line unless the shit has really hit the fan. The small data period has been stretched out too much by the rectangle. Over time, I’ve gotten used to thinking in the perspective of six hours and it seems logical to me. The Dex screen, being taller, actually shows nice visual rate of change data over three hours; but at the same time, on the 6-hour screen can make a leisurely excursion look like a disaster. The other thing I don’t like about three hour screens is that the duration of action of fast-acting insulin is 4-hours and I think it is important to always be thinking about your BGL in the perspective of how it relates to your last shot, and how much more insulin might still be in play. Dex also features a 1-hour and 24-hour screen in addition to the three and six. The Med-T does not have a 1-hour display.

My biggest single bitch about the Med-T Guardian is its petite little voice and the fact it won’t squawk and vibrate at the same time (OK, so maybe that is two bitches). Imagine my delight at hearing a very loud Dex alarm during the setup of the monitor. And it vibrates too! Well, at least it is supposed to. The loaner I got will only utter a peep on the set up screen. It has not once used its voice when it gives a real alarm. Maybe I got a lemon, but still a bummer.

The Dex screen shows a trace made up of little + signs, one for each sensor reading. As the Dex is designed to ignore the occasional funky reading, the trace lines are erratic, with occasional holes in them, which I find disturbing. Top right is your current sensor glucose with an Abbott-style compass rose arrow indicating (in case you are blind) the rate of change. Actually, I kind of like this feature. Below that, the current time. Below that, the “hour screen,” telling you how many hours are being displayed. On the bottom right is the battery strength (ohmyGod! Find a plug! Quick!) and a telemetry icon letting you know the transmitter and the monitor are talking to each other.

The reason I emphasized transmitter, is that the Dex monitor will report telemetry with the transmitter sitting on your desk, unconnected. Med-T transmitters will only report telemetry when hooked up to a properly functioning sensor. This means that positive telemetry on a Dex monitor has nothing to do what-so-ever with the sensor’s ability to function. If you’ve somehow pulled out a Med-T sensor in a moment of wild passion (hey, I’m told it happens) you’ll lose telemetry and know where to look for the problem. Not so with the Dex. So Dex-wearing Diabetics are not allowed to have moments of wild passion.

On the left of the screen is BGL from 50 to 400 in 50-point increments. The body of the screen is blank with only two horizontal dotted lines showing your high and low thresholds; and this leads us nicely into another weakness of the Dex system. The Guardian lets you, basal-rate-style, to choose different high and low thresholds for different times of day. This is damn handy, as you might want to have tighter glucose control during the day without being woken up a night because your sugar just went over 150, or whatever.

Dex forces you to choose one high and one low threshold 24-7. And speaking of alarms, the Dex is less advanced in this respect than either the Med-T Guardian or the Abbott Navigator. Dex has no predictive alarms. I was so surprised by this I flipped through the manual several times and even double checked the internet; and the sad fact is that the Dex Seven only has threshold and rate of change alarms. How… primitive.

I think, given the weaknesses of CGM and interstitial fluid, predictive alarms are a must. This is the spice that make the recipe work. Also, given that the Dex shares the every-five-minute sampling time that Med-T uses; a predictive alarm is all that much more needed. Navigator (which does have predictive alarms) could probably have gotten away without one, as they have every-sixty-second sampling, but the Dex system is sorely lacking without one.

Now, ignoring these issues for the moment, let us just talk about the accuracy of the Dex sensor. Yeah, it rocks.

The two CGMs trended much the same over the week, but the Dex seemed more sensitive to change. If I was going up rapidly, the Dex seemed to pick up on it more quickly than the Med-T sensor did. Same was true for lows. The Dex was more responsive to both lows and the rebounds for the corrections. In 20 minutes they were always neck-in-neck; but in the heat of battle I have to tip my hat to the Dex. It responded more like the one-minute-sampling Abbott Navigator in lows, but unlike Navigator, Dex reports accurately on the high end as well.

I’ve been wearing the current Guardian model for almost three years and I’m pretty impressed with it overall, but I have noticed it does run a bit late to the party. If I’ve gone low the CGM reports the numbers accurately about 10-15 minutes later (which is OK, as the predictive alarm has already given me a heads up before I ever got low). Guardian is also slow on reporting a rise rate after treating a low. The Dex is faster to report, but far, but still leaves me bush-whacked with no advance warning. It is also much faster to report the rebound.

Within 25 minutes either system is accurately reporting the overall situation.

The performance of the Dex is so noticeably better that if the device were not so crappy I’d switch teams.

But… you have a gun to your head now… do you want the super sensor with the lousy machine; or the good sensor with the super machine? I want my cake and be able to eat it too (and then be informed about the high blood sugar that follows).

Sorry, Dex, a super sensor with a poor monitor does NOT trump the good sensor with a super machine. As a system, the Guardian still delivers more. Just having an awesome sensor is not enough. We don’t rely on sensors, we rely on systems that include a sensor.

I should mention that the Dex system has a very nice software, but that like the monitor screen, uses colored dots to show data points. On modal-day type overlays of data it is visually confusing to the point of nausea.

Now I do need to talk about the whole issue of calibration, as this is one of the great make-or-break elements of using CGM. The Abbott device is the domineering parent, strictly regulating when one can and when one cannot calibrate, so much so that the device suffers the devastating consequence of not working at all if it is not 100% satisfied.

Med-T systems need to be calibrated in calm water, when not much is changing, and seem to thrive on fewer, rather than a greater number of calibration finger sticks. I am totally convinced that most of the trouble people have with Med-T CGMs are caused by calibration issues.

The Dex is a whole different kind of animal, and in this one regard might make it the better choice for the majority of diabetics needing CGM. Yeah, you read that right.

Here’s the deal: you can calibrate a Dex at any time, even when your blood sugar is changing rapidly, without freaking it out. I don’t know how they did it, black magic, I suspect; but it is true.

I’ve also noticed that when you give the Dex a fingerstick, it serves not only as a calibration, but also a correction. Like all CGMs, the Dex “trends” well. In other words if it says you are going up, you are most likely going up. If it says you are going up very fast, you are most likely going up very fast. Now, one should not expect, however, that the number on the CGM monitor is going to match the number on your meter.

Remember that the CGM is only checking every five minutes. It isn’t really continuous at all. And of course it is also not checking blood sugar, it is checking glucose in the water between your cells. And on top of that, meters really aren’t all that good in the first place. In fact, the first calibration that kicks off a Dex sensor run requires two finger sticks which the device averages (you can steal this gem from the Dex play book, even if you use a Med-T device, but if you are using a Navigator you can only calibrate with the built-in FreeStyle meter).

OK, so where I was going with all of this is that CGMs frequently have a different opinion of your blood sugar than your meter does. Usually they are close, but every once and a while they can get quite far off.

Guardians use a daisy chain of calibration sticks, each new stick contributes to some sort of algorithm that keeps the ship sailing in the right general direction. Now when the sensor seems to have drifted off course, a calibration nudges it in the right direction, but does nothing radical to the readings. This can, in theory, leave it reading somewhat inaccurately for a significant period of time. But it is very stable.

The Dex, on the other hand, almost treats calibration sticks like correction sticks. If it is off by 30 points a correction makes a significant change in the sensor readings. To me it seems like the Dex algorithm is very heavily weighted towards the most recent fingerstick while the Med-T algorithm is comparing a number of fingersticks. The Med-T sensors seems to get better and better the longer they run, and this may have something to do with the accumulated calibration knowledge of the sensor over time. Dex is good, but I didn’t sense a change in performance one way or another over the life of the run.

The weakness in this approach, of course, is that a “bad” fingerstick is going to disproportionally effect the performance of the sensor. Oh, I suppose I should mention that right now I’m using a AgaMatrix WaveSense Presto meter and strips. (And I just got a new leopard/cheetah print meter case that is either very Safari Macho or Women’s under wear—depending on who you ask.) Presto strips are heaps more accurate than many options out there. I had noticed that my Guardian started behaving much better when I started using the Presto system too. So I guess the bottom line for CGM users is why spend all that money on sensors and then try to guide them through the night with a crappy meter.

So if you have a Dex, based on my very limited experience with it, I think I would encourage you to calibrate more often rather than less often. Which is the opposite from the advice I usually give. I guess I’d also worry much less about what conditions I calibrate under, which is great for kids or other “brittle” folks who suffer a lot of glycemic ups and downs.

One other cool thing that I do like about the Dex is that when you go to enter a calibration stick it displays the current sensor glucose, while the Med-T always starts at 100. This is a nice, user friendly extra, as often the two are close. It gets old scrolling up from 100 all the time. Bottom line on this: it is faster to enter a manual fingerstick in to the Dex than it is to enter the same fingerstick into the Med-T.

But, again, the great performance and flexible calibrations are not enough to make me switch. The system suffers greatly from the lack of a predictive alarm, the lack of ability to stay turned on for quick evaluation, the need for a wall plug to recharge, the lack of a rechargeable transmitter, the lack of variable threshold alarms, and the poor build quality of the monitor. When I first heard the nicely loud alarm during set up, I thought that this feature alone might be enough to make me change, but in operation it has never worked, so that added to my concerns about the physical quality of the monitor, and its lack of potential for functional longevity.

Also in the mix are the poor layout of controls for lefties (although in fairness, the Med-T device is two-handed and the Dex can be run with the right hand alone). Too bad the engineers didn’t incorporate some sort of sensor to “know” which side up the monitor is and then flip the screen.

But Med-T has some stiff competition here. If Dex comes out with a monitor that addresses these issues before Med-T launches their next generation (which seems over due, but then again the economy sucks) the Dex could become the clear choice.

All of that said, I did put a very young Type-1 on the Dex, the small sensor size being 50% of the equation (she’s a 32-pound skinny little thing, I dreaded the thought of putting the whopping Med-T sensor into her tiny little body. Hell, her arms are almost as small as the Med-T sensor needle!). The other 50% of my decision coming from the fact she NEVER has stable blood sugar to calibrate a Guardian.

I like to have a lot of tools in the tool chest. I’m very impressed with the Dex, and I can’t really say that about the Abbott Navigator. The Navigator has some fine features, but it is more like dating a Neanderthal. Fine device, back then. Also the loooooong spool up time almost killed one of my best friends who had a DKA crisis in the time it took the damn sensor to come online.

But Dex. The Dex I’ll add to my tool kit. And if she comes back from Sweden, I wouldn’t mind hooking up with her myself for another week or two.

(And before you all start comment-spamming me about my overdue CGM book please know that I am taking 16 days off around the end of the year to finish it. After all, who wants to see their diabetes educator three days before Carbmass?)

Sunday, November 01, 2009

Weird and wonderful

So it is here at last. The Spanish version of Taming the Tiger. It is ever so slightly larger, as Spanish words, it turns out, are in general longer than English words which caused nightmare layout and hyphenation problems.

Rio was very concerned. “But Daddy, then it won’t fit in diabetic’s pockets!”

It’s OK, baby, people who speak Spanish have bigger pockets.

“Oh, well… OK then.”

So it is kinda weird having your words translated into a language you do not speak. But kinda wonderful at the same time.