People with type 1 can and do successfully use ketogenic diet with metabolic ketosis.
I do typically eat very low carb diet - though i am not this week because i am in Germany for work and there seem not to be low carb options available. The breakfast buffet at my hotel has nothing green, though plenty of white (bread!, and Beer halls seem to be a national pastime here - and, i have never been known to abstain when a pint was offered.
Back to topic. I don’t test for ketones. As far as i know there is no test kit available for urine ketones where i live. There is 1 available for blood ketones but too expensive to consider. So ketones are only tested through lab urinalysis.
From my understanding, for dka to occur one needs a number of things to happen all at once: 1. Lack of insulin (this also may occur during illness, when insulin requirement goes up) + dehydration + resulting metabolic disarray which then compounds the situation. High ketones are seen, but these are the result of rather than the cause if the problem. If one can ensure adequate insulin and hydration then all can be ok. If one is sick one must be extra careful. Presence of ketones alone is not an alarm.
It does concern me that this drug can mask inadequate insulin. This would probably be more likely if one was running sugars high (the insert paper talked about studies where patients had a1c of 7.5 or higher to join - so these people were running sugars in the 180s+ - as per ada targets). For further study. I think the biggest risk may be in people wrongly diagnosed as type 2, and having inadequate insulin present.
I personally suspect that running a very right blood sugar in the 70 - 90 range, where relative sugar loss is less (insulin is definitely needed) may lessen the risk.
I am 5 days in on jardiance. After the first 24 - 36 hours with no insulin and low sugars and feeling yucky, i am back taking my regular basal insulin (18 -20 units/day) and sugars are slightly lower (particularly seems to help with darn phenomenon and blunting post eating numbers. Bolus is less but I’m still having to cover Germany carbs - travel also shakes things up.