Medtronic makes a distinction between a “square wave” bolus, which does what you describe, and a “dual wave,” which waits until a specified time and then delivers. I think its primary purpose is for high-fat meals, where you can get a delayed BG rise.
ON edit: turns out this is not correct–see comments below.
My dawn phenomenon starts between 3 and 4 AM, and if I don’t arise, bolus, and eat my BG will increase 40-45 points by about 10:30 or 11:00 whether I sleep that late or get up and just dink around without bolusing and eating.
Like many septuagenarians, I typically have to get up at least once during the night. If it is after midnight, I can eat a piece of cheese while I’m up without bolus, and that seems to trick my liver enough that the later increase in BG will be only about half of what it would have been without the snack. Eating too early doesn’t seem to help me, but my bedtime tends to be earlier.
Since your son is 18, it isn’t likely he gets up for a bladder call in the night like the elderly, but I suspect there at least some nights he doesn’t even get to bed by midnight. He might try a low-carb snack before bed and see if that helps.
Actually the Medtronic pump does it the same as Animas. You deliver a pre-determined amount of your bolus immediately. The rest of the bolus is delivered as a Square Wave over the period specificied by you. It does not wait until the end time to deliver the remaining amount which is what you are implying. Maybe we saying the same thing and just expressing it differently. But having used both pumps, the Medtronic and Animas deliver these boluses the same. With Medtronic it is called a dual wave. With Animas it is called a combo bolus.
DEVICE: MiniMed® 530G (551/751), Revel (523/723), 522/722, 515/715, 512/712
[MiniMed 530G User Guide Page 79-81; Revel User Guide page 81-83; X22 User Guide page 93-95; X15 User Guide page 88 ; X12 User Guide page 67-68]
Did You Know: Dual Wave bolus delivers a combination of an immediate Normal bolus followed by a Square Wave bolus. The Square Wave portion is delayed evenly over a period of time. A Dual Wave bolus is useful for meals with both rapidly and slowly absorbed carbohydrates.
For me my DP starts once I get up. For years I used to just give a small bolus upon my feet hitting the ground and that worked OK, but it did seem like I was always chasing my BG rise rather than controlling it. Recently I switched things up and did a pretty aggresive Basal rate change (50% increase) about 1.5 hours prior to getting up. I now skip the bolus upon getting up and things seems to run smoother in the mornings. Net effect same amount of insulin just changing the timing of when it is delivered. So far I am happy with the results.
I always thought a square wave was just delivering the entire bolus over X number of hours, while a dual wave was delivering X amount up front and X amount over a certain number of hours (which the Ping just calls a Combo Bolus, though I’m pretty sure the Cozmo had two menu options for these). If what you’re saying is the case, then the Medtronic pump has something that I don’t think any other pump has.
Huh–as it was explained to me when I got the thing it seemed more distinct from a square wave than that, but I take the point. At any rate it’s easier to guesstimate than setting a temp basal, which is kind of another variant on the same thing, or adjusting my basal settings, which I do sometimes, but most times the amount I want to dial in is variable enough that it’s easier to do it this way.
There is no pump that is capable of delivering a standard bolus delayed by X number of hours (this would be a hugely unsafe feature). @DrBB, may I suggest you edit that particular post, not to confuse people who may read just the post and skip the replies.
Depends on what you mean by “there is no pump that is capable of delivering a delayed bolus”… My daughter uses the OmniPod system and she uses a dual wave bolus when she eats pizza, Chinese, and a few other “difficult” foods. You are correct about pumps not “delivering a delayed bolus” if what you mean is that you cannot program a zero percent up front bolus with 100% of the bolus delivered either gradually over an extended period of time or all at once some time later. You can, however, program a bolus so that it delivers a certain percentage up front, with the remainder delivered over an extended period of time. For example, for pizza I program my daughter’s pump to deliver 1.5 times the amount of carbs contained in however many slices of pizza she is going to eat with 75% to 85% delivered up front and the remaining 15% to 25% extended over the next 4 hours. In this case, the pump actually does deliver a percentage of the total bolus in a delayed fashion.
My Ping can do the first scenario mentioned (deliver 0% up front with the entire bolus spread out over X number of hours). What no pump can do is deliver an entire bolus delayed by X number of hours.
My dawn phenomenon starts when I wake up. There seems to be a surge of activity that happens in my system, and my glucose starts creeping up. I’ve got a consistent trend line on my CGM daily. Most days I catch it, but I’ve been in the bad habit lately of jumping into work as soon as I wake up. A few times I’ve completely forgotten to check and take a correction until I get an alarm from my CGM that my glucose level is getting too high.
If it’s happening that way for you, even though it’s irritating, it’s pretty easy to manage: wake up, test your glucose level, and take a correction.
And note, I’m currently on an indefinite pump break, so I’m on MDI right now too.
After I started using a CGM I noticed that much of the BG rise I had attributed to uncountered Dawn Phenomenon was actually being caused by the fact that I was taking my pump off to get in the shower in the morning. My basal rate was accurately set to dose for DP but it was sitting on a counter while I showered, right at the time I needed that bump in insulin. My super simple solution has been to take a 1 unit bolus before getting in the shower. This has worked great.
I noticed again recently (trying to really watch what I eat) that when I am really careful about low carbing and thus keeping my BG really well in control, my morning BG is much lower. This makes me wonder if the high morning values that I had attributed to Dawn Phenomenon are really that, or delayed bg rise that occurs at night because of what i ate during the day… Can’t explain it but its all good.
I tried several basal insulins as they kept improving through the years, but they did not help my DP, even in split doses. Going on a pump did, and solved other issues too. It is simply the gold standard for managing BG becaise of the flexibility it gives.
T1D, I use old fashioned NPH for the dawn phenomenon. And why is it a phenomenon that your body releases sugar/energy in the waking hours? That always got me.
10-15 units of NPH (Over the counter at Walmart) before bed for 20 years. A1C 5.8