Methylated arginines and nitric oxide in end-stage renal disease: impact of inflammation,oxidative stress and haemodialysis

Abstract

Objectives: To determine whether inflammation (C-reactive protein, CRP), oxidative stress (malondialdehyde, MDA) or haemodialysis (HD) affect associations between asymmetric (ADMA), symmetric (SDMA) dimethylarginine, NG-monomethyl-L-arginine (L-NMMA) and nitrite/nitrate (NOx) in end-stage renal disease (ESRD).

Method: Metabolites were measured pre-HD, after 1 hour and end-HD in 40 ESRD patients (age 63?±?14 years).

Results: Positive associations between NOx and ADMA (p?=?0.04), SDMA (p?<?0.001) and L-NMMA (p?=?0.04) were observed pre-HD. Associations weakened during HD but were not significantly influenced by CRP or MDA.

Conclusions: HD, oxidative stress or inflammation did not significantly affect the positive associations between methylated arginines and NOx in ESRD.     

Biological and metabolic response in STS-135 space-flown mouse skin

Abstract

There is evidence that space flight condition-induced biological damage is associated with increased oxidative stress and extracellular matrix (ECM) remodeling. To explore possible mechanisms, changes in gene expression profiles implicated in oxidative stress and in ECM remodeling in mouse skin were examined after space flight. The metabolic effects of space flight in skin tissues were also characterized. Space Shuttle Atlantis (STS-135) was launched at the Kennedy Space Center on a 13-day mission. Female C57BL/6 mice were flown in the STS-135 using animal enclosure modules (AEMs). Within 3–5 h after landing, the mice were euthanized and skin samples were harvested for gene array analysis and metabolic biochemical assays. Many genes responsible for regulating production and metabolism of reactive oxygen species (ROS) were significantly (p < 0.05) altered in the flight group, with fold changes >1.5 compared to AEM control. For ECM profile, several genes encoding matrix and metalloproteinases involved in ECM remodeling were significantly up-/down-regulated following space flight. To characterize the metabolic effects of space flight, global biochemical profiles were evaluated. Of 332 named biochemicals, 19 differed significantly (p < 0.05) between space flight skin samples and AEM ground controls, with 12 up-regulated and 7 down-regulated including altered amino acid, carbohydrate metabolism, cell signaling, and transmethylation pathways. Collectively, the data demonstrated that space flight condition leads to a shift in biological and metabolic homeostasis as the consequence of increased regulation in cellular antioxidants, ROS production, and tissue remodeling. This indicates that astronauts may be at increased risk for pathophysiologic damage or carcinogenesis in cutaneous tissue.     

Thiobarbituric acid-reactive substances relate to arterial stiffness and blood pressure in 6 to 8-year-old boys stratified by maternal risk

Early cardiovascular disease (CVD) onset can be inflicted by familial cardiovascular and lifestyle risk factors. We aimed to compare phenotypic characteristics and explore associations between oxidative stress and vascular function in boys stratified by maternal cardiovascular and lifestyle risk. We included 40 Black and 41 White boys (ages 6–8 years), along with the biological mother of each child. The study population was divided into two groups (nonmaternal risk vs. maternal risk) according to maternal risk predetermined by their selfreported cardiovascular and lifestyle risk factors. Pulse wave velocity (PWV) was measured at various sites and blood pressures were recorded. Urine samples were collected for analyses of thiobarbituric acid-reactive substances (TBARS), 8-hydroxy-2-deoxy guanosine (8-OHdG), albumin, and creatinine. Higher levels of urinary albumin to creatinine ratio (uACR) were found in the maternal risk group compared to the nonmaternal risk group (p?=?.038). Multiple regression analysis in the maternal risk group revealed diastolic blood pressure (R²?=?0.159; β?=?0.293; p?=?.050), carotid femoral PWV (R²?=?0.158; β?=?0.297; p?=?.038) and carotid dorsalis pedis PWV (adj R²?=?0.322; β?=?0.505; p?R²?=?0.161; β?=??0.261; p?=?.046) with TBARS was observed. Also, in the maternal risk group, independent associations of DBP (R²?=?0.273; β?=?0.289; p?=?.040) and uACR (R²?=?0.283; β?=?0.268; p?=?.027) with 8-OHdG were indicated. In boys, as young as 6 years of age, oxidative stress related to arterial stiffness and diastolic blood pressure was observed. This association was only evident in boys with linked maternal lifestyle and cardiovascular risk factors, suggesting potential family-related early onset of cardiovascular risk.     

The association of oxidative stress with arterial compliance and vascular resistance in a bi-ethnic population: the SABPA study

A loss of arterial elasticity increases the risk for cardiovascular events. Oxidative injury to the vessel wall may be one of the underlying mechanisms influencing arterial elasticity. We compared markers of oxidative stress, antioxidant capacity, inflammation, windkessel compliance (Cwk), and total peripheral resistance (TPR) in black and white South Africans. Associations of arterial compliance and vascular resistance (as indicated by TPR) with oxidative stress, antioxidant capacity and inflammatory markers were also investigated. We included 146 black and 181 white men and women. Measurements from the Finometer device were used to calculate Cwk and TPR while thiobarbituric acids reactive substances (TBARS), glutathione peroxidase (GPx), C-reactive protein (CRP), and interleukin-6 (IL-6) were analyzed in serum or urine samples. Black participants had higher TPR, TBARS, GPx, CRP, and IL-6 levels (all p?≤?0.018) and lower Cwk (both p?≤?0.013) compared to white participants. Multiple regression analyses revealed independent associations of Cwk (β?=??0.27, p?=?0.015) and TPR (β?=?0.18, p?=?0.018) with TBARS in black participants, while Cwk (β?=??0.10; p?=?0.019) and TPR (β?=?0.13, p?=?0.047) were independently associated with GPx in white participants. Decreased arterial compliance and increased vascular resistance associated with increased oxidative damage independent of hypertensive status in black participants. These results suggest that oxidative stress plays a role in early vascular changes in a black population prone to the development of cardiovascular disease.     

Evaluation of mediators of oxidative stress and inflammation in patients with acute appendicitis

Context: This study aims to explore the potential of new inflammatory markers for improving the challenging diagnosis of acute appendicitis (AA).

Methods: Levels of IL-1, IL-6, IL-8, IL-10, CRP, INF-γ, and TNF-α in serum were measured in 73 patients with AA. Oxidative stress and antioxidant enzymes were analyzed.

Results: Serum levels of interleukins, TNF-α, and INF-γ were significantly elevated in patients with appendicitis (p?<?0.0001), except for IL-10, which presented decreased levels. There were no significant differences in SOD (p?=?0.29), CAT (p?=?0.19), or TBARS levels (p?=?0.18), whereas protein carbonyls presented significant increase (p?<?0.0001).

Conclusion: Evaluating these biomarkers could aid in diagnosing AA.     

Increased oxidative stress in children with attention deficit hyperactivity disorder

Objectives: The purpose of this study was to investigate oxidative stress in children with attention deficit hyperactivity disorder (ADHD).

Methods: Total oxidant status (TOS), total antioxidant status (TAS), paraxonase-1 (PON-1) and arylesterase (ARE) activity were measured in 76 children (44 boys, 32 girls) diagnosed with ADHD according to the DSM-IV and 78 healthy children (46 boys, 32 girls).

Results: Age and sex were similar between the groups (P?>?0.05). TOS and the oxidative stress index (OSI) were higher in the patient group than the control group (P?<?0.001). PON-1 (P?=?0.002), ARE (P?=?0.010) activity and TAS (P?<?0.001) were lower in the patient group than the control group.

Discussion: We found decreased PON-1, ARE activity and TAS, and increased TOS and OSI in children with ADHD. Our study showed that there is significantly increased oxidative stress in children with ADHD.     

Oxidative stress is associated with decreased heart rate variability in patients with chronic kidney disease

Objectives: Elevated oxidative stress and reduced heart rate variability (HRV) is prevalent in patients with chronic kidney disease (CKD) and is associated with increased morbidity and mortality. Previous studies have identified a positive association between elevated oxidative stress and autonomic dysfunction, however this relationship has not yet been investigated in the CKD population.

Methods: Plasma was collected from 78 patients with stage 3–4 CKD (estimated glomerular filtration rate 25–60?ml/min/1.73?m²) for the assessment of oxidative stress, including plasma total F2-isoprostanes, glutathione peroxidase activity and total antioxidant capacity. Time and frequency HRV parameters were measured from a three lead electrocardiogram.

Results: Participants with elevated F2-isoprostanes had reduced HRV compared to patients with normal levels of F2-isoprostanes. A number of HRV parameters were found to be inversely correlated with F2-isoprostanes in all CKD patients, including SDNN (r?=??0.337; P?r?=??0.281, P?=?0.01), LF (r?=??0.315, P?r?=??0.288, P?=?0.01). Multiple linear regression found F2-isoprostanes to be an independent predictor of SDNN (r²?=?0.287, β?=??0.272, P?=?0.01).

Discussion: Oxidative stress is significantly and independently associated with HRV in patients with CKD. Identifying oxidative stress in the pathogenesis of autonomic dysfunction may help target therapeutic strategies.     

Dynamic thiol/disulphide homeostasis as indicator of oxidative stress in automotive workers

Abstract

Purpose: To examine thiol-disulphide homeostasis auto painters.

Materials and methods: A total of 115 male workers, including 60 auto painters workers and 55 reference group, of the painting and assembly line units respectively, were included in the study. Thiol-disulphide parameters and ischaemia-modified albumin (IMA) of groups were determined. Urinary hippuric acid, (HA) phenol, hexanedione, trichloroacetic acid, arsenic and blood lead and manganese were analysed.

Results: The median urinary HA level was significantly higher in auto painters when compared to the reference group [(2461 (1212) vs. 520 (513) µgr/L), (p?<?0.001)] . The mean disulphide level [19.7 (4.3) vs 0.15.1(4.1) μmol/L, (p?<?0.001)], the disulphide/native thiol ratio [4.72 (1.47) vs. 3.13 (1.21, (p?<?0.001)] and the disulphide/total thiol ratio [4.31 (1.23) vs. 2.94 (1.06), (p?<?0.001)] were higher in auto painters when compared to the reference group. There was a statistically significant positive correlation between urinary HA and disulphide concentrations (r?=?0.536 and p?<?0.001), disulphide/native thiol ratio (r?=?0.564 and p?<?0.001) and the disulphide/total thiol ratio (r?=?0.564 and p?<?0.001) and IMA (r?=?0.396 and p?<?0.001).

Conclusion: The results presented in this study showed that oxidative stress can be associated with occupational exposure to toluene denoted by alteration of thiol disulphide homeostasis and ischaemia-modified albumin levels.     

Circulating biomarkers of hypertrophy and fibrosis in patients with hypertrophic cardiomyopathy assessed by cardiac magnetic resonance

Abstract

Background: Myocardial fibrosis in hypertrophic cardiomyopathy (HCM) is associated with worse clinical outcomes. The availability of circulating biomarkers of myocardial fibrosis and hypertrophy would be helpful in clinical practice.

Objective: The aim of this study was to evaluate usefulness of various biomarkers of myocardial fibrosis and hypertrophy in HCM.

Methods: Levels of biomarkers: soluble ST2 (sST2), galectin-3 (Gal-3), growth differentiation factor-15 (GDF-15), NT-proBNP and high-sensitivity cardiac troponin T (hs-cTnT) were measured in 60 patients with HCM. All patients underwent cardiac magnetic resonance imaging to calculate parameters of hypertrophy and fibrosis.

Results: We observed positive correlations among sST2 levels and left ventricular mass (LVM) (r?=?0.32, p?=?0.012), LV mass indexed for the body surface area (LVMI) (r?=?0.27, p?=?0.036) and maximal wall thickness (MWT) (r?=?0.31, p?=?0.015). No correlation was found between Gal-3 and GDF-15 levels and hypertrophy and fibrosis parameters. We observed positive correlations among hs-cTnT levels and LVM (r?=?0.58, p?<?0.0001), LVMI (r?=?0.48, p?=?0.0001), MWT (r?=?0.31, p?=?0.015) and late gadolinium enhancement (LGE) mass (r?=?0.37, p?=?0.003). There were positive correlations between NT-proBNP levels and LVM (r?=?0.33, p?=?0.01), LVMI (r?=?0.41, p?=?0.001), MWT (r?=?0.42, p?<?0.001) and LGE mass (r?=?0.44, p?<?0.001).

Conclusions: Although no correlation between sST2 levels and myocardial fibrosis was found, sST2 may provide some additional information about hypertrophy extension. NT-proBNP and hs-cTnT are useful biomarkers in assessment of hypertrophy and fibrosis in HCM.     

Association between gestational diabetes and biomarkers: a role in diagnosis

Background: We investigated the association between markers of insulin resistance, chronic inflammation, and adipokines and GDM.

Methods: In our case-cohort study in Johannesburg we included women with GDM and controls. We tested the ability of biomarkers to identify women at high risk of GDM.

Results: Of the 262 pregnant women, 83 (31.7%) had GDM. Women with GDM were heavier (p?=?0.04) and had more clinical risk factors (p?=?0.008). We found a significant difference in fasting insulin (p?p?=?0.046), HOMA (p?p?Conclusions: Insulin sensitivity markers are promising tools to identify women at high risk of GDM.     

Association between circulating irisin levels and epicardial fat in patients with treatment-naïve overt hyperthyroidism

Abstract

Background: Hyperthyroidism is associated with increased metabolic activity and thermogenesis. Irisin is a key molecule in thermogenesis and energy expenditure via adipose tissue browning. Epicardial fat was previously defined as brown-like fat. Thus, here we aimed to evaluate the association between serum irisin level and epicardial fat thickness (EFT) in patients with hyperthyroidism.

Methods: A total of 25 hyperthyroid patients and 24 age-, sex- and BMI-matched healthy controls were enrolled. Serum irisin levels, thyroid hormone levels, and body compositions were compared. EFT was measured via transthoracic echocardiography.

Results: Serum irisin level and EFT were significantly higher in the hyperthyroid group (p?<?0.001 and p?=?0.001, respectively). The distributions of fat-free mass, muscle mass and fat mass were similar between the study groups. Serum irisin level was negatively correlated with TSH (p?<?0.001) and positively correlated with fT3 (p?<?0.001), fT4 (p?<?0.001) and TSH receptor antibody (p?=?0.002) levels and EFT (p?=?0.001). In multivariate linear regression analysis, TSH (β?=??0.475, p?<?0.001) and EFT (β?=?0.290, p?=?0.023) levels were significantly associated with serum irisin levels.

Conclusions: An increased serum irisin level associated with EFT might contribute to metabolic derangement in hyperthyroidism. Further studies are needed to elucidate whether irisin levels and EFT are affected by hyperthyroidism or vice versa.     

Cystatin C,NT-proBNP,and inflammatory markers in acute heart failure: insights into the cardiorenal syndrome

Background: Inflammation is thought to be a mediator in the pathophysiology of the cardiorenal syndrome. We evaluated the interactions between kidney function, cardiac stress, and various inflammatory cytokines in patients with acute heart failure (AHF). The effect on 1-year mortality was also assessed.

Methods and results: Plasma levels of cystatin C, NT-proBNP, and inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor-α [TNF-α], IL-10) were measured in consecutive patients (n?=?465) hospitalized for AHF. After adjustment for demographic characteristics and comorbidities, TNF-α had the strongest relation with renal function (β?=?0.39, P?<?0.0001). Elevated TNF-α levels were seen in patients with high cystatin C, irrespective of NT-proBNP. Levels of IL-6 (β?=?0.26, P?<?0.0001) and IL-10 (β?=?0.15, P?<?0.01), but not TNF-α, were associated with NT-proBNP. Moreover, the most elevated levels of IL-6 were seen in patients with combined high NT-proBNP and high cystatin C. Cox regression analysis found IL-6 above median to be independently predictive of mortality (hazard ratio 1.9; 95% CI 1.2–2.9, P?=?0.003). TNF-α was not significantly associated with prognosis in the overall population after adjustment for multiple covariates, but improved risk stratification in the subgroup with low cystatin C and NT-proBNP.

Conclusion: Levels of TNF-α in AHF are related to kidney function, but not to NT-proBNP. IL-6 seems to be more associated with cardiac stress. Patients with severe dual organ dysfunction have the highest levels of IL-6 and TNF-α. Different relations of inflammatory cytokines to renal function and cardiac stress need to be considered when evaluating heart–kidney interactions.     

Hyperglycaemia,oxidative stress and inflammatory markers

Introduction: The increasing prevalence of hyperglycaemia implicates a state of oxidative stress and inflammation. Traditional and emerging biomarkers associated with increasing hyperglycaemia were assessed to clarify their role they play in hyperglycaemia.

Results: 309 participants attending a rural diabetic screening program were categorised into control and quintile groups based upon glucose levels: 1st quintile - <4.5?mmol/L and 4th, 5th quintile - >6.1?mmol/L. Significant results were obtained for anthropometric data and biochemical markers - glucose, HbA1c and total cholesterol (P?P?P?P?Conclusion: This study provided further evidence that inflammatory and oxidative stress biomarkers may contribute to diagnostic information associated with preclinical increases in BGL. Further we have provided a unique study in the analysis of ratios of inflammatory biomarkers and correlations with increasing BGL.     

Reduced antioxidant capacity and increased subclinical inflammation markers in prepubescent obese children and their relationship with nutritional markers and metabolic parameters

Objective: There are associations between some inflammatory and oxidative markers and obesity in adults, but whether prepubescent children of different weights also have such markers has not been studied. We investigated multiple inflammatory markers and levels of erythrocyte oxidant/antioxidant enzymes in prepubescent children of different weights.

Methods: Children aged 2–11 years were divided into three groups: 80 were underweight, 90 were obese but otherwise healthy, and 80 were healthy age- and sex-matched children of normal-weight. We analyzed inflammatory markers and the total oxidant status, total antioxidant status (TAS), and total thiol level were also determined, and the oxidative stress index was calculated as an indicator of the degree of oxidative stress.

Results: The obese group exhibited higher levels of fasting glucose, insulin, total cholesterol, triglycerides, the homeostatic model assessment of insulin resistance (HOMA-IR), and the homeostatic model assessment of β-cell function (HOMA-β), C-reactive protein (CRP), neutrophils, and neutrophil/lymphocyte ratio (NLR), as well as lower TAS and total thiol levels than the other two groups (all P?<?0.001). Moreover, TAS and total thiols were negatively correlated with age in the obese group (r?=??0.212, P?=?0.001; r?=??0.231, P?<?0.001, respectively). CRP levels in plasma were positively correlated with the body mass index (BMI), insulin and glucose levels, HOMA-IR, HOMA-β, WBC and neutrophil counts, and the NLR, and were negatively correlated with TAS and total thiol levels in the overall studied population.

Discussion: The coexistence of increased obesity-related subclinical inflammation and decreased antioxidant capacity can be observed even in prepubescence, and may eventually increase the risk of long-term vascular damage.     

Diagnostic utility of MR-proANP and NT-proBNP in elderly outpatients with a high risk of heart failure: the Copenhagen heart failure risk study

Abstract

Background: Amino-terminal-pro-B-type-natriuretic-peptide (NT-proBNP) is a diagnostic biomarker for heart failure (HF), but plasma concentrations are influenced by numerous factors. Mid-regional-pro-atrial-natriuretic-peptide (MR-proANP) have comparable diagnostic value in acute HF. However, data are lacking in the non-acute setting. This study sought to assess the diagnostic utility of MR-proANP in outpatients with a high risk of HF.

Methods: This prospective study included 399 outpatients. Inclusion criteria were: age?≥?60?years, ≥1 risk factor for HF (diabetes, chronic kidney disease, vascular disease, atrial fibrillation, hypertension), without known or suspected HF. Unrecognized HF was diagnosed based on clinical signs, patient-reported symptoms and echocardiography. Plasma concentrations of MR-proANP and NT-proBNP were analysed.

Results: In total, 65 patients were diagnosed with HF or asymptomatic left ventricular systolic dysfunction (N?=?12 LVEF?≤?40%, N?=?7 LVEF?>?40% to ≤50%, N?=?46 LVEF?>?50%). Both MR-proANP (odds-ratio: 1.77; 95% CI:1.16–2.72; p?=?0.009) and NT-proBNP (odds-ratio: 1.49; 95% CI:1.22–1.82; p?<?0.001) were associated with HF. Area under receiver-operator characteristics curve (AUC) for the diagnosis of HF or asymptomatic left ventricular systolic dysfunction was higher for MR-proANP (AUC?=?0.886; p?<?0.001) and NT-proBNP (AUC?=?0.910; p?<?0.001) compared to patient-reported symptoms of HF (AUC?=?0.830), but NT-proBNP added more diagnostic information compared to MR-proANP (p?=?0.022).

Conclusions: Both NT-proBNP and MR-proANP are useful biomarkers in the diagnosis of HF or asymptomatic left ventricular systolic dysfunction in a non-acute setting. However, NT-proBNP added more diagnostic information compared to MR-proANP.     

Fibulin-5, an integrin-binding matricellular protein: its function in development and disease

Interactions between the extracellular matrix (ECM) and cells are critical in embryonic development, tissue homeostasis, physiological remodeling, and tumorigenesis. Matricellular proteins, a group of ECM components, mediate cell-ECM interactions. One such molecule, Fibulin-5 is a 66-kDa glycoprotein secreted by various cell types, including vascular smooth muscle cells (SMCs), fibroblasts, and endothelial cells. Fibulin-5 contributes to the formation of elastic fibers by binding to structural components including tropoelastin and fibrillin-1, and to cross-linking enzymes, aiding elastic fiber assembly. Mice deficient in the fibulin-5 gene (Fbln5) exhibit systemic elastic fiber defects with manifestations of loose skin, tortuous aorta, emphysematous lung and genital prolapse. Although Fbln5 expression is down-regulated after birth, following the completion of elastic fiber formation, expression is reactivated upon tissue injury, affecting diverse cellular functions independent of its elastogenic function. Fibulin-5 contains an evolutionally conserved arginine-glycine-aspartic acid (RGD) motif in the N-terminal region, which mediates binding to a subset of integrins, including α5β1, αvβ3, and αvβ5. Fibulin-5 enhances substrate attachment of endothelial cells, while inhibiting migration and proliferation in a cell type- and context-dependent manner. The antagonistic function of fibulin-5 in angiogenesis has been demonstrated in vitro and in vivo; fibulin-5 may block angiogenesis by inducing the anti-angiogenic molecule thrompospondin-1, by antagonizing VEGF₁₆₅-mediated signaling, and/or by antagonizing fibronectin-mediated signaling through directly binding and blocking the α5β1 fibronectin receptor. The overall effect of fibulin-5 on tumor growth depends on the balance between the inhibitory property of fibulin-5 on angiogenesis and the direct effect of fibulin-5 on proliferation and migration of tumor cells. However, the effect of tumor-derived versus host microenvironment-derived fibulin-5 remains to be evaluated.     

Relationship of troponin to incident atrial fibrillation occurrence,recurrence after radiofrequency ablation and prognosis: a systematic review,meta-analysis and meta-regression

Objective: To explore the association between the levels of troponin (Tn) and incident atrial fibrillation (AF) occurrence, AF recurrence after radiofrequency ablation (RFA), and the risk trend of AF related prognosis (stroke, major bleeding and mortality).

Methods: Twenty-seven studies were included after a systematic search in PubMed from 2005 to 2017, including 13 associated with incident AF occurrence, 8 associated with AF recurrence after RFA and 6 studies evaluating the risk trend of AF-related prognosis with increased Tn levels.

Results: Compared with ‘no incident AF occurrence’ patients, the incident AF occurrence group had similar baseline troponin I (TnI) levels (standardized mean differences [SMD]?=?0.42, 95% CI: ?0.02–0.86, p?=?0.06; I²?=?87.0%, N?=?6), but higher troponin T (TnT) levels (SMD?=?3.77, 2.13–5.42, p?<0.001; I²=99.7%, N?=?8). AF recurrence patients had similar peri-ablation TnI levels, but higher peri-ablation TnT levels compared to the ‘no AF recurrence’ group with pooled SMD. (TnI: SMD: ?0.61, ?1.22to 0, p?=?0.049; I²?=?87.1%; TnT: 0.38, 0.14–0.62, p?=?0.002; I²?=?64.7%). On meta-regression, there was an increased risk trend for stroke/systemic embolism (SE) (r²?=?0.93, p?=?0.04) or major bleeding (r²?=?0.99, p?r²?=?0.09, p?=?0.25) or TnT (r²?=?0.20, p?=?0.31), and stroke/SE (r²?=?0.02, p?=?0.74) or major bleeding (r²?=?0.002, p?=?0.92) was non-significantly related to increasing TnI levels.

Conclusions: In our systematic review, meta-analysis and meta-regression, TnT was associated with both incident AF occurrence and AF recurrence after RFA, as well as stroke/SE and major bleeding. In contrast, TnI was not associated with incident AF occurrence, AF recurrence after RFA or prognosis (stroke/SE, major bleeding).     

Snoring and aortic dimension in Marfan syndrome

Recent reports suggest that self-reported snoring, which is a feature of obstructive sleep apnea, is associated with aortic enlargement in Marfan syndrome (MFS). Objective assessment of snoring although lacking, could provide a rational for OSA screening in MFS patients. Our goal in this study was to examine the association between objective measurements of snoring with OSA and aortic size in persons with MFS. Consecutive persons with MFS who reported snoring were recruited at Johns Hopkins, completed the Epworth Sleepiness Scale (ESS) and underwent overnight polysomnography during which inspiratory sound was captured. We measured breath-by-breath peak decibel levels and snoring was defined as flow limitation with sound?≥?40 dB(A). OSA was defined as an apnea–hypopnea-index (AHI)?≥?15 or AHI: 5–15 and ESS?>?10. Participants’ aortic data were collated to ascertain aortic root diameter. Regression models were used to determine the relationship of snoring breath% with OSA and aortic root diameter. In our cohort (M|F:13|16, Age: 37.0?±?15.5 years, Aortic diameter; 38.9?±?4.8 mm), a 1-unit increase in snoring breath percentage increased the odds of having OSA by 5% in both the unadjusted (OR?=?1.05, p?=?0.040) model, and a model adjusted for age and sex (OR?=?1.05, p?=?0.048). Similarly, a 10-unit increase in snoring breath percentage was associated with a 1 mm increase in contemporaneous aortic-root-diameter in both unadjusted (β?=?0.09, p?=?0.007), and adjusted (β?=?0.08, p?=?0.023) models. Objective snoring assessment could provide a means for identifying persons with MFS who need sleep studies, who may also be at risk for more severe aortic disease.

     

Effects of exercise and lifestyle intervention on oxidative stress in chronic kidney disease

Objectives: Determine the effects of a 12-month exercise and lifestyle intervention program on changes in plasma biomarkers of oxidative stress in pre-dialysis chronic kidney disease (CKD) patients.

Methods: A total of 136 stage 3–4 CKD patients were randomized to receive standard nephrological care with (N?=?72) or without (N?=?64) a lifestyle and exercise intervention for 12 months. Plasma total F₂-isoprostanes (IsoP), glutathione peroxidase (GPX) activity, total antioxidant capacity (TAC), anthropometric and biochemical data were collected at baseline and at 12 months.

Results: There were no significant differences between groups at baseline. There were no significant differences in changes for standard care and lifestyle intervention, respectively, in IsoP (p?=?0.88), GPX (p?=?0.87), or TAC (p?=?0.56). Patients identified as having high IsoP at baseline (>250 pg/mL) had a greater decrease in IsoP with lifestyle intervention compared to standard care; however, the difference was not statistically significant (p?=?0.06). There was no difference in the change in kidney function (eGFR) between standard care and lifestyle intervention (p?=?0.33).

Discussion: Exercise and lifestyle modification in stage 3–4 CKD did not produce changes in systemic biomarkers of oxidative stress over a 12-month period, but patients with high IsoP may benefit most from the addition of intervention to standard care.     

Increased oxidative stress alters nucleosides metabolite levels in sickle cell anemia

Objectives: This study was conducted to assess the markers of oxidative stress, myeloperoxidase (MPO), acetylcholinesterase (AChE) and xanthine oxidase (XO) activities as well as the levels of nucleotide metabolites in sickle cell anemia (SCA) patients.

Methods: Fifteen SCA treated patients and 30 health subjects (control group) were selected. The markers of oxidative stress (levels of reactive oxygen species (ROS), plasma proteins, carbonyl content, lipid peroxidation (TBARS), total thiols (T-SH), glutathione and catalase activity), MPO, AChE and XO activities as well as the levels of nucleotide metabolites were measured in SCA patients.

Results: ROS, thiobarbituric acid-reactive substances (TBARS) and T-SH levels as well as the activities of catalase and MPO were significantly increased while glutathione level was reduced in SCA patients. Furthermore, a significant (P?P?P?P?Discussion: The altered parameters in SCA patients suggest that the generation and impairment of oxidative stress in this disease as well as antioxidant markers are contributory factors towards cellular redox homeostasis and alteration of purine metabolites.