Anti-Inflammatory, Antioxidant, and Anti-Atherosclerotic Effects of Natural Supplements on Patients with FMF-Related AA Amyloidosis: A Non-Randomized 24-Week Open-Label Interventional Study.

We aimed to evaluate the effect of a combination of natural products on parameters related to inflammation, endothelial dysfunction, and oxidative stress in a cohort of familial Mediterranean fever (FMF) patients with Serum Amyloid A amyloidosis, in a non-randomized, 24-week open-label interventional study. Morinda citrifolia (anti-atherosclerotic-AAL), omega-3 (anti-inflammatory-AIC), and extract with Alaskan blueberry (antioxidant-AOL) were given to patients with FMF-related biopsy-proven AA amyloidosis. Patients were >18 years and had proteinuria (>3500 mg/day) but a normal estimated glomerular filtration rate (eGFR). Arterial flow-mediated dilatation (FMD), carotid intima media thickness (CIMT), and serum biomarkers asymmetric dimethylarginine (ADMA), high sensitivity C-reactive protein (hs-CRP), pentraxin (PTX3), malondialdehyde (MDA), Cu/Zn-superoxide dismutase (Cu/Zn-SOD), and glutathione peroxidase (GSH-Px) were studied at baseline and after 24 weeks of treatment. A total of 67 FMF-related amyloidosis patients (52 male (77.6%); median age 36 years (range 21−66)) were enrolled. At the end of a 24-week treatment period with AAL, AIC, and AOL combination therapy, ADMA, MDA, PTX3, hsCRP, cholesterol, and proteinuria were significantly decreased compared to baseline, while CuZn-SOD, GSH-Px, and FMD levels were significantly increased. Changes in inflammatory markers PTX3, and hsCRP were negatively correlated with FMD change, and positively correlated with decreases in proteinuria, ADMA, MDA, cholesterol, and CIMT. Treatment with AAL, AIC and AOL combination for 24 weeks were significantly associated with reduction in inflammatory markers, improved endothelial functions, and oxidative state. Efficient control of these three mechanisms can have long term cardiovascular and renal benefits for patients with AA amyloidosis.

The Effect of Corrected Inflammation, Oxidative Stress and Endothelial Dysfunction on Fmd Levels in Patients with Selected Chronic Diseases: A Quasi-Experimental Study.

While the pathophysiology of chronic disorders varies there are three basic mechanisms - inflammation, oxidative stress and endothelial dysfunction - that are common in many chronic diseases. However, the failure of these mechanisms to work synchronously can lead to morbidity complicating the course of many chronic diseases. We analyzed data of 178 patients from cohorts with selected chronic diseases in this quasi-experimental study. Endothelial dysfunction was determined by flow-mediated dilatation (FMD) and asymmetric dimethylarginine (ADMA) levels. Serum ADMA, high sensitive C-reactive protein (hs-CRP), serum PTX3, malondialdehyde (MDA), Cu/Zn-superoxide dismutase (Cu/Zn-SOD), glutathione peroxidase (GSH-Px) levels and FMD were studied in baseline and after 12 weeks of Morinda citrifolia (anti-atherosclerotic liquid- AAL), omega-3 (anti-inflammatory capsules- AIC) and extract with Alaskan blueberry (anti-oxidant liquid- AOL). Stepwise multivariate regression analysis was used to evaluate the association of FMD with clinical and serologic parameters. Serum ADMA, MDA, PTX3, hsCRP and albumin levels, and proteinuria were significantly decreased while CuZn-SOD, GSH-Px and FMD levels were significantly increased following AAL, AIC and AOL therapies. The FMD was negatively correlated with serum ADMA, MDA, PTX3, and hsCRP levels and positively correlated with CuZn-SOD and eGFR levels. ADMA and PTX3 levels were independently related to FMD both before and after AAL, AIC and AOL therapies. Our study shows that serum ADMA, MDA, PTX3 levels are associated with endothelial dysfunction in patients with selected chronic diseases. In addition, short-term AAL, AIC and AOL therapies significantly improves a number of parameters in our cohort and can normalize ADMA, PTX3, hsCRP and MDA levels.

Role of vascular calcification inhibitors in preventing vascular dysfunction and mortality in hemodialysis patients.

Cardiovascular events make up the primary cause of death in hemodialysis patients, and the risk for cardiovascular mortality is significantly increased by vascular calcification, a condition observed frequently in this patient population. The mechanisms underlying the pathogenesis of vascular calcification are complex, and many factors facilitate or hinder the development of calcification. In this review, we first summarize the main factors contributing to the pathogenesis of vascular calcification in patients with end-stage renal disease. We then explore the role of calcification inhibitors in the calcification process, as well as their effect on vascular dysfunction and mortality in hemodialysis patients.

Hormonal changes in hemodialysis patients: Novel risk factors for mortality?

Patients with end-stage renal disease undergoing dialysis commonly experience derangements in the hypothalamic-pituitary-gonadal axis together with alterations at the level of synthesis and clearance of many hormones. This hormonal imbalance, even if asymptomatic, has recently been associated with increased mortality in these patients. In this review, we summarize observational and mechanistic evidence linking hormonal alterations at the level of the thyroid and sex-hormone systems with this mortality risks.

IL-33 and ST2 levels in chronic kidney disease: Associations with inflammation, vascular abnormalities, cardiovascular events, and survival.

OBJECTIVE: Increased inflammation, associated with the increase in chronic kidney disease (CKD) stage, has a very important influence in vascular injury and cardiovascular diseases. In this study, we aimed to investigate the levels of IL-33 and ST2 in the different stages of CKD and to determine their effect on vascular damage and cardiovascular events (CVE). METHODS: This was an observational cohort study in which serum IL-33 and ST2 were obtained from 238 CKD (stages 1-5) patients. We examined the changes in IL-33/ST2 levels in CKD patients, as well as the association with a surrogate of endothelial dysfunction. Fatal and non-fatal CVE were recorded for a mean of 24 months. We also performed a COX regression analysis to determine the association of IL-33/ST2 levels with CVE and survival. RESULTS: IL-33 and ST2 levels were significantly increased and estimated glomerular filtration rates (eGFR) were decreased. Flow-mediated dilatation (FMD) was significantly decreased from stage 1 to stage 5 CKD. IL-33 and ST2 levels were associated with FMD, and ST2 was a predictor. Multivariate Cox analysis showed that the presence of diabetes mellitus, smoking, and proteinuria and haemoglobin, Hs-CRP, IL-33, and ST2 were associated with the risk of CVE. Kaplan-Meier survival curves showed that patients with IL-33 and ST2 levels below the median value (IL-33 = 132.6 ng/L, ST2 = 382.9 pg/mL) had a higher cumulative survival compared with patients who had IL-33 and ST2 levels above the median value (log-rank test, p = 0.000). CONCLUSION: This is the first study that demonstrates that serum IL-33 and ST2 are associated with vascular injury, cardiovascular events, and survival in CKD patients.

Visceral adiposity index and triglyceride/high-density lipoprotein cholesterol ratio in hypogonadism

ABSTRACT Background Cardiometabolic risk is high in patients with hypogonadism. Visceral adiposity index (VAI) and triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio are the practical markers of atherosclerosis and insulin resistance and independent predictors of cardiaovascular risk. To date, no study has evaluated VAI levels and TG/HDL-C ratio in hypogonadism. Subjects and methods A total of 112 patients with congenital hypogonadotrophic hypogonadism (CHH) (mean age, 21.7 ± 2.06 years) and 124 healthy subjects (mean age, 21.5 ± 1.27 years) were enrolled. The demographic parameters, VAI, TG/HDL-C ratio, asymmetric dimethylarginine (ADMA), high-sensitivity C-reactive protein (hs-CRP), and homeostatic model assessment of insulin resistance (HOMA-IR) levels were measured for all participants. Results The patients had higher total cholesterol (p = 0.04), waist circumference, triglycerides, insulin, and HOMA-IR levels (p = 0.001 for all) than the healthy subjects. VAI and ADMA and TG/HDL-C levels were also higher in patients than in healthy subjects (p < 0.001 for all). VAI was weakly correlated with ADMA (r = 0.27, p = 0.015), HOMA-IR (r = 0.22, p = 0.006), hs-CRP (r = 0.19, p = 0.04), and total testosterone (r = −0.21, p = 0.009) levels, whereas TG/HDL-C ratio was weakly correlated weakly with ADMA (r = 0.30, p = 0.003), HOMA-IR (r = 0.22, p = 0.006), and total testosterone (r = −0.16, p = 0.03) levels. Neither VAI nor TG/HDL-C ratio determined ADMA, HOMA-IR, and hs-CRP levels. Conclusions The results of this study demonstrate that patients with hypogonadism have elevated VAI and TG/HDL-C ratio. These values are significantly correlated with the surrogate markers of endothelial dysfunction, inflammation, and insulin resistance. However, the predictive roles of VAI and TG/HDL-C ratio are not significant. Prospective follow-up studies are warranted to clarify the role of VAI and TG/HDL-C ratio in predicting cardiometabolic risk in patients with hypogonadism.

Visceral adiposity index and triglyceride/high-density lipoprotein cholesterol ratio in hypogonadism.

BACKGROUND: Cardiometabolic risk is high in patients with hypogonadism. Visceral adiposity index (VAI) and triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio are the practical markers of atherosclerosis and insulin resistance and independent predictors of cardiaovascular risk. To date, no study has evaluated VAI levels and TG/HDL-C ratio in hypogonadism. SUBJECTS AND METHODS: A total of 112 patients with congenital hypogonadotrophic hypogonadism (CHH) (mean age, 21.7 ± 2.06 years) and 124 healthy subjects (mean age, 21.5 ± 1.27 years) were enrolled. The demographic parameters, VAI, TG/HDL-C ratio, asymmetric dimethylarginine (ADMA), high-sensitivity C-reactive protein (hs-CRP), and homeostatic model assessment of insulin resistance (HOMA-IR) levels were measured for all participants. RESULTS: The patients had higher total cholesterol (p = 0.04), waist circumference, triglycerides, insulin, and HOMA-IR levels (p = 0.001 for all) than the healthy subjects. VAI and ADMA and TG/HDL-C levels were also higher in patients than in healthy subjects (p < 0.001 for all). VAI was weakly correlated with ADMA (r = 0.27, p = 0.015), HOMA-IR (r = 0.22, p = 0.006), hs-CRP (r = 0.19, p = 0.04), and total testosterone (r = -0.21, p = 0.009) levels, whereas TG/HDL-C ratio was weakly correlated weakly with ADMA (r = 0.30, p = 0.003), HOMA-IR (r = 0.22, p = 0.006), and total testosterone (r = -0.16, p = 0.03) levels. Neither VAI nor TG/HDL-C ratio determined ADMA, HOMA-IR, and hs-CRP levels. CONCLUSIONS: The results of this study demonstrate that patients with hypogonadism have elevated VAI and TG/HDL-C ratio. These values are significantly correlated with the surrogate markers of endothelial dysfunction, inflammation, and insulin resistance. However, the predictive roles of VAI and TG/HDL-C ratio are not significant. Prospective follow-up studies are warranted to clarify the role of VAI and TG/HDL-C ratio in predicting cardiometabolic risk in patients with hypogonadism.

Effect of testosterone replacement therapy on vitamin D and FGF-23 levels in congenital hypogonadism.

INTRODUCTION: Patients with hypogonadism are at increased risk of cardiac and metabolic diseases and osteoporosis. Vitamin D and Fibroblast growth factor-23 (FGF-23) play role in the regulation of bone mineral metabolism and endothelial functions. Low vitamin D levels are reported in hypogonadism, while there is no data about the effect of testosterone replacement therapy (TRT). We investigated the effect of TRT on vitamin D and FGF-23 levels along with endothelial functions and insulin resistance in hypogonadal patients. MATERIAL AND METHODS: Patients with congenital hypogonadotrophic hypogonadism (CHH) (n=32, age 20.6 ±1.58 years) were enrolled. TRT was implemented in transdermal form. The demographic parameters, FGF-23, 25(OH)D3, Asymmetric dimethylarginine (ADMA) and homeostatic model assessment of insulin resistance (HOMA-IR) levels were measured both before and after TRT. RESULTS: After a follow-up period of 3.63±1.33 months, ADMA and FGF-23 levels were significantly increased (p=0.03 and p=0.005 respectively), while the 25(OH)D3 and HOMA-IR index were not significantly changed. The body mass index and waist circumference levels of the patients were also increased (p<0.001 and p=0.02) along with a significant decrease in the HDL cholesterol levels (p=0.006). CONCLUSIONS: The results show that a short term TRT increases plasma FGF-23 and ADMA levels, in young, treatment naive patients with CHH. Whether this is an early implication of TRT related adverse effects in this very young and treatment naïve population of CHH is not clear. Future prospective studies are required to find out the long-term effects of TRT on cardio-metabolic morbidity and mortality in this specific population.

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.

Thyroid function and cardiovascular events in chronic kidney disease patients.

BACKGROUND AND AIMS: Abnormalities of thyroid function are commonly seen in chronic kidney disease (CKD) patients. They are associated with adverse clinical conditions such as atherosclerosis, endothelial dysfunction, inflammation and abnormal blood pressure variability. We investigated the association between thyroid disorders and endothelial function, assessed by flow-mediated dilatation (FMD) and carotid intima-media thickness (CIMT), and cardiovascular events (CVE) in CKD patients. MATERIALS AND METHODS: This observational cohort study included 305 CKD (stages 1-5) patients. Routine biochemistry, including free T3, free T4 and thyroid stimulating hormone, fibroblast growth factor-23 (FGF-23) and FMD, CIMT were measured. We divided patients into four groups according to thyroid hormone status: euthyroidism, subclinical hyperthyroidism, subclinical hypothyroidism, and euthyroid sick syndrome. Fatal and composite CVE were recorded for a median 29 months. RESULTS: Patients with subclinical hypothyroidism had a higher prevalence of hypertension and diabetes and also were more likely to have higher values of systolic CIMT, phosphorus, intact parathormone (iPTH), FGF-23, homeostasis model assessment-insulin resistance and lower levels of FMD than euthyroid patients. In the unadjusted survival analysis, subclinical hypothyroidism and euthyroid sick syndrome were associated with an increased risk for the outcome as compared with euthyroidism [hazard ratio 30.63 (95 % confidence interval 12.27-76.48) and 12.17 (3.70-39.98), respectively]. The effects of subclinical hypothyroidism and euthyroid sick syndrome were maintained even in fully adjusted models. CONCLUSION: We demonstrated that subclinical hypothyroidism and euthyroid sick syndrome are associated with increased CVE in CKD patients. Further studies are needed to explore these issues.

Chitotriosidase as a novel biomarker of early atherosclerosis in hemodialysis patients.

INTRODUCTION: Increasing evidence suggests that inflammation and increased macrophage activity have a central role in pathogenesis of atherosclerosis. It is shown that chitotriosidase (CHIT-1) is a marker of macrophage activity in atherosclerotic plaque, and is found associated with severity of atherosclerotic lesion. There is no data about CHIT-1 activity of hemodialysis patients in the literature. Thus, we hypothesized that in hemodialysis patients, CHIT-1 levels might be a novel biomarker in early atherosclerosis. METHODS: Forty-five hemodialysis patients were included in the study (age: 61.93 ± 13.34). Intima media thickness (IMT) was evaluated with high-resolution B-mode ultrasonography. Biomarker levels were measured in serum of patients. FINDINGS: We found positive correlation among IMT, age (R: 0.426, P: 0.004) and, CHIT-1 value (R: 0.462, P: 0.001) in spearman correlation analysis. When age, CRP, creatinine, P, Alb, CHIT-1 were chosen as measures that can effect IMT in multiple regression model, IMT level was related with CHIT-1 (Beta: 0,396, P: 0.012) and age (Beta: 0,313 P: 0,048) independently. DISCUSSION: In conclusion, this is the first report showing that serum CHIT-1 level was related independently with carotid IMT in hemodialysis patients. This biomarker might have an unknown role in the development of atherosclerosis during uremia.

Colchicine in Renal Medicine: New Virtues of an Ancient Friend.

Colchicine is a plant-derived alkaloid that disrupts the cell microtubule system and accumulates in neutrophils, inhibiting neutrophil adhesion and recruitment. Colchicine has been used extensively in the prevention and treatment of gouty arthritis attacks, familial Mediterranean fever attacks and resultant AA amyloidosis, and recurrent pericarditis. Colchicine also disrupts the intracellular traffic of additional inflammatory and fibrosis mediators. Renal fibrosis is the final common pathway of chronic renal disease. Colchicine had anti-fibrotic effects in experimental diabetic nephropathy, renal mass reduction, and cyclosporine nephrotoxicity among others and is undergoing clinical trials for non-diabetic metabolic syndrome and diabetic nephropathy. In this review, we summarize the anti-inflammatory and anti-fibrotic properties of colchicine in experimental and clinical studies in renal diseases or other fibrotic disease processes with renal consequences. We also discuss the potential future uses of colchicine in renal medicine and challenges faced with its use in patients with impaired kidney function.

Investigation of the knowledge and attitudes of patients who are undergoing hemodialysis treatment regarding their arteriovenous fistula.

PURPOSE: The major cause of morbidity in hemodialysis patients is arteriovenous fistula deficiency. The patient should have adequate knowledge to ensure arteriovenous fistula patency. Our aim is to investigate the knowledge and attitude of the patients undergoing hemodialysis treatment regarding arteriovenous fistula. METHODS: This study was conducted on 335 patients who met the study criteria. Data collection forms evaluating the "Socio-Demographic and Medical Characteristics" and "Knowledge and Attitudes about arteriovenous fistula" of the patients were developed following a literature review by the investigators. RESULTS: The rules most known and implemented were "to not measure blood pressure" and "to not draw blood from arms with fistula", while the least known and implemented were "to use blood vessels on the hands in arms without fistula for intravenous intervention" and "to know which situations cause hypotension". CONCLUSIONS: Hemodialysis patients with arteriovenous fistulas need to know that developing self-care behavior is a means to reconcile lifestyles with current health status. Accordingly, planned training in self-care should be provided to hemodialysis patients and their families, and nurses should repeat information to patients who demonstrate a lack of knowledge.

The Prevalence of Fabry Disease in Patients with Chronic Kidney Disease in Turkey: The TURKFAB Study.

BACKGROUND/AIMS: Fabry disease is a treatable cause of chronic kidney disease (CKD) characterized by a genetic deficiency of α-galactosidase A. European Renal Best Practice (ERBP) recommends screening for Fabry disease in CKD patients. However, this is based on expert opinion and there are no reports of the prevalence of Fabry disease in stage 1-5 CKD. Hence, we investigated the prevalence of Fabry disease in CKD patients not receiving renal replacement therapy. METHODS: This prospective study assessed α-galactosidase activity in dried blood spots in 313 stage 1-5 CKD patients, 167 males, between ages of 18-70 years whose etiology of CKD was unknown and were not receiving renal replacement therapy. The diagnosis was confirmed by GLA gene mutation analysis. RESULTS: Three (all males) of 313 CKD patients (0.95%) were diagnosed of Fabry disease, for a prevalence in males of 1.80%. Family screening identified 8 aditional Fabry patients with CKD. Of a total of 11 Fabry patients, 7 were male and started enzyme replacement therapy and 4 were female. The most frequent manifestations in male patients were fatigue (100%), tinnitus, vertigo, acroparesthesia, hypohidrosis, cornea verticillata and angiokeratoma (all 85%), heat intolerance (71%), and abdominal pain (57%). The most frequent manifestations in female patients were fatigue and cornea verticillata (50%), and tinnitus, vertigo and angiokeratoma (25%). Three patients had severe episodic abdominal pain attacks and proteinuria, and were misdiagnosed as familial Mediterranean fever. CONCLUSIONS: The prevalence of Fabry disease in selected CKD patients is in the range found among renal replacement therapy patients, but the disease is diagnosed at an earlier, treatable stage. These data support the ERBP recommendation to screen for Fabry disease in patients with CKD of unknown origin.

Vasopressin-related copeptin is a novel predictor of early endothelial dysfunction in patients with adult polycystic kidney disease.

BACKGROUND: In this study, we examined the relative usefulness of serum copeptin levels as a surrogate marker of vasopressin (AVP) in adult polycystic kidney disease (ADPKD) by correlating it with baseline and longitudinal changes in markers of both renal function and common CVD manifestations (hypertensive vascular disease, atherosclerosis and endothelial dysfunction) that accompany the progression of this disease. METHODS: We studied a cohort of young and otherwise healthy ADPKD patients (n = 235) and measured cardiovascular function using flow-mediation dilatation (FMD), carotid intima media thickness (cIMT) and pulse wave velocity (PWV), as well as serum copeptin (commercial ELISA, a stable marker of AVP activity). The same analyses were carried out at baseline and after 3 years of follow-up. RESULTS: At baseline, median eGFR was 69 mL/min./1.73 m2, mean FMD 6.9 ± 0.9%, cIMT 0.7 ± 0.1 mm, and PWV 8.1 ± 1.2 m/s. At follow-up, equivalent values were 65 (44-75) mL/min./1.73 m2, 5.8 ± 0.9%, 0.8 ± 0.1 mm. and 8.2 ± 1.3 m/s. with all changes statistically significant. Plasma copeptin also rose from 0.62 ± 0.12 to 0.94 ± 0.19 ng/mL and this change correlated with ΔeGFR (-0.33, p < 0.001), ΔFMD (0.599, p < 0.001), ΔcIMT (0.562, p < 0.001) and ΔPWV (0.27, p < 0.001) also after linear regression modeling to correct for confounders. Finally, ROC analysis was done for a high baseline copeptin with ΔeGFR [cut-off:≤59], ΔFMD [cut-off: ≤7.08], ΔcIMT [cut-off:>0.76], and ΔPWV [cut-off:≤7.80]. CONCLUSIONS: Vascular dysfunction as reflected by FMD and cIMT, but not PWV or an altered cardiac geometry, precede most other signs of disease in ADPKD but is predicted by elevated levels of the circulating AVP-marker copeptin.

Endostatin in chronic kidney disease: Associations with inflammation, vascular abnormalities, cardiovascular events and survival.

BACKGROUND AND AIMS: Endostatin, generated from collagen XVIII, and endorepellin, possess dual activity as modifiers of both angiogenesis and endothelial cell autophagy. Plasma endostatin levels are elevated in a large number of diseases, and may reflect endothelial cell dysfunction. Few data on endostatins are available for patients with chronic kidney disease (CKD). We tested whether serum endostatin values are predictive for all-cause mortality and cardiovascular events (CVEs) in a CKD population. MATERIALS AND METHOD: A total of 519 CKD pre-dialysis patients were included. Baseline plasma endostatin levels were measured in all patients. All included patients were followed-up (time-to-event analysis) until occurrence of death, fatal or nonfatal CVEs. Fatal and nonfatal CVE including death, stroke, and myocardial infarction were recorded prospectively RESULTS: The mean age of the patients was 52.2±12.3years. There were 241 (46.4%) males, 111 (21.4%) had diabetes, 229 (44.1%) were smokers and 103 (19.8%) had a previous CVE. After a median follow-up of 46months, 46 patients died and 172 had a new CVE. In the univariable Cox survival analysis, higher endostatin levels were associated with a higher risk for both outcomes. However, after adjusting for traditional (age, gender, smoking status, diabetes, systolic blood pressure, HDL and total cholesterol) and renal-specific (eGFR, proteinuria and hsCRP) risk factors, endostatin levels remained associated only with the CVE outcome (HR=1.88, 95% CI 1.37-2.41 for a 1 SD increase in log endostatin values). CONCLUSION: Endostatin levels are independently associated with incident CVE in CKD patients, but show limited prediction abilities for all-cause mortality and CVE above traditional and renal-specific risk factors.

Relevance of uric acid and asymmetric dimethylarginine for modeling cardiovascular risk prediction in chronic kidney disease patients.

BACKGROUND: Both elevated serum uric acid and serum asymmetric dimethylarginine (ADMA) are risk factors for cardiovascular disease. We hypothesized that combined elevation of uric acid and ADMA amplifies the risk of all-cause mortality and/or cardiovascular events (CVE) in patients with chronic kidney disease (CKD). METHODS: A total of 259 patients with CKD stages 1-5 were followed up in a time-to-event analysis for all-cause mortality and fatal and non-fatal CVE (including death, stroke, and myocardial infarction). Baseline measurements included serum uric acid and ADMA and endothelial function [ultrasound determined flow-mediated dilatation (FMD)]. RESULTS: As a measure of endothelial function, log FMD value was positively associated with log eGFR, but negatively associated with log ADMA and log uric acid levels. During follow-up (median 38 months), 24 (9.3 %) deaths, 90 (34.7 %) CVE, and 95 (36.7 %) deaths and CVE (composite outcome) occurred. In the univariate Cox analysis, patients with both serum uric acid and ADMA levels above the median had an increased risk of all-cause mortality, CVE, and the composite outcome (HR 5.06, 95 % CI 2.01-12.76; HR 4.75, 95 % CI 2.98-7.59; and HR 4.13, 95 % CI 2.66-6.43, respectively). However, after adjustment for renal-specific risk factors (glomerular filtration rate, proteinuria, and hsCRP), this association was maintained only for CVE and the composite outcome. The addition of both biomarkers into a model with traditional and renal-specific risk factors did not increase the prediction abilities of the model for none of the three outcomes. CONCLUSION: Elevated serum uric acid and ADMA levels are associated with an increased cardiovascular risk, but their combination does not improve risk prediction. The effects are not additive, possibly because uric acid may lie in the causal pathway by which ADMA acts.

Osteoprotegerin in Chronic Kidney Disease: Associations with Vascular Damage and Cardiovascular Events.

Vascular injury and dysfunction contribute to cardiovascular disease, the leading cause of death in patients with chronic kidney disease (CKD). Osteoprotegerin (OPG) is a soluble member of the tumor necrosis factor receptor superfamily that has been linked to atherogenesis and endothelial dysfunction. Elevated circulating OPG levels predict future cardiovascular events (CVE). Our aim was to evaluate the determinants of circulating OPG levels, to investigate the relationship between OPG and markers of vascular damage and to test whether OPG improves risk stratification for future CVE beyond traditional and renal-specific risk factors in a CKD population. 291 patients with CKD stage 1-5 not on dialysis were included in the study. In the multivariate analysis, OPG was a significant predictor for flow-mediated dilatation, but not for carotid intima media thickness levels. During follow-up (median 36 months, IQR = 32-42 months), 87 patients had CVE. In the Cox survival analysis, OPG levels were independently associated with CVE even after adjustment for traditional and renal-specific cardiovascular risk factors. The addition of OPG to a model based on commonly used cardiovascular factors significantly improved the reclassification abilities of the model for predicting CVE. We show for the first time that OPG improves risk stratification for CVE in a non-dialysis CKD population, above and beyond a model with established traditional and renal-specific cardiovascular risk factors, including estimated glomerular filtration rate and fibroblast growth factor 23.

Serum neutrophil gelatinase-associated lipocalin is associated with cardiovascular events in patients with chronic kidney disease.

BACKGROUND: Neutrophil gelatinase-associated lipocalin (NGAL) is a member of the lipocalin family best known as a novel and early marker of acute kidney injury (AKI). Recent data suggest that NGQueryAL is not only a marker of AKI, but also an important player in the vascular remodeling, atherosclerotic plaque stability and thrombus formation. We conducted this study to investigate the association of serum NGAL levels with fatal and composite (fatal and non-fatal) cardiovascular events (CVE) in a cohort of patients with stage 1-5 CKD. METHODS: This was an observational cohort study in which serum NGAL was obtained from 298 CKD (stages 1-5) patients. Fatal and composite CVE were recorded for a median 41 months. We examined alteration of serum NGAL through CKD groups as well as association with inflammatory markers. We also performed a Cox regression analysis to determine the association of NGAL with predefined clinical outcomes. RESULTS: The median value of NGAL was 50.5 ng/mL (IR 47.6-54.9 ng/mL), and higher NGAL values were recorded in diabetic patients. In a multiple linear regression model, including all univariate associates of NGAL, only log eGFR, log hs-CRP and log HDL cholesterol maintained an independent association with log NGAL. During the observational period, 30 patients died due to cardiovascular causes and 69 non-fatal CVE were registered. In the fully adjusted model, we observed a 2.08-fold increase in the risk of fatal CVE and a 1.50-fold increase in the risk of fatal and non-fatal CVE for each increment of 1 SD in log NGAL values. CONCLUSIONS: This is the first study that shows that serum NGAL is associated with cardiovascular events (fatal and non-fatal) in patients with CKD, independently of traditional risk factors, renal function and inflammation.

Predictive Value of Atrial Electromechanical Delay on Long-Term Cardiovascular Outcomes in Hemodialysis Patients.

BACKGROUND: Atrial electromechanical delay (AEMD) times were considered independent predictors of cardiovascular morbidity among the general population. We aimed at evaluating AEMD times and other risk factors associated with 2-year combined cardiovascular (CV) events in HD patients. MATERIAL AND METHODS: Sixty hemodialysis (HD) and 44 healthy individuals were enrolled in this prospective study. Echocardiography was performed before the mid-week dialysis session for HD patients. Data were expressed as mean ± SD. Spearman test was used to assess linear associations. Survival was examined with the Kaplan-Meier method. Multivariate Cox regression analysis was used to determine the predictors of combined CV events in this cohort. RESULTS: At the beginning of the study, left intra-atrial-AEMD times were significantly longer in HD patients compared to the left intra-atrial-AEMD times in healthy individuals. After 24 months, 41 patients were still on HD treatment and 19 (31.6%) had died. Serum triglyceride, total cholesterol and albumin were found to be higher and C-reactive protein (CRP) levels, left intra-atrial EMD time (LIAT) and interatrial EMD times were found to be lower in survived HD patients. With the cut-off median values of 3.5 g/dl for albumin, 0.87 mg/dl for CRP, 157 mg/dl for total cholesterol and 151 mg/dl for triglyceride, the Kaplan-Meier curves demonstrated significant differences in terms of all-cause mortality. We also demonstrated the Kaplan-Meier survival curves of HD patients according to tertile values of LIAT. Cox regression analysis revealed that increased CRP and higher LIAT were found to be independent predictors of combined CV events. CONCLUSIONS: Increased LIAT and inflammation were found to be closely associated with 2 years combined CV events and all-cause mortality in HD patients.