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.