I believe there is a large study that goes through most of the American data and it concludes that diabetes is not a predictor of bad outcomes when it comes to Covid. If you control for age and especially weight, you will see diabetes is not a factor. I think the three factors with the highest predictive correlation are Age, Weight and Vitamin D. Some think Vitamin D is also associated with the other two.
People with low vitamin k do worse if they get the wuhan coronavirus.