Characterization of soluble thrombomodulin levels in patients with stage 3–5 chronic kidney disease

Abstract

Objective: This study aims to test the serum levels of soluble thrombomodulin (TM) in patients with chronic kidney disease (CKD)3–5 and to assess their connection with the different stages and severity of disease.

Methods: Sixty-seven patients with CKD are included, disease severity was evaluated accordingly to CKD staging and clinical data is collected. Nineteen healthy volunteers served as healthy controls. Serum soluble TM is analyzed by ELISA.

Results: The levels of soluble TM in all patients with CKD were significantly higher than those of healthy controls (p?<?0.001). CKD5 patients showed higher serum levels of soluble TM, in comparison to CKD4 patients (p?=?0.001), CKD3 patients (p?<?0.001), and healthy controls (p?<?0.001). The correlation analysis revealed significant correlation between serum soluble TM and disease severity (r?=?0.714, p?<?0.001). Serum soluble TM was found to be correlated with eGFR (r?=??0.766; p?<?0.001) and serum creatinine (r?=?0.778, p?<?0.001).

Conclusion: Soluble TM concentrations significantly increase in the CKD patients and are associated with the severity of the disease. Soluble TM may play critical roles in the development of CKD, as a biomarker of endothelial cells damage, anticoagulation and anti-inflammation.     

Variability of salivary markers of oxidative stress and antioxidant status in young healthy individuals

Objectives: Salivary advanced glycation end-products (AGEs), advanced oxidation protein products (AOPP), total antioxidant capacity (TAC), and ferric reducing ability of saliva (FRAS) are increased in various diseases. Little data exist for these markers in the healthy population. The aim of this study was to assess the inter-individual and intra-individual variability of AGEs, AOPP, TAC, and FRAS in the saliva of young healthy individuals.

Methods: Unstimulated saliva samples were collected from 16 females and 18 males daily over a period of 30 days. Markers were measured using spectrophotometric and spectrofluorometric microplate-based methods.

Results: All salivary markers measured were significantly higher in men than in women (P?<?0.05 for AGEs; P?<?0.001 for AOPP, TAC, and FRAS). The inter-individual variability was approximately 60% for AGEs and AOPP and 30–40% for TAC and FRAS in both genders. The inter-individual variability of FRAS was higher in men vs. women (P?<?0.01). Intra-individual variability ranged from 20% for TAC, to 30% for AGES and FRAS and 45% for AOPP.

Discussion: Intra-individual variability of salivary AGEs, AOPP, TAC, and FRAS indicates that their use is currently limited to large cohort studies. Identifying the underlying factors related to the high inter-individual and intra-individual variability is needed. Sex differences should be considered in future studies.     

Prostaglandin Endoperoxide H Synthase-2 (PGHS-2) Variants and Risk of Obesity and Microvascular Dysfunction Among Tunisians: Relevance of rs5277 (306G/C) and rs5275 (8473T/C) Genetic Markers

The purpose of this study was to determine the impact of six PGHS-2 genetic variants on obesity development and microvascular dysfunction. The study included 305 Tunisian subjects (186 normal weights, 35 overweights and 84 obeses). PCR analyses were used for allelic discrimination between polymorphisms. Prostaglandin (PGE2, PGI2), leptin, and matrix metalloproteinase (MMP1, 2, 3, 9) levels were evaluated by ELISA. Fatty acid composition was performed by gas chromatography–mass spectrometry. Our results revealed that subjects carrying the PGHS-2 306CC (rs5277) and 8473CC (rs5275) genotypes present higher anthropometric values compared to wild-type genotypes (306GG, BMI (Kg/m²): 27.11?±?0.58; WC (cm): 93.09?±?1.58; 306CC, BMI: 33.83?±?2.46; WC: 109.93?±?5.41; 8473TT, BMI: 27.75?±?0.68; WC: 93.96?±?1.75; 8473CC, BMI: 33.72?±?2.2; WC: 117.89?±?2.94). A reduced microvascular reactivity and a higher PGE2 level were also found in individuals with the 306CC and 8473CC genotypes in comparison to 306GG and 8473TT carriers (306GG, Peak Ach-CVC (PU/mmHg): 0.46?±?0.03; PGE2 (pg/ml): 7933.1?±?702; 306CC, Peak Ach-CVC: 0.24?±?0.01; PGE2: 13,380.3?±?966.2; 8473TT, Peak Ach-CVC: 0.48?±?0.05; PGE2: 7086.41?±?700.31; 8473CC, Peak Ach-CVC: 0.23?±?0.01; PGE2: 13,175.7?±?1165.8). Fatty acid analysis showed a significant increase of palmitic acid (PA) (34.2?±?2.09 vs. 16.82%?±?1.76, P?<?0.001), stearic acid (SA) (25.76?±?3.29 vs. 9.05%?±?2.53, P?<?0.001), and linoleic acid (LA) (5.25?±?1.18 vs. 0.5%?±?0.09, P?<?0.001) levels in individuals carrying the PGHS-2 306CC genotype when compared to GG genotype individuals. Subjects with the 8473CC genotype showed also a significant increase of PA, SA ,and LA levels when compared to TT genotype carriers (PA: 38.02?±?1.51 vs. 12.65%?±?1.54, P?<?0.001; SA: 32.96?±?1.87 vs. 1.38%?±?0.56, P?<?0.001; LA: 26.84?±?2.09 vs. 3.7%?±?1.54, P?<?0.001). Logistic regression analysis revealed that PGHS-2 306CC and 8473CC variants are significantly associated with obesity status (OR 6.25, CI (1.8–21.6), P?=?0.004; OR 3.01, CI (1.13–8.52), P?=?0.03, respectively). Haplotypes containing the C₃₀₆:T₈₄₇₃ (OR 2.91; P?=?0.01) and G_306:C₈₄₇₃ (OR 5.25; P?=?0.002) combinations were associated with an enhanced risk for obesity development in the studied population. In conclusion, our results highlight that PGHS-2 306G/C and 8473T/C variants could be useful indicators of obesity development, inflammation, and microvascular dysfunction among Tunisians.

     

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.     

Systematic analysis of long non-coding RNA and mRNA expression changes in ApoE-deficient mice during atherosclerosis

Hypertension (HT), a common age-related disorder, is an important risk factor for cardiovascular disease. This study aims to identify the prevalence of HT in Portuguese centenarians and evaluate whether gene polymorphisms encoding key molecules in blood pressure (BP) regulation are associated with longevity. There were recruited 253 centenarians (100.26?±?1.98 years) and 268 control subjects (67.51?±?3.25 years). Hypertension (ESH/ESC2013 and JNC8) and diabetes (WHO) were evaluate. Genetic polymorphisms of renin-angiotensin-aldosterone system (RAAS) and NOS3 were determined. The prevalence of HT among centenarians was 64.4% and the majority (58.9%) were controlled, differing from control group both on frequency (P?<?0.001) and on their control (P?<?0.001). We found that HT is a risk factor for not achieving longevity (OR 2.531, 95% CI 1.688–3.793, P?<?0.001), the same for diabetes (OR 5.669 95% CI 2.966–10.835, P?<?0.001), and male gender (OR 2.196, 95% CI 1.493–3.29, P?<?0.001). Hypertension, adjusted for gender and diabetes, was independent risk factor anti-longevity (OR 2.007, 95% CI 1320–3.052, P?=?0.001). The ACE_D and NOS3_G alleles were more frequent in centenarians compared to controls (P?<?0.001, both cases). ACE_II and NOS3_TT genotypes, adjusted for BP, gender and diabetes, increased risk in 3.748 (95% CI 1.887–7.444) and 2.533 (95% CI 1.483–4.327), respectively, in relation to ACE_DD (P?<?0.001) and NOS3_GG (P?=?0.001), against longevity. Our findings suggest that the prevalence of hypertension was lower in Portuguese centenarians than in the elderly, reinforcing the importance of better cardiovascular risk profiles to achieve longevity even in the presence of genetic condition.

     

Paraoxonase and arylesterase levels in autoimmune thyroid diseases

Objective: The aim of this study was to evaluate serum paraoxonase-1 (PON1) activity and its association with oxidative stress in autoimmune thyroid disease (AITD).

Methods: A total of 50 patients with AITD, including 25 with Hashimoto's thyroiditis and 25 with Graves’ disease were enrolled. The control group comprised 27 healthy subjects. Blood samples were obtained in the euthyroid period and 3 months after initiation of medical treatment. Serum samples from patients with AITD and the healthy control group were analyzed for basal PON1, salt-stimulated PON1, and arylesterase (ARE) activities, along with lipid hydroperoxide (LOOH) and total free sulfhydryl (–SH) levels.

Results: Serum PON1 activities and –SH levels were significantly lower (P?<?0.001, for each), whereas LOOH levels were significantly higher (P?<?0.001, for each) in patients with AITD, compared to the control group. We observed no significant differences in ARE levels between the patient and healthy control groups (P?>?0.05). PON1 activity was positively correlated with –SH (r?=?0.522, P?<?0.001) and negatively correlated with LOOH (r?=??0.487, P?<?0.001). PON1 phenotype distribution of the subjects was not significantly different among the three groups (P?=?0.961).

Conclusions: Serum PON1 activity is decreased in patients with AITD, and correlated positively with –SH, a well-known antioxidant, and negatively with LOOH, an index of lipid oxidation.     

Changes of urinary phospholipids in the chronic kidney disease patients

Abstract

Objective: To evaluate whether urinary phospholipids could be regarded as biomarkers of chronic kidney disease.

Materials and methods: Thirteen healthy volunteers and 26 consecutive chronic kidney disease patients were included. Urinary phospholipids were quantified by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

Results: Urinary phosphatidylcholines concentrations (PC 16:0/16:0, 16:0/22:3, 16:0/18:1 and 16:0/18:2) were significantly higher both in glomerulonephritis group (all p?<?0.001) and in tubulointerstitial injury group (all p?<?0.05) than in healthy control group. Meanwhile, sphingomyelin concentrations (SM 18:1/16:0 and 18:1/18:0) in glomerulonephritis group were significantly higher than those in healthy control group (all p?<?0.001). Urinary PCs and SMs were positively correlated with proteinuria but negatively correlated with serum albumin. Meanwhile, PCs were positively correlated with serum creatinine.

Conclusion: Our work first demonstrated that urinary phospholipids might be biomarkers for the chronic kidney disease patients. Increased urinary phospholipids in chronic kidney disease patients might result from proteinuria, damaged kidney function or proteinuria induced hypoalbuminemia or lipotoxicity.     

A comparison of creatinine vs. specific gravity to correct for urinary dilution of cotinine

Context: The validity of urinary correction standards has not been established for most analytes. Methods: We compared urinary creatinine and specific gravity as dilution correction standards for cotinine in a community-based study of smokers.

Results: Models of blood cotinine regressed against CR or SG (measured by total soluble solids) significantly improved the fit compared to a model without a dilution measure (P?<?0.01). There were no differences in model fit between CR- and SG-corrected values. Both CR and SG were significant predictors of urinary cotinine regressed against cigarettes smoked per day (P?<?0.01). Conclusion: CR and SG are valid and interchangeable correction standards.     

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.     

SPARCL1 as a biomarker of maladaptive right ventricular remodelling in pulmonary hypertension

Abstract

Aim: This study assessed the utility of SPARC-like protein 1 (SPARCL1) as a biomarker of maladaptive right ventricular (RV) function in patients with pulmonary hypertension (PH).

Methods: In this prospective study, we examined SPARCL1 levels in 105 patients with adaptive (n?=?34) and maladaptive RV (n?=?32) pressure overload caused by PH, dilated cardiomyopathy (DCM, n?=?18) with LVEF < 35% and preserved RV function and controls without LV or RV abnormalities (n?=?21).

Results: The median SPARCL1 concentration in patients with maladaptive RV function was higher than in those with adaptive RV function (p?<?0.01), DCM (p?<?0.001) or controls (p?<?0.001). Patients with adaptive RV function had higher SPARCL1 concentrations than controls (p?<?0.05), whereas there was no difference between adaptive RV and DCM. SPARCL1 showed good predictive power for maladaptive RV (AUC 0.77, p?<?0.001) with an optimal cut-off value of 9.66?ng/ml. The TAPSE/PASP ratio was the only independent predictor of SPARCL1?≥?9.66?ng/ml in multivariable logistic regression analysis.

Conclusion: SPARCL1 shows potential as novel biomarker of RV pathological remodelling and is associated with RV maladaptation and ventriculoarterial uncoupling in PH.     

Resting Heart Rate as a Predictor of Body Weight Gain in the Early Stage of Hypertension

We did a prospective study to investigate whether clinic heart rate (HR) and 24‐h ambulatory HR were independent predictors of subsequent increase in body weight (BW) in young subjects screened for stage 1 hypertension. The study was conducted in 1,008 subjects from the Hypertension and Ambulatory Recording Venetia Study (HARVEST) followed for an average of 7 years. Ambulatory HR was obtained in 701 subjects. Data were adjusted for lifestyle factors and several confounders. During the follow‐up BW increased by 2.1 ± 7.2 kg in the whole cohort. Both baseline clinic HR (P = 0.007) and 24‐h HR (P = 0.013) were independent predictors of BMI at study end. In addition, changes in HR during the follow‐up either measured in the clinic (P = 0.036) or with 24‐h recording (P = 0.009) were independent associates of final BMI. In a multivariable Cox regression, baseline BMI (P < 0.001), male gender (P < 0.001), systolic blood pressure (BP) (P = 0.01), baseline clinic HR (P = 0.02), and follow‐up changes in clinic HR (P < 0.001) were independent predictors of overweight (Ov) or obesity (Ob) at the end of the follow‐up. Follow‐up changes in ambulatory HR (P = 0.01) were also independent predictors of Ov or Ob. However, when both clinic and ambulatory HRs were included in the same Cox model, only baseline clinic HR and its change during the follow‐up were independent predictors of outcome. In conclusion, baseline clinic HR and HR changes during the follow‐up are independent predictors of BW gain in young persons screened for stage 1 hypertension suggesting that sympathetic nervous system activity may play a role in the development of Ob in hypertension.     

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.     

Feeding habits of two sympatric loliginid squids,Uroteuthis (Photololigo) chinensis (Gray, 1849) and Uroteuthis (Photololigo) duvaucelii (d’Orbigny, 1835), in the lower part of the South China Sea

The feeding habits of two sympatric squid species, Uroteuthis (Photololigo) chinensis and Uroteuthis (Photololigo) duvaucelii from the southwestern Gulf of Thailand were studied. They fed on low numbers of food types (AF) and had a low diet breadth; 1.18 and 0.01 for U. (P.) chinensis and 1.49 and 0.05 for U. (P.) duvaucelii, respectively. Three major prey types (fishes, crustaceans and molluscs) were always detected and cannibalism was observed. Fish was the greatest contributor to the diet of both species, contributing 89.5% for U. (P.) chinensis and 69.9% for U. (P.) duvaucelii. Fish size significantly affected fullness index (FL) and AF for U. (P.) chinensis (P?<?0.001) and U. (P.) duvaucelii (P?<?0.001). Depth affected the FL of U. (P.) chinensis (P?<?0.001) but not of U. (P.) duvaucelii (P?>?0.05). Maturity stages of both male and female U. (P.) chinensis influenced FL (male: P?<?0.001; female: P?<?0.05) and AF (male: P?<?0.05; female: P?<?0.01). The FL of squid from cast nets was higher than those from trawls. The multivariate results showed dietary grouping between size classes of both species.     

What are the determinants of explicit and implicit motor imagery ability in stroke patients?: a controlled study

Abstract

Purpose: The purposes of the study were to (a) investigate both explicit and implicit motor imagery ability (MIA) impairment after stroke, (b) examine predictive effects of clinical characteristics for MIA after stroke.

Materials and Methods: Forty one patients with stroke (PwS) (mean age 59.41?±?10.19?years; %41 female) and 36 healthy participants (mean age 62.47?±?9.29?years; %47 female) completed Chaotic Motor Imagery Assessment-Hand Rotation for implicit MIA and Movement Imagery Questionnaire-3 (MIQ-3) and Box and Block Test (BBT) for explicit MIA. The severity of motor and sensory impairments were determined by the Fugl-Meyer Assessment-Upper Extremity (FMAUE) scores. The Turkish version of Motor Activity Log-28 was used to assess amount of use (AUS) and quality of movement in daily life.

Results: Our results indicated that both implicit and explicit MIA (except kinaesthetic imagery of MIQ-3) in PwS were statistically impaired compared to controls (p?<?0.05). The sensorimotor impairment level, amount of use and movement quality of the affected upper limb were found to be correlated with MIA in various degrees. Total motor scores in FMAUE and AUS were significant predictors of explicit MIA (p?<?0.01). Additionally, explicit MIA scores of stroke subgroups were statistically different between severely and mildly impaired patients, in favour of mildly impaired group (p?<?0.05).

Conclusion: In conclusion, both motor impairment level and amount of daily use of upper extremity were found to be predictive factors for explicit MIA. Further investigation with brain imaging techniques is needed to explore the validity of these findings in establishing MIA.     

Body mass index related electrocardiographic findings in healthy young individuals with a normal body mass index

Introduction

An increased body mass index (BMI) (>25 kg/m²) is associated with a wide range of electrocardiographic changes. However, the association between electrocardiographic changes and BMI in healthy young individuals with a normal BMI (18.5–25 kg/m²) is unknown. The aim of this study was to evaluate the association between BMI and electrocardiographic parameters.

Methods

Data from 1,290 volunteers aged 18 to 30 years collected at our centre were analysed. Only subjects considered healthy by a physician after review of collected data with a normal BMI and in sinus rhythm were included in the analysis. Subjects with a normal BMI (18.5–25 kg/m²) were divided into BMI quartiles analysis and a backward multivariate regression analysis with a normal BMI as a continuous variable was performed.

Results

Mean age was 22.7 ± 3.0 years, mean BMI was 22.0, and 73.4% were male. There were significant differences between the BMI quartiles in terms of maximum P-wave duration, P-wave balance, total P-wave area in lead V1, PR-interval duration, and heart axis. In the multivariate model maximum P-wave duration (standardised coefficient (SC) = +0.112, P < 0.001), P-wave balance in lead V1 (SC = +0.072, P < 0.001), heart axis (SC = −0.164, P < 0.001), and Sokolow-Lyon voltage (SC = −0.097, P < 0.001) were independently associated with BMI.

Conclusion

Increased BMI was related with discrete electrocardiographic alterations including an increased P-wave duration, increased P-wave balance, a leftward shift of the heart axis, and decreased Sokolow-Lyon voltage on a standard twelve lead electrocardiogram in healthy young individuals with a normal BMI.

     

Unpleasant Pictures Exposure Evokes Different Repercussion on Emotional State and Heart Rate Response in Healthy Women and Men

To evaluate the heart rate response, emotion and changes in anxiety and anger levels after exposure to unpleasant pictures from the International Assessment Pictures System (IAPS) compared with neutral picture exposure in healthy individuals. Forty participants (23 women) visited the laboratory on two occasions. State anger and state anxiety levels were evaluated pre- and post-visualization of a set of IAPS pictures and heart rate was monitored during exposure. Two different picture sets were utilized—one with neutral pictures (that served as the control) and the other with unpleasant pictures. State anxiety and state anger were higher in post-unpleasant session for women than before (p?<?0.001). For men, only state anxiety was higher in the post-unpleasant session (p?<?0.001). State anxiety (p?=?0.004) and state anger (p?<?0.001) post-unpleasant session was higher for women than in men. The pleasure and dominance domains were lower in the unpleasant session for both men and women (p?<?0.001), and the arousal domain was higher for both men and women (p?<?0.001) than in the neutral session. In the unpleasant session, arousal was higher (p?=?0.004), and dominance was lower (p?<?0.001) among women than among men, but no difference in pleasure was found (p?>?0.05). For women, average heart rate was higher on unpleasant session, compared to neutral (p?=?0.01), but not for men (p?>?0.05). Women are more sensitive and react strongly to unpleasant picture exposure. The IAPS unpleasant session was not able to induce anger levels in men.

     

Decreased Serum Selenium Levels are Correlated with Diminished Coronary Flow Reserve Among Hemodialysis Patients

Cardiovascular diseases are the main reason of high mortality among hemodialysis patients. Decreased serum selenium levels may have a role in accelerated atherosclerosis in this patient group. The hypothesis of this study was to show a correlation between decreased serum selenium levels and coronary flow reserve as an indicator of endothelial dysfunction and atherosclerosis in HD patients. Seventy-one chronic hemodialysis patients and age 65 and sex-matched healthy controls were included in the study. Plasma selenium levels were measured by spectrophotometry, and coronary flow reserve was assessed by transthoracic Doppler echocardiography. Serum selenium levels (34.16?±?6.15 ng/ml vs. 52.4?±?5.51 ng/ml, P?<?0.001) and coronary flow reserve values (1.73?±?0.11 vs. 2.32?±?0.28, P?<?0.001) were significantly lower in hemodialysis patients compared with controls, respectively. There was a significant positive correlation between coronary flow reserve and serum levels of selenium (r?=?0.676, P?<?0.001). A linear regression analysis showed that serum levels of selenium were independently and positively correlated with coronary flow reserve (regression coefficient?=?0.650, P?<?0.05). This study was the first to show a positive and independent correlation between decreased selenium levels and diminished coronary flow reserve as an indicator of endothelial dysfunction and atherosclerosis in hemodialysis patients. Our data suggest that decreased serum selenium levels may facilitate the development of endothelial dysfunction and disruption of coronary flow reserve which occur before the development of overt atherosclerosis.     

Stability and Fragmentation of the Activity Rhythm Across the Sleep-Wake Cycle: The Importance of Age,Lifestyle, and Mental Health

The rhythms of activity across the 24-h sleep-wake cycle, determined in part by the circadian clock, change with aging. Few large-scale studies measured the activity rhythm objectively in the general population. The present population-based study in middle-aged and elderly persons evaluated how activity rhythms change with age, and additionally investigated sociodemographics, mental health, lifestyle, and sleep characteristics as determinants of rhythms of activity. Activity rhythms were measured objectively with actigraphy. Recordings of at least 96?h (138?±?14?h, mean?±?SD) were collected from 1734 people (age: 62?±?9.4?yrs) participating in the Rotterdam Study. Activity rhythms were quantified by calculating interdaily stability, i.e., the stability of the rhythm over days, and intradaily variability, i.e., the fragmentation of the rhythm relative to its 24-h amplitude. We assessed age, gender, presence of a partner, employment, cognitive functioning, depressive symptoms, body mass index (BMI), coffee use, alcohol use, and smoking as determinants. The results indicate that older age is associated with a more stable 24-h activity profile (β?=?0.07, p?=?0.02), but also with a more fragmented distribution of periods of activity and inactivity (β?=?0.20, p?<?0.001). Having more depressive symptoms was related to less stable (β?=??0.07, p?=?0.005) and more fragmented (β?=?0.10, p?<?0.001) rhythms. A high BMI and smoking were also associated with less stable rhythms (BMI: β?=??0.11, p?<?0.001; smoking: β?=??0.11, p?<?0.001) and more fragmented rhythms (BMI: β?=?0.09, p?<?0.001; smoking: β?=?0.11, p?<?0.001). We conclude that with older age the 24-h activity rhythm becomes more rigid, whereas the ability to maintain either an active or inactive state for a longer period of time is compromised. Both characteristics appear to be important for major health issues in old age.     

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.     

Renalase in children with chronic kidney disease

Abstract

Background: Renalase is kidney-derived molecule initially considered as catecholamine-inactivating enzyme. However, recent studies suggest that renalase exerts potent cardio- and nephroprotective actions, not related to its enzymatic activity.

Purpose: To assess renalase level in children with chronic kidney disease (CKD).

Material and methods: Serum renalase, BMI, arterial stiffness, peripheral and central blood pressure, intima-media thickness (IMT), medications, and biochemical parameters were analyzed in 38 children with CKD (12.23?±?4.19?years) (stage G2-5). Control group consisted of 38 healthy children.

Results: In the study group, GFR was 25.74?±?8.94?mL/min/1.73 m²; 6 children were dialyzed; 26 had arterial hypertension. Renalase level was higher in the study group compared to control group (p?<?0.001). In CKD children renalase correlated (p?<?0.05) with BMI Z-score (r?=?–0.36), alfacalcidol dose (r?=?0.41), GFR (r?=?–0.69), hemoglobin (r?=?–0.48), total cholesterol (r?=?0.35), LDL-cholesterol (r?=?0.36), triglycerides (r?=?0.52), phosphate (r?=?0.35), calcium-phosphorus product (r?=?0.35), parathormone (r?=?0.58), and pulse wave velocity Z-score (r?=?0.42). In multivariate analysis GFR (β?=?–0.63, p?<?0.001), triglycerides (β?=?0.59, p?=?0.002), and alfacalcidol dose (β?=?–0.49, p?=?0.010) were determinants of renalase.

Conclusions: In children with CKD there is a strong correlation between renalase level and CKD stage. Furthermore, in these patients renalase does not correlate with blood pressure but may be a marker of arterial stiffness.