This trial is conducted in Europe. The aim of this trial is to compare the pharmacodynamics (the effect of the investigated drug on the body) and pharmacokinetics (the exposure of the trial drug in the body) of insulin degludec (insulin 454), an explorative formulation, not similar to the proposed commercial formulation, with insulin glargine in subjects with type 1 and type 2 diabetes.

Inclusion Criteria:

• Glycosylated haemoglobin (HbA1c) below or equal to 10 procent based on central laboratory results
• Specific inclusion criteria for subject with type 1 diabetes:
• Diagnosed with type 1 diabetes mellitus and treated with insulin for at least 12 months prior to screening
• Body Mass Index (BMI) between 18.0 and 27.0 kg/m^2 (both inclusive)
• Specific inclusion criteria for subject with type 2 diabetes:
• Diagnosed with type 2 diabetes mellitus for at least 12 months prior to screening
• Treated with insulin for the past 3 months prior to screening
• Body Mass Index (BMI) between 22.0 and 35.0 kg/ m^2 (both inclusive)

Exclusion Criteria:

• Subject with a history of significant multiple drug allergies or with a known allergy or suspected allergy to the trial product or any medicine chemically related to the trial product,as judged by the Investigator.
• Subject with a history of or presence of cancer
• Any condition that the Investigator and/or Sponsor feels would interfere with study
• Specific exclusion criteria for subject with type 2 diabetes:
• Therapy with oral antidiabetic drugs within the past 3 months prior to screening