Augmentation index and carotid intima-media thickness are differently related to age, C-reactive protein and oxidized low-density lipoprotein

Objective Ageing, plasma circulating C-reactive protein (CRP), oxidized low-density lipoprotein ( OxLDL) and homocysteine (Hcy) are associated with atherosclerosis. The aim of this study was to evaluate the relationship between age, inflammatory and oxidative stress-related markers with functional and structural changes of the arteries in asymptomatic persons. Methods CRP, OxLDL and Hcy were measured in 175 clinically healthy subjects, aged 40-70 years. Ultrasonography and pulse wave analysis were used to measure carotid intima-media thickness (IMT) and augmentation index (AIx). Results OxLDL was correlated with IMT (r=0.24, P=0.003), whereas CRP was correlated with AIx (r=0.21, P=0.005). No correlation was detected between Hcy and AIx or age-adjusted IMT. There was a significant association between AIx and age <= 50 years (r=0.33; P=0.001) and between IMT and age > 50 years (r=0.40; P=0.001). In stepwise regression analysis age, weight, white blood cell count, OxLDL, heart rate and timing of the reflected waveform adjusted for height were significantly and independently associated with IMT (R-2=0.41; P < 0.001). At the same time, AIx as the dependent variable correlated positively with age, gender, CRP and mean arterial pressure, and negatively with heart rate, weight and height, in stepwise regression analysis (R-2=0.63; P < 0.001). Conclusion The results of the present study showed that CRP, OxLDL, Hcy and age are not similarly related to AIx and IMT in asymptomatic persons. The results suggest that CRP and younger age are related to arterial stiffness, whereas OxLDL and older age become more important determinants of structural changes of the arteries in asymptomatic