I think that depends on your socioeconomic class and your insurance in the US. I'd say for the median citizen, life expectancy in Cuba with diabetes is probably higher as insulin cost isn't an issue and they do very frequent health check-ins that would be prohibitively expensive for a lot of Americans.
But seeing how you post on HN, chances are you have better healthcare available to you than the median American...
Then again, it seems like Cuba has some pretty cool homegrown diabetes treatments available: https://www.sfchronicle.com/opinion/article/Let-s-open-the-d...
> Who can I trust for relevant statistics and information?
That's a good question and I don't have a good answer. Consensus internationally seems to be that the Cuban healthcare system is legit, but I must admit i haven't dug all that deep.