This trial is conducted in Europe. The aim of this trial is to investigate the impact of low blood sugar during the night on sleep in subjects with type 2 diabetes.

Inclusion Criteria:

• Type 2 diabetes mellitus (diagnosed clinically) for at least 24 weeks prior to screening
• Currently treated with any anti-diabetic treatment (incl. diet and exercise) except insulin with a stable dose for more than 4 weeks prior to screening
• Body mass index below 35 kg/m^2

Exclusion Criteria:

• Severe hypoglycaemic event during the past 6 months or hospitalisation for diabetic ketoacidosis during the previous 6 months
• Any other chronic disorder or severe disease by clinical information (including chronic obstructive pulmonary disease (COPD), sleep apnoea and epilepsy) which, in the opinion of the investigator might jeopardise subject's sleep, safety or compliance with the protocol, or subjects with mental incapacity or language barriers precluding adequate understanding or co-operation or who, in the opinion of the investigator, should not participate in the trial
• Use of antidepressants, antipsychotics, hypnotics, sedatives or other drugs known to influence sleep within 12 weeks prior to screening