Fine Tuning the Pump - slight lows

From about 2:00 to 5:00, my blood sugar slowly drifts down and gets to 65 by 5:00. Though coincidence, I'm not eating any carbs today so I thought today would be a great day to get a rough idea how my basal rate is doing. If my basal still does this today, which would you do:

1. Lower my basal rate for right before I go low, so around 4:30?


2. Lower my basal rate for three or four hours before I go low, so, like, now.

No rights or wrongs, just wondering WWYD :)

John Walsh says to alter basal for the period two hours before the "problem". That's what I do and it seems to correlate. But if your blood sugar starts the drift down at 2:00, you might want to alter the basal rate for around 12 to stop that drift. (Depending of course on how big a drift it is, if you are starting at a high number, of course you wouldn't want to do that).

Ultimately you just want to try things out and see what the results are.

You must fast, no food if you are going to check basal rates, just eliminating carbs is not enough.

I don’t think you have to fast. If you chane a basal rate and get results, you should be able to use them…

WIWD is lower the basal rate a couple of hours before the down drift but not by much. I don't make changes unless a pattern is on my day is not a pattern.

This is an every day habit, I just couldn't tell if it was the leftovers from the I:C at lunch or not. Since I didn't use I:C, it's more likely than not the basal. :)

Awesome! Thank you! I'll start by lowing it two hours before I go low and wiggle it from there. :)

I have recently been needing to adjust my own basal rates. My bolus is also reduced all of the sudden...I call this the pattern of spring :)

I agree you can change your basal anytime and see what happens, but loading up on fat and protein and saying your doing a basal test, just because your not eating carbs probably does not equal very useful basal test...JMHO

But I would also tend to agree that someone who is using a CGMS does not really need to fast, because we have enough SG data to determine if our basal is high or low at just about anytime of the day or night.

Are you using CGM? If so it's really easy to skip lunch, spot the exact time at which it starts to drift down, and back off the basal slightly from a point 2 hours earlier. I find that really small changes in basal rates (0.05 or even 0.025) can have quite significant effects. It you are just relying on fingersticks, it's a bit harder to be so precise, but it is do-able.

I have found that correcting change basal needs with a CGM to be 'approaching' easy. Check the activity profile of your insulin and review how long it is active in your system. Most users say that humalog (the insulin I use) last for 4 hours and peaks in 2 hours. check out the first post by Tim on this page:

Since my humalog peaks in 2 hours, I always go back 2 hours before the problem time. If I noted that my BG was dropping below my target range at 2PM, then I would adjust my noon basal rate down and monitor. Notes: a small basal change can have bigger changes then you expect. I recomend changing the minimum and reviewing your results. I like to wait 3 days before further changes as, I am sure you know, every day has its own variablility.

It is great that you are trying to figure this out as I hope every insulin user reaches this point. We simply can't wait for the next 3 month appointment or for the CDE to get back to us. Please be aware that you are aiming at an invisible, moving target called T1D. Your rates can and will change in ways that do not make sense and are unexpected- there are just to many factors to consider (weight loss/gain, carb intake, fat/protein intake, exercise, stress, digestion, etc.) Do not beat yourself up if you adjust inaccurately or not enough. Keep working at it. I often find it is like the children's game whack-a-mole - you correct your post-breakfast BGs and then your nighttime BGs are out of whack for unknown reasons. Most importantly, keep an open mind and be ready to adjust your basals/boluses logically and reasonably.

Yeah, this is all data from a cgm. It was always so frustrating when I got to that point of the day, and know... well, in 2 hours I'm gonna have a low!

Thank you!! :)

I've been doing much better since I've been able to adjust myself without waiting on the CDEs. :)