A Trial Investigating the Pharmacokinetic and Pharmacodynamic Properties of FIAsp in Geriatric and Younger Adult Subjects With Type 1 Diabetes

Inclusion Criteria: * Male or female aged 18-35 years (both inclusive) (younger adult group) or below or equal to 65 years (geriatric group) at the time of signing informed consent * Type 1 diabetes mellitus (as diagnosed clinically) for at least 12 months * Body mass index (BMI) 18.5-28.0 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 at least one cigarette, cigar or pipe daily) * Not able or willing to refrain from smoking and use of nicotine substitute products during the inpatient period