The Relationship Between Plasma Whole Blood Viscosity and Cardiovascular Events in Patients With Chronic Kidney Disease.

BACKGROUND: Plasma levels of estimated whole blood viscosity (eWBV) have been increased by endothelial inflammation. Because there were no consistent data for assessing the eWBV levels for prediction of cardiovascular event (CVE) in patients with chronic kidney disease (CKD). We aimed to investigate the relationship between plasma eWBV levels and CVEs in patients with CKD. MATERIALS AND METHODS: We conducted a prospective, cross-sectional, long-term follow-up study, assessing the relationship between plasma eWBV levels and CVE (either fatal or nonfatal) in patients with newly diagnosed CKD. We also evaluated estimated glomerular filtration rate (eGFR), pentraxin 3 (PTX3), high-sensitivity C-reactive protein (hsCRP), and flow-mediated dilatation (FMD). RESULTS: Study patients were divided into 2 groups: patients with CVE and patients without CVE. The eWBV levels were higher in patients with CVE. Additionally, PTX3 and hsCRP were higher, and FMD and eGFR were lower in patients with CVE compared to those without CVE. According to the Cox regression analysis, WBV, plasma asymmetric dimethylarginine levels, FMD, hsCRP, eGFR, systolic blood pressure, calcium, and history of diabetes were independent predictors of CVEs in patients with CKD. Kaplan Meier survival curves were generated to establish the impact of the WBV on the cumulative survival of the cohort. Patients with eWBV values higher than 5.2 centipoise (cP) had lower survival rates when compared to patients with eWBV values lower than 5.2 cP (log rank = 4.49 df = 1 P = .034). CONCLUSION: In conclusion, plasma eWBV levels may increase the presence of lower eGFR and affect CVE in patients with CKD independent of classical and unconventional risk factors.

Effect of hyperbaric oxygen on flow-mediated vasodilation: an ultrasound study.

OBJECTIVE: The purpose of this study was to investigate the effect of hyperbaric oxygen (HBO) treatment on flow-mediated vasodilation (FMD) by ultrasound examination. METHODS: We studied 14 young patients without cardiovascular problems who underwent HBO treatment. The indications for HBO treatment were osteomyelitis (n = 8), Crohn disease (n = 2), perianal abscesses (n = 2), lingual artery embolization (n = 1), and aseptic necrosis (n = 1). The ultrasound evaluation for FMD was performed before HBO treatment, after 1 session of HBO treatment, and after 10 sessions of HBO treatment. The right brachial artery FMD response was evaluated by the mean of the baseline right brachial artery diameter, absolute change in the diameter before and after cuff inflation/deflation, and percent change in the diameter. RESULTS: Statistical analysis showed a significant change in the preinflation right brachial artery diameter before (mean +/- SD, 3.6 +/- 0.54 mm) and after (3.76 +/- 0.56 mm) 10 sessions of HBO treatment (P < .05). The absolute changes in the right brachial artery diameter before and after cuff inflation/deflation (0.36 +/- 0.2 mm before HBO treatment, 0.37 +/- 0.22 mm after 1 session of HBO treatment, and 0.38 +/- 0.21 mm after 10 sessions) and percent change in FMD (10% +/- 5.8% before HBO treatment, 10.6% +/- 7.5% after 1 session of HBO treatment, and 10.6% +/- 7.7% after 10 sessions) after induction of a hyperemic response by cuff inflation were not statistically significant (P > .05). CONCLUSIONS: Hyperbaric oxygen treatment did not have an immediate effect on FMD (absolute change in the right brachial artery diameter after cuff inflation/deflation); however, the right brachial artery diameter increased after 10 sessions of HBO treatment. This may suggest chronic stress on the vascular endothelium after HBO.

The determinants of endothelial dysfunction in CKD: oxidative stress and asymmetric dimethylarginine.

BACKGROUND: Oxidative stress is related to endothelial dysfunction (ED) and cardiovascular outcomes in patients with chronic kidney disease. Increased asymmetric dimethylarginine (ADMA) levels are among the main causes of ED. We aim to investigate any association between ED and ADMA levels, as well as levels of oxidative stress markers, in patients with chronic kidney disease. METHODS: One hundred fifty-nine patients without diabetes with chronic kidney disease were studied. Staging was performed according to glomerular filtration rate, determined as stages 1 to 5 according to the Kidney Disease Outcomes Quality Initiative (n = 30, 33, 28, 32, and 36, respectively). The control group consisted of 30 healthy subjects. Oxidative stress markers (plasma malondialdehyde [MDA], erythrocyte superoxide dismutase [SOD], glutathione peroxidase [GSH-Px]), trace elements (erythrocyte zinc [EZn], erythrocyte copper [ECu]), plasma selenium (Se), and serum ADMA were studied. Brachial artery endothelium-dependent vasodilatation (FMD) was calculated for all. RESULTS: FMD, SOD, GSH-Px, EZn, ECu, and Se values were lower, whereas MDA and ADMA levels were higher in patients than controls. Glomerular filtration rate correlated negatively with MDA and ADMA levels and positively with FMD, SOD, and GSH-Px values. These parameters were significantly different among patients with stages 2, 3, 4, and 5 (hemodialysis group; P < 0.001 for all). Regression analysis showed that ADMA (beta = -0.228; P < 0.01), SOD (beta = 0.405; P < 0.001), and oxidized low-density lipoprotein levels (beta = -0.428; P < 0.001) were related independently to FMD, whereas glomerular filtration rate was not involved in the model. CONCLUSION: The present results imply that FMD, oxidative stress, and ADMA levels all are associated with stage of chronic kidney disease. Additionally, levels of oxidative stress markers and ADMA independently determine endothelial function.