Pulse wave velocity and augmentation index, but notintima-media thickness, are early indicators ofvascular damage in hypercholesterolemic children

BACKGROUND: Arterial stiffness is an important determinant of cardiovascular risk. It is associated with several cardiovascular risk factors, including hypertension, diabetes and cigarette smoking. However, there are conflicting data about the relationship between arterial stiffness and hypercholesterolemia. Furthermore, augmentation index (AIx), a measure of systemic arterial stiffness, has not been previously investigated in hypercholesterolemic (HCh) children. Aim of our study was to evaluate local and systemic arterial stiffness as well as carotid intima-media thickness (IMT) in HCh children and also to investigate the relation between serum cholesterol levels and arterial stiffness. MATERIALS AND METHODS: We determined lipid profile, body mass index, blood pressure, heart rate, carotid IMT and several arterial stiffness parameters, as beta-index, elastic modulus (E(p)), arterial compliance (AC), pulse wave velocity (PWV) and AIx, in 44 untreated HCh children (mean age 10.7 +/- 2.8 years; 18 with familial hypercholesterolemia, FH, and 26 with primary hypercholesterolemia, PHC) and 18 age- and sex-matched controls. HCh children never received any medication, including antihypertensive and lipid lowering drugs. RESULTS: Respect to controls and to PHC, FH had significantly higher (P < 0.001) beta-index (5.22 +/- 1.13 vs. 3.13 +/- 0.74 and 3.60 +/- 1.02), PWV (4.72 +/- 0.72 m s(-1) vs. 3.66 +/- 0.55 m s(-1) and 4.10 +/- 0.67 m s(-1)), AIx (3.55 +/- 3.97% vs. -4.43 +/- 4.09% and 0.61 +/- 2.39%) and E(p) (64.4 +/- 19.6 kPa vs. 36.2 +/- 11.3 kPa and 42.9 +/- 13.1), whereas AC (1.25 +/- 0.48 mm(2) kPa(-1) vs. 1.9 +/- 0.43 mm(2) kPa(-1) and 1.62 +/- 0.43 mm(2) kPa(-1)) was lower (P < 0.001). There was no significant difference in carotid IMT and blood pressure values between the groups. The multiple regression analysis showed a significant association of arterial stiffness values with plasma cholesterol levels (P < 0.0001). CONCLUSION: Our findings show that local and systemic arterial stiffness are increased in asymptomatic, normotensive HCh children, suggesting that HCh plays a key role in arterial mechanical impairment since the paediatric age.