The purpose of this study is to evaluate the effects of the add-on of extra vergin olive oil or butter to a high glycemic index meal on endothelial function in subjects with type 1 Diabetes and healthy subjects.

Impaired endothelial function is an early manifestation of atherosclerosis and predictor of incident cardiovascular events. Diabetes affects arterial vasodilation by reducing the bioavailability of NO and more in general affecting the balance between the atheroprotective and atherothrombotic properties of the endothelium. A consistent number of studies has so far documented that Mediterranean-style diet associates with reduced risk of cardiovascular diseases and diabetes. Intake of extra virgin olive oil (EVOO), that is a common but not necessary ingredient of the Mediterranean diet, seems to further enhance the beneficial cardiovascular effect and reduce the incidence of diabetes. We have designed the present study to test whether EVOO supplementation acutely influences endothelial function in T1DM. EVOO supplementation wil be compared to butter supplementation in the context of a high glycemic index (GI) meal that is known to increase PP glycemic burden.

Inclusion Criteria:

• age ≥ 18 years,
• diagnosis of type 1 diabetes since at least 1 year,
• HbA1c <8.5% (69 mmol/mol),
• stable insulin therapy for at least 3 months before the enrolment into the study

Exclusion Criteria:

• pregnancy, celiac disease, history of cardiovascular diseases, hypertension, hyperlipidemia, retinopathy, nephropathy, neuropathy, and ongoing treatment with vasoactive drugs.