Conditions: Vascular Stiffness Insulin Sensitivity
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 15
Healthy volunteers: yes

Brief summary:
The investigators are studying the effects of Hyperglycemia on vascular function and insulin sensitivity on healthy adults

Detailed description:
The investigators will study 22 healthy subjects (18-35 yrs) four times as follows:

1. Saline + Octreotide + euglycemia;
2. Octreotide + hyperglycemia;
3. Octreotide + hyperglycemia + insulin clamp and
4. Octreotide + Euglycemia + insulin clamp.

The sequence of admissions will be assigned randomly. The investigators will assess function in conduit (pulse wave velocity-PWV, augmentation index-AI and flow-mediated dilation-FMD), resistance (post-ischemic flow velocity-PIFV) and heart and skeletal muscle microvascular (contrast enhanced ultrasound-CEU) vessels.

This work will:

a) identify whether vascular stiffness and indices of NO action are impaired throughout the arterial tree with hyperglycemia.

Arms:
arm 1: octreotide is 30 ng/kg/min x 240 min insulin 0.15mU/kg/min x 240 min Dextrose 20% at variable rate to maintain euglycemia for 240 min arm 2: octreotide is 30 ng/kg/min x 330 min insulin 0.15mU/kg/min x 210 min insulin 1.0mU/kg/min x 120 min Dextrose 20% at variable rate to maintain euglycemia for 330 min arm 3: octreotide is 30 ng/kg/min x 330 min insulin 0.15mU/kg/min x 330 min Dextrose 20% at variable rate to maintain euglycemia for 90 min Dextrose 20% at variable rate to maintain hyperglycemia for 240 min arm 4: octreotide is 30 ng/kg/min x 330 min insulin 0.15mU/kg/min x 210 min insulin 1.0mU/kg/min x 120 min Dextrose 20% at variable rate to maintain euglycemia for 90 min Dextrose 20% at variable rate to maintain hyperglycemia for 240 min

Interventions: intervention 1: Octreotide intervention 2: Insulin intervention 3: Dextrose 20% solution
Intervention descriptions: intervention 1: we are using it to block insulin secretion from the pancreas intervention 2: we are using to replace basal insulin and in two protocols to raise insulin concentrations during the insulin clamp intervention 3: We are using dextrose to maintain glycemia level

Protocol document:
Prot_SAP_000.pdf: