Study design and intervention: A controlled, cross-over multi-centre study in a Prospective, Randomised, Open, Blinded Endpoint (PROBE) design. Each treatment period last for 12 months. Patients will be randomised to treatment with basal-bolus therapy with insulin aspart/degludec or insulin aspart/glargine in random order. Endpoints will be assessed during the last 9 months of each treatment arm.