Red Blood Cells as a Reflection of Endothelial Function in Old Age

Groups 1-3: Inclusion Criteria: * healthy subjects * informed consent Exclusion Criteria: * hypertension (blood pressure ≥140/90 mmHg), * hypercholesterolemia (LDL ≥250 mg/dl, HDL ≤45 mg/dl), * diabetes mellitus (fasting plasma glucose ≥128 mg/dl) * acute inflammation (CRP \>0.5 mg/dl) * malignant diseases * heart failure (NYHA III-IV) * arrhythmia of high degree * acute or terminated kidney disease * cardiovascular diseases ( cardiac artery disease, peripheral vascular disease and cerebrovascular diseases) * anemia * pregnancy Group 4 : Inclusion Criteria: * angiographical signs of apparent atherosclerosis (cardiac artery disease or peripheral vascular disease or degenerative valvular heart disease) * informed consent Exclusion Criteria: * Hypertension (blood pressure ≥140/90 mmHg), * Hypercholesterolemia (LDL ≥250 mg/dl, HDL ≤45 mg/dl), * Diabetes mellitus (fasting plasma glucose ≥128 mg/dl) * acute inflammation (CRP \>0.5 mg/dl) * malignant diseases * heart failure (NYHA III-IV) * arrhythmia of high degree * acute or terminated kidney disease * cardiovascular diseases ( cardiac artery disease, peripheral vascular disease and cerebrovascular diseases) * anemia * pregnancy