The study seeks to use microdialysis and microperfusion techniques to assess the feasibility of combining insulin delivery and glucose sensing at a single subcutaneous tissue site.

Current treatment of in type 1 diabetes comprises the measurement of glucose in capillary blood obtained by fingersticking and administration of exogenous insulin in the form of a subcutaneous bolus injection or subcutaneous infusion. This treatment could be simplified if there were a stable ratio between blood glucose concentration and tissue glucose level at the site of insulin delivery so that tissue glucose levels could be used to estimate blood glucose levels, thereby circumventing the need for fingerstick blood glucose monitoring.

The aim of this study is to ascertain whether a stable ratio between the blood glucose concentration and the glucose levels at the tissue site of insulin infusion exists when this tissue site is exposed to variable insulin infusion rates. To achieve this, microdialysis and microperfusion probes are applied in healthy and type 1 diabetic subjects to perform insulin delivery and glucose sampling at the same adipose tissue site during euglycemic clamps and oral glucose tolerance tests.

Inclusion Criteria:

• Type 1 diabetes mellitus patients aged 18 - 65
• Healthy subjects aged 18 - 65
• Informed consent obtained before any trial-related activities.

Diabetic subjects:

• C-peptide negative (≤ 0.05 nmol/L)
• HbA1c (glycosylated haemoglobin A1c) < 10%

Exclusion Criteria:

• Severe diabetic complications (e.g., proliferative retinopathy, severe nephropathy)
• Female of childbearing potential who is pregnant, breast-feeding or intends to become pregnant or is not using adequate contraceptive methods
• Subject with mental incapacity or language barriers