Great rundown at https://siderea.dreamwidth.org/1617381.html
Summary: plenty of evidence that COVID-19 is causing blood clots in younger people, which leads to noticeable increases in strokes and cardiac arrests, which may not be counted in the official statistics as of now.
https://www.nejm.org/doi/full/10.1056/NEJMc2009787?query=RP is one of the primary sources.
I like the theory that this coronavirus is a blood disease that just mostly seems to hit the lungs because it causes respiratory symptoms.
Diabetes and metabolic syndrome and heart disease seem like the most significant risk factors for serious covid19 cases. I haven't noticed the weight of patients being noted in any of the primary sources on this, but I strongly suspect that most are obese or at least overweight.