METODICHE DI VALUTAZIONE DELLA RIGIDITA’ ARTERIOSA: IMPLICAZIONI CLINICHE NEL SOGGETTO ANZIANO

The compliance of the arteries declines with age. Different measures of arterial stiffness are available even in the elderly, such as pulse pressure, pulse wave velocity (PWV), augmentation index (AI), QKD and systemic arterial compliance (SAC). Increased arterial stiffness, assessed by carotid-femoral Pulse Wave Velocity, is an independent Cardiovascular Diseases risk factor and it has been recognized as an index of subclinical atherosclerosis. Each component of the metabolic syndrome (MS), such as abdominal fat, dyslipidemia, high blood pressure and hyperglycemia, are independent CV risk factors. It has been shown that body fat distribution, in terms of central adiposity, plays a key role in the development of CV diseases and mortality, even in the elderly. On the other hand it has been demonstrated the protective role of peripheral adipose tissue on the CV risk. However only a few studies evaluated the relationships between body fat distribution and arterial stiffness in the elderly. Moreover just a few studies compared different classifications of MS in terms of suclinical vascular damage’s prediction. Therefore the first outcome of this study was to assess the relationships between body composition, metabolic syndrome (MS), its components and arterial stiffness in elderly healthy subjects of both sexes. As IDF and NCEP definition consider different waist circumference cut-off to identify abdominal obesity, the second aim of the present study was to evaluate which of waist circumference cut-off considered in IDF and NCEP MS definition was more accurate to identify subclinical vascular damage. In a subgroup of elderly women we wanted to evaluate the possible protective effect of peripheral adipose tissue on suclinical vascular damage. Finally another aim of this study was to compare in a subgroup of 52 elderly subjects two different measures of arterial stiffness such as QKD and PWV in the assessment of the subclinical vascular damage. In each subject we evaluated body mass index, waist circumference, systolic and diastolic blood pressure, metabolic variables, body composition by Dual energy X-ray Absorptiometry and arterial stiffness by carotid-femoral (PWVcf) and carotid-radial pulse wave velocity (PWVcr). PWVcf but not PWVcr was significantly higher in patients with MS than in those without MetS, independently of its definition (IDF or NCEP). By using more conservative values of waist cut-off, as suggested by IDF, it was possible to recognize higher percentage of subjects with subclinical vascular damage (PWV higher than 12 m/sec) than by using those suggested by NCEP. In a subgroup of women we found negative association between peripheral FM and PWVcf, showing a possibile protective role of the peripheral adopose tissue on suclinical vascular damage. Finally, comparing two different measures of arterial stiffness in a subgroup of our elderly subjects, we showed that both PWVcf and QKD 100-60 are good indexes of arterial compliance related to CV risk factors, eventhough they explore different arterial segments and should be probably used togheter to better identify subjects at higher subclinical CV risk.