Severe hypoglycaemia is hampering the lives of many diabetic patients. The effect on the occurrence of severe hypoglycaemia during two different insulin regimens are to be investigated. In total, 250 hypoglycaemia prone type 1 diabetic patients will be randomised to receive analogue and human insulin for one year in random order. Outcomes will be number of episodes of severe hypoglycaemia

The primary objective is to evaluate the effects of insulin analogue and human insulin on incidence of severe hypoglycaemia in type 1 diabetic patients prone to hypoglycaemia.Secondary endpoints are effect on incidence of symptomatic and asymptomatic documented hypoglycaemia.

Study Design: An open, randomised, controlled, cross-over multi-centre study. Each treatment period lasts for one year. Patients will be randomised to treatment with basal bolus therapy with insulin detemir / aspart and insulatard / actrapid in random order. Endpoints will be assessed during the last 9 months of each treatment arm.

Patient population: 250 type 1 diabetic patients with a history of two or more episodes of severe hypoglycaemia during the preceding year.

Interventions: Basal bolus therapy with insulin detemir / aspart and insulatard / human actrapid in random order. Each treatment period lasts 12 months.

Methods: Patients will record all events of severe hypoglycaemia, documented symptomatic and asymptomatic hypoglycaemia in a diary and report all events of severe hypoglycaemia by telephone within 24 hours. All patients will be instructed to do and record home blood glucose monitoring (SMBG) i.e. 7 point profiles twice per week and nocturnal measurements once every month.

Outcomes: Severe hypoglycaemia, documented symptomatic and asymptomatic hypoglycaemia Efficacy: Number of reported episodes of severe, documented symptomatic and asymptomatic hypoglycaemia during the last 9 months of treatment - during daytime and night time.

Safety: Adverse reactions

Inclusion Criteria:

• Type 1 diabetes for 5 years.
• Age>18 years.
• Two or more episodes of hypoglycaemia during the last year,

Exclusion Criteria:

• History of Addisons disease
• Growth hormone deficiency or untreated myxoedema
• CVD within 6 months
• Cancer within 5 years
• Alcohol or drug abuse
• Pregnant or lactating women
• Fertile women without effective contraception
• Participation in another trial within 30 days
• Inability to understand the informed consent