The interrelationship between baroreflex sensitivity expressed in ms/mm Hg (BRS) or in Hz/mm Hg (BRSf), carotid wall thickness (IMT), and age was investigated in hypertensive and normotensive subjects with respect to the mean inter-beat interval (IBI) and blood pressure (BP). BP monitoring was performed in 25 treated hypertensives (Hy; 47.4±9.2 years of age) and 23 normotensives (Norm; 44.5±8.1 years). IMT was measured by ultrasonography. BRS and BRSf were determined by the spectral method (five-minute non-invasive beat-to-beat recording of BP and IBI, Finapres, controlled breathing at a frequency of 0.33 Hz). Significant differences between Hy and Norm were detected in IMT (Hy: 0.624±0.183, Norm: 0.522±0.070 mm; p<0.01), BRS (Hy: 3.5±1.6, Norm: 5.7±2.3 ms/mm Hg; p<0.01), BRSf (Hy: 0.005±0.002, Norm: 0.009±0.004 Hz/mm Hg; p<0.01), systolic BP (Hy: 131±21, Norm: 116±17 mm Hg; p<0.01) and diastolic BP (Hy: 77±16, Norm: 64±12 mm Hg; p<0.01). A significant correlation was found between age and IMT (Norm: 0.523, p<0.05; Hy+Norm: 0.419, p<0.01), age and BRS (Norm: -0.596, p<0.01; Hy+Norm: -0.496, p<0.01), age and BRSf (Norm: -0.555, p<0.01; Hy: -0.540, p<0.01; Hy+Norm: -0.627, p<0.01), age and IBI (Hy: 0.478, p<0.05), age and diastolic BP (Hy: -0.454, p<0.05), BRS and IMT (Hy+Norm: -0.327, p<0.05) and BRSf and IMT (Hy+Norm: -0.358, p<0.05). Hypertensive patients have increased IMT and decreased BRS and BRSf. The positive correlation between age and IMT and the negative correlation between age and BRS and BRSf are in agreement with the hypothesis that the age-dependent decrease of baroreflex sensitivity corresponds to the age-related structural changes of the carotid wall. Using two indices of baroreflex sensitivity, BRS and BRSf, we could show that baroreflex sensitivity in hypertensives is lower not only due to thickening of the carotid wall, but also due to aging.
Circulating lipopolysaccharide-binding protein (LBP), a metabolic endotoxemia marker, was identified as an independent predictor of atherosclerosis. Although increases in carotid intima-media thickness (CIMT) were repeatedly reported in obstructive sleep apnea (OSA), neither the role of OSA in metabolic endotoxemia nor of LBP in early atherosclerosis were explored in patients with OSA. At a tertiary university hospital we investigated the relationships between OSA, LBP and CIMT in 117 men who underwent full polysomnography and CIMT assessment by B-mode ultrasound. Circulating LBP concentrations and average CIMT increased from patients without OSA to those with mild-moderate and severe OSA (from 32.1±10.3 to 32.3±10.9 to 38.1±10.3 μg.ml-1, p=0.015; from 0.52±0.09 to 0.58±0.06 to 0.62±0.10 mm, p=0.004, respectively). Oxygen desaturation index (ODI) was a predictor of serum LBP levels independent of age, waist-to-hip ratio (WHR), smoking, hypertension, HDL cholesterol, triglycerides and fasting glucose [p (ANOVA)=0.002, r 2=0.154], with no independent effect of the ODI*WHR interaction term on LBP. Furthermore, serum LBP predicted CIMT independently of known risk factors of atherosclerosis including obesity (p<0.001, r 2=0.321). Our results suggest that OSA severity contributes to metabolic endotoxemia in patients with OSA independently of obesity, and that LBP might represent a contributing factor promoting early atherosclerosis in such patients., I. Trojová, M. Kozarová, D. Petrasová, Z. Malachovská, I. Paranicová, P. Joppa, R. Tkacová., and Seznam literatury
Patients with chronic renal failure are prone to cardiovascular complications. The mechanisms and the assessment of the risk of cardiovascular diseases (CVD) in this population are of interest. The purpose of this study was to investigate the traditional and potential risk factors for the development of CVD and their contribution to ischemic heart disease (IHD) and variation in carotid intima media thickness (IMT) in hemodialyzed patients (HD). Twenty-one chronically HD patients and nineteen healthy volunteers were recruited. Studied parameters were intima-media thickness, body mass index (BMI), mean arterial blood pressure (MAP), hemoglobin, fibrinogen (Fbg), serum lipids, lipoprotein (a) [Lp(a)], total homocysteine (tHcy). Mean carotid IMT, tHcy, Fbg and Lp(a) were higher in HD patients compared to the control group. There were no differences in cholesterol (tCh) and triglycerides between these groups. Patients with ischemic heart disease were older and they had higher values of carotid IMT, tCh, triglycerides, Fbg and Lp(a). There were no differences in MAP, time on dialysis and tHcy between the two subgroups (with vs without IHD). Carotid IMT correlated positively with age (r=0.68, p=0.001), BMI (r=0.50, p=0.02), tCh (r=0.58, p<0.01), LDL- cholesterol (r=0.55, p=0.01) and Fbg (r=0.57, p<0.01) but not with tHcy or Lp(a) in the patients group. Carotid intima media thickness thus reflects the risk for ischemic heart disease in hemodialyzed patients. Elevated fibrinogen concentration and dyslipidemia influence arterial remodelling.