CoQ10 supplements may improve heart health and blood sugar and help manage high cholesterol and high blood pressure in individuals with diabetes. High blood pressure, high cholesterol, and heart disease are all common problems associated with diabetes. Despite some concern that CoQ10 may cause a sudden and dramatic drop in blood sugar (called hypoglycemia), two recent clinical studies of people with diabetes given CoQ10, 200 mg 2 times daily, showed no hypoglycemic response. If you have diabetes, talk to your doctor or registered dietitian before using CoQ10.