This study aims at investigating the effect of hyperglycaemia on physical performance and local energy stores in the muscle in patients with type 1 diabetes mellitus under exercise conditions.

Inclusion Criteria:

• Male
• Aged from 20 to 40 years
• Patients with type 1 diabetes mellitus lasting for at least 5 years (C-Peptide ≤ 0.3 nmol/l in the presence of a plasma glucose level ≥ 7 mmol/L, indicating insulin dependence)
• Insulin delivery by CSII (continuous subcutaneous insulin infusion) for at least 6 months
• Acceptable to good metabolic control, reflected by an HbA1c 5-8%
• Normal insulin sensitivity, reflected by a daily insulin requirement of 0.3-1.0 U/kg body weight
• minimum 30' of moderate exercise 3 times per week
• BMI in the range of 18-25 kg/m2

Exclusion Criteria:

• Chronic complications of diabetes:

  • Microalbuminuria (Mogensen nephropathy stadium ≥ III)
  • Sensory neuropathy (vibration better than 5/8 at the metatarsophalangeal articulation of digitus I)
  • Proliferating retinopathy
  • No history of macro-vascular complications
  • Clinically relevant autonomous neuropathy

• Smoking

• Abnormal thyroid function

• Major depression, psychosis and other severe personality disorders, claustrophobia

• Active neoplasia

• Contraindications to exposure to a 1.5 T magnetic field (pace-makers, osteosynthetic material, etc.)

• Abnormal liver or renal function (creatinine > 130 µmol/L; ASAT and ALAT > 3 times the upper reference limit)

• Excessive alcohol consumption (>60g/d) or drug-abuse

• Refusal to give written informed consent

• Participation in another study

• Patients, who are not suitable for the study according to the study physician