The study will include approximately 200 patients, male and female, with DM1 who are being followed in the outpatient diabetic clinic of our hospital.~Each patient will visit the Research Laboratory of the Diabetes Centre of our Department. The visit will take place in the morning in a fasting state of about 12 hours. Demographic data will be recorded along with the patients' habits, lifestyle, current medication and complete medical history of concomitant diseases.~This will be followed by anthropometric measurements (weight, height, BMI) and afterwards blood samples will be taken for the determination of urea, creatinine, glucose, HbA1c and lipids. Part of each blood sample will be collected in tubes containing EDTA to determine fasting c-peptide concentrations. The presence of microalbuminuria will be assessed from a morning urine sample by calculating urinary albumin to creatinine ratio (ACR).~The functionality of the heart's autonomic nervous system will be assessed through the use of heart rate variability (HRV) measurements, using the standard Ewing's tests panel: deep inhalation, standing up and Valsalva's manoeuvre. Changes in blood pressure when changing from the supine to the standing position will also be recorded. Subsequently, the distensibility of the large vessels will be determined, by calculating the conduction velocity of the pulse wave between the carotid and the femoral artery (pulse wave velocity (PWV)).~Finally, a full transthoracic echocardiographic study will be carried out to assess functionality, systolic and diastolic, of the left ventricle (LV).~All data will be recorded in an electronic database for statistical processing.
The purpose of this study is to investigate the presence of residual insulin secretion in patients with DM1 and its correlation with the possible protection against early microvascular and macrovascular complications, emphasizing on the functionality of the myocardium.