Can someone summarize current pump/Dexcom advice?


I mentioned elsewhere that my family has used their deductible for the year for the first time ever. I have an appointment with an endo in a month (my last endo retired and I’ve been going without for the last few years). My previous endo was my primary care also, and really wasn’t involved in my diabetes management, other than writing prescriptions. (He never looked at my meter results for example). A nice guy, but whatever I learned about diabetes I learned on my own or from books (and more recently from the internet, thank you!)

This time I’ll be going to Joslin, with a newly minted endo, so I suspect he will have much more advice for management, and will probably promote a CGM and or pump. I’ve had T1 for 43 years and have considered a pump/CGM many times in the past, but decided to wait until there was a decent Open-loop APS before pulling the trigger. I like the freedom and simplicity of injections and BG tests without requiring attached technology. But it sounds like the Tandem/Dexcom or OpenAPS/Dexcom solutions may be worth pulling the trigger for. From what I’ve read the Dexcom and Tandem are a good match with current technology. In the future I may decide to go with OpenAPS using an old Minimed pump. I will be paying 10% of whatever I get this year, so doing it now makes sense if it can be done.

I apologize in advance for asking here what I could probably find by reading a bunch of posts. But because the tech is always changing, and new versions coming out, I hope its OK if I ask here for the latest summary.

First question - would the cannula, etc. from a Tandem be usable with an old Minimed pump?

Second - has anyone compared the Tandem/Dexcom to OpenAPS and have any advice? I write software for a living and got OpenAPS running on a Pi as an experiment a couple years ago, and think it is even easier now, so I am not intimidated by the technology.

Third - I think I read that the Tandem/Dexcom combination requires the G6? I’ve seen some complaints about the G6 - is there any reason to consider getting a G5 instead?

Fourth - is either the Tandem/Dexcom or OpenAPS usable without being constantly connected to Xdrip or whatever? I don’t like the idea of being wifi connected all the time.

Fifth - is it even realistic to think I could get all this in place before the end of the year? I would plan to contact the pump and CGM companies to start the ball rolling so the paperwork would be ready when I see the endo, assuming that is feasible.

Anything I’ve completely missed?


@Thomas probably has the latest on this one. Tandem made recent (about 1 year?) changes. I think they might have gone to proprietary tech only?

As of today, Tandem is only implementing predictive suspend, which, to me, is already a pretty big deal. On the other hand, both OpenAPS and Loop have both ends of the business (hypo/hyperglycemia) covered. However, Tandem is announcing an aggressive deployment schedule for their closed loop plans: I think @bkh published their last quarterly briefing with an updated schedule. They have held their development and deployment timelines lately, so there is a fair chance they will hold to schedule—although their deployment schedule is FDA dependent…

Their latest solution does. I figure that G6 supply issues will be ironed out in a couple of months.

Neither of them requires to be wifi connected for BG control. But, to be able to access and manipulate the data, that is another thing.

It probably depends upon your endo clinic, your pump/CGHM reps, and your insurance. I think it is quite aggressive, but not impossible if you are lucky in all 4 dimensions. But if you hit a glitch anywhere you won’t make it.

One thing you might need to look into: your endo clinic may require that you take pump and CGM classes before signing off on your prescription. These classes can take quite a while to schedule. For us, they took a whole summer.


The current infusion sets from Tandem have a proprietary connector at the end of the tube.

But if you happen to have a supply of minimed/paradigm tubes that mate with the tandem infusion set, you could throw away the tandem tube and use your own minimed tube. The tube can be reused multiple times, but the infusion set must be moved every 3rd day or so to minimize the risk of developing “scar tissue” that will impair future absorption of insulin. (Actually, the 3-day interval is just one that is “generally safe”. I’ve read that some folks start to have set failures within the first 24 hours, whereas others can go 7 days on a site without issues, but if you ruin your interstitial tissue by not changing the site frequently enough, there’s no way back to healthy sub-q tissue.)

My general impression from reading the internet (so it must be true) is that overall the G6 is well received and considered an improvement over the G5. Highlights are better first day accuracy and easier insertion. There have been some adhesion issues with the G6; at the recent Dexcom quarterly conference they stated that they are testing a better adhesive and expect to be shipping the improved version relatively soon. I think the G6 sensor may be a bit more difficult to restart, but it can be done if you think it will last more than 10 days for you.

Tandem/Dexcom does not require an internet connection to work. It is local bluetooth radio between pump and transmitter. The same is true of LOOP on an iPhone with a dexcom sensor and compatible medtronic pump. Likely this is also true for openAPS.

It’s plausible. The companies are motivated to complete sales during this year. I suggest you call Tandem and say you want the t:slim X2 / G6 with Basal-IQ but only if they can complete it under this year’s insurance. Explain the date that you will first see the new endo — but first you may wish to consider whether you have an internist/GP/family doctor who would write a prescription and statement of medical necessity now, so that you don’t have to wait for the new endo. If you show up to the new endo already wearing a pump and CGM they won’t turn you away.