Comparing Pharmacodynamic and Pharmacokinetic Properties of Insulin Degludec and Insulin Glargine 300 U/mL at Steady-state Conditions in Subjects With Type 1 Diabetes Mellitus

Inclusion Criteria: * Male or female aged 18-64 years (both inclusive) at the time of signing informed consent * Subjects diagnosed (clinically) with type 1 diabetes mellitus at least 365 days prior to the day of screening * Body mass index 18.5-29.0 kg/m\^2 (both inclusive) Exclusion Criteria: * Subject who has donated any blood or plasma in the past month or more than 500 mL within 3 months prior to screening * Smoker (defined as a subject who is smoking more than 5 cigarettes or the equivalent per day)who is not able or willing to refrain from smoking or use of nicotine gum or transdermal nicotine patches during the in-patient period