Hi. By the time diabetes has been diagnosed there has typically been abnormal blood sugars for a long time (months to years).
High sugar has lots of detrimental effects on health, including on blood flow and healing.
Incidence / risk of cancer is higher, and there may be more risk of infection.
In case you have diabetes, your best bet is to do all you can to normalize sugar levels using diet (low carb) and exercise, and medications.