Friday, July 30, 2010

Lame.


There it is - the low blood sugar that wouldn't quit.

Today was one of those days - the ones where you're rollercoastering all over the place, and can't figure out why.  My "ride" ended with me not being able to get above 87 for the last three hours.  I'm finally 115 again, but it was pretty hairy there for a while.  I've had two fruit strips (11g carb each), two glucose tabs (4g carb each), an unknown amount of brownies, straight from the pan (???g carb), and a slice of cinnamon raisin bread (maybe 15g carb?).  I have had my basal rate set to 0 for the last two hours, and have been sitting in the air conditioning, so I can't blame the heat.  Or exercise.  I was sitting at my desk at work!  These sorts of things baffle me.

Oh, diabetes.

Tuesday, July 27, 2010

Stuff.

I have a lot of it.

Kitchen stuff, clothing stuff, accessory stuff.  This is pretty normal stuff to have, but then on top of that, I have to have a lot of diabetes stuff.  So much stuff, in fact, that I have to keep it in several different places.  Two of the four drawers in our entertainment are reserved for D stuff, as well as a kitchen drawer, most of a cabinet in the kitchen, and a shelf in the fridge.  (This justifies why I needed a big kitchen, right?)  Behold:


The Drawer Of Boxes.  Pump supplies, test strips, and a heckuva lot of alcohol swabs.


Drawer that holds the stuff I use all the time. 


Fridge door full o' insulin, and the obligatory Glucagon kit.


Glucose tabs, extra meters, lancets, and other shenanigans.


The box my insulin pump came in, which now houses manuals and random parts/accessories.

Thursday, July 22, 2010

Setting The Record Straight.

My local paper runs a national column by Dr. Peter Gott, a general internist who has a practice in Connecticut.  Though I don't usually read his column, it happens to run right under another column I read, so more often than not, I skim it.  Today, Dr. Gott attempted to answer the following question:

Dear Dr. Gott: I have been a Type 2 diabetic for four years now. What is the difference between Type 1 and Type 2 diabetes?

Of course, this instantly got my attention.  As I read his answer, I became at first surprised - then shocked - and finally, angry.  He had a chance to finally provide the public an accurate account of the differences between the two diseases, and he totally blew it.  When members of the medical community who have a public spotlight make such blatant errors, it's a little unbelievable.  I will be writing Dr. Gott a letter this evening, but also wanted to address it here.  I will copy his reply (so you can see what I'm disagreeing with) in italics, with my responses in bold, following his text.

Dear Reader: Diabetes is a disorder in which blood-glucose levels are above normal. People develop diabetes either because the pancreas doesn't produce adequate insulin or because the cells in the muscles, liver and fat don't use insulin properly. This results is glucose remaining in the blood and elevating levels at the same time cells crave the energy necessary to function properly. 

No arguments here.

 
There are two types of diabetes, Type 1 and Type 2, with the latter being most common. Type 1 indicates a person is dependent on insulin and requires regular injections that are self-administered because the body fails to produce enough, if any, insulin. This form generally develops before the age of 30 and affects about 10 percent of all diabetics. 

Wrong.  There are more than two types of diabetes - actually, there are at least four (type 1, type 2, LADA, and gestational).  In addition, it should be noted that EVERY person is dependent on insulin - diabetic or not.  Insulin is a naturally occurring digestive hormone in the human body.  Perhaps this is what he meant, but it could have been better expressed.

Type 2, on the other hand, signifies insulin resistance. These people produce adequate insulin levels, but the body is unable to use it properly. Some may even need insulin injections in order to stimulate the pancreas. This form can occur in people of all ages and is more prevalent in obese people, Hispanics and Native Americans. Some cases of Type 2 diabetes have a strong genetic basis while others do not. 

The last sentence pertains to type 1 diabetes as well - while some of us "inherited" the gene from a family member, others have no family history of the condition.

Prevention is key with the disorder to prevent your diabetes from progressing to Type 1. If appropriate, try to lose weight, since excess weight can keep your body from making and using insulin properly. Reduce your salt and alcohol intake. Make better choices when grocery shopping. 

Wow.  This paragraph is so many kinds of wrong, that I'm really not sure where to begin.  First off, type 2 does not progress to type 1.  Type 1 is an auto-immune disease.  Type 2 is a metabolic disease.  Type 1's can acquire insulin resistance, which is a hallmark of Type 2, while Type 2's can become insulin-dependent, which is a hallmark of Type 1.  (You can see why this gets confusing for people who aren't living with or working with this every day - but, c'mon, he's a doctor!)  What he most likely (at least, I hope) meant to say here was "insulin-dependent" instead of "Type 1".  However, it needs to be clear that the need to inject or infuse insulin does not, in itself, justify a diagnosis of Type 1.

Secondly, excess weight has nothing to do with developing Type 1, and is only a trigger (not a CAUSE) for Type 2.  Salt and alcohol intake also have no bearing on the likelihood of developing Type 1.

It's exactly this kind of misinformation that leads to the general public not really knowing what Type 1 is.  So, in an effort to balance the injustice of Dr. Gott's response, here's what Type 1 Diabetes is (taken from http://www.jdrf.org/):
Type 1 diabetes is a chronic, debilitating disease affecting every organ system that strikes children and adults suddenly, and lasts a lifetime. Type 1 diabetes is an autoimmune disease in which a person's pancreas stops producing insulin, a hormone that enables people to get energy from food. (Type 1 diabetes occurs when the body's immune system attacks and destroys certain cells in the pancreas, an organ about the size of a hand that is located behind the lower part of the stomach. These cells -- called beta cells -- are contained, along with other types of cells, within small islands of endocrine cells called the pancreatic islets. Beta cells normally produce insulin, a hormone that helps the body move the glucose contained in food into cells throughout the body, which use it for energy. But when the beta cells are destroyed, no insulin can be produced, and the glucose stays in the blood instead, where it can cause serious damage to all the organ systems of the body.) People with type 1 diabetes must take multiple injections of insulin daily or continuous infusion of insulin through a pump just to survive. Taking insulin does not cure any type of diabetes nor prevent the possibility of its eventual and devastating effects: kidney failure, blindness, nerve damage, amputation, heart attack, and stroke. Unlike type 1 diabetes, type 2 diabetes is a metabolic disorder that is often diagnosed in adulthood in which a person's body still produces insulin but is unable to use it effectively.
Okay, back to Dr. Gott.

Keep fresh vegetables such as carrot and celery sticks readily available to snack on while watching television. Eat properly and coordinate a program of regular exercise, such as riding a bicycle or golfing. A simple walk around the block daily is good.  Ask your physician or endocrinologist if referral to a dietitian would help. If you have a community center nearby, sign up for swimming or aerobics classes. Get a friend to join you. There's more incentive if you have company.  

That's good advice for anyone.  However, this is given in the context of "preventing" Type 2 from turning into Type 1.  There is no cure for Type 1, and there is also no prevention for it.  Doesn't Dr. Gott know what JDRF does?

If medication is appropriate, take it according to your physician's directions. Follow my No Flour, No Sugar diet. I have received countless communications from readers stating they have brought their diabetes, cholesterol levels and hypertension under control and have been able to discontinue their medication while on my diet

Again, it needs to be specified what sort of diabetes we're talking about here.  He's directing this advice towards a reader with type 2 - because, believe me, if a simple change in diet could suddenly kick-start my pancreas into producing insulin again, and could stop my immune system from killing off my beta cells, don't you think I would have done it by now?

For those interested, here is a link to an online version of the article:  http://www.pasadenastarnews.com/ci_15571806 .  If you want to write Dr. Gott, he can be reached at Dr. Gott c/o United Media, 200 Madison Ave., Fourth Floor, New York, NY 10016.

Do it!



Wednesday, July 21, 2010

Victory Is Mine!

Today was the Big Day.

At least, to me, every time I get my A1C checked, it's a Big Day.

As I've discussed before, I have mixed feelings about the amount of importance we place on A1C results as the sole indicator of control.  I've worked so, so hard on keeping my numbers as close to "normal" as I could in the last three months, but I know that my A1C doesn't mean I was "good" or "bad" - it's supposed to be viewed as just another number to help me determine which way to go from here.  However, I still can't keep myself from feeling like I'm getting a report card - and when I get a report card this great, I can't help but show it off to a few friends.  (That's you!)

6.5!

This is huge!  For those unfamiliar with A1C testing, here is a brief explanation, courtesy of the CDC's website:
[An A1C test is] A test that sums up how much glucose has been sticking to part of the hemoglobin during the past 3–4 months. Hemoglobin is a substance in the red blood cells that supplies oxygen to the cells of the body. The AIC goal for patients in general is an AIC goal of less than 7%. The AIC goal for the individual patient is an AIC as close to 6% as possible without a considerable amount of low blood glucose.
So, I'm finally in range.  I haven't had an A1C this low in a long, long time.  In fact, my P.A. printed off for me every A1C I've had while in their care, and they've usually been in the lower 8's.  In April, I had a 7.1, which I thought was GREAT - and now, I've graduated to the 6's.  It's a great feeling.  You know what else is a great feeling?  Getting high fives, congratulations, and "We're proud of you!"s from your medical team.  :)

Tuesday, July 20, 2010

Just The Spectator.

Sometimes, we have moments that feel like Diabetes is talking right to us.  In these moments, it doesn't feel like we're the ones with our hands on the steering wheel - instead, it's Diabetes, and he's self-centered, mean, and untimely.  And, sometimes - he's just downright cruel.  It doesn't happen often, but even the most optimistic diabetic knows The Voice:

No, actually, you really can't do everything everyone else can.  Not all the time.  You see, I'm the one in charge here.  I'm the one who decides if you're getting a full night's sleep.  I'm the one who decides what you're eating (or not eating) today.  Want to exercise?  Not unless I give you the signal...  you could try anyway, but you'll only make things worse.  I call the shots.  I come first.  You have to make your plans around me. 

You have to give me the attention I require, or I'll throw a tantrum.  I'll give you a headache, take away all of your energy and patience, make you break out in a cold sweat, and embarrass you by hijacking your motor skills.  I'll make your hands shake so badly that others notice.  I'll drain the color out of your face, and numb your tastebuds.  I can do all of this with no warning, too.  I hold the power here, not you.  You're just the spectator!

If you don't plan ahead, I'll lash out.  And, sometimes, I'll lash out even when you think you've planned for every possible scenario.  Even when you've paid careful and diligent attention to me all day long.  Even when it doesn't make any sense for me to misbehave.  Even when you were just fine half an hour ago.

I'll wiggle my way into every decision you make.  You will eat, sleep, and breathe me.  And, even when you do, I can still betray you.  After all, you're just the spectator.

Friday, July 16, 2010

My Insulin Pump Story, Part Two: Where Do I Put This Thing?

As I mentioned in Part One, I finally got to the point where I was more interested than bothered by the insulin pump idea, and at my doctor's insistence, chose the Deltec Cozmo.  This insulin pump is no longer being made, but at the time, was one of the four or five insulin pumps available in the U.S.  For some reason, my doctor loved that one.  I'm not sure why, either.

Once the pump came in, the CDE at the doctor’s office did my training.  We spent a lot of time getting the pump programmed with the date, time, and then all of the many diabetes-related settings.  For whatever reason, even though I had been studying everything about this pump, I hadn’t given much thought to where the pump would physically go on me.  The CDE didn't have any ideas for me, so I ended up leaving the endo’s office with it clipped to the top of my pants.  Right where everyone could see it.  Right where I didn't want it to be.  Blerg.

When I went to work, having the pump clipped to my pants seemed too bulky and in the way.  I didn't have anyone else to ask for ideas, so I tried putting it in my pocket.  Well, that didn't work - it kept sliding out (dress pants tend to have shallow pockets, and the Cozmo was a pretty girthy pump.  Didn't exactly lay flat.).  I had a couple of pairs of dress pants with those small pockets on the outside (for coins?), so I started wearing those a lot more often - the pump fit pretty well in those pockets.  I also took a couple pairs of pants to the tailor, and had them add a inside pocket, just big enough to hold the pump.  That worked okay, too, but you could always still tell that there was "something" there.

The insulin pump I have now has a lower profile, so it hides a little more easily under clothing.  It still sticks out sometimes, but that's just something I have to deal with.  Most times, my pump is somehow attached to underwear, somewhere.  I mean, where the heck else can you put it?  It's not an ideal situation, but it's the best solution out of the options I have.

As I've talked to more and more people who also have T1, I'm becoming aware of more ideas.  Even though most of the accessories out there are geared towards kids, there are a few that I would actually consider getting if I thought I could rock it - and people with some great ideas that I can't wait to see come to life.  There is one website in particular, Hanky Pancreas (love that name, by the way), that looks pretty sweet.

If you know of another company with grown-up insulin pump accessories, please let me know - I'd love to check it out!

Thursday, July 15, 2010

My Insulin Pump Story, Part One: How A Tiny Robot Threatened My Mad Ninja Skillz.

I orginally intended to do one long post about my process of accepting an insulin pump into my life, and how I wear it.  But, like usual, that got me going on other semi-related points, and before I knew it, it was going to be a small novel...  soooo...  I'm breaking it into two parts, spread out over two days.  You're welcome.

******************************************************************

Prior to actually wearing one, insulin pumping was never something I was all that, er, "pumped" about.  (HA! I love D-humor.)   

The idea of me actually wearing an insulin pump was first brought up to me in 2004, by a new endocrinologist I started seeing (Doctor B).  He was all about technology, and I was very comfortable with my injections, thank you.  Even making the move to insulin pens from syringes and vials had taken some coaxing.  I mean – this would be a big step.  And one I didn’t feel prepared to take.  The only times I’d seen someone wearing one, they had it clipped to the outside of the waist of their pants, and I really didn’t like how that looked.  Not very subtle, right?  I dreaded the idea of having to have it “on display” all the time.

As I’ve said before, sometimes I like to be discreet about my D.  A diabetic ninja, if you will.  I don’t necessarily want my robot parts to be the first thing someone notices about me – I’d like to have the say-so in who knows and when, in some situations.  Job interviews, or meeting new people for the first time, for example.

Another reason I had for putting off getting a pump was dating.  It sounds ludicrous to me now, but I thought any guy who saw that a machine was attached to me at all times (albeit, a small, life-saving machine) would be turned off.  I was scared that no one would want to date me while I was wearing that thing.  I made a deal with myself that once I was in a stable relationship, I’d give the insulin pump idea another look – but not until then.  I really wasn't giving myself enough credit - or looking at it from a logical standpoint.  Because, really:  anyone who doesn't want to date you solely based on the fact that you wear a piece of equipment that helps you stay healthy isn't worth dating in the first place.  Would I really want to be with someone like that for the long haul?  Would I really want to live the rest of my life with someone who values appearance over health?  That would be a long, hard road to walk with someone.

Destiny spoke in 2005.  I started dating my now-husband, A, in January of that year, and our relationship might be the only good thing to ever come out of MySpace.  I was browsing through my friends' friends one day, and came across a picture of a guy with a huge beard who was playing bass guitar (and seemed to be having a lot of fun doing so).  I thought "Hey, this guy looks like fun.  And he's cute.  And he plays guitar.  Friend request!"  A and I chatted online for a week or so, and got along really well.  He invited me to come see his band play, I did, and we were inseperable from pretty much that moment on.  He has an infallible knack for getting me to burst into giggles, he's the most patient and easy-going person I've probably ever met, and he gives one heck of a great hug.  How could you not love this man?

By the end of that first year, I finally started thinking that an insulin pump might be kind-of okayish.  I knew that my A1C needed improvement (I had been consistently hanging out in the 8's and 9's), and I was told that a pump could help me with that.  I still didn't like the idea of being attached to something at all times, but I knew the benefits would probably outweigh the inconveniences.  On a few occasions, I’d brought up the idea to A, and he always said that “If it means you’ll be healthier, I think you should do it”.  (That's how you know you have a keeper!) 

I worried about what others would think of it.  Would I get stares?  Would people even know I was wearing one?  Was I being too paranoid about this?  (In most cases, the answer to that last question is "yes" for me, but I still think it's a valid concern.)  I didn't have anyone else to talk to at the time, to ask real-life questions of.  Having someone like that to talk to probably would have coaxed me into trying an insulin pump sooner, but that's just how it went.  I finally caved, my doctor did the footwork required, and I had my Deltec Cozmo insulin pump.

My next issue was... where the heck do I wear this thing?

Monday, July 12, 2010

Choices In Care.

I'm interested to hear what other T1s do for their care - do you see an endocrinologist, or someone else for your diabetic care?

To my understanding, most diabetics (type 1, at least) see an endocrinologist for their primary care.  (Endocrinologists specialize in the diagnosis and treatment of conditions affecting the endocrine system.  The endocrine system is made up of glands that secrete hormones which regulate the body, through the blood stream.  Insulin is one of those hormones, and because diabetes - type 1, type 2, LADA, gestational - is such a prevalent thing, their focus tends to be on diabetic care.) 

It makes sense to do this.  They are the doctors most likely to be up-to-speed on the technologies we have available to us.  They should have plenty of experience to draw upon, and be able to keep an eye open for other auto-immune diseases.  They are supposed to be the experts.

Everyone has to decide what the right decision is for them, for their own particular situation, when it comes to who you see and how often.  I've been through 6 (I think) endocrinologists in the 24 years I've been diabetic - and some were great.  I am especially appreciative of the one who finally caught onto my hypothryoidism - he really saved my life, quite literally.  My childhood endocrinologist was good, as well - I don't remember much about him, but I do remember him being a friendly, kind man. 

On the flipside of that, however, are a couple of endos who didn't quite cut it.  They missed important red flags.  They were derogatory and sometimes downright mean.  I got to the point where getting to and leaving appointments with one doctor in particular caused me extreme anxiety and stress.  (How does any of that, in any way, help my overall health?)  I won't name names - their reputations are consistent and easy to locate.  Anyone who lives around where I live will be able to find their names, if they so desire.  The inability of either one to provide quality, considerate, and meaningful care was the catalyst for me to find another way.

Doctor A failed to diagnose (or maybe even think to test for) my thryoid condition.  In addition to Type 1 diabetes, I also have Hypothyroidism, which basically means my thyroid gland is underactive.  It's an auto-immune disease, just as type 1 diabetes is.  The two aren't technically related, but it seems to be that once you have one auto-immune disease, you're more prone to developing others.  Anyway - I digress.  The thyroid thing should have been an easy diagnosis - and yet A never caught it.  I experienced a large shift in personality, became depressed, my hair thinned out, I'd get ridiculous muscle cramps, and I could never sleep enough.  All of the classic symptoms.  No bells rang, apparently.  I also got reprimanded by A, though I will admit that my care (or lack of it) was asking for it.  I can recall getting an A1C result of close to 13.  That means my average blood sugar was almost 340.  The only memory I have of this doctor is being asked the question "Are you trying to kill yourself?  Because you're doing a pretty good job so far."  While I can now appreciate what she meant by that, Former Kim didn't want to hear that. 

Doctor B was my the last endocrinologist I saw.  B was very educated and proactive.  B is the endo who finally got me on an insulin pump five years ago, even if B didn't let me choose which one I could get.  I had been reading about the Minimed pump, and decided that was the one I wanted, but when I brought it up in my next appointment, B told me I had to get the Deltec Cozmo, because that's the pump they were familiar with.  (But, won't I be the one who has to live with and operate it every day?  And you'll only see it every 3 months?  Oh, I guess that doesn't matter.)  B also found the right combination of thyroid medication to get me feeling energetic again - so I am always thankful for that.  However, B had horrible manners.  Not the normal pleasantries - those were there - but the way B worded things.  B also never really taught me anything.  My insulin pump would get whisked away, reprogrammed, and handed back to me.  I'd hand B my blood sugar results for the past two weeks (all hand-written, on the ridiculously annoying forms B had self-designed, because they were "easier" to read.  My insulin pump had software that made everything downloadable and printable, but B didn't want to see any of that.), B would make adjustments, write them all down, and send me on my way.  No excess amount of time was ever spent on me.  I'd wait for 45 minutes past my appointment time, only to get maybe 10 minutes of B's time.  One of the last straws was when B told me I was "obese", and suggested I go on the South Beach diet.  While that may have been true under the clinical definition of the word, there's no reason to use that particular word.  You know what?  I realize I weigh more than I should.  I have a mirror, and I can see the sizes of clothes I buy.  I don't need you telling me any of that; it's not helpful.  Why couldn't I say that to his face?  And why, if that was his opinion, couldn't he set me up with a nutritionist or CDE to set up a food plan, instead of just telling me to "go buy a South Beach diet book"?

Okay, enough rambling.  My point is that my other way, instead of seeing an endo, is seeing an internist and a P.A.  The internist and P.A. are in the same office, and work with each other on my care.  I see the internist once a year, and the P.A. every 6 - 8 weeks.  And it's GREAT.  Really, I've never been so happy to go to doctor appointments.  Both of them have such great attitudes, and are willing to listen to me and what I know about my condition.  They accept feedback and suggestions from me on my care.  It is just absolutely a breath of fresh air, after years with B.

An unintended consequence of not seeing an endo is that I am now more educated and up-to-date on diabetes care than I ever have been.  I have to be - while they do have other T1 patients, they don't specialize in diabetic care.  As a child and even into my teens, my mom was the go-to person who shouldered much of the burden with doctor appointments and dosage decisions.  (Mom, correct me if I'm wrong.)  As a college student and for a bit beyond that, no one shouldered it.  I simply lived as though injections and sporadic blood tests would do the job - which makes it no surprise that I saw that really high A1C I mentioned before.  So, the past few years with this new medical team has been a brand new experience.  There are even some cases where I'm more knowledgable on a particular topic than they are!  For example, the Dexcom CGM I got was the first Dexcom that office had seen.  I actually have gotten to teach a few people on my medical team about how it works and what it's capable of, which I think is kind of fun.  When I wanted a new insulin pump, and explained the benefits to them of the particular one I wanted, they were more than willing to do the footwork to get me one. 

Switching to an internist was really the best decision, for me, that I could have made.  It's forced me to take more responsibility for my own care, and I wish I could have jumped on that bandwagon long ago.  I guess it just wasn't my time yet to do so.

Thursday, July 8, 2010

Have You Ever?

You've heard of the game "I Never"... well, this is sort of the opposite.  I've done all of these things, and found them kind of funny, so I thought I'd share.  Enjoy!

Have you ever....

...thought insulin smelled like bandaids?  It totally does.
...gotten your insulin pump tubing caught on something (most often for me, it's a door handle), and been tugged back when you tried to walk away?
...considered not eating what you planned on, because you didn't want to "mess up" your in-range blood glucose number?  Whenever I see a flat line on the CGM in the 80 - 120 range, I wish I had a "freeze" button.
...had a higher proportion of diabetes supplies in your purse than anything else in there?
...wanted to throw a shoe at anyone in the media who can't differentiate type 1 and type 2?  More on this later...
...reached the point where you don't even have to say your name at the pharmacy counter, because you're in there so often that they already know who you are?

Feel free to add to my list with a comment...  :)

Wednesday, July 7, 2010

When 3 + 5 = Cheese.

How am I supposed to attain "tight control" with equipment that only works sometimes?

Last night, I put in a new CGM sensor. (I say "in", because while the transmitter rests on top of my skin with some adhesive, underneath that is a small wire that stays under my skin, as long as I'm wearing the sensor.) I let New Jim calibrate for two hours while I was sleeping, got up at 1:30 am to do the two finger sticks required to calibrate it, and went back to sleep.

Since I've gotten up, Jim's results have been all over the place. I've already done 8 finger sticks today, and it's only 10:30 am.

Usually, Jim is very accurate. I would say he's typically within 10 - 15 mg/dL of what my meter comes up with when I do a finger stick. Today, he's been as much as 50 points off. He's also told me I'm trending upwards, when I was actually falling. Later, as a test, I did two finger sticks 20 minutes apart, and verified those results against what Jim was telling me. My finger sticks were 84 and 83, respectively. Jim, on the other hand, thought I had dropped from 124 to "LOW". (A reading of "LOW" means that I'm below 40, on the CGM.)

This is pretty frustrating. I actually ended up just shutting down the receiver, since the results have been so wrong. Jim has been vibrating and beeping all morning, and very unnecessarily, since his results have been consistently off. I would really, really like to throw him out the 3rd floor window of my office building - but instead, I'll just keep testing every 45 minutes or so, and hope that I catch everything.

Days like this make me wonder, though - how does anyone expect a person in my position to gain "good" control - much less "perfect" control? The tools we have available to us can be inaccurate and unreliable. Did you know that blood glucose meters are only required to provide results that are within 20% of a laboratory standard, 95% of the time? 20%! That's ridiculous! How is it that an iPad, WiFi, and GPS systems exist - or any other modern technology you want to name - but 30 years after home glucose monitors became widely available, we can't better accuracy for our health? C'mon, ISO and FDA - you can do better than that. And not only can you, you should.

The continuous glucose monitor is no different, in that a large amount of error is "allowable".  According to my Dexcom Seven Plus User Guide, a clinical study showed that for the range of 40 to 400 mg/dL (which is the full range of the CGM), only 76% of readings were within 20% of the laboratory's glucose readings.  That's a whole lot of room for error, people.

Let's go back to the 20% margin of error for glucose meters results - the very results that I'm using to make decisions on food, insulin, and so many other things.  Here is why inaccuracy is so dangerous:  if my meter reads 100, that means that in actuality I could be either 80 (on the low side of normal, and would probably convince me to eat something) or 120 (the high end of normal, which might cause me to take a corrective amount of insulin).  Let's take this a step further and say that I test, and the meter spits out 300.  If I see this, I'm following my corrective formula of 1:20 over 100, which means I'll be taking 10 units of insulin to bring myself back down to 100 (hopefully).  But what about the margin of error?  Accepting the 20% possibility, I could really be 240 (in which those 10 units of insulin would likely bring me down to 40, which is frighteningly low), or I could be 360 (and those 10 units would only bring me down to 160 - still out of range).

I don't believe that my good health is too much to ask for.  I'm willing to do the work, but that effort can be fruitless if I don't have tools that work properly, and work accurately together. 

As Mark Twain (or someone else, equally wise) said:  The man with a watch always knows what time it is.  The man with two watches is never quite sure.