The complications of diabetes can dramatically impair quality of life and cause long-lasting disability. Overall, complications are far less common and less severe in people with well-controlled blood sugar levels.[3][4][5] Some non-modifiable risk factors such as age at diabetes onset, type of diabetes, gender, and genetics may influence risk. Other health problems compound the chronic complications of diabetes such as smoking, obesity, high blood pressure, elevated cholesterol levels, and lack of regular exercise. Complications of diabetes are a strong risk factor for severe COVID-19 illness.[6]
^"The effect of intensive diabetes therapy on the development and progression of neuropathy. The Diabetes Control and Complications Trial Research Group". Annals of Internal Medicine. 122 (8): 561–568. April 1995. doi:10.7326/0003-4819-122-8-199504150-00001. PMID7887548. S2CID24754081.