Serum phosphate and social deprivation independently predict all-cause mortality in chronic kidney disease

Background: Hyperphosphataemia is linked to cardiovascular disease and mortality in chronic kidney disease (CKD). Outcome in CKD is also affected by socioeconomic status. The objective of this study was to assess the associations between serum phosphate, multiple deprivation and outcome in CKD patients. Methods: All adult patients currently not on renal replacement therapy (RRT), with first time attendance to the renal outpatient clinics in the Glasgow area between July 2010 and June 2014, were included in this prospective study. Area socioeconomic status was assessed as quintiles of the Scottish Index of Multiple Deprivation (SIMD). Outcomes were all-cause and cardiovascular mortality and commencement of RRT. Results: The cohort included 2950 patients with a median (interquartile range) age 67.6 (53.6–76.9) years. Median (interquartile range) eGFR was 38.1 (26.3–63.5) ml/min/1.73 m 2 , mean (±standard deviation) phosphate was 1.13 (±0.24) mmol/L and 31.6 % belonged to the most deprived quintile (SIMD quintile I). During follow-up 375 patients died and 98 commenced RRT. Phosphate ≥1.50 mmol/L was associated with all-cause (hazard ratio (HR) 2.51; 95 % confidence interval (CI) 1.63-3.89) and cardiovascular (HR 5.05; 95 % CI 1.90–13.46) mortality when compared to phosphate 0.90–1.09 mmol/L in multivariable analyses. SIMD quintile I was independently associated with all-cause mortality. Phosphate did not weaken the association between deprivation index and mortality, and there was no interaction between phosphate and SIMD quintiles. Neither phosphate nor SIMD predicted commencement of RRT. Conclusions Multiple deprivation and serum phosphate were strong, independent predictors of all-cause mortality in CKD and showed no interaction. Phosphate also predicted cardiovascular mortality. The results suggest that phosphate lowering should be pursued regardless of socioeconomic status

Risk factors of ischemic stroke and subsequent outcome in hemodialysis patients

Background and purpose: End stage renal disease (ESRD) requiring hemodialysis (HD) carries up to a 10-fold greater risk of stroke than normal renal function. Knowledge concerning risk factors and management strategies derived from the general population may not be applicable to those with ESRD. We studied a large ESRD population to identify risk factors and outcomes for stroke. Methods: All adult patients receiving HD for ESRD from 01/01/2007 to 31/12/2012 were extracted from the electronic patient record. Variables associated with stroke were identified by survival analysis; demographic, clinical, imaging and dialysis related variables were assessed and case-fatality determined. Follow-up was until 31/12/2013. Results: 1382 patients were identified (mean age 60.5 years, 58.5% male). The prevalence of AF was 21.2% and 59.4% were incident HD patients. 160 (11.6%) experienced a stroke during 3471 patient-years of follow-up (95% ischemic). Stroke incidence was 41.5/1000 patient-years in prevalent and 50.1/1000 patient-years in incident HD patients. Factors associated with stroke on regression analysis were prior stroke, diabetes and age at starting renal replacement therapy. AF was not significantly associated with stroke and warfarin did not affect stroke risk in warfarin treated patients. Fatality was 18.8% at 7, 26.9% at 28 and 56.3% 365 days after stroke.<p></p> Conclusions: Incidence of stroke is high in patients with ESRD on HD with high case-fatality. Incident HD patients had the highest stroke incidence. Many, but not all, important risk factors commonly associated with stroke in the general population were not associated with stroke in patients receiving HD

Kidney function and markers of renal damage after renal denervation. Does method of measurement matter? The Reshape CV-Risk Study

Data suggest that renal denervation (RDN) in treatment-resistant hypertension (TRHT) is safe in terms of renal function. However, most studies report kidney function as creatinine-based estimated glomerular filtration rate (eGFR), which may be biased by non-renal factors. Damage markers other than albuminuria have never been evaluated after RDN. In this non-randomized RDN trial, we studied changes in kidney function, assessed as measured GFR (mGFR) and various GFR estimates, six months and two years after RDN. We also examined changes in albuminuria and a biomarker of tubular dysfunction. Adult non-diabetic patients with TRHT and eGFR ≥45 ml/min/1.73 m2 were recruited from hypertension clinics. Before bilateral RDN, mGFR was measured by iohexol clearance. We estimated eGFR from serum creatinine and cystatin C (eGFRcrea, eGFRcys, and eGFRcreacys), and albumin-creatinine ratio (ACR) and N-acetyl-β-D-glucosaminidase (NAG)-creatinine ratio (NAG-CR) were measured in spot urines. All measurements were repeated after six and twenty-four months. Twenty patients, mean age 54 (±9) years and baseline mGFR 83 (±20) ml/min/1.73 m2 underwent RDN. After six months, mGFR fell, eGFRcrea remained unchanged, whereas eGFRcys and eGFRcreacys increased. At 2 years’ follow-up, eGFRcreacys was significantly lower than at baseline. mGFR was 78 (±28) ml/min/1.73 m2. Change in ambulatory systolic BP predicted change in eGFRcrea. Urinary NAG-CR, but not ACR, increased during follow-up. Different GFR assessments gave diverging results after RDN. Therefore, care should be taken to method when evaluating kidney function after RDN. Increases in a tubular dysfunction biomarker suggest that kidney damage may occur. Long-term renal follow-up is needed after RDN

Impaired Fasting Glucose Is Associated With Renal Hyperfiltration in the General Population

Increased glomerular filtration rate (GFR), also called hyperfiltration, is a proposed mechanism for renal injury in diabetes. The causes of hyperfiltration in individuals without diabetes are largely unknown, including the possible role of borderline hyperglycemia. We assessed whether impaired fasting glucose (IFG; 5.6–6.9 mmol/L), elevated HbA1c, or hyperinsulinemia are associated with hyperfiltration in the general middle-aged population. A total of 1,560 individuals, aged 50–62 years without diabetes, were included in the Renal Iohexol Clearance Survey in Tromsø 6 (RENIS-T6). GFR was measured as single-sample plasma iohexol clearance. Hyperfiltration was defined as GFR >90th percentile, adjusted for sex, age, weight, height, and use of renin-angiotensin system inhibitors. Participants with IFG had a multivariable-adjusted odds ratio of 1.56 (95% CI 1.07–2.25) for hyperfiltration compared with individuals with normal fasting glucose. Odds ratios (95% CI) of hyperfiltration calculated for a 1-unit increase in fasting plasma glucose (FPG) and HbA1c, after multivariable-adjustment, were 1.97 (1.36–2.85) and 2.23 (1.30–3.86). There was no association between fasting insulin levels and hyperfiltration. A nonlinear association between FPG and GFR was observed (df = 3, P < 0.0001). GFR increased with higher glucose levels, with a steeper slope beginning at FPG ≥5.4 mmol/L. Borderline hyperglycemia was associated with hyperfiltration, whereas hyperinsulinemia was not. Longitudinal studies are needed to investigate whether the hyperfiltration associated with IFG is a risk factor for renal injury in the general population

Predictors of atherosclerotic events in patients on haemodialysis: post hoc analyses from the AURORA Study

Background: Patients on haemodialysis (HD) are at high risk for cardiovascular events, but heart failure and sudden death are more common than atherosclerotic events. The A Study to Evaluate the Use of Rosuvastatinin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events (AURORA) trial was designed to assess the effect of rosuvastatin on myocardial infarction and death from any cardiac cause in 2773 HD patients. We studied predictors of the atherosclerotic cardiovascular events in AURORA. Methods: We readjudicated all deaths and presumed myocardial infarctions according to the criteria used in the Study of Heart and Renal Protection (SHARP); these were specifically developed to separate atherosclerotic from non-atherosclerotic cardiovascular events. The readjudicated atherosclerotic end point included the first event of the following: non-fatal myocardial infarction, fatal coronary heart disease, non-fatal and fatal non-haemorrhagic stroke, coronary revascularization procedures and death from ischaemic limb disease. Stepwise Cox regression analysis was used to identify the predictors of such events. Results: During a mean follow-up of 3.2 years, 506 patients experienced the new composite atherosclerotic outcome. Age, male sex, prevalent diabetes, prior cardiovascular disease, weekly dialysis duration, baseline albumin [hazard ratio (HR) 0.96; 95% confidence interval (CI) 0.94–0.99 per g/L increase], high-sensitivity C-reactive protein (HR 1.13; 95% CI 1.04–1.22 per mg/L increase) and oxidized low-density lipoprotein (LDL) cholesterol (HR 1.09; 95% CI 1.03–1.17 per 10 U/L increase) were selected as significant predictors in the model. Neither LDL cholesterol nor allocation to placebo/rosuvastatin therapy predicted the outcome. Conclusions: Even with the use of strict criteria for end point definition, non-traditional risk factors, but not lipid disturbances, predicted atherosclerotic events in HD patients

Comparing prevalence of chronic kidney disease and its risk factors between population-based surveys in Russia and Norway.

BACKGROUND: Little data exists on the prevalence of chronic kidney disease (CKD) in the Russian population. We aimed to estimate the prevalence of CKD in a population-based study in Russia, compare with a similar study in Norway, and investigate whether differences in risk factors explained between-study differences in CKD. METHODS: We compared age- and sex-standardised prevalence of reduced eGFR (< 60 ml/min/1.73m2 CKD-EPI creatinine equation), albuminuria and or a composite indicator of CKD (one measure of either reduced eGFR or albuminuria) between participants aged 40-69 in the population-based Know Your Heart (KYH) study, Russia (2015-2018 N = 4607) and the seventh Tromsø Study (Tromsø7), Norway (2015-2016 N = 17,646). We assessed the contribution of established CKD risk factors (low education, diabetes, hypertension, antihypertensive use, smoking, obesity) to between-study differences using logistic regression. RESULTS: Prevalence of reduced eGFR or albuminuria was 6.5% (95% Confidence Interval (CI) 5.4, 7.7) in KYH and 4.6% (95% CI 4.0, 5.2) in Tromsø7 standardised for sex and age. Odds of both clinical outcomes were higher in KYH than Tromsø7 (reduced eGFR OR 2.06 95% CI 1.67, 2.54; albuminuria OR 1.54 95% CI 1.16, 2.03) adjusted for sex and age. Risk factor adjustment explained the observed between-study difference in albuminuria (OR 0.92 95% CI 0.68, 1.25) but only partially reduced eGFR (OR 1.42 95% CI 1.11, 1.82). The strongest explanatory factors for the between-study difference was higher use of antihypertensives (Russian sample) for reduced eGFR and mean diastolic blood pressure for albuminuria. CONCLUSIONS: We found evidence of a higher burden of CKD within the sample from the population in Arkhangelsk and Novosibirsk compared to Tromsø, partly explained by between-study population differences in established risk factors. In particular hypertension defined by medication use was an important factor associated with the higher CKD prevalence in the Russian sample

β-Amyloid 25-35 Peptide Reduces the Expression of Glutamine Transporter SAT1 in Cultured Cortical Neurons

β-Amyloid (Aβ) peptides may cause malfunction and death of neurons in Alzheimer’s disease. We investigated the effect of Aβ on key transporters of amino acid neurotransmission in cells cultured from rat cerebral cortex. The cultures were treated with Aβ(25-35) at 3 and 10 μM for 12 and 24 h followed by quantitative analysis of immunofluorescence intensity. In mixed neuronal–glial cell cultures (from P1 rats), Aβ reduced the concentration of system A glutamine transporter 1 (SAT1), by up to 50% expressed relative to the neuronal marker microtubule-associated protein 2 (MAP2) in the same cell. No significant effects were detected on vesicular glutamate transporters VGLUT1 or VGLUT2 in neurons, or on glial system N glutamine transporter 1 (SN1). In neuronal cell cultures (from E18 rats), Aβ(25-35) did not reduce SAT1 immunoreactivity, suggesting that the observed effect depends on the presence of astroglia. The results indicate that Aβ may impair neuronal function and transmitter synthesis, and perhaps reduce excitotoxicity, through a reduction in neuronal glutamine uptake

Detection of Babesia divergens in southern Norway by using an immunofluorescence antibody test in cow sera

<p>Abstract</p> <p>Background</p> <p>The incidence of bovine babesiosis, caused by <it>Babesia divergens </it>(Apicomplexa: Piroplasmida) has decreased markedly since the 1930 s, but may re-emerge as a consequence of climate change and changes in legislation and pasturing practices. This is a potentially serious disease, with both economical and animal welfare consequences. Therefore, there is a need to survey the distribution of <it>B. divergens</it>.</p> <p>Methods</p> <p>We tested sera from 306 healthy pastured cows from 24 farms along the southern Norwegian coast by using an indirect immunofluorescence IgG antibody test (IFAT). Fractions of seropositive cows were compared by calculating 95% CI.</p> <p>Results</p> <p>The results of this test showed that 27% of the sera were positive for <it>B. divergens </it>antibodies. The fraction of antibody-positive sera that we detected showed a two-humped distribution, with a high fraction of positives being found in municipalities in the western and eastern parts of the study area, while the municipalities between these areas had few or no positive serum samples.</p> <p>Conclusions</p> <p>Neither the farmers' observations nor the Norwegian Dairy Herd Recording System give an adequate picture of the distribution of bovine babesiosis. Serological testing of cows by using IFAT is a convenient way of screening for the presence of <it>B. divergens </it>in an area.</p