Category Archives: Data-betes

Baby Steps Toward Less “Winging It”

Posted on April 6, 2011 by Jeff Mather

I have previously mentioned that I wing it . . . a lot. My endo and I have devised carb:insulin bolus ratios based on some prior experiences, and I settled on my basal rates by testing — days and days and even a night or two of hungry, grumpy testing. And having done all this work, what do I do? I ignore it. Still.

Months after saying I wasn’t going to be so scurred of dosing the appropriate amount of insulin, I still don’t always feel confident giving all of the insulin that my pump’s bolus wizard suggests. And I also see lots of times where I set a temporary basal or treat incorrect basal rates with extra food.

It occurred to me this afternoon that I can use my pump’s data (via CareLink) to find my effective carb:insulin ratios and probably my insulin sensitivity for corrections, too. I saw when I was parsing the CSV file I downloaded from CareLink that it contains the full bolus wizard info, including estimated carbs, suggested bolus amount, and actual insulin delivered. Now that I can parse the file, I can get those values, compute the carb:insulin ratio for each bolus, and see whether my BG values behaved as I would have liked. Given enough data, I hope to see what ratios work the best. And then, of course, program those into my pump settings and (hopefully) use them with more confidence. Less winging it.

I like having a mini-project to help keep larger projects moving forward.

Posted in CGM, Data-betes, Diabetes | Leave a comment

Winging It like a Penguin

Posted on April 3, 2011 by Jeff Mather

Last Thursday, I saw my endocrinologist. We all agreed that my 7.8% A1c should be lower. Not in the sense of “Hey, you know you should lower your A1c,” rather “Your BG readings and CGM data look great; I don’t know why your A1c isn’t lower . . . yet.” There was general agreement that if I keep going the way that I have been for the last couple months, my A1c should show actual improvement the next time we meet in late July. I want to be optimistic, but it’s been so long since I’ve seen the low 7s or — g-d help me if I dare to dream — the 6s, that I think I’ll just keep my feelings low-key. After all, my heart got a little broken last week, when I saw a more-or-less unchanged A1c result in my labs.

They — my endo and her newish physician’s assistant — thought it was great that I ran a half-marathon and that I’m doing a triathlon in five weeks. And they thought my lipid profile was probably as good as it could possibly get. (My HDL and LDL were almost identical at 66 and 67.) They also made sure that my education order form got sent to Joslin so that I could see an exercise physiologist there this coming Friday.

I’ve been trying to see an exercise physiologist at Joslin for a while, because I need a little help. As I told my endo and PA, “I love all of the exercise and training for events, but I feel like I’m winging it on the insulin and nutrition front.” Where I am now has come mostly through trial and error. Sometimes, like during the half marathon it isn’t quite right, and other days (like today) everything works out really well.*

I don’t like winging it. I don’t expect rainbows and unicorns every time, but it would be nice to understand a little bit more of what’s going on and what I can do to maximize my chances of success, how I can make sure most of workouts are quality ones, and what post-exercise things I might do to prevent lows.

That’s why I want to get some professional help. So far, I’ve mostly been trying to repeat what works — and fortunately most of what I’m doing these days seems to work, even if it feels sketchy — and to learn as much as I can from the days that don’t go quite right.

Last Friday, the day after my endo appointment, is a good example. On Wednesdays and Fridays, I wake up at 5:00 to go to my local high school pool and swim laps. It’s early, and I usually feel tired, but I know that it’s what I’ve got to do, so I go. This particular Friday, though, I didn’t get the chance to swim the laps because I had hypoglycemia before I started. Since I had eaten like I normally do before going swimming, I decided to see what happens has to my blood sugar from the food when I don’t actually swim. How long does it really take those carbs to hit my bloodstream? When should I eat them so that they actually help me when I’m working out?

Here’s the data:

2:01 - 83 mg/dL - Uh oh, better eat a tiny bit
5:03 - 88
5:15 - Energy gel (22g) and 2 glucose tablets (8g)
5:30 - Shovel snow for 10 minutes (grr . . .winter in April)
5:50 - 59 - Treat with 3 glucose tables (12g)
  No swimming :'^(
6:22 - 157 - Going up! Better correct w/ 0.5u
7:27 - 302 - Oy! Better correct some more, plus I'm hungry.
  1.9u (correction) + 6.6u (for the food)
7:51 - 289 - Well, a man's gotta eat despite the BGs, so I did.
10:15 -143

What do I take away from this? Not sure exactly, but here are some thoughts.

  • The amount I corrected was almost exactly what I would have bolused for the 22g of the energy gel. Yay?!
  • Use a lower basal overnight after days that I do crazy awesome half-mile repeat running workouts.**
  • Leave all of the shoveling for Lisa. Have a snack before shoveling.
  • Try moving my energy gel consumption about 15 minutes earlier to about 45 minutes before exercise.
  • Consider lowering my AM basals on days when I swim.

We’ll see what happens when I go swimming tomorrow morning to make up for last Friday.


* — I had never thought I would ever say, “I just did an easy 11 mile run,” but that’s what happened today. Yeah!

** — I haven’t run 800m repeats since high school; I don’t think I’ve run a timed half-mile since there either. But running them was on my training plan, so I did four sets, and I was pleased to see the results: 3:13, 3:15, 3:15, 3:25. Boo-yah!

Posted in Data-betes, Diabetes, Reluctant Triathlete, Running, Swimming | 3 Comments

App Update

Posted on April 1, 2011 by Jeff Mather

Today a bunch of my online peeps were in California visiting Medtronic. I wish I’d been invited to go to, but that was not the case. Had I been there, I would have squealed like a little schoolgirl at the pre-announcement that they’re rolling out support for uploading and using CareLink on a Mac next week.

Not only is that great for me when working with my own data, it will make developing my app easier. People may still need to take the extra step of downloading a CSV file containing their data, but at least they’ll be able to do it on their platform. Not perfect, but better.

In an ideal world — the one that I would have advocated for at pump/CGM HQ — third-party app developers (like me) would be able to ask the online CareLink database for a person’s diabetes data via an application programming interface (API). Mobile app developers could then hold on to that data for offline or mobile use without ever needing to talk directly to the medical devices themselves. Frankly, writing code to connect directly to a life-preserving medical device is quite risky and something I would like to avoid; it’s also the kind of thing that requires rigorous, time-consuming, expensive FDA approval. Not very appealing when all I want to be is a data consumer.

I’m hoping that Medtronic provides a mechanism to open up this data soon, because I’m getting close to being able to benefit from it. And when I say “this data,” I mean “our data” because it really is ours. We’re the ones who generated the data through our self-managment decisions, and we’re the ones who will benefit the most from using that data to make decisions. All I’m really asking for is a way to log in to CareLink without using a web browser and to retrieve data securely.

I’ve been working on my pump+CGM data visualizer a lot recently — most evenings in fact. On my Mac, I can extract events from a comma-separated value (CSV) file generated on the CareLink website, and I can pick out “interesting” events that are relevant for self-management. Now I’m working on being able to store those interesting events in a form that I can send to my iPod. (Then there are the tasks related to visualizing the data, but I’m starting small.)

It’s taking me longer than I expected to build this application. Objective-C isn’t hard, but learning the ins and outs of any new framework library is always a bit involved. (Turns out I’ve been using a lot more C++ than I had expected . . . not that there’s anything wrong with that.) And I realized that I actually need to build two applications: one part that sits on a “traditional computer” that can talk to CareLink and the other that visualizes the data on an iPhone, iPod, iPad.

Here’s a little example of the raw data that I will eventually use to generate graphs and an annotatable logbook:

3/30/11|16:20:00|GlucoseSensorData|AMOUNT=106, ISIG=10.2
3/30/11|16:25:00|GlucoseSensorData|AMOUNT=98, ISIG=9.71
3/30/11|16:30:00|GlucoseSensorData|AMOUNT=98, ISIG=10.59
3/30/11|16:35:00|GlucoseSensorData|AMOUNT=100, ISIG=10.66
3/30/11|16:40:00|GlucoseSensorData|AMOUNT=102, ISIG=10.94
3/30/11|16:45:00|GlucoseSensorData|AMOUNT=102, ISIG=10.6
3/30/11|16:50:00|GlucoseSensorData|AMOUNT=102, ISIG=10.56
. . .
3/30/11|18:14:01|BolusWizardBolusEstimate|BG_INPUT=195, BG_UNITS=mg dl,
  CARB_INPUT=0, CARB_UNITS=grams, CARB_RATIO=8, INSULIN_SENSITIVITY=50,
  BG_TARGET_LOW=110, BG_TARGET_HIGH=110, BOLUS_ESTIMATE=1.7,
  CORRECTION_ESTIMATE=1.7, FOOD_ESTIMATE=0, UNABSORBED_INSULIN_TOTAL=0,
  UNABSORBED_INSULIN_COUNT=2, ACTION_REQUESTOR=pump
3/30/11|18:14:01|BolusNormal|AMOUNT=1.7, CONCENTRATION=null,
  PROGRAMMED_AMOUNT=1.7
Posted in CGM, Data-betes, Diabetes, Fodder for Techno-weenies, Software Engineering | Leave a comment

What’s on My Pump’s Mind?

Posted on March 28, 2011 by Jeff Mather

Sorry for the geeky/nerdy digression, but I’m just so pleased that I’ve been able to start to parse through the data from my pump. It’s nice to make some progress.

According to the CSV file generated from my Medtronic CareLink data, this is what my Minimed Paradigm pump thinks about. The number is how many times the keyword appears in the log.

carelink_parser_2 - There are 14121 items in the array.
1 AlarmPump
154 AlarmSensor
99 BGReceived
393 BolusNormal
35 BolusSquare
391 BolusWizardBolusEstimate
315 CalBGForGH
502 CalBGForPH
4 ChangeBGTargetRange
4 ChangeBGTargetRangePattern
18 ChangeBatteryEnable
18 ChangeBatteryEnableGH
2 ChangeBolusWizardSetup
4 ChangeBolusWizardSetupConfig
12 ChangeCarbRatio
4 ChangeCarbRatioPattern
8 ChangeInsulinSensitivity
4 ChangeInsulinSensitivityPattern
1 ChangeMaxBolus
1 ChangeParadigmLinkID
35 ChangeSensorSetup
70 ChangeSensorSetupConfig
15 ChangeSuspendEnable
7 ChangeTempBasal
2 ChangeTempBasalPercent
1 ChangeTempBasalType
1 ClearAlarm
3 CurrentActiveBasalProfilePattern
3 CurrentAlarmClockEnable
3 CurrentAlarmNotifyMode
3 CurrentAudioBolusStep
3 CurrentAutoOffDuration
3 CurrentBGReminderEnable
3 CurrentBGTargetRange
3 CurrentBGTargetRangePattern
21 CurrentBasalProfile
9 CurrentBasalProfilePattern
3 CurrentBatteryStatus
3 CurrentBeepVolume
3 CurrentBolusReminderEnable
3 CurrentBolusWizardBGUnits
3 CurrentBolusWizardCarbUnits
3 CurrentBolusWizardEnable
3 CurrentBolusWizardSetupStatus
9 CurrentCarbRatio
3 CurrentCarbRatioPattern
3 CurrentChildBlockEnable
3 CurrentDisplayLanguage
3 CurrentErrorStatus
3 CurrentGlucoseHistoryPageNumber
3 CurrentHistoryPageNumber
3 CurrentInsulinActionCurve
6 CurrentInsulinSensitivity
3 CurrentInsulinSensitivityPattern
3 CurrentKeypadLockedEnable
3 CurrentMaxBasal
3 CurrentMaxBolus
3 CurrentParadigmLinkEnable
9 CurrentParadigmLinkID
3 CurrentPumpModelNumber
3 CurrentPumpStatus
3 CurrentRFEnable
9 CurrentRemoteControlID
3 CurrentReservoirWarningUnits
3 CurrentReservoirWarningValueInsulin
3 CurrentSensorAlarmSnoozeTime
3 CurrentSensorBGUnits
2 CurrentSensorCalFactor
3 CurrentSensorCalReminderEnable
3 CurrentSensorCalReminderTime
3 CurrentSensorEnable
3 CurrentSensorHighGlucoseAlarmEnable
3 CurrentSensorHighGlucoseLimit
3 CurrentSensorHighGlucoseSnoozeTime
3 CurrentSensorLowGlucoseAlarmEnable
3 CurrentSensorLowGlucoseLimit
3 CurrentSensorLowGlucoseSnoozeTime
3 CurrentSensorMissedDataTime
3 CurrentSensorTransmitterID
3 CurrentTempBasal
3 CurrentTempBasalType
3 CurrentTimeDisplayFormat
3 CurrentTotalRemaining
3 CurrentTotalToday
3 CurrentTotalYesterday
3 CurrentVariableBasalProfilePatternEnable
3 CurrentVariableBolusEnable
9427 GlucoseSensorData
3 GlucoseSensorDataHigh
2 JournalEntryPumpLowBattery
35 JournalEntryPumpLowReservoir
39 Prime
48 ResultDailyTotal
20 Rewind
2 SelfTest
57 SensorCal
200 SensorCalFactor
10 SensorError
130 SensorPacket
34 SensorStatus
26 SensorSync
60 SensorTimestamp
20 SensorWeakSignal
1669 UnabsorbedInsulin

As far as I can tell:

  • UnabsorbedInsulin is metadata that’s used to compute active insulin for the bolus wizard.
  • SensorPacket is data from the sensor during the warm-up period before it starts streaming GlucoseSensorData.
  • BGReceived is data that comes from a paired meter, which always updates the sensor calibration (for my pump) since they’re paired with CalBGForPH. (I guess that’s why you’re supposed to turn that feature off.)
  • I have no idea (yet) what the difference is between CalBGForPH and CalBGForGH.

Don’t worry. I’m not going to flood users with most of this data. I just needed to know what it is possible to show.

Posted in CGM, Data-betes, Diabetes | Leave a comment

Seriously Now. Let’s Start Coding.

Posted on March 2, 2011 by Jeff Mather

Okay, I’ve picked up a smattering of Objective-C, learned about a few of the frameworks, and sketched some of the interface. I’ve contemplated the data model, and I’ve worked out a few of the interactions.

Isn’t it about time to put aside my “iPhone developer impostor” feelings and just start coding? Yes it is. I’m not going to build this app unless I start writing it.

ABC: Always Be Coding.

Posted in Data-betes, Life Lessons, Software Engineering | Leave a comment

Ready to Start Coding

Posted on February 26, 2011 by Jeff Mather

It’s been a week since I announced that I was going to write an iPhone app. I’m still excited about it, even though someone told me that Medtronic is working on their own version of the same thing I proposed — a working prototype, she said. Well, I for one am glad that they seem some value in having a mobile app, but I plan to keep working on mine. Competition is good. We’ll see who can get their app out there first: the newbie picking up iPhone development skills or the large medical company who is going through FDA approval.

Since last Saturday I’ve learned a lot. I’ve picked up the syntax of Objective-C, which is causing this C++ programmer to “think differently.” I like what I’ve seen from it so far, but we’ll see what I think after building something real. I’ve made a couple “Hello, World!” applications, just enough to get a few basic skills using Xcode and Interface Builder.

Now the hard work begins.

I’ve made a list of requirements for the first couple of (internal) versions of the app; so I know what needs I plan to satisfy. I’ve picked an external library to plot the CGM data. And I’ve started working on the functional design, sketching a few different views that people will use to interact with their data. (I usually hate graphical user interface design, but something about the UIKit components seem to be amplifying my scanty abilities with interaction design.) I still have to figure out the data model — that is to say, the architecture — but I think that should follow from the views I create, which of course is supposed to visualize items in the pump/CGM data model.

Tomorrow I’ll try to put a few components together. Stay tuned!

Posted in CGM, Computing, Data-betes, Diabetes, Fodder for Techno-weenies, Software Engineering | 1 Comment

Helpful iOS Apps for Diabetes

Posted on February 23, 2011 by Jeff Mather

I’ve been thinking about iPod/iPhone/iPad apps for good reason lately. My research into how to write such an app of my own continues apace, and I’ve contemplating exactly what I can make it do.

I’ve also been thinking thinking about the apps I have now that I find useful for diabetes. To be perfectly honest, none of them are the typical journaling apps. I downloaded a few, used a couple, but stuck with none. Journaling just takes too much time and/or sustained attention. You either stick with it and get a lot of use out of it, or you have a life. I’m trying not to make that same mistake with my own app. Let the machines collect the data, I say. We’ll use our brains to make decisions based on their hard work. Thinking, that’s our proper role.

Anyway, what apps do I have on my iPod Touch (a.k.a., cheapo iPhone) that help me with my diabetes?

  • Tap & Track: Calorie Tracker ($3.99) — It has a ridiculous amount of foods in its onboard database, including loads of restaurants and name-brand packaged foods. No network connection required. Easily access things you eat regularly. Get details about your own recipes. A bargain at twice the price.
  • Twitter (Free) — Gotta keep in touch with my diabetes online community.
  • Things ($9.99) — This GTD app is a bit pricey, but it’s the best I’ve found. Among other things, I use it to keep track of my diabetes and health-related projects and tasks. I can set it to remind me to get my A1c drawn months in the future, when it’s actually relevant. It reminded me to “write that weblog entry about iPod apps” before DSMA. Oh, and since I made a recurring task to take my vitamins, I’ve gotten much better at doing that. I like checking things off a To-Do list. :^)
  • Due ($2.99) — I try to bolus for breakie 15 minutes before I eat. This little reminder app has reminded me more than once that it’s finally time to stop working and go eat that cereal.
  • Reeder ($2.99) — This RSS aggregator hooks up to Google Reader and helps me keep up to date with all y’all’s weblogs. (Thanks to Pearlsa for recommending this.)
  • iBooks (Free) — I keep my running plan that I built on a running web site in a PDF here, along with a few exercisey things that I scanned from magazines. (What I really want is a tear-sheet app, but until then . . .)

So what am I missing? What do you use? Please leave a comment!

Posted in Computing, Data-betes, Diabetes, Fodder for Techno-weenies, Health Care | 6 Comments

Total Diabetes Awareness, The App

Posted on February 19, 2011 by Jeff Mather

I am terrible with personal software projects. At work, I have no problem getting things started and finished. But elsewhere, I’m just a bit too distracted by everything else in my life to engage in some casual programming.

But this morning, as I was putting on my socks — and checking my diabetic feet, of course — I struck upon a project that I would gladly spend at least a few evenings and weekends to get working.

Throughout the day I’ve been talking myself into writing an iPhone app to display all of the data from my pump and continuous glucose monitor. I’ve already learned a great deal from my CGM, but what I need now is a memory device that collects all (or at least most) of my diabetes data in one place, so that I can use what’s worked in the past (as well as what didn’t work so well) in order to make better decisions.

The idea behind the as-yet-unwritten software is to transfer all of the data and events from my part of Medtronic’s CareLink website — it stores my CGM sensor values, blood glucose readings, insulin boluses, temporary basals, infusion set changes, etc. — and store them on my iPod, where I can review and plot them graphically. (And if it works on my iPod Touch, it would run on an iPhone or iPad, too.)

Why do I want to do this? There are many situations that happen regularly but not quite frequently enough for me to remember what happened. What happened the last time I had Thai food? How much insulin did I give? What did I estimate the carbs to be? And what about the last time I went for a long bike ride? What temporary basal did I use? I could write all this down, but (as I’ve recently discovered) there’s a great deal of value in seeing the CGM trace surrounding the event.

So my app will be fairly small to begin with:

  • Import data from a CSV file that I can download from the CareLink site.
  • Plot the CGM graphs and display the insulin, BG, and pump events.
  • Display details about these events. What did I enter into the pump’s bolus wizard? What did I end up doing?

That’s a first version. That will let me carry around a self-updating logbook. Journaling is something we hate to do, so why not just aggregate the data that I already produce minute by minutes?

One or two improvements would make this app truly useful. The pump and CGM have a lot of data, but they lack context. I need to be able to add a tag or two and some notes to the handful of events that I want to highlight. That’s the first step; the next is to be able to search for those events and then look at what happened.

Once I’ve got that app working, who knows what could happen?

Of course, why do I want to make this app, when I’m usually so reluctant to write software away from the office? Plainly put, I need this application to improve my self-management. Observations of daily living are among the most powerful components of managing a chronic illness, but they are a complete pain in the ass to record manually.

Clearly this is something that Medtronic should be doing. It would greatly simplify things if I could sync directly from my pump to my iPod, and I’ve already tried without success to get them to tell me the data protocol of my pump. It’s my data after all, but they won’t talk. (Hell, it would be much better if I could download directly from CareLink to my iPod rather than doing a kind of crazy two step of saving a .csv file and uploading it to my iPod.) Perhaps Medtronic already is working on such an application, but I can’t count on it. Seeing the results of my actions is so useful that I will take one for the team and start writing this application.

My ultimate goal is to share the app and the code with the world. I would like very much to make this an open source project . . . the first salvo in a “test strip rebellion” where we people with diabetes take back the data stored on our medical devices. If the medical device manufacturers won’t make these apps, we must. If the FDA is going to make it difficult for commercial ventures to produce innovative solutions, we patients will have to turn the tables; it’s true that we’ll have to accept the risk for what we do, but at least we will have what we need to improve our health.

Oh! And I will need your help. I’ve never written an iOS application. If you have some skills, I might want to ask you a couple of qustions. First up: I need recommendations for newbies making their first forays into iPhone app development.

Posted in CGM, Data-betes, Diabetes, Software Engineering | 2 Comments

Personalized Health Data (via CGM)

Posted on February 15, 2011 by Jeff Mather

I’m going to start right off by saying that I love my CGM.

Once I made a few calibratrion-related changes and after I decided that it was never going to give me very good information during the first half-hour (or more) of exercise, I’ve started to feel more comfortable with its accuracy.

But that’s small potatoes.

Much more important is that I’ve started to look beyond the actual numbers, as recommended in Beyond Fingersticks, to see meaning in the swoops, peaks, dips, plateaus, and flat lines in my CGM data plots. A rise with a plateau? Probably not enough bolus insulin. A slow, steady climb or fall? Probably an incorrect basal rate or the hangover from exercise (also a basal rate issue). A big spike that comes right back down — after a couple hours, that is? Maybe I should bolus earlier for food or add something to the meal to slow down the hit.

This knowledge is especially empowering. For the first time in a long while I have hope that I can improve how I manually do what my pancreas should be doing. I’m starting to draw better inferences about the relationship between the actions I take and the effects they have on my blood glucose. And because the CGM has low and high alarms that act as a safety net and early warning system, I feel more confident in giving some of the larger insulin boluses that I’ve been too chickenshit in the past to take. Back in the pre-CGM days, I didn’t have the level of trust in those recommendations that I really needed in order to “do the right thing.” Now . . . well, I’m getting there.

All this was already on my mind before I saw the TedMed talk by Wired‘s Thomas Goetz. It’s a must see for people trying to improve their own health behaviors or those in their patients. (It even singles out a very bad ad campaign by the American Diabetes Association. sigh)

Goetz’s argument that we need personalized data to improve health outcomes has three main parts. (1) When it comes to behavior modification, fear is less important to patients/people than a sense of our own efficacy. (2) There’s a powerful and positive feedback loop when we have an emotional connection to data that’s by and about us. And (3) most medical data isn’t presented in a way that helps us create those strong emotional bonds.

The feedback cycle starts with personalized data, which leads to a sense of personal relevance that informs which health options are best and helps us take action. When done right we should be able to see the results of those actions in a new batch of personalized medical information. For those times when we do create new health data, we should be asking ourselves these questions:

  • Can I have my results?
  • What does this mean?
  • What are my options?
  • What’s next? How do I integrate this information into the rest of my life?

This is the amazing power of CGM that I’m beginning to harness: I see the results of my eating, dosing, and exercise decisions in a tight loop. I’m still learning how to understand how these three factors (and others) appear visually on my little CGM screen, but the fact that I can see them in anything approaching realtime is just so powerful.

Goetz concludes by noting that “compliance is not the same as engagement,” which is having the opportunity to act as one’s own agent.

I feel like I have a whole new model for engagement with my diabetes.

Posted in CGM, Data-betes, Diabetes, Health Care, Life Lessons, Video | 4 Comments

Flying Below the Radar

Posted on January 17, 2011 by Jeff Mather

This morning before work* I put in my second “undocumented” continuous glucose monitor sensor. That’s the best way that I can think of to describe my use of the sensors that read my blood glucose levels, since I haven’t yet had training about how to do it. I used one last week for about five days, and I’m going to use this new one until Thursday. Then, on Friday, I’ll get my official training from Medtronic Minimed — along with my endocrinologist’s nurse educator.

Why am I using the CGM without training? First off, I was really anxious to use this gizmo that everyone has been talking up. And secondly, all of my online diabetes peeps told me it was no big deal to insert the sensor and use it.

And I’m really glad that I have used it, because now I have questions for the MM rep/nurse on Friday. If I had waited until Friday to start using it, I wouldn’t have had these questions in mind until well afterward.

I imagine our meeting going something like this: “Hey there, MM person. Nice to meet you. I’m Jeff. And I’m noncompliant. I’ve used a couple sensors already, so we can take for granted that I’m not squeamish about the big-ass insertion needle that’s part of the process, motor through the mechanics, and get down to the nitty gritty of how to get the most out of this thing.**”

All of my questions revolve around accuracy. So far I haven’t been exactly impressed with the numbers that I’ve seen appear on my pump. I want this thing to show me what’s happening to my blood glucose as I go through my normal day, giving me a chance to identify trends and then make changes. I hope that it will also alert me when I’ve gone into a high or low BG area where I should take some action.*** And believe me, I fully acknowledge that there are plenty of times when I’m going to need to make some changes and take some action.

Hopefully the MM instructor will be able to tell me what I need to do differently so that when my BG is 63, as it was the other day, it won’t read 135. Or so that it won’t say “199,” as it does right now, when my meter reports “120.” Perhaps she’ll be able to tell me what to do so that when the sensor reports a value in the high 80s, I’ll know whether to expect that it really means the low seventies. I want her to explain the average lag time between big changes in my BG and when those show up on the CGM. Maybe she will even be able to tell me what to do have more confidence in the CGM readings during exercise.

So far these have all been areas where I’ve been less than impressed with the CGM versus fingersticks. To be fair, from time to time the CGM and my meter have been exactly the same. And I shouldn’t complain too much yet, since I’m doing all of this “off the books.” But I need to know what to do — whether that’s changing how I calibrate or where I put the sensor or something else entirely — so that I get on with the intense business of improving my BG self-management, lowering my A1c, and feeling really confident that something extra is there to help catch me when I go low (or high) during exercise.

Onward to Friday . . . and legitimacy!


* — Yes, I have to work on MLK Day. No, I don’t think it’s right to work on the day dedicated to (arguably) the most important American of the 20th century. But I do like my job. That’s all that I’m going to say on that subject.

** — ”Oh, and do you have samples for the other kinds of tapes that I can use to attach this thing (and my pump’s infusion sets) more securely? I plan on wearing this thing all the time, and I don’t want to lose it while swimming or have it come unhinged during exercise. Thanks!”

*** — The CGM/pump did wake me up last week when I had dipped into the low 60s in the middle of the night. That was useful.

Posted in CGM, Data-betes, Diabetes, Life Lessons | 4 Comments

CGM in the House!

Posted on January 5, 2011 by Jeff Mather

After many, many months of wondering whether to get a continuous glucose monitor, I actually have one in my hands. Yes, my Minimed Real-Time Mini-Link transmitter and sensors arrived today. Soon I’ll be able to track an approximation of my current blood glucose (BG) more-or-less as it changes. I have high hopes along with some reservations.

On the awesome side: I’ll be able to see how my BG changes when I eat and when I don’t. After a couple weeks, I hope to notice some trends and make bolus ratio and basal rate changes that will get me closer to Awesometown. I will know more quickly when my BG is going high or low, so I can take care of it sooner — especially overnight or while driving. I also hope to find out what actually happens when I exercise so that I can get more out of my workouts. Basically, we’re talking about better readings and more peace of mind.

Given all the benefits of CGM — to paraphrase Gina when we had dinner in New York City last month — why didn’t I make this decision earlier?

Because it’s scary, that’s why. And kinda expensive. But mostly scary. First off, I had wicked buyers remorse after committing to the Minimed CGM. It has pros and cons — just like its rival Dexcom does — but a lot of people said they switched from Minimed to Dexcom. Nevertheless, I got this one because the objections that people gave didn’t match my experience with the blind sensor I wore last summer, and I didn’t really want to carry around another device. (We’ll see if I actually did make a mistake by not going with Dex.)

But the actual scary reason lies deeper. What if I wear this new sensor and I can’t get my three-month A1c lower? What if the high/low alarms are just a constant reminder of how much I suck at taking care of my own disease? What if having a constant flow of information makes me feel like I am defined or controlled by diabetes all the time? I guess we’ll just have to see and have some faith.

But for now, I’m just really excited. It’s like Christmas (again).

Posted in Data-betes, Diabetes | Leave a comment

30 Days of Posts (and iPod/iPhone Apps, too!)

Posted on November 30, 2010 by Jeff Mather

I just wasn’t feeling “National” Blog Post Month (NaBloPoMo) this year. Last November I think everything came together: I had just started setting free my thoughts about diabetes, and I was just getting back into the swing of writing here. This year it just felt like a bit of a chore.

It wasn’t an awful experience. It did help keep me posting photographs and whatnot, but it doesn’t seem that I set aside enough time to write some of the longer articles that I hoped to create. In fact, I often found myself remembering right at the end of the day that I needed to write something. Now that the month is over, I’ll keep going with the occasional posting — with more substantial content, I hope.

See you back here real soon.

. . . I guess there’s no time like the present to write a bit more and say that I got an iPod Touch for an early Christmas present. (Thanks, Mom and Miles!) I like it very much as a media device — navigating playlists and moving around the interface is just much more awesome than my old 6th generation “classic” iPod — and I’m starting to look around at some of the apps for it.

Let’s see here, there’s Twitter and Facebook and the New York Times reader and Netflix and Skype and the ESPN app which I’m sure will be useful once baseball season starts again. (It has rugby, but no Australian scores. Go Rabbitohs!) And I’ve just started looking for things that could help me out with diabetes and exercise.

Here’s where I need your advice.

What are your favorite iPhone / iPod Touch apps? What do you use to help you manage your diabetes? What should I download just for fun or because no properly decked out Apple gizmo is complete without it?

Posted in Computing, Data-betes, Diabetes, MetaBlogging, NaBloPoMo, NaBloPoMo 2010 | 2 Comments

Interpreting the CGM Data

Posted on November 6, 2010 by Jeff Mather

Quick Update: It’s day #6 in National Blog Post Month and the ninth in my exercise streak. At the pool this afternoon, I did three flip-turns; they weren’t pretty, but I did them.

It’s been a while since I talked about where I am with diabetes. I got the data from the CGM trial a while ago, and I spent some time marking up copies of the graphs that the Medtronic rep gave my endocrinologist. It was difficult to draw definitive conclusions from the data because it was full of variability. Hey, that’s diabetes! Nevertheless, here are some of my observations:

  • There is a rise many days, starting at 2-3 AM.
  • Almost every day has a “V” at 11:00AM – noon, a dip ending sharply at lunch.
  • The CGM readings were very spiky.
  • I see a rise after exercise.
  • I over-treated many times.
  • The CGM didn’t catch many big, rapid dips with rebounds (especially during exercise).
  • The first meal has a larger than normal (?) effect.
  • There’s a post-shower bump.
  • My corrective boluses didn’t really work.
  • Often my pump wizard said not to bolus because of insulin on board (IOB), but I really needed it.

The biggest thing I noticed is that my BG levels never really went into the normal range. They started high, went higher after I ate, and then came down to the low end of high. I had previously worried that I was going to have lows (probably because of my experience with NPH) but those worries were more or less unfounded.

Add to these conclusions one feeling I have that I cannot prove definitively. I suspect that my basal rates were too high, leading to an excess of active insulin that masked problems with bolus ratios and timing.

From these observations, I settled on a few actions:

  1. Don’t be such a ‘fraidy-cat about lows.
  2. Do an overnight basal test.
  3. Give a small bolus before disconnecting for my shower.
  4. Bolus 10-15 minutes before meals.
  5. Ask about IOB and “bolus stacking” (which I did).
  6. Get a prescription for CGM sensors.
  7. Only 4-8g for a defensive treat.
  8. Try to do less defensive treating.
  9. Bolus for everything I eat.

Some of these are easier to do, some harder. The overall realization that my blood glucose stays high and that it doesn’t take long for my BGs to rise after eating were very illuminating. It seems to me that my BG readings have been better since I started making these changes. I know that my fasting readings have been inside the target range more often than not. And exercise has been easier, too. And although I’ve been surprised by my A1c on many occasions, I hope to see some improvement because of these changes.

Posted in Data-betes, Diabetes, Life Lessons, NaBloPoMo, NaBloPoMo 2010 | 1 Comment

Catching Up with Mr. Mather

Posted on October 11, 2010 by Jeff Mather

Hey y’all. It’s Columbus day; and, yes, I am at work again.

I know it’s been a little quiet around here recently. There are a few reasons for that. (1) I’ve been really busy with swimming, bicycling, running, yard work, birthday celebrations, and visiting friends. (2) I’m doing something fun (to me) at the office, that’s taking a lot of my attention. (3) The camera club that I sometimes attend has restarted. It’s the same as it ever was. Evidently I am, too. (4) We went to Montréal this past weekend. (5) I’m trying to keep up more with my Twitter peeps. (6) I’m reading a lot, although I’m very slow at it. Most recently I’ve finished Ahmed Rashid’s Taliban, and I picked up The Discovery of Insulin by Michael Bliss just where I left it this spring, about a third of the way through. (More about each of those books later.) And (7) I have a boatload of things that I want to do.

Runners and dude roller-skiing in Mont-Royal park, Montreal

I’ve been having some interesting diabetes things going on. I finally finished annotating my CGMS data, matching the graph’s spikes and troughs with my food/exercise/insulin logbook. The data was all over the place — literally — but mostly high. I tried a few of the suggestions that my endocrinologist gave, with mixed results; but I have decided to focus on what I can observe myself and fix on my own: namely my basal rates. After making a couple small corrections and overnight tests, I’ve managed to wake up with almost exactly the same blood glucose readings as when I went to bed. And the last couple times that I’ve exercised in the afternoon have worked out very, very well. I’m steadily getting where I want to be.

Photo of a week's worth of CGM data

Of course, eating a multi-course meal at Le Keg on Saturday presented a new challenge: How exactly do you bolus for something that involves about 12oz of incredibly tasty New York strip sirloin — not to mention bread, a Caesar salad, pain au fromage, a (small) baked potato, veggies, and a chocolate brownie sundae? I did quite well for the first three hours after dinner — I had multiple readings in the 120s, which is almost perfect — but then I steadily climbed quite high over the next five hours. Somehow I need to figure out when I need to give extra insulin and then figure out how to give those additional 7.5 units* over the next four hours. It seems to me that I need extra practice!

Crêpe de framboises avec chocolat
Breakfast on the day after the feast

Until next time.


* — I learned while reading The Discovery of Insulin that a “unit” was the amount of insulin that would cause a healthy rabbit to go into hypoglycemic shock. Lisa and I have started talking about insulin in terms of “rabbits.”

Posted in Data-betes, Diabetes, General, Photography, Travel | 2 Comments

NPH Exorcism

Posted on September 23, 2010 by Jeff Mather

Editor’s Note: It’s Thursday, which means that something related to my CGM trial must have happened. That’s right, the CGM data from my endocrinologist’s office finally arrived. I’ve spent a little time looking over the graphs and charts and matching them up to my logbook. Let’s just say this: While my blood glucose did run high, I don’t think that’s related to food choices as much as other factors. I’ll write about that later, since I need to investigate more.

Welcome to my exorcism. I’ve already sprinkled some holy water Diet Coke around my laptop in preparation, so let’s get to it. Here’s our demon:

NPH insulin vial and packaging

It first got into my body eleven years ago, through one of the shaded areas shown below:

NPH injection sites

It would enter twice daily, at 7:00 AM and 9:00 PM. Here was how I was forced to summon it:

Preparing to draw-up NHP

The demon kept me in its power day and night, forcing me to eat six times daily whether I was hungry or not, causing me to stop eating after consuming exactly 15 or 60 grams of carbs depending on the meal, fogging my brain between 11:00AM and noon, and giving me high blood glucose readings the rest of the day. This demon starts out benign, gathers strength slowly, grows to full strength after 5-6 hours, and sticks around to toss my internal furniture about for another 12 hours.

Graph of insulin action times

NPH was the only insulin I was on at the time, and I hated it. Every day was the same, and every day sucked. When I think back on it, I’m amazed that my doctor never had me use Humalog with my meals and never swapped out this demon for a long-acting insulin like Lantus.

It messed me up right good, leading me to think that food is medicine and that the way to treat insulin issues was to eat. As my first diabetes experience — a very laissez faire one by my first endo, it seems to me — it also had me thinking that this might be what diabetes was supposed to be like, that it was the best I could expect.

Those thoughts are what we’re exorcising here today. In my mind, this is a crucial part of the reboot. And we’re going to do that with sunlight and the basics.

  1. Diabetes has very few absolute rules. Food makes blood glucose go up, but mostly just the carbs. Insulin makes blood glucose go down, provided you have enough of it. Activity brings blood glucose down, but often not if it’s anaerobic.
  2. Diabetes has many heuristics: insulin peak times, onset lag, and duration; glycemic index values; etc. . . . and Chinese food always needs more insulin than you think.
  3. Diabetes has a billion variables: other people’s food, the intensity of activity, insulin freshness, meter accuracy, stress, caffeine, temperature, weight, girly stuff. Even my pancreas’s beta cells, which continually regenerate just to be killed off again, are slightly more potent in their feebleness from one day to the next.

So while the biological rules are as close as we can get to absolutes in diabetes, the heuristics cover the basic things that we can almost convince ourselves are under our control. The variables, though . . . Oy! They make it impossible to predict anything 100%.

Not that I expect anything close to 100% predictability. I’m realistic, and I know the body has more subtlety than just food and insulin. There’s glucagon and amylin. In a healthy person, those hormones dump into the bloodstream quickly and are mutually self-correcting. This system is organic and continuous — unlike the discrete, large decisions we artificial pancreases have to make.

The reboot is all about learning more about my body’s variables and discovering my own heuristics, so that I can have confidence to follow the few absolute rules all of the time. But that demon NPH has had me thinking that 2 + 2 = 5.

So how do I exorcise NPH from my thinking? How do I get that little shoulder devil behind me? How do I banish the voices that say, “If you bolus for that snack, you’ll go low?” And, “Your numbers are great now, but shouldn’t you have a little snack anyway?”

I don’t know. Exorcising personal demons is hard, but naming them is a good start. And Lisa may have the best advice: “Snap out of It!”

Okay. Done! What’s next?

Posted in Data-betes, Diabetes, Life Lessons | 1 Comment