Cardiovascular disease in chronic kidney disease: untying the Gordian knot

Chronic kidney disease awareness among the general population: tool validation and knowledge assessment in a developing country

Introduction

Good knowledge and early identification of chronic kidney disease (CKD) can help in preventing disease progression in its early stages and reducing undesired outcomes. The aim of the current study was to assess the level of public knowledge about CKD, determine predictors of better knowledge, and to construct and validate a CKD knowledge scale for public health assessment and research use.

Methods

A community-based cross-sectional study was conducted using an electronic self-administered questionnaire. All people living in Lebanon and being 18 years of age and above were considered eligible for recruitment. CKD knowledge was assessed by a 37-item scale that was constructed by principal component analysis and then validated. The score of the CKD knowledge scale was computed from the extracted factors. A multivariable binomial logistic regression model evaluated the sociodemographic and clinical predictors of the knowledge score.

Results

A total of 1308 participants were included. The scale items converged over 9 factors with Eigenvalue greater than 1 and explaining 53.26% of the total variance, and the total scale had a high Cronbach’s alpha of 0.804. All items of the scale significantly correlated with the full scale with correlation coefficients ranging from 0.082 to 0.558. The ROC curve analysis determined an optimal cutoff point of better knowledge at 47.5 with 70.6% sensitivity and 44.2% specificity. The CKD knowledge score had a median of 51.00 (IQR 47.00–55.00). Higher knowledge score was significantly associated with old age (ORa = 1.018, 95% CI 1.006–1.030, P = 0.003),, occupation (ORa = 3.919, 95% CI 2.107–7.288, P <  0.001), and recent renal function assessment (ORa = 2.314, 95% CI 1.532–3.495, P <  0.001). However, a lower knowledge score was significantly associated with lower level of education (ORa = 0.462, 95% CI 0.327–0.653, P <  0.001).

Conclusion

A reliable tool to assess public knowledge and awareness about CKD was developed and validated. The overall knowledge was good, however, important gaps in CKD awareness were detected in some areas and subpopulations. Therefore, public health stakeholders need to implement targeted CKD educational activities to minimize the disease burden.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02889-2.

Prognostic Value of Cardiorespiratory Fitness in Patients with Chronic Kidney Disease: The FIT (Henry Ford Exercise Testing) Project

PURPOSE

We conducted this study to investigate the association of cardiorespiratory fitness and all-cause mortality among patients with chronic kidney disease.

METHODS

We studied a retrospective cohort of patients from the Henry Ford Health System who underwent clinically indicated exercise stress testing with baseline cardiorespiratory fitness and estimated glomerular filtration rate measurement. Cardiorespiratory fitness was expressed as metabolic equivalents of task, and kidney function was categorized into stages according to estimated glomerular filtration rate. Multivariable-adjusted Cox proportional hazard models were used to examine the association between metabolic equivalents of task and all-cause mortality among patients with chronic kidney disease stages 3-5. Discrimination of mortality was assessed using receiver operating characteristic curves, while reclassification was evaluated using net reclassification index (NRI).

RESULTS

Among 50,121 participants, the mean age was 55 ± 12.6 years; 47.5% were women, 64.5% were white, and 6877 (13.7%) participants had chronic kidney disease stage 3-5. Over a median follow-up of 6.7 years, 6308 participants died (12.6%). Each 1-unit higher metabolic equivalents of task was associated with a significant 15% reduction in all-cause mortality (hazard ratio 0.85; 95% confidence interval [CI], 0.84-0.87). Metabolic equivalents of task improved discriminatory ability of mortality prediction when added to traditional risk factors and estimated glomerular filtration rate (area under the curve 0.7996; 95% CI, 0.789-0.810 vs 0.759; 95% CI, 0.748-0.770, respectively; P < .001). The addition of metabolic equivalents of task to traditional risk factors resulted in significant reclassification (6% for events, 5% for non-events: NRI = 0.13, P < .001).

CONCLUSIONS

Cardiorespiratory fitness improves mortality risk prediction among patients with chronic kidney disease. Cardiorespiratory fitness provides incremental prognostic information when added to traditional risk factors and may help guide treatment options among patients with renal dysfunction.

Arterial Remodelling in Chronic Kidney Disease: Impact of Uraemic Toxins and New Pharmacological Approaches

Chronic kidney disease (CKD) is a major public health concern that affects around 10 percent of the world's population. The severity of CKD is mainly due to the high prevalence of cardiovascular (CV) complications in this population. The aim of this review is to describe the arterial remodelling associated with CKD, to provide a quick overview of the mechanisms involved and to review the recent pharmacological approaches aimed at improving vascular health in CKD. CKD patients are exposed to metabolic and haemodynamic disorders that may affect the CV system. Large artery functional and geometric abnormalities have been well documented in CKD patients and are associated with an increase in arterial stiffness and a maladaptive remodelling. Uraemic toxins, such as indoxyl sulphate, p-cresyl sulphate, protein carbamylation and advanced glycation products, exert various effects on vascular smooth muscle cell functions. The low-grade inflammation associated with CKD may also affect arterial wall composition and remodelling. It is worth noting that the CV risk for CKD patients remains high despite the pharmacological control of traditional CV risk factors, suggesting the need for innovative therapeutic strategies. An interventional study targeting the NLRP3 inflammasome has provided some interesting preliminary results that need to be confirmed, especially in terms of safety.

Identifying community chronic kidney disease risk profile utilising general practice clinical records and spatial analysis: approach to inform policy and practice

BACKGROUND

Chronic kidney disease (CKD) causes a significant health burden in Australia, and up to 50% of Australians with CKD remain undiagnosed.

AIMS

To estimate the 5-year risk for CKD from general practice (GP) clinical records and to investigate the spatial variation and hot spots of CKD risk in an Australian community.

METHOD

A cross-sectional study was designed using de-identified GP clinical data recorded from 2010 to 2015. A total of 16 GP participated in this study from West Adelaide, Australia. We used health records of 36 565 patients aged 35-74 years, with no prior history of CKD. The 5-year estimated CKD risk was calculated using the QKidney algorithm. Individuals' risk score was aggregated to Statistical Area Level 1 to predict the community CKD risk. A spatial hotspot analysis was applied to identify the communities with greater risk.

RESULTS

The mean estimated 5-year risk for CKD in the sample population was 0.95% (0.93-0.97). Overall, 2.4% of the study population was at high risk of CKD. Significant hot spots and cold spots of CKD risk were identified within the study region. Hot spots were associated with lower socioeconomic status.

CONCLUSIONS

This study demonstrated a new approach to explore the spatial variation of CKD risk at a community level, and implementation of a risk prediction model into a clinical setting may aid in early detection and increase disease awareness in regions of unmet CKD care.

Vitamin D and cardiovascular disease in chronic kidney disease

Chronic kidney disease (CKD) is considered an independent risk factor for cardiovascular disease, with increased cardiovascular morbidity and mortality seen even in the early stages of CKD. Several studies have shown a high prevalence of vitamin D deficiency in individuals with CKD. Low vitamin D levels upregulate the renin-angiotensin-aldosterone system (RAAS), cause endothelial dysfunction, and increase inflammation. Epidemiological studies show an association between vitamin D deficiency and risk factors for cardiovascular disease, but a causal relationship has not been established. The high cardiovascular morbidity and mortality associated with CKD in adults requires therapies to decrease this elevated risk. However, results from several meta-analyses and randomized clinical trials in adults have not shown convincing evidence for the use of vitamin D therapy in improving cardiovascular outcomes. Lack of high-quality evidence from randomized clinical trials in children regarding the effectiveness and long-term safety of vitamin D treatment precludes any recommendations on its use to mitigate the cardiovascular burden of CKD.

Chronic Kidney Disease and Associated Risk Factors Assessment among Diabetes Mellitus Patients at A Tertiary Hospital, Northwest Ethiopia

BACKGROUND

The prevalence of chronic kidney disease, particularly in diabetic patients, is increasing rapidly throughout the world. Nowadays, many individuals in developing nations are suffering from diabetes which is one of the primary risk factors of chronic kidney disease.

METHODS

Institution based cross-sectional study was conducted at the University of Gondar Hospital from February to April 2016. A total of 229 study participants were selected using systematic random sampling technique. Urine sample was collected for albumin determination by dipstick. The Simplified Modification of Diet in Renal Disease study equation was used to estimate glomerular filtration rate. Binary logistic regression model was used to identify risk factors.

RESULTS

Of the total 229 study participants, 50.2% were females and the mean age was 47±15.7 years. Among study participants, the prevalence of chronic kidney disease (CKD) was found to be 21.8% (95% CI: 16% - 27%). Of all study participants, 9(3.9%) had renal impairment (eGFR < 60 ml/min/ 1.73 m2) and 46 (20.1%) had albuminuria. Older age (AOR: 5.239, 95% CI: 2.255-12.175), systolic blood pressure ≥140mmHg (AOR: 3.633, 95% CI: 1.597-8.265), type 2 diabetes mellitus (AOR: 3.751, 95% CI: 1.507-9.336) and longer duration of diabetes (AOR: 3.380, 95% CI: 1.393-8.197) were independent risk factors of CKD.

CONCLUSIONS

The study identified high prevalence (21.8%) of CKD among diabetic adults. CKD was significantly associated with older age, systolic blood pressure, type 2 DM and longer duration of DM. Thus, DM patients should be diagnosed for chronic kidney disease and then managed accordingly.

Emergency medicine evaluation and management of the end stage renal disease patient

BACKGROUND

End stage renal disease (ESRD) is increasing in the U.S., and these patients demonstrate greater all-cause mortality, cardiovascular events, and hospitalization rates when compared to those with normal renal function. These patients may experience significant complications associated with loss of renal function and dialysis.

OBJECTIVE

This review evaluates complications of ESRD including cardiopulmonary, neurologic, infectious disease, vascular, and access site complications, as well as medication use in this population.

DISCUSSION

ESRD incidence is rapidly increasing, and patients commonly require renal replacement therapy including hemodialysis (HDS) or peritoneal dialysis (PD), each type with specific features. These patients possess greater risk of neurologic complications, cardiopulmonary pathology, infection, and access site complications. Focused history and physical examination are essential. Neurologic issues include uremic encephalopathy, cerebrovascular pathology, and several others. Cardiopulmonary complications include pericarditis, pericardial effusion/tamponade, acute coronary syndrome, sudden cardiac death, electrolyte abnormalities, pulmonary edema, and air embolism. Infections are common, with patients more commonly presenting in atypical fashion. Access site infections and metastatic infections must be treated aggressively. Access site complications include bleeding, aneurysm/pseudoaneurysm, thrombosis/stenosis, and arterial steal syndrome. Specific medication considerations are required for analgesics, sedatives, neuromuscular blocking agents, antimicrobials, and anticoagulants.

CONCLUSIONS

Consideration of renal physiology with complications in ESRD can assist emergency providers in the evaluation and management of these patients. ESRD affects many organ systems, and specific pharmacologic considerations are required.

Urinary Angiotensinogen and Renin Excretion are Associated with Chronic Kidney Disease

BACKGROUND/AIMS

Several studies sought to identify new biomarkers for chronic kidney disease (CKD). As the renal renin-angiotensin system is activated in CKD, urinary angiotensinogen or renin excretion may be suitable candidates. We tested whether urinary angiotensinogen or renin excretion is elevated in CKD and whether these parameters are associated with estimated glomerular filtration rate (eGFR). We further tested whether urinary angiotensinogen or renin excretion may convey additional information beyond that provided by albuminuria.

METHODS

We measured urinary and plasma angiotensinogen, renin, albumin and creatinine in 177 CKD patients from the Greifswald Approach to Individualized Medicine project and in 283 healthy controls from the Study of Health in Pomerania. The urinary excretion of specific proteins is given as protein-to-creatinine ratio. Receiver operating characteristic (ROC) curves, spearman correlation coefficients and linear regression models were calculated.

RESULTS

Urinary angiotensinogen [2,511 (196-31,909) vs. 18.6 (8.3-44.0) pmol/g, *P<0.01] and renin excretion [0.311 (0.135-1.155) vs. 0.069 (0.045-0.148) pmol/g, *P<0.01] were significantly higher in CKD patients than in healthy controls. The area under the ROC curve was significantly larger when urinary angiotensinogen, renin and albumin excretion were combined than with urinary albumin excretion alone. Urinary angiotensinogen (ß-coefficient -2.405, standard error 0.117, P<0.01) and renin excretion (ß-coefficient -0.793, standard error 0.061, P<0.01) were inversely associated with eGFR. Adjustment for albuminuria, age, sex, systolic blood pressure and body mass index did not significantly affect the results.

CONCLUSION

Urinary angiotensinogen and renin excretion are elevated in CKD patients. Both parameters are negatively associated with eGFR and these associations are independent of urinary albumin excretion. In CKD patients urinary angiotensinogen and renin excretion may convey additional information beyond that provided by albuminuria.

Does statins promote vascular calcification in chronic kidney disease?

BACKGROUND

In end-stage renal disease (ESRD), coronary artery calcification (CAC) and inflammation contribute to cardiovascular disease (CVD). Statins do not improve survival in patients with ESRD, and their effect on vascular calcification is unclear. We explored associations between CAC, inflammatory biomarkers, statins and mortality in ESRD.

MATERIALS AND METHODS

In 240 patients with ESRD (63% males; median age 56 years) from cohorts including 86 recipients of living donor kidney transplant (LD-Rtx), 96 incident dialysis patients and 58 prevalent peritoneal dialysis patients, associations of CAC score (Agatston Units, AUs), interleukin-6 (IL-6) with high-sensitivity C-reactive protein (hsCRP), tumour necrosis factor (TNF), use of statins and all-cause mortality were analysed. Cardiac CT was repeated in 35 patients after 1·5 years of renal replacement therapy. In vitro, human vascular smooth muscle cells (hVSMCs) were used to measure vitamin K metabolism.

RESULTS

Among 240 patients, 129 (53%) had a CAC score > 100 AUs. Multivariate analysis revealed that independent predictors of 1-SD higher CAC score were age, male gender, diabetes and use of statins. The association between CAC score and mortality remained significant after adjustment for age, gender, diabetes, CVD, use of statins, protein-energy wasting and inflammation. Repeated CAC imaging in 35 patients showed that statin therapy was associated with greater progression of CAC. In vitro synthesis of menaquinone-4 by hVSMCs was significantly impaired by statins.

CONCLUSION

Elevated CAC score is a mortality risk factor in ESRD independent of inflammation. Future studies should resolve if statins promote vascular calcification and inhibition of vitamin K synthesis in the uremic milieu.

Potential Use of Autologous Renal Cells from Diseased Kidneys for the Treatment of Renal Failure

Chronic kidney disease (CKD) occurs when certain conditions cause the kidneys to gradually lose function. For patients with CKD, renal transplantation is the only treatment option that restores kidney function. In this study, we evaluated primary renal cells obtained from diseased kidneys to determine whether their normal phenotypic and functional characteristics are retained, and could be used for cell therapy. Primary renal cells isolated from both normal kidneys (NK) and diseased kidneys (CKD) showed similar phenotypic characteristics and growth kinetics. The expression levels of renal tubular cell markers, Aquaporin-1 and E-Cadherin, and podocyte-specific markers, WT-1 and Nephrin, were similar in both NK and CKD kidney derived cells. Using fluorescence- activated cell sorting (FACS), specific renal cell populations were identified and included proximal tubular cells (83.1% from NK and 80.3% from CKD kidneys); distal tubular cells (11.03% from NK and 10.9% from CKD kidneys); and podocytes (1.91% from NK and 1.78% from CKD kidneys). Ultra-structural analysis using scanning electron microscopy (SEM) revealed microvilli on the apical surface of cultured cells from NK and CKD samples. Moreover, transmission electron microscopy (TEM) analysis showed a similar organization of tight junctions, desmosomes, and other intracellular structures. The Na⁺ uptake characteristics of NK and CKD derived renal cells were also similar (24.4 mmol/L and 25 mmol/L, respectively) and no significant differences were observed in the protein uptake and transport characteristics of these two cell isolates. These results show that primary renal cells derived from diseased kidneys such as CKD have similar structural and functional characteristics to their counterparts from a normal healthy kidney (NK) when grown in vitro. This study suggests that cells derived from diseased kidney may be used as an autologous cell source for renal cell therapy, particularly in patients with CKD or end-stage renal disease (ESRD).

Innovative non-invasive model for screening reduced estimated glomerular filtration rate in a working population

AIM

Most of the existing risk scores for identifying people with reduced estimated glomerular filtration rate (eGFR) involve laboratory-based factors, which are not convenient and cost-effective to use in a large population-based screening programme. We aimed at using non-invasive variables to identify subjects with reduced eGFR in a Chinese working population.

METHODS

Two study populations were recruited in 2012 and 2015, respectively. The 2012 study population (n = 14 374) was randomly separated as the training dataset (n = 9621) or the internal testing dataset (n = 4753) at a ratio of 2:1, and the 2015 study population (n = 4371) was used as the external testing dataset. Stepwise logistic regression analysis with age, gender, hypertension and body mass index (BMI) status were first performed in the training dataset and then validated in both internal and external testing dataset. A nomogram was further developed based on the final model.

RESULTS

Results showed that older females with higher BMI status were more likely to have reduced eGFR. The model had excellent discrimination (AUC: 0.887 [95%CI: 0.865, 0.909] in the internal validation and 0.880 [95%CI: 0.829, 0.931] in the external validation) and calibration (Hosmer-Lemeshow test, P = 0.798 and 0.397 for internal and external dataset, respectively). The probability of having reduced eGFR increased gradually from <0.1% at a total score of 0 to 26% at a total score of 58 shown in the nomogram.

CONCLUSION

Non-invasive variables could help identify individuals at high risk of reduced eGFR for further kidney function testing or intervention, aiding in decision-making and resource allocation in large population screening.

Accuracy and precision of the CKD-EPI and MDRD predictive equations compared with glomerular filtration rate measured by inulin clearance in a Saudi population

BACKGROUND

Predictive equations for estimating glomerular filtration rate (GFR) in different clinical conditions should be validated by comparing with the measurement of GFR using inulin clearance, a highly accurate measure of GFR.

OBJECTIVES

Our aim was to validate the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) equations by comparing it to the GFR measured using inulin clearance in chronic kidney disease (CKD) patients.

DESIGN

Cross-sectional study performed in adult Saudi patients with CKD.

SETTING

King Saud University Affiliated Hospital, Riyadh, Saudi Arabia in 2014.

PATIENTS AND METHODS

We compared GFR measured by inulin clearance with the estimated GFR calculated using CKD-EPI and MDRD predictive formulas.

MAIN OUTCOME MEASURE(S)

Correlation, bias, precision and accuracy between the estimated GFR and inulin clearance.

RESULTS

Comparisons were made in 31 participants (23 CKD and 8 transplanted), including 19 males (mean age 42.2 [15] years and weight 68.7 [18] kg). GFR using inulin was 51.54 (33.8) mL/min/1.73 m2 in comparison to inulin clearance, the GFR by the predictive equations was: CKD-EPI creatinine 52.6 (34.4) mL/ min/1.73 m2 (P=.490), CKD-EPI cystatin C 41.39 (30.30) mL/min/1.73 m2 (P=.002), CKD creatinine-cystatin C 45.03 (30.9) mL/min/1.73 m2 (P=.004) and MDRD GFR 48.35 (31.5) mL/min/1.73 m2 (P=.028) (statistical comparisons vs inulin). Bland-Altman plots demonstrated that GFR estimated by the CKD-EPI creatinine was the most accurate compared with inulin clearance, having a mean difference (estimated bias) and limits of agreement of -1.1 (15.6,-17.7). By comparison the mean differences for predictive equations were: CKD-EPI cystatin C 10.2 (43.7,-23.4), CKD creatinine-cystatin C 6.5 (29.3,-16.3) and MDRD 3.2 (18.3,-11.9). except for CKD-EPI creatinine, all of the equations underestimated GFR in comparison with inulin clearance.

CONCLUSIONS

When compared with inulin clearance, the CKD-EPI creatinine equation is the most accurate, precise and least biased equation for estimation of GFR in the Saudi population and in all subgroups by age, stage of CKD and transplantation status.

LIMITATIONS

Small sample size and the study did not include patients with comorbid diseases such as diabetes, hepatitis C virus infection, and other co-morbidities as well as old age ( > 80 years).

Impaired longitudinal deformation measured by speckle-tracking echocardiography in children with end-stage renal disease

BACKGROUND

Left ventricular dysfunction is an important co-morbidity of end-stage renal disease (ESRD) and is associated with a poor prognosis in the adult population. In pediatric ESRD, left ventricular function is generally well preserved, but limited information is available on early changes in myocardial function. The aim of this study was to investigate myocardial mechanics in pediatric patients with ESRD using speckle-tracking echocardiography (STE).

METHODS

Echocardiographic studies, including M-mode, tissue Doppler imaging (TDI) and STE, were performed in 19 children on dialysis, 17 transplant patients and 33 age-matched controls. Strain measurements were performed from the apical four-chamber and the short axis view, respectively.

RESULTS

The interventricular and left ventricular posterior wall thickness was significantly increased in dialysis and transplant patients compared to healthy controls. No significant differences were found in shortening fraction, ejection fraction and systolic tissue Doppler velocities. Dialysis and transplant patients had a decreased mean longitudinal strain compared to healthy controls, with a mean difference of 3.1 [95 % confidence interval (CI) 2.0-4.4] and 2.7 (95 % CI 1.2-4.2), respectively. No differences were found for radial and circumferential strain.

CONCLUSIONS

Speckle-tracking echocardiography may reveal early myocardial dysfunction in the absence of systolic dysfunction measured by conventional ultrasound or TDI in children with ESRD.

The uses and abuses of Vitamin D compounds in chronic kidney disease-mineral bone disease (CKD-MBD)

Vitamin D is of paramount importance to skeletal development, integrity and health. Vitamin D homeostatis is typically deranged in a number of chronic conditions, of which chronic kidney disease is one of the most important. The use of vitamin D based therapy to target secondary hyperparathyroidism is now several decades old, and there is a large body of clinical practice, experience, guidelines and research to underpin this. However, there are many unknowns, of significant clinical relevance. Amongst which is what "species" of vitamin D we should be using, in what patient, and, under what conditions. Sadly, there has been a real dearth of randomised controlled trials, and trials with outputs of clinical relevance, which means our clinical practice has not developed and refined adequately ove the last 4 decades. This article will discuss the vexed but critical questions of which vitamin D therapies might suit which kidney patients, and will high-light the many important clinical questions which urgently require answering.

Urate lowering therapy to improve renal outcomes in patients with chronic kidney disease: systematic review and meta-analysis

Background

Hyperuricemia may contribute to renal injury. We do not know whether use of treatments that lower urate reduce the progression of chronic kidney disease (CKD) and cardiovascular disease. We performed a systematic review and meta-analysis of randomized controlled trials to assess the benefits and risks of treatments that lower urate in patients with stages 3-5 CKD.

Methods

We searched MEDLINE, EMBASE, CENTRAL, Web of Science and trial registers for randomized controlled trials (RCTs) without language restriction. Two authors independently screened articles, assessed risk of bias and extracted data. Data obtained included serum uric acid, serum creatinine or other estimates of glomerular filtration rate, incidence of end-stage renal disease (ESRD), systolic and diastolic blood pressure, proteinuria, cardiovascular disease and adverse events.

Results

From the 5497 citations screened, 19 RCTs enrolling 992 participants met our inclusion criteria. Given significant heterogeneity in duration of follow-up and study comparators, only trials greater than 3 months comparing allopurinol and inactive control were meta-analyzed using random effects models. Pooled estimate for eGFR was in favour of allopurinol with a mean difference (MD) of 3.2 ml/min/1.73 m², 95% CI 0.16-6.2 ml/min/1.73 m², p = 0.039 and this was consistent with results for serum creatinine. Statistically significant reductions in serum uric acid, systolic and diastolic blood pressure were found, favouring allopurinol. There were insufficient data on adverse events, incidence of ESRD and cardiovascular disease for analysis.

Conclusions

Adequately powered RCTs are needed to establish whether treatments that lower urate have beneficial renal and cardiovascular effects.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0047-z) contains supplementary material, which is available to authorized users.

Hypomagnesemia and atherogenic dyslipidemia in chronic kidney disease: surrogate markers for increased cardiovascular risk

BACKGROUND

Recent reports suggest that 40-70 % chronic kidney disease (CKD) patients receiving dialysis have significant coronary artery disease. Magnesium depletion is being considered as the missing link between the cardiovascular risk factors and atherosclerosis in CKD. The present work aimed to study the association between magnesium status and lipid alterations in pre-dialysis CKD patients attending the Nephrology Clinic in a tertiary care hospital in South India.

METHODS

90 cases of CKD and 90 age and gender matched healthy controls were included in the study. Framingham risk scoring was done and presence of metabolic syndrome was assessed. Lipid profile, serum and urine magnesium, blood glucose, calcium, phosphorus, urea and creatinine levels were assayed in all study subjects.

RESULTS

In this study we observed a significantly lower serum magnesium levels and dyslipidemic alterations, a significantly raised total cholesterol and low-density lipoprotein and non-HDL in patients with CKD. We also observed a significant correlation between the lowered serum magnesium concentrations and atherogenic dyslipidemia, suggesting a link to increased cardiovascular risk in CKD patients. CKD patients had higher risk of cardiovascular disease (according to their Framingham risk score), which also showed significant correlation with the hypomagnesaemia.

CONCLUSIONS

Our results suggest a strong association of hypomagnesemia and atherogenic dyslipidemia in patients with CKD. This gains particular importance in the high cardiovascular risk-borne CKD patients, as supplementing magnesium would go a long way in reducing the risk of cardiovascular morbidity and mortality in CKD.

The EVOLVE study is negative, so what does this 'bitter pill' of disappointment mean now for renal patients?

The extremely high morbidity and mortality experienced by subjects with chronic kidney disease (CKD) has often been described and reviewed, but this familiarity should not breed indifference to the huge burden of premature cardiovascular disease – something which becomes more obvious, but increasingly challenging to treat, as GFR declines, or proteinuria increases. The health outcomes for a middle-aged person entering renal replacement therapy are as bad as those seen with a major solid organ malignancy; while there has been modest progress in improving outcomes over the last two decades, the diagnosis of significant or progressive CKD should and thus still does continue to cast a shadow over patients, carers and healthcare professionals alike.

Raising awareness of acute kidney injury: a global perspective of a silent killer

Worldwide, acute kidney injury (AKI) is associated with poor patient outcomes. Over the last few years, collaborative efforts, enabled by a common definition of AKI, have provided a description of the epidemiology, natural history, and outcomes of this disease and improved our understanding of the pathophysiology. There is increased recognition that AKI is encountered in multiple settings and in all age groups, and that its course and outcomes are influenced by the severity and duration of the event. The effect of AKI on an individual patient and the resulting societal burden that ensues from the long-term effects of the disease, including development of chronic kidney disease (CKD) and end-stage renal disease (ESRD), is attracting increasing scrutiny. There is evidence of marked variation in the management of AKI, which is, to a large extent, due to a lack of awareness and an absence of standards for prevention, early recognition, and intervention. These emerging data point to an urgent need for a global effort to highlight that AKI is preventable, its course is modifiable, and its treatment can improve outcomes. In this article, we provide a framework of reference and propose specific strategies to raise awareness of AKI globally, with the goal to ultimately improve outcomes from this devastating disease.

Management of atrial fibrillation in chronic kidney disease: double trouble

Chronic kidney disease (CKD) has a very well-established link with cardiovascular disease. Below stage 3 CKD (glomerular filtration rate <60 mL/min), there is a progressive increase in both total mortality and cardiovascular-specific mortality as kidney function declines; indeed, it is more likely for a patient with CKD stage 3 to die of cardiovascular disease than to progress to CKD stage 4 and beyond. Arrhythmia is particularly common in patients with CKD. Depending on the study and measurement used, the prevalence of patients with CKD with chronic atrial fibrillation (AF) is quoted at 7% to 18%, rising to 12% to 25% for those older than 70 years. These rates are up to 2 to 3 times higher than in the general population. Of all patients with AF, 10% to 15% will have CKD. However, not all standard rate and rhythm methods are suitable for this population and those that are tend to be less effective. Meanwhile, anticoagulation has long been a thorny subject, with much conflicting evidence around the balance between bleeding and stroke risk. To help clarify this, we first highlight the challenges of performing evidence-based medicine in the patient with renal disease, and then review recent and emerging research to suggest an approach to the management of patients with renal disease who have AF. We also review the potential role of the different new oral anticoagulant drugs in CKD.

Effects of uric acid on endothelial dysfunction in early chronic kidney disease and its mechanisms

Background

An increase in serum uric acid (UA) occurs during the early and middle stages of chronic kidney disease (CKD) and aggravates the deterioration of kidney function. This study aims to explore the relation between UA and endothelial dysfunction in early CKD and its mechanisms in a murine model.

Methods

The experimental animals were randomly divided into three groups (n = 10): sham-operation group (control group), right nephrectomy only group (CKD group) and right nephrectomy with oxonic potassium group (CKD with hyperuricemia group). Furthermore, we analyzed the relation between UA and endothelial dysfunction indices in early CKD as well as its mechanisms.

Results

Linear regression analysis showed that the level of serum UA had a significant positive correlation with serum endothelin-1 and the percentage of collagen I positive area, but a negative correlation with serum nitric oxide (NO) and NO/endothelin-1 ratio. In addition, the level of serum UA had significant positive correlations with serum malonaldehyde, serum C-reactive protein, serum oxidatively-modified low-density lipoprotein and serum low-density lipoprotein, but a negative correlation with serum superoxide dismutase.

Conclusions

Endothelial dysfunction in the CKD group was significant and had a positive correlation with the level of serum UA. Endothelial dysfunction in early CKD with hyperuricemia is perhaps related to oxidative stress, micro-inflammation and lipid oxidation.

Prevalence and predictors of abdominal aortic calcification in healthy living kidney donors

BACKGROUND

Vascular calcification (VC) is common and is both a marker and a cause of increased cardiovascular morbidity and mortality, especially so in chronic kidney disease (CKD) patients. Renal transplantation is the cornerstone of the successful long-term management of CKD, and in order to satisfy transplantation needs, more use is made now of living kidney donors (LKD). Prior to selection for transplantation, much screening of potential LKD takes place, including for cardiovascular issues. It is not known; however, how much these potentially healthy LKD may be prone to clinically silent VC.

METHODS

We identified 103 living kidney donors from 2011 renal transplant records. Abdominal aortic calcification (AAC) was assessed using existing abdominal CT imaging using multi-channel CT aortograms (used primarily to assess renal vascular anatomy). Using these CT scans, manual calcium scoring was undertaken to calculate total aortic calcium load (AAC severity score). The prevalence, severity and associations of AAC between calcified and non-calcified donors were then compared.

RESULTS

A total of 103 donors were identified from records. Ninety three of these had detailed clinical records to complement their CT scans. Fifty of ninety-three donors were male, and the mean age was 45.9 ± 1.8 years. Mean MDRD eGFR was 88.73 ± 2.97 ml/min/1.73 m(2). 7.14 ± 3.07 % of the aorta in these donors was calcified with a mean AAC severity score of 0.98 ± 0.56. In kidney donors >50 years of age, there was significantly more AAC than in those <50: 2.47 ± 1.56 versus 0.31 ± 0.29, p < 0.001. There was no relationship between the presence or severity of aortic VC and donor GFR, systolic blood pressure, pulse pressure, calcium-phosphate product or smoking.

CONCLUSIONS

AAC prevalence, patterns and severity in this important donor population have not previously been described in the literature. There was relatively little VC in what would be regarded as a "healthy" donor population. VC was more common with age, but the other possible risk factors for the presence or severity of VC did not impact on overall AAC scores. VC did not influence vascular stiffness as represented by pulse pressure. Following the evolution of AAC over time in those who have donated a kidney, and lost some global renal function as a consequence, would be of considerable interest.

The prevalence of electrocardiographic early repolarization in an adult cohort with chronic kidney disease and its impact upon all-cause mortality and progression to dialysis

BACKGROUND

Electrocardiographic early repolarization (ER) occurring in <5% of general/atherosclerotic populations, is a marker of sudden cardiac death (SCD). The prevalence of ER in chronic kidney disease (CKD) patients, in whom SCD is common, is unknown. We aimed to determine the prevalence, contributing factors, and relationship of ER to all-cause mortality and progression to dialysis in CKD patients.

METHODS

A retrospective study of 197 patients with stage 3-5 CKD. Full demographic data were collected including cardiovascular risk factors and history. All patients underwent a 12-lead ECG, analysed for the presence of ER and other ECG findings. ER was defined as elevation of the QRS-ST junction (J point) by at least 0.1 mV from baseline with slurring/notching of the QRS complex. The primary and secondary endpoints were all cause mortality and progression to dialysis respectively at 1 year. To control for the effects of CKD, we evaluated the ECGs of 39 healthy renal transplant donors (RTD).

RESULTS

CKD patients had a mean age of 61.5 (±16.1). Prevalence of ER in pre-dialysis patients with CKD stage 4 and 5 was higher than in RTD (26.4 vs. 7.7%, p = 0.02). ER frequency increased with CKD stage (stage 3: 7.7%, stage 4: 29.7%, and pre-dialysis stage 5: 24.6%), but decreased in dialysis patients (13%). On multivariate analysis only the QRS duration was a significant independent predictor of ER (OR 0.97, 95% CI, 0.94-0.99, p = 0.01). At 1-year follow-up, there were 24 (12%) deaths in the patients with CKD of whom 5 (21%) had ER. ER was not a predictor of all cause mortality (p = 1.00) and had no effects on the rate of progression to dialysis (p = 0.67).

CONCLUSIONS

ER is more common in pre-dialysis CKD patients, compared to healthy RTD but is not associated with increased 1-year mortality or entry onto dialysis programs. Further longitudinal studies are indicated to determine whether this increased prevalence of ER is associated with the rate of SCD seen in this population.

Vitamin K status in chronic kidney disease: a report of a study and a mini-review

Hepatic vitamin K-dependent proteins (e.g., Factors II, VII, IX and X) form part of the clotting cascade. Factor II (FII)/Prothrombin incorporates 10 Glu residues on the N-terminal region that are γ-carboxylated to Gla residues by the action of γ-glutamyl carboxylase to confer biological activity. Vitamin K is also required for the normal function of Matrix Gla Protein (MGP)--one of several non-clotting-related extra-hepatic vitamin K-dependent proteins. MGP is known to have protective action against vascular calcification--indeed it is a powerful tissue-bound inhibitory mechanism and can be found in blood vessel walls. The mature protein is also dependent on activation by γ-glutamyl carboxylase enzyme to convert Glu residues in its amino acid sequence to Gla. This reaction can only take place when the enzyme is activated in the presence of vitamin K. It is of great potential interest to investigate whether subtle deficiencies of vitamin K may, through its effect on the action of MGP, be a contributing factor to vascular calcification in CKD patients, in whom CV disease is greatly accelerated and in whom vascular calcification is not only common, but progresses aggressively, and is something for which as yet there is no clinically applicable remedy.