The Role of Endogenous Lactate in Brain Preservation and Counterregulatory Defenses Against Hypoglycemia

Inclusion criteria

for healthy subjects

• Age: 18-40 years
• Body-Mass Index: 18-30 kg/m2
• Blood pressure: <160/90 mmHg
• Recreationally active: i.e. taking part in competitive sport or regular exercise training, of a non-professional nature, once or more a week.

Inclusion criteria

T1DM patients with normal hypoglycemic awareness

• Diabetes duration ≥ 1 year
• Age: 18-40 years
• Body-Mass Index: 18-30 kg/m2
• HbA1c: 42-75 mmol/mol (6-9%)
• Outcome Clarke questionnaire: 0-1
• Blood pressure: <160/90 mmHg
• Recreationally active: i.e. taking part in competitive sport or regular exercise training, of a non-professional nature, once or more a week

Inclusion criteria

T1DM patients with hypoglycemia unawareness

• Diabetes duration ≥ 1 year
• Age: 18-40 years
• Body-Mass Index: 18-30 kg/m2
• HbA1c: 42-75 mmol/mol (6-9%)
• Outcome Clarke questionnaire: =>3
• Blood pressure: <160/90 mmHg
• Recreationally active

Exclusion criteria

• Inability to provide informed consent
• Presence of any medical condition that might interfere with the study protocol, such as brain injuries, epilepsy, a major cardiovascular disease event or anxiety disorders
• Use of any medication, except for oral contraceptives
• MR(I) contraindications (pregnancy, severe claustrophobia, metal parts in body)
• Orthopedic and/or neurological diseases that impair exercise
• Cardiopulmonary disease as stated in the 2001 American heart association and 2002 American college of cardiology/American heart association guidelines

Additional exclusion criteria for all T1DM patients:

• Use of any other medication than insulin, except for oral contraceptives or stable thyroxine supplementation therapy
• complications of T1DM, including proliferative retinopathy, neuropathy or nephropathy