2 months on Loop today. Initial review is as follows (this may change down the line). I’m sure you all will provide feedback if your assessments differ:
I recently did some fine tuning on baseline insulin delivery rates and and started running the system in open loop. I’m not seeing a ton of difference in basal system behavior. During some time periods, open loop behavior looks better than closed loop, absent any influence of exercise variables. Its not a medically significant difference.
For sure, system controls are better than pre-loop. This is mostly due to insulin delivery at mealtime. That is MUCH more effective. System variability has decreased significantly because of this.
A1c, was identical to pre-loop (I’ve only been running loop for 2 months, so this is only 2/3 Loop data, and 1/3 non-loop data). a1c = 6.1. So, the average stayed the same, but system variability definitely decreased. That’s real clear.
The main benefit from system automation is that it adjusts the basals when there are impending lows and when basal dosages drift over time. But, it seems more significant that insulin delivery surrounding meal times is producing much, much better results. I don’t think I can really attribute the majority of my improvement to ‘system automation.’ Although, it does soften the lows, which is invaluable when its needed.
One thing that got me is that as the basals drifted over the past 2 months (I gained 10 lbs), I didn’t notice because the system was overcoming it. So, when I opened up the loop, things were more out of whack than I expected. Not terrible. But, its good to periodically run open loop, just to prepare for a Loop failure due to lack of sensor supplies or something.
My BT communications are pretty unreliable with the G6, compared with the G4, so that has been the most common point of failure. There are concerns about the newest iPhone update. I have not updated. They are still working on it. If you are considering starting on Loop, you might wait for the all clear that its worked out.