Overnight Basal Rate Testing

I'm ignoring that outlier (281 mg/dl) - see how it doesn't fit?

Numbers and Lines

I had a hunch that I could use some fine-tuning.  But overnight fasting basal rate testing sucks, so I kept putting it off.  My doc finally convinced me to bite the bullet, and I’m actually very glad I did.

The idea behind basal rate testing is to eliminate as many variables as possible, so that any changes you see in your blood sugar are most likely from your basal rate.

Wait – am I getting ahead of things here?  Do you guys know what “basal” is?

You need insulin all the time.  I mean ALL the time.  Even when you’re not eating, you need a bit of insulin in you.  In a person without diabetes, the pancreas has a way of knowing exactly how much is needed for each minute of the day.  In my case, I need to figure out how much my pump should deliver on an hourly basis.  That hourly insulin is called my “basal” insulin.

In theory, if your basal insulin is set right, you should be able to fast indefinitely and your blood sugar should stay relatively stable (without extra influences like exercise or illness).

In order to test your basal rate, the idea, again, is to eliminate as many variables as possible.  The typical variables include food and bolus insulin (boluses are what you take for highs or when you eat).  There are a million other variables involved, but we’re only worried about the ones we can influence.  Get rid of as many of them as possible, and any changes you see in blood sugar are most likely from that basal insulin.

I woke during the night to test every two hours.  There’s nothing nice about doing that.  And every single time my phone alarm buzzed me, my wife popped upright and asked “what was that?!”  Poor thing is so accustomed to listening to any sort of pump or CGM alert coming from my side of the bed…

So we both had a less-than-great night of sleep, and I felt bad about how it disturbed her.  I thought about the torture that is overnight basal rate testing and how it affected more than just me.  It’s not fair that it should mess up her sleep too.

But look what I found!  Nearly 100 point rise between midnight and 8:00 AM!  I had a hunch, but holy smokes!  To be fair, this was only ONE night of information, and there were a couple things that might have skewed the results.  The only real way to know if it’s a fluke, or reliable data would be to do another overnight test.  Which I will, soon…  but not too soon.

I will probably make some adjustments based on this information, even though it may not be exact (what in diabetes is ever exact?), then recover a while before repeating the test.

Basal rate testing is a pain, but once you get your basal rates really dialed in, rumor has it that things with blood sugar management get a lot better.

Wise words from my friend Dan (who impressively maintains a 5.x A1C by the way…):

If you can own the night, you can also own a majority of the day AND the weekend! Keep at it! It sucks, but it will help!

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19 thoughts on “Overnight Basal Rate Testing

  1. Glad you didnt see any darn spiders to mess it all up 🙂 I haven’t basal tested in 4-ev-er! Might as well now when Im up with the kiddo almost every two hours some nights anyway right? I think my basal result will be my next blog post…wish me no spiders or spikes!

  2. thanks for this thread, and the conversation about it. Keeping a consistent blood sugar through the night is important as one sleeps 6-10 hours a night and this is a substantial amount of time to be in your goal BS range to keep a1c down. Not ingesting carbs and covering with insulin at night while sleeping is a great motivator to fine tune basal rates to keep a level BS as there is less variables than wake hours with meals, bolusing and activity. Using a CGM provides me BS information all night and alarms alert me if I go above or below my set thresholds. I find my CMG to be accurate and provide information which allows me to fine tune basal rates. Thanks for the information as just going to bed and waking up in your goal range does not necessarily mean one is in that range all night. I would like to talk with pump users more about different basal rates at different times of the day for comparison. As I use about 6 different basal rates through the day and night to keep BS level; ranging from 0.7u/hr to 1.15 u/hr. It seems strange our bodies need for basal insulin levels could be so variable at different times of the day.

  3. Hi Scott

    Thanks for the post. As you know my Lantus basal amount has caused me A1c issues in the past, and I now think that I am in a much better place with my current higher Lantus dosage. However, I am basing that view purely on my improved morning blood sugar levels. It would probably be valuable for me to do the overnight basal rate testing to confirm.

    Thanks for the heads up

  4. Scott, Thanks for the post. I got an education from your basal insulin description that beats anything I’ve read elsewhere. Describing the ordeal of collecting measurements every two hours made me think of the latest gadgets that Amy Tenderich (DiabetesMine) reviewed from the CES conference on health tech. One that caught my attention was the Ford Motors partnership with Medtronic to link the Guardian RT CGM to sync with Bluetooth so you could read your levels from the dashboard. In addition, they have another prototype of a heart rate monitor that reads data from the car seat (electrodes are built into the seat). Anyway, those devices got me thinking that there ought to be a sleeping mat that can continuously read glucose data so that you don’t have to keep getting up during the night. Scott, you ought to approach a company like West Wireless or Medtronic to build something like that. You need your sleep!

  5. But if you basal test sleeping on the couch, I think you will always have to sleep on the couch. That just might be a variable that would affect your glucose levels. 😛

  6. Basal testing blows but I love all the info! J is always like holy smokes. When he sees the dex in the morning.

    We need a basal testing party we can alternate Bg checks!

  7. GOOD FOR YOU for doing the dreaded overnight basal testing!
    It’s can be such torture to do it – But we always find something interesting when we finally do it!!!

  8. Totally right, Scott. Not a fan of basal testing here, and I’ve been putting it off myself. Almost use the CGM as an excuse to NOT do it. Glad you got some good info to move forward on, my friend!

  9. I love your description of the overnight test, and your honesty about resisting doing the test, and what the test is actually like. Dan’s quote is priceless!

  10. I am so very proud of you for overnight basal testing. What your friend says is true! It’s hard stuff, this every 2 hours, but it gives such good info. Glad you did it, my friend!

  11. I agree with your friend Dan. That is the one time I can manage to have steady BS without the roller coasters. I can’t believe you didn’t sleep on the couch though! Your wife deserves some flowers or dinner out for that one.

  12. I feel your pain. I did an overnight basal test when I got the pump 2 weeks ago and now I new to do another tonight. Fun fun!