"Rate of change" alerts vs low alerts for catching lows? What's your method?

I’m wondering whether the rate of change alert can catch lows better than the low alert?

If you are dropping which alert usually triggers first? Do you prefer the 3 or 2 mg/dl per min alert? I have never used the PLUS and I can only guess I would set it for 3 mg/dl per min and the low alert at 90. Opinions, anyone?

Is the rate of change alert useful overall? Is the 2 mg/dl per min alert too intrusive because it triggers whenever insulin peaks after a meal?

Any comments appreciated!

I haven’t found it particularly useful to use the rate of change alerts. I can jump pretty quickly either direction, but not necessarily be heading high OR low. I found it annoying because occasionally I get a “jumpy” sensor and it felt like it was constantly alarming… so I disabled that.

Using the low alarm at a higher threshold (like 80) might be helpful for “predicting” lows, but I found that I would get a lot of false alerts (meaning dex thinks I’m <80, but I’m really in the mid to upper 80’s or even low 90’s) because I don’t like to “hang out” with higher #'s, so I usually leave my low alarm at 60 or 70. Usually when my dex alarms at 60 with a true low, I’m already 50ish, which is okay with me… my aim is to use dex to prevent the severe lows in the 30’s… if I can treat in the 50’s I am still head of the game, even if my endo freaks out a bit by the number of “hypos” I have.

I wish there were more sophisticated ways to set the alarms… like “alert me of a 3mg/dl per min change if I am <100” for example, because that might actually be helpful, where as dropped at 3mg/dl per minute from 140 to 120 isn’t, but as of right now, it obviously can’t do that.

I have both the rise & fall set at 2 mg. I have gastroparesis and it is usually several hours after I eat that my BS starts going up - I like to get as much notice as possible when it does because the sooner I can get insulin working, the better. I also have had problems with passing out from lows so I like to get as much notice as possible when it is going down also. One way to know for sure if you find it obtrusive or not is to try it and see how if it drives you nuts or not!

I have my low alarm set at 70. I usually try to keep my BS in the 70s or 80s so really don’t want my alarm higher than 70.

Thanks, it makes sense to me that you don’t use the rate of change alert. Your idea to improve it is great and requires only a change in software. It would make the rate of change and low alerts work together to better avoid lows. Does the PLUS system have a similar 20-30 point lag like the SEVEN when dropping fast? If so, I’d have to set the low alert at 90 to be sure to avoid feeling the low and just accept that false alerts will happen.

Hmm…maybe I would use the rate of change alert. I also have delayed digestion with similar effect of gastroparesis (I split my meal doses into two shots one hour apart). Seems like your low alert at 70 won’t save you from feeling the misery!

Anyone know what is a typical rise in bg after eating? If you dose correctly will the rise still hit 2 mg/dl per min?

I was doing 2-3 shots per meal when I was on MDI. Now I am doing 2-3 button hits with the pump. It is the fast drops that cause a problem for me so being alerted to the rapid falls do help.

Yes, essentially it’s the same… the main difference I could tell between the two systems is that the plus has a few more options on the receiver (events, plus the different time views - the original seven only had one hour, 3 hours, and 9 hours I think), but I’m pretty sure the algorithms they use are very similar.

The alarms on the original seven were a bit louder too.

I have my low alarm set at 70 and the fall rate at 2 mg/minute. That works pretty well for me in that it catches lows in the 50’s or sometimes 60’s and I don’t get the nuisance alarms when bg is steady.

My high alarm settings vary widely from day to day depending on circumstances.


I do allow my alarms to be VERY intrusive, because I need to know. So my preference might not be a good guide…

But when I’m heading into trouble, the ‘rate’ alarm nearly ALWAYS goes off first. I use 2mg/dL per minute in both directions, low of 80 mg/dL, and high of 140 mg/dL. And yes, it screams at least 20 times every day, usually with “rate of change” alarms.

You might not like all of that buzzing and screaming, and extra re-charging.

I’ve always assumed I could jettison the 2 bolus regimen if on pump–it is not just the shots that are tiresome but also having to constantly set alarms and take the shots no matter what I’m doing. I thought a single combo bolus might replace my usual 2 shots per meal. If you don’t mind the question, have you tried that or does it not work for you? Or maybe a Normal bolus followed by an Extended bolus?

Rick, does it work to snooze the rate of change alert when in normal range and once the 30 minute snooze is over, the alert can trigger again when you might actually be in low territory?

Thank you all.

I only tried the extended bolus once so I didn’t actually give it a fair shot. My fear with doing that is even though I follow a gastroparesis diet, it is a crap shot when my meals will digest. Since I try to run my BS on the low side, I am afraid I will end up crashing if I have insulin trickling in without food digesting. I eat the same things pretty much every day. Some days after lunch, my BS starts going up about 2 and other days it might be 4 or 5. Today, I ran low all afternoon. One nice thing about the Dex is that it lets me know when my food starts to digest so that is a big help. I just started the pump at the end of June so I am still kind of playing with that stuff. If yours is more just delayed digestion than full-blown gastroparesis, the extended bolus would most likely work for you.

The rate of change alert & the low alert are two separate alarms so as long as one or both are in need of alarming, they will both keep alerting you.

I have kind of a funny story about Dex alarms. Lately I’ve had a little bit of time available to read so have been reading either murder mysteries or science fiction. The other night I had these weird dreams which were a conglomeration of various sci-fi things and somebody trying to murder me. I kept being saved though because the villain kept getting interrupted because he had to run off and shut off a snooze alarm. I finally woke up enough to realize my Dex had been beeping.


Yes, in my case the delayed digestion is consistent. I see that for you CGM is absolutely worth the effort. Thanks.