Opinions, please on overnight basals

I have a MM pump and CGM. I went back to the CGM recently after a major low.

I began having (over the last week) lows every night around 2:00am, and then again around 7:00 am. The CGM would alert me, I would treat with 6-8 ounces of apple juice at 2:00. Same at 7:00. The CGM readings were 50-60, as my pump is set to alert me to a low at 60. When I tested at 8 am, I was in the 90-100 range regularly.

Yesterday, I changed my overnight basal from .3 to .275, from midnight to 7:00 am. Between 2:30 am and 7:30 am my CGM readings went from 104 to 182 with a meter reading at 7:30 of 199. That is only an insulin reduction of .175 units over a 7 hour time period.

1. I cannot believe that lowering the basal by .175u could make that much difference and 2. I cannot make any intermediate dosage changes from .3 to .275.

I know I will be asked. I had a normal, low fat, low carb meal at 5:30 and tested at 71 when I went to bed at 10. I did drink about 4 ounces of apple juice, as I hate to go to bed when trending down.

I am flummoxed. Opinions, please!?! Thanks.

Sounds like some variable dawn phenomena might be at play? I have found that one tick on my basals can affect my BG from 20-40 points. Your one tick is more signifigant than that, but I can easily believe it.

I would target the areas that you are having trouble and leave the other areas alone. I have about 15 different basal rates on my pump and if I start bottoming out at a certain time I will make an adjustment to help compensate.

If you are going hypo at 2 and 7 am, then I would look at adjusting your basals at midnight and 5 am down one tick. This is assuming that your insulin peaks in activity at 2 hours. I would lower the basals one tick from midnight to 1 am and from 5 am to 6 am. Then re-assess after 2-3 days so that you have a little bit of data to use, unless it is very obvious that you need further adjustments.

Did your CGM report normal BGs between 10 p.m. bedtime and midnight? Was your CGM tracking your fingerstick BGs well? A hypo between 10 p.m. and midnight could have led to a liver dump that drove up your overnight BGs.

Other than that, I would encourage you to maintain your new overnight basal rates and see what happens over the next few nights. Sometimes it takes a day or two for the change to normalize. Changing basals based on one episode, I have found, is not a good idea.

For your overall safety, you might want to set an alarm to wake you to test. At least then, if you are ranging high, you can take corrective doses. If you do take a correction, say at midnight, I would set another alarm for 2-2:30 a.m. to check.

Your situation does seem mysterious. I encourage you to gather more data before making any other changes. A CGM that is tracking well is a great tool for this. Good luck!

Don't jump the gun on one night of data :D

I'm still getting my settings in order after a month on the pump and 2 months on the CGM. I try not to treat when I'm trending down unless I'm at an unsafe number. Like 50 and trending down = eat now. 80 and trending down is a wait and see. Though I usually shoot for @110 pre bed time.

Give it a few more nights and see how it works out. I was similar where I would wake up at 3am nightly with hypo's and I ended up adding a high protein snack an hour before bedtime to help out with it.

I agree with everyone not to make another change based on one night's data. If it continues, though I would do exactly what Capn suggests: break it down into smaller "time zones" and target those low spots, rather than increase it over the whole period. I'm always surprised what a small amount of basal change can do.

Yes. Readings from dinner time to bedtime were steady between 70 and 100, and the 10 pm to 2am were all in that CGM. I calibrated at 5:30, checked the comparison of a finger stick about 8 and then calibrated at 71 at bedtime.

OK. I will try it at the lower rate tonight and tomorrow and see what happens. Thanks

I break my 24 hours into 8 times slices of 3 hours each. My basal rate maxes at 3am-6am and then goes down at each of the 7 times slices following. So my 12am-3am slot has the lowest basal rate. This is possibly THE best feature of the pump. You can nuke the dawn phenomenon without risking a bad low at 2 am.

I can't think of a better way of starting a roller-coaster than having to over-treat a nocturnal low.

My highest is from 7 am to 12 pm at .7. My total basal per day is 9.95 units.

I am also getting ready for a five day road trip. My son is moving to Colorado and I am riding out with him. Now that I think about it, this is a pretty stressful time, as I saw my grandbabies for the last time before they move 1700 miles away last night. Did not consider stress as a factor. Should have. MAN, THERE ARE TOO MANY VARIABLES IN THIS (INSERT EXPLETIVE) DISEASE! It is hard to think of everything.

I just want to seem as normal as possible (and stay safe) on this trip.

Quick note about Basel changes. It will take ~48-72 hrs for a Basel adjustment to stabilize. Also, a lowered Basel from 12-3am may impact Basel and active insulin from ~12-9 am. This is dependent on how long your insulin remains active. For example, my temp Basel adjustments impact my I:C ratio for ~6 hours. So, if I use a lower temp Basel, I will add extra insulin to meal dosage to occomodate the reduced active Basel insulin for that time slot.

If you set different Basel dosages for <4-6 hrs, you may find that you are masking the incorrect Basel settings an may never find the appropriate Basel for that block of time…

Thanks! I understand the effects and timing of making basal changes. I only use 4 basal rates over 24 hours: 12am-7am, 7am to 12pm, 12pm to 6pm and 6pm to 12am. All four of them are within .025 of each other, except the morning rate, which is about .3 units higher. My activity time for insulin is pretty consistent at 4 hours.

I am on the 3rd 24 hours of the lower rates, but still had higher readings (with CGM and meter)this morning and overnight that I like. We will see what happens tonight.

It takes some tweaking for sure. I run different patterns depending on my daily physical activity and the shape I’m in. Now I’m less active and not working out regularly so I am using .525 from 12am to 5am, and .925 the rest of the day. I sit at a keyboard most of the day. On weekends I use lower temp Basels. When I am in shape I use .5 from 11 - 5am, .75 from 5-10am and .7 the rest of the day. I worked these numbers out by doing 5-10 hour Basel test, with no food and normal activity and work schedule. It takes up to a week or two to get it adjusted sometimes.

I would definitely suggest breaking those time periods down a bit so that you target only the problem times when you go low and avoid becoming high.

This was the post I was looking for today. I have the same problems. A small tick in basal change makes more of a change than I think. And I agree that you need to wait 2 days at least to make sure the change is stable. Often I get too excited and change it again after 24 hours. I need to tell myself to be more patient.

Sometimes the problem isn't with the amount of the change, but the time zone. Many people just have two time zones - day and night, so a small change makes a big difference. It helps to break it down to smaller time frames.

Smaller time frames also means that your changes in basal rate are less abrupt. I find this makes control one hell of a lot easier to achieve. You are more likely to correctly match your basal requirements. Those basal rate graphs in "Think like a pancreas" are quite convoluted.

Re the timeframe issue, I use 12:00 midnight to 2:00 AM, 2:00AM to 5:00AM and 5:00 AM to 6:30. I've been cutting them back lately, a couple tries, and it's working ok. I do .85 @ 12, .875@ 2, .975 @ 5 and then go back to .85 at 6:30. Whether the basal is up or down, it seems like I get the big bump from 2-7AM. I like the idea of confirming your observations but I don't like waking up at 180 I might try the different timeframes.

Note that too short of basal rate periods my create the illusion of one basal rate really having a dosage that is different than what the pump is dosing. I.e., as acidrock23 described his dose rate, the actual from 2-5 may the rate set for 2-5 is ± the difference in the dose rate from 12-2 because the insulin is still active for up to 6 hour. This needs to be taken into account when setting up your basal rates. Take your time and check bgs w/0 meals for >4 hours. I use 8 hour minimum to make sure the only active insulin is the current basal dose rate. However, if the setting for acidrock23 works, it’s the right setting.