This trial is conducted in Europe. The aim of this trial is to investigate the safety, tolerability, pharmacokinetics (the exposure of the trial drug in the body) and pharmacodynamics (the effect of the investigated drug on the body) of insulin degludec (insulin 454), an explorative formulation, not similar to the proposed commerical formulation.

Inclusion Criteria:

• HEALTHY SUBJECTS:
• Subjects will be healthy male subjects, who are considered to be generally healthy based on an assessment of medical history, physical examination and clinical laboratory data, as judged by the Investigator
• Body mass index (BMI) between 18.0-27.0 kg/m^2 (both inclusive)
• SUBJECTS WITH TYPE 1 AND TYPE 2 DIABETES:
• Subjects will be male volunteers, who are considered to be generally healthy, except for the underlying diabetes mellitus, based on an assessment of medical history, physical examination and clinical laboratory data, as judged by the Investigator
• Diagnosed with type 1 diabetes mellitus and treated with insulin for at least 12 months or diagnosed with type 2 diabetes mellitus for at least 12 months
• Body Mass Index (BMI) between 18.0-27.0 kg/m^2 (both inclusive) for subjects with type 1 diabetes or 25.0-35.0 kg/m^2 (both inclusive) for subjects with type 2 diabetes
• Glycogylated haemoglobin (HbA1c) maximum 8.5 % based on central laboratory results
• Subjects with type 2 diabetes must have been treated with insulin for the past 3 months prior to screening

Exclusion Criteria:

• Participation in any other trials involving investigational products within 3 months preceding the start of dosing
• History of significant multiple drug allergies or with a known allergy to the trial product or any medicine chemically related to the trial product, as judged by the investigator
• Hepatitis or carrier of the Hepatitis B surface antigen (HBsAg) or Hepatitis C antibodies or a positive result to the test for human immunodeficiency (HIV) antibodies
• Any clinically significant abnormal haematology or biochemistry screening tests, as judged by the investigator
• Subjects who have donated any blood or plasma in the past month or in excess of 1000 ml within the 12 weeks preceding screening