The CDC study does have methodological problems, but there's also been prior research that suggests similar effects (in more severely ill patients), as well as observing destruction of insulin-creating pancreas cells by COVID19. Here's a meta-analysis of 8 studies on the topic, with similar conclusions, done across China, Italy, and the U.S.:

https://dom-pubs.onlinelibrary.wiley.com/doi/10.1111/dom.142...