Hypertension in chronic kidney disease: navigating the evidence

Colonoscopy as Part of Pre-Transplant Work-Up in Successful Kidney Transplant Candidates: Single-Center Experience and Review of Literature

Background

Screening colonoscopy is not obligatory in kidney pre-transplant work-up guidelines. According to recommendations, only transplant recipients over age 50 years should be screened. The aim of this study was to characterize endoscopic findings revealed as part of pre-transplant work-up.

Material/Methods

We retrospectively reviewed pre-transplant work-up charts of 434 adult patients who received a cadaveric donor kidney transplantation (KT) from 2012 to 2015. Endoscopic findings analysis with age subgroup (<50 and ≥50) analysis were performed.

Results

Out of 434 of patients that underwent KT, 29% have had a colonoscopy. In 75.6% of those, pathologies were found. Hemorrhoids were found in 33% and polyps in 30.7% of patients. Adenoma detection rate (ADR) was 18.1% (67.5% distal predominance). Advanced ADR was 10.2% (distal predominance). Diverticulosis was found in 28.3% of patients and ulcerative colitis was found in 2.4%. In age subgroup analysis, ADR was higher in patients ≥50 years compared to those <50 years (21.6% vs. 4%; p=0.041).

Conclusions

Colonoscopy as part of pre-transplant work-up enables removal of precancerous lesions and management of benign findings. All candidates meeting criteria for the general population should be screened. Patients under age 50 years could also benefit from colonoscopy as part of the pre-transplant work-up. Therefore, we suggest that baseline colonoscopy should be included in pre-transplant work-up guidelines for all patients, regardless of age. However, further studies are needed to confirm this recommendation.

Renal Dysfunction among Ghanaians Living with Clinically Diagnosed Hypertension in the Asutifi-South District: A Cross-Sectional Descriptive Study at the St. Elizabeth Hospital, Hwidiem

BACKGROUND

This study aimed at evaluating the burden of renal dysfunction among people living with hypertension in the Asutifi-South District of the Brong Ahafo Region, who were attending clinic at the St. Elizabeth Hospital in Hwidiem.

METHODOLOGY

A hospital-based, cross-sectional study was conducted among two hundred (200) hypertensive clients aged between 27 and 88 years who reported for clinical management from January to March, 2018. Data on sociodemography, comorbid disease status, antihypertensive medication, and their duration was obtained using a semistructured questionnaire and patient folders. Blood pressure, weight, and creatinine were measured using standard methods. Kidney function was assessed using Cockcroft Gault (CG), Four-Variable Modification of Diet in Renal Disease (4v-MDRD) and the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equations. The 2012 Kidney Disease Improvement Global Outcome (KDIGO) Criteria were used to categorize renal function among study participants.

RESULTS

Renal impairment was observed among 25.00%, 9.50%, and 10.50% of study participants using CG, 4v-MDRD, and CKD-EPI equations, respectively. With the exception of CKD-EPI equation, females significantly recorded higher scores compared to their male counterparts (28.95% vs 12.5%, 11.84%, vs 2.08%) using CG and 4v-MDRD, respectively. Participants aged 50 years or more recorded the highest renal impairment.

CONCLUSION

Renal dysfunction is common among people living with hypertension in the Asutifi-South District of the Brong Ahafo Region. Femininity, older age, disease comorbidity with diabetes, Thiazide diuretic and AR Blocker usage, and increasing duration of medication accounted for higher kidney dysfunction. Regular screening and management are therefore recommended to avert progression to end-stage renal failure (ESRD).

Sleep duration and risk of end-stage renal disease: the Singapore Chinese Health Study

OBJECTIVES

Although epidemiological evidence suggests that short sleep duration may affect renal function, the influence of long sleep and risk of end-stage renal disease (ESRD) is unclear. We examined the association between sleep duration and risk of ESRD.

METHODS

We investigated sleep duration and ESRD risk in the Singapore Chinese Health Study, a prospective population-based cohort of 63,257 Chinese in Singapore, who were aged 45-74 years at recruitment (1993-1998). Information on daily sleep duration (including naps), diet, medical history and other lifestyle factors was collected at recruitment from in-person interviews. ESRD cases were identified via linkage with the nationwide Singapore Renal Registry through year 2014. We used the Cox proportional hazards regression method to estimate hazard ratio (HR) and 95% confidence interval (CI) of ESRD in relation to sleep duration.

RESULTS

After an average 16.8 years of follow-up, 1143 (1.81%) ESRD cases were documented. Sleep duration had a U-shaped association with risk of ESRD (P for quadratic trend < 0.001). Compared with participants with 7 h/day of sleep, the multivariable adjusted HR (95% CI) of ESRD was 1.43 (1.18-1.74) for short sleep (≤5 h/day) and 1.28 (1.03-1.60) for long sleep duration (≥9 h/day). The increased risk was stronger in participants with more than 10 years of follow-up compared to those with shorter follow-up time, especially for long sleep (P for interaction = 0.003).

CONCLUSIONS

Our findings demonstrated that both short and long sleep durations were associated with a higher risk of ESRD in this Asian population.

Magnesium taurate attenuates progression of hypertension and cardiotoxicity against cadmium chloride-induced hypertensive albino rats

The present study was designed to evaluate the antihypertensive activity and cardioprotective effects of magnesium taurate against cadmium chloride (CdCl₂)-intoxicated albino rats. Sprague Dawley male albino rats (120-150 g) were divided into five groups having six animals in each group. Hypertension and cardiotoxicity were induced in animals by administration of CdCl₂ (0.5 mg/kg/day, i.p.) for four weeks. Magnesium taurate (2 and 4 mg/kg/day) was administered orally after induction of hypertension (after two weeks) in their respective groups concurrently with CdCl₂ for next two weeks. Amlodipine (3 mg/kg/day, p.o.) was used as a standard and administered after induction of hypertension. Blood pressure was monitored biweekly by using non-invasive blood pressure system and biochemical parameters and histopathology of the heart were evaluated after four weeks of the experimental protocol. During the four weeks of the experimental protocol, the toxic control group showed significant elevation of systolic and diastolic blood pressure concomitant with augmentation of cardiotoxicity as indicated by reduction in myocardial antioxidants including glutathione peroxidase, catalase, superoxide dismutase, reduced glutathione and increased malondialdehyde level in heart as compared to the normal group. The oral administrations of magnesium taurate significantly restored the blood pressure, myocardial antioxidants and malondialdehyde level as compared to toxic control group. In addition, histopathological examination showed that magnesium taurate treatments substantially reduced the myocardial damages against CdCl₂ treatment. The results suggest that magnesium taurate has prominent antihypertensive and cardioprotective activity via its potent antioxidant activity and can be used as a nutrition supplement to improve the cardiovascular health.

A translational model of chronic kidney disease in swine

Animal models of chronic kidney disease (CKD) are critical for understanding its pathophysiology and for therapeutic development. The cardiovascular and renal anatomy and physiology of the pig are virtually identical to humans. This study aimed to develop a novel translational model of CKD that mimics the pathological features of CKD in humans. CKD was induced in seven domestic pigs by bilateral renal artery stenosis and diet-induced dyslipidemia. Animals were observed for a total of 14 wk. Renal hemodynamics and function were quantified in vivo using multi-detector CT after 6, 10, and 14 wk of CKD. Urine and blood were collected at each time-point, and blood pressure was continuously measured (telemetry). After completion of in vivo studies, pigs were euthanized, kidneys were removed, and microvascular (MV) architecture (μCT), markers of renal injury, inflammation, and fibrosis were evaluated ex vivo. Additional pigs were used as controls ( n = 7). Renal blood flow and glomerular filtration were reduced by 50% in CKD, accompanied by hypertension and elevated plasma creatinine, albumin-to-creatinine ratio and increased urinary KIM-1 and NGAL, suggesting renal injury. Furthermore, 14 wk of CKD resulted in cortical and medullary MV remodeling and loss, inflammation, glomerulosclerosis, tubular atrophy, and tubule-interstitial fibrosis compared with controls. The current study characterizes a novel model of CKD that mimics several of the pathological features observed in human CKD, irrespective of the etiology. Current approaches only slow rather than halt CKD progression, and this novel model may offer a suitable platform for the development of new treatments in a translational fashion.

Anthropometric and Biochemical Determinants of Estimated Glomerular Filtration Rate in a Large Cohort of Obese Children

OBJECTIVE

We aimed to investigate which clinical and metabolic factors could influence the estimated glomerular filtration rate (eGFR) levels, evaluating a large population of obese children without suspect of primary kidney disease.

DESIGN

Retrospective, cross-sectional study.

SETTING

Pediatric university department.

SUBJECTS

We enrolled 2,957 obese children and adolescents consecutively attending our department between January 2000 and 2017. Inclusion criteria were body mass index (BMI) > 95th percentile and eGFR > 90 mL/min/1.73 m². Exclusion criteria were secondary forms of obesity, eGFR < 90 mL/min/1.73 m², proteinuria/hematuria at urine dipstick, or consumption of any medication.

INTERVENTIONS

Weight, waist circumference, height, waist to height ratio (W/Hr), BMI-standard deviation score (SDS), pubertal stage, systolic blood pressure (SBP) and diastolic blood pressure (DBP), duration of obesity, insulin, eGFR, and homeostasis model assessment (HOMA-IR) were obtained. A general linear model was performed for a multiple variable analysis.

MAIN OUTCOME MEASURE

The population was divided in tertiles for BMI-SDS, W/Hr, SBP- and DBP-SDS, HOMA-IR, and duration of obesity. We compared eGFR levels among these tertiles.

RESULTS

The eGFR levels significantly increased across both BMI-SDS and W/Hr tertiles. Conversely the eGFR levels significantly decreased across SBP-SDS, HOMA-IR, and duration of obesity tertiles. No significant differences in eGFR levels across DBP-SDS tertiles were detected. Pubertal patients presented significantly lower eGFR values compared with prepubertal patients. A general linear model for eGFR variance including as covariates W/Hr, HOMA-IR, duration of obesity, pubertal stage, BMI-SDS, and SBP-SDS (model R² 39.7%; model P < .00001) was performed. It confirmed a direct association of eGFR values with BMI-SDS and an indirect association with HOMA-IR, duration of obesity, pubertal stage, and SBP-SDS.

CONCLUSIONS

We showed a positive correlation of eGFR with both BMI-SDS and a negative one with SBP-SDS, HOMA-IR, pubertal stage, and duration of obesity. The duration of obesity was the variable most significantly associated to eGFR levels.

Antihypertensive therapy in nondiabetic chronic kidney disease: a review and update

Hypertension is an important contributor to progression of nondiabetic chronic kidney disease (CKD). Compelling observational evidence indicates that the divergence of blood pressure (BP) away from an ideal range in either direction is associated with a progressive rise in the risk of mortality and cardiovascular and renal disease progression. To date, various clinical trials and meta-analyses examining strict versus less intensive BP control in nondiabetic CKD have not conclusively demonstrated a renal advantage of one BP-lowering approach over another, except in certain subgroups such as proteinuric patients where evidence is circumstantial. As recent data have come to light suggesting that intensive BP control yields superior survival and cardiovascular outcomes in patients at high risk for cardiovascular disease, interest in the prospect of whether such benefit extends to individuals with CKD has surged. This review is a comprehensive analysis of antihypertensive literature in nondiabetic renal disease, with a particular emphasis on BP target.

Prediction of Incident Hypertension Within the Next Year: Prospective Study Using Statewide Electronic Health Records and Machine Learning

BACKGROUND

As a high-prevalence health condition, hypertension is clinically costly, difficult to manage, and often leads to severe and life-threatening diseases such as cardiovascular disease (CVD) and stroke.

OBJECTIVE

The aim of this study was to develop and validate prospectively a risk prediction model of incident essential hypertension within the following year.

METHODS

Data from individual patient electronic health records (EHRs) were extracted from the Maine Health Information Exchange network. Retrospective (N=823,627, calendar year 2013) and prospective (N=680,810, calendar year 2014) cohorts were formed. A machine learning algorithm, XGBoost, was adopted in the process of feature selection and model building. It generated an ensemble of classification trees and assigned a final predictive risk score to each individual.

RESULTS

The 1-year incident hypertension risk model attained areas under the curve (AUCs) of 0.917 and 0.870 in the retrospective and prospective cohorts, respectively. Risk scores were calculated and stratified into five risk categories, with 4526 out of 381,544 patients (1.19%) in the lowest risk category (score 0-0.05) and 21,050 out of 41,329 patients (50.93%) in the highest risk category (score 0.4-1) receiving a diagnosis of incident hypertension in the following 1 year. Type 2 diabetes, lipid disorders, CVDs, mental illness, clinical utilization indicators, and socioeconomic determinants were recognized as driving or associated features of incident essential hypertension. The very high risk population mainly comprised elderly (age>50 years) individuals with multiple chronic conditions, especially those receiving medications for mental disorders. Disparities were also found in social determinants, including some community-level factors associated with higher risk and others that were protective against hypertension.

CONCLUSIONS

With statewide EHR datasets, our study prospectively validated an accurate 1-year risk prediction model for incident essential hypertension. Our real-time predictive analytic model has been deployed in the state of Maine, providing implications in interventions for hypertension and related diseases and hopefully enhancing hypertension care.

The treatment of type 2 diabetes mellitus in patients with chronic kidney disease: What to expect from new oral hypoglycemic agents

Worldwide, an estimated 200 million people have chronic kidney disease (CKD), whose most common causes include hypertension, arteriosclerosis, and diabetes. About 40% of patients with diabetes develop CKD and intensive blood glucose control through pharmacological intervention can delay CKD progression. Standard therapies for the treatment of type 2 diabetes mellitus include metformin, sulfonylureas, meglitinides, thiazolidinediones, and insulin. While these drugs have an important role in the management of type 2 diabetes, only the thiazolidinedione pioglitazone can be used across the spectrum of CKD (stages 2-5) and without dose adjustment. Newer therapies, particularly dipeptidyl peptidase-IV inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose cotransporter-2 inhibitors, are increasingly being used in the treatment of type 2 diabetes; however, a major consideration is whether these newer therapies can also be used safely and effectively across the spectrum of renal impairment.

The Impact of Hemodialysis Frequency and Duration on Blood Pressure Management and Quality of Life in End-Stage Renal Disease Patients

Cardiovascular complications are the most prominent causes of morbidity and mortality among chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients undergoing standard hemodialysis (HD) therapy. Cardiovascular disease risk is increased significantly through persistent hypertension and blood pressure (BP) fluctuation, which are the most common complications of CKD. It was hypothesized that an extended approach with lengthier and more frequent dialysis sessions, referred to in this paper as "extended hemodialysis" (EHD), can potentially lower and stabilize blood pressure, and consequently reduce the rate of morbidity and mortality. A greater reduction of volume (salt and water) with higher frequency can improve patient quality of life (QOL). Eleven papers, including clinical trials and systematic reviews were chosen and analyzed. The extracted data was used to evaluate the change in blood pressure levels between standard HD and EHD. Overall, the studies showed that EHD resulted in improved blood pressure management; therefore, we concluded that there will be a decrease in cardiovascular disease risk, stroke, and morbidity and mortality rate. There will be also an improvement in patient QOL due to beneficial effects of the EHD.

Renin-angiotensin-aldosterone (RAAS): The ubiquitous system for homeostasis and pathologies

Renin-angiotensin-aldosterone system (RAAS) is a vital system of human body, as it maintains plasma sodium concentration, arterial blood pressure and extracellular volume. Kidney-secreted renin enzyme acts on its substrate to form angiotensin II, a versatile effector peptide hormone. Every organ is affected by RAAS activation and the resultant hypertension, cell proliferation, inflammation, and fibrosis. The imbalance of renin and angiotensin II can result in an overwhelming number of chronic and acute diseases. RAAS is influenced by other enzymes, hormones, pumps and signaling pathways, hence, this review discusses important facets of this system, its crosstalk with other crucial factors like estrogen, thyroid, cortisol, kallikrein-kinin system, Wnt/β-catenin signaling, and sodium-potassium pump. The nexus of RAAS with the above-discussed systems was scantily explored before. So, this review furnishes a new perspective in comprehension of inflammation diseases. It is followed by the formulation of hypotheses, which can contribute to better management of an array of pathologies plaguing mankind. Manipulation of RAAS, by bending it towards ACE2 expression can regulate endocrine functions, which can be critical for a number of pathological management. Dietary intervention can restore RAAS to normalcy.

End Stage Renal Disease: Not a Contraindication for Minor Oral Surgery-Protocol for the Management of Oral Surgery patients with ESRD on Hemodialysis

OBJECTIVE

To describe a safe and effective protocol for the management of patients with end stage renal disease (ESRD) undergoing minor oral surgery.

SUBJECTS AND METHODS

A prospective cohort study was conducted on all patients with ESRD who were referred for dental consultation. A definite protocol was designed in consultation with the nephrologist to minimize the risk of bleeding and wound healing complications during and after the minor surgical procedures. 36 patients consented for the protocol to be followed while 4 patients did not comply with the protocol and in 2 cases the protocol could be followed. The intra operative, post operative bleeding, and the wound healing were assessed in these patients.

RESULTS

36 patients had uneventful extractions as the blood pressure was brought down to pre hypertensive stage following the protocol. 4 patients who did not comply with the protocol had episodes of bleeding in the post operative period. There were two special scenarios where additional precautions had to be taken have been discussed. The wound healing was satisfactory in all these patients.

CONCLUSION

The protocol discussed in this article helps us provide safe minor oral surgical treatment in patients with ESRD.

Patient-Reported Barriers to the Prekidney Transplant Evaluation in an At-Risk Population in the United States

Background:

Despite our knowledge of barriers to the early stages of the transplant process, we have limited insight into patient-reported barriers to the prekidney transplant medical evaluation in populations largely at-risk for evaluation failure.

Methods:

One-hundred consecutive adults were enrolled at an urban, Midwestern transplant center. Demographic, clinical, and quality of life data were collected prior to patients visit with a transplant surgeon/nephrologist (evaluation begins). Patient-reported barriers to evaluation completion were collected using the Subjective Barriers Questionnaire 90-days after the initial medical evaluation appointment (evaluation ends), our center targeted goal for transplant work-up completion.

Results:

At 90 days, 40% of participants had not completed the transplant evaluation. Five barrier categories were created from the 85 responses to the Subjective Barriers Questionnaire. Patient-reported barriers included poor communication, physical health, socioeconomics, psychosocial influences, and access to care. In addition, determinants for successful evaluation completion included being of white race, higher income, free of dialysis, a lower comorbid burden, and reporting higher scores on the Kidney Disease Quality of Life subscale role-emotional.

Conclusion:

Poor communication between patients and providers, and among providers, was the most prominent patient-reported barrier identified. Barriers were more prominent in marginalized groups such as ethnic minorities and people with low income. Understanding the prevalence of patient-reported barriers may aid in the development of patient-centered interventions to improve completion rates.

A nationwide cross-sectional survey on prevalence, management and pharmacoepidemiology patterns on hypertension in Chinese patients with chronic kidney disease

Limited data are available on epidemiology and drug use in Chinese hypertensive patients with chronic kidney disease (CKD). We determined the prevalence; awareness, treatment, and control rates of hypertension; anti-hypertensive use, expenditure pattern; and factors associated with hypertension prevalence and control in Chinese patients with CKD. This was one of the largest cross-sectional surveys that enrolled 6079 CKD participants (mean age, 51.0 ± 16.37 years) with or without hypertension from 22 centres across China. The prevalence, awareness, and treatment rates were 71.2%, 95.4%, and 93.7%, respectively. Control rates 1 and 2 (Blood pressure, BP <140/90 and <130/80 mmHg) were 41.1% and 15.0%, respectively. Patients were treated mostly with monotherapy (37.7%) or 2-drug anti-hypertensive combination (38.7%). Factors associated with prevalence of hypertension included age; smoking; body mass index; physical exercise; family history of hypertension; hyperuricaemia; and CKD. Control rate was associated with CKD stage, BP monitoring at home, and use of drug combinations. Despite high rates of awareness and treatment, the control rates are low. CKD stages 4 and 5 adversely affect the control rate. The results suggest the immediate need of comprehensive controlling measures to improve the control of hypertension in Chinese patients with CKD.

An Analysis of Anthropometric Indicators and Modifiable Lifestyle Parameters Associated with Hypertensive Nephropathy

The surge in prevalence of chronic noncommunicable diseases like hypertension and chronic kidney disease has been linked with modifiable lifestyle practices and increased body fat. This study sought to compare the association between different modifiable lifestyle practices, adiposity indices, renal function parameters, and hypertension as well as the predictive implications for levels of these parameters in target cardiac organ damage among an urban Ghanaian hypertensive population. Using a hospital-based case-control study design, 241 Ghanaian indigenes from the Kumasi metropolis were recruited for this study. The case group was made up of 180 hypertensives and 61 normotensives served as controls. In addition to sociodemographic data, standard haemodynamic, anthropometric, renal function, and cardiac organ damage assessments were done. The prevalence of chronic kidney disease (CKD) ranged from 13.3% to 16.6% depending on the equation used in estimating the glomerular filtration rate (eGFR). Percentage cluster distribution by chronic kidney disease was observed to be significantly tilted toward the upper quartiles (3rd and 4th) of the haemodynamic parameters measured. Chronic kidney disease was significantly higher among self-reported smokers and alcoholic hypertensives. In this urban population, adiposity was associated with hypertension and renal insufficiency. Chronic kidney disease was associated with hypertension and cardiac abnormalities.

The effects of valsartan on renal glutathione peroxidase expression in alleviation of cyclosporine nephrotoxicity in rats

Introduction: Nephrotoxicity as a side effect caused by the immunosuppressive drug, cyclosporine-A (CsA), can be a major problem in transplant medicine. Oxidative stress may play an important role in the CsA-induced nephrotoxicity. It has been shown that the antihypertensive drug, valsartan (Val), has also renoprotective effects but, its molecular mechanism is largely unknown. In the present study, it was aimed to evaluate the Val effect in the alleviation of CsA nephrotoxicity via probable renal glutathione peroxidase (GPx) upregulation and oxidative stress decrease.

Methods: Thirty-two Sprague-Dawley rats were divided into four groups based on CsA and/or Val administration: group A (Control, 1 mL/kg/day of olive oil as vehicle), group B (CsA, 30 mg/kg/day), group C (CsA+Val, 30+30 mg/kg/day), and group D (Val, 30 mg/kg/day). After the administration period (six weeks), renal GPx expression was evaluated by real-time polymerase chain reaction (PCR). Plasma levels of GPx and 8-Hydroxydeoxyguanosine (8-OHdG) were measured by enzyme-linked immunosorbent assay (ELISA). Malondialdehyde (MDA) and protein carbonyl groups (PCG) were measured by spectrophotometer. Plasma levels of urea and creatinine were measured by an autoanalyzer.

Results: CsA treatment led to the decrease in renal expression and plasma levels of GPx in comparison to other study groups. Rats received CsA were detected to have significantly (p<0.05) higher plasma 8-OHdG, MDA, PCG, urea, and creatinine levels in comparison to other groups. Plasma urea and creatinine levels were negatively correlated with renal GPx expression and positively correlated with the oxidative stress markers.

Conclusion:Administration of Val may result in attenuating the nephrotoxic side effect of CsA via probable renal GPx upregulation, and subsequently oxidative stress decrease.

The treatment of type 2 diabetes in the presence of renal impairment: what we should know about newer therapies

Worldwide, an estimated 200 million people have chronic kidney disease (CKD), the most common causes of which include hypertension, arteriosclerosis, and diabetes. Importantly, ~40% of patients with diabetes develop CKD, yet evidence from major multicenter randomized controlled trials shows that intensive blood glucose control through pharmacological intervention can reduce the incidence and progression of CKD. Standard therapies for the treatment of type 2 diabetes include metformin, sulfonylureas, meglitinides, thiazolidinediones, and insulin. While these drugs have an important role in the management of type 2 diabetes, only the thiazolidinedione pioglitazone can be used across the spectrum of CKD (stages 2–5) and without dose adjustment; there are contraindications and dose adjustments required for the remaining standard therapies. Newer therapies, particularly dipeptidyl peptidase-IV inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose cotransporter-2 inhibitors, are increasingly being used in the treatment of type 2 diabetes; however, a major consideration is whether these newer therapies can also be used safely and effectively across the spectrum of renal impairment. Notably, reductions in albuminuria, a marker of CKD, are observed with many of the drug classes. Dipeptidyl peptidase-IV inhibitors can be used in all stages of renal impairment, with appropriate dose reduction, with the exception of linagliptin, which can be used without dose adjustment. No dose adjustment is required for liraglutide, albiglutide, and dulaglutide in CKD stages 2 and 3, although all glucagon-like peptide-1 receptor agonists are currently contraindicated in stages 4 and 5 CKD. At stage 3 CKD or greater, the sodium-glucose cotransporter-2 inhibitors (dapagliflozin, canagliflozin, and empagliflozin) either require dose adjustment or are contraindicated. Ongoing trials, such as CARMELINA, MARLINA, CREDENCE, and CANVAS-R, will help determine the position of these new therapy classes and if they have renoprotective effects in patients with CKD.

The cytoskeleton as a novel target for treatment of renal fibrosis

The incidence of chronic kidney disease (CKD) is increasing, with an estimated prevalence of 12% in the United States (Synder et al., 2009). While CKD may progress to end-stage renal disease (ESRD), which necessitates renal replacement therapy, i.e. dialysis or transplantation, most CKD patients never reach ESRD due to the increased risk of death from cardiovascular disease. It is well-established that regardless of the initiating insult - most often diabetes or hypertension - fibrosis is the common pathogenic pathway that leads to progressive injury and organ dysfunction (Eddy, 2014; Duffield, 2014). As such, there has been extensive research into the molecular and cellular mechanisms of renal fibrosis; however, translation to effective therapeutic strategies has been limited. While a role for the disruption of the cytoskeleton, most notably the actin network, has been established in acute kidney injury over the past two decades, a role in regulating renal fibrosis and CKD is only recently emerging. This review will focus on the role of the cytoskeleton in regulating pro-fibrotic pathways in the kidney, as well as data suggesting that these pathways represent novel therapeutic targets to manage fibrosis and ultimately CKD.

A Systematic Review on the Efficacy of Amlodipine in the Treatment of Patients With Hypertension With Concomitant Diabetes Mellitus and/or Renal Dysfunction, When Compared With Other Classes of Antihypertensive Medication

The long-term cardiovascular (CV) effects of calcium channel blockers, with special focus on amlodipine, were compared with other classes of antihypertensive medications in high-risk hypertensive patient subgroups. A systematic literature review and meta-analysis was undertaken of 38 unique randomized, active-controlled, parallel-group trials comparing amlodipine/calcium channel blockers with diuretics, β-blockers, α-blockers, angiotensin-converting enzyme inhibitors, or angiotensin II receptor blockers, with ≥6-month follow-up, and which had included assessment of blood pressure (BP) and CV events [all-cause death, CV death, myocardial infarction (MI), stroke, congestive heart failure (CHF), or major CV events (MACE: MI, CHF, stroke, and CV death)], in hypertensive patients (baseline systolic/diastolic BP ≥140/≥90 mm Hg) with either concomitant diabetes and/or renal dysfunction. In hypertensive patients with diabetes, no difference was found for amlodipine versus comparators with respect to all-cause death, CV death, MACE, and MI; a decrease in stroke risk, and an increase in CHF risk, was seen. In hypertensive patients with renal dysfunction, no difference was found for amlodipine versus comparators with respect to all-cause death, CV death, MACE, MI, and CHF; a decrease in stroke risk was seen. Amlodipine was found to be at least as efficacious as all the other classes of antihypertensive agents in reducing systolic and diastolic BP. Long-term control of BP is critical for avoiding complications of hypertension in high-risk patients, particularly CV and cerebrovascular events such as stroke. This analysis has provided evidence that amlodipine is an appealing therapeutic option in the long-term management of hypertension in both diabetic and renal dysfunction patients.

Tacrolimus Modulates TGF-β Signaling to Induce Epithelial-Mesenchymal Transition in Human Renal Proximal Tubule Epithelial Cells

Epithelial-mesenchymal transition (EMT), a process which describes the trans-differentiation of epithelial cells into motile mesenchymal cells, is pivotal in stem cell behavior, development and wound healing, as well as contributing to disease processes including fibrosis and cancer progression. Maintenance immunosuppression with calcineurin inhibitors (CNIs) has become routine management for renal transplant patient, but unfortunately the nephrotoxicity of these drugs has been well documented. HK-2 cells were exposed to Tacrolimus (FK506) and EMT markers were assessed by RT PCR and western blot. FK506 effects on TGF-β mRNA were assessed by RT PCR and TGF-β secretion was measured by ELISA. The impact of increased TGF-β secretion on Smad signaling pathways was investigated. The impact of inhibition of TGF-β signaling on EMT processes was assessed by scratch-wound assay. The results presented in this study suggest that FK506 initiates EMT processes in the HK-2 cell line, with altered expression of epithelial and myofibroblast markers evident. Additionally, the study demonstrates that FK506 activation of the TGF-β/ SMAD pathways is an essential step in the EMT process. Overall the results demonstrate that EMT is heavily involved in renal fibrosis associated with CNI nephrotoxicity.

Markers of increased atherosclerotic risk in patients with chronic kidney disease: a preliminary study

BACKGROUND

The prevalence of chronic kidney disease is rising continuously. Cardiovascular disease is among leading causes of death and premature mortality of patients with chronic kidney disease. Even the earliest stages of chronic kidney disease are associated with higher risk of subsequent coronary heart disease. The aim of this study was to determine markers of increased risk of atherosclerosis in CKD.

METHODS

The study group consisted of a total of 80 patients (20 patients with stage I/II CKD, 20 with stage III CKD, 20 stage IV CKD and 20 stage V/dialysis) and 24 healthy volunteers. Levels of proteins (osteoprotegerin, osteopontin, osteocalcin, matrix γ-carboxyglutamic acid protein, fetuin A, MMP-2, MMP-9, TIMP-1, TIMP-2) and biochemical parameters were measured to analyse their influence on atherosclerosis risk in CKD patients. Cardiac echocardiography was performed to assess structural integrity and function, presence of left ventricular hypertrophy and systolic and diastolic function dysfunction.

RESULTS

This study shows that the prevalence of ventricular hypertrophy (95.3 %) and diastolic dysfunction (93.2 %) in CKD patients is high. Also E/E' ratio was significantly higher (13.6 ± 4.4, p = 0.001), tricuspid insufficiency (27.3 in CKD I/II vs. 71.4 in CKD V, p = 0.016), contractile dysfunction (33.3 in CKD I/II vs. 78.9 in CKD V, p = 0.040), mitral valve calcification (0 in CKD I/II vs. 28.6 in CKD V, p = 0.044) and aortic valve calcification (0 in CKD I/II vs. 61.9 in CKD V, p = 0.0008) were significantly more frequent in patients with CKD stage V/dialysis than in other groups. Only MMP-2, MMP-2/TIMP-2 ratio and TIMP-1 differed significantly between groups.

CONCLUSIONS

This study shows high prevalence of ventricular hypertrophy and diastolic dysfunction in CKD patients. Contractile dysfunction, mitral and aortic valve calcification in HD patients were significantly more frequent than in patients with other CKD stages. Significantly increased levels of MMP-2, MMP-2/TIMP-2 ratio and lower TIMP-1 suggests that these factors may be involved in the pathogenesis of atherosclerosis in CKD patients.

Evening -versus morning- dosing drug therapy for chronic kidney disease patients with hypertension: a systematic review

BACKGROUND/AIMS

There is a strong correlation between non-dipping status and cardiovascular events in chronic kidney disease (CKD) patients. Our study is designed to identify the effect of evening administration of antihypertensive drugs to hypertensive CKD patients.

METHODS

A comprehensive search of Medline, Embase, the Chinese Biomedical Literature Database, Wanfang Data, Chinese National Knowledge Infrastructure, and the Cochrane Central Register of Controlled Trials was performed in July 2014. Concurrent controlled or crossover trials (including randomized and non-randomized experimental trials) designed to evaluate the effects of evening- versus morning-dosing hypertensive drug regimens on clinical outcomes in CKD patients with hypertension were included. All statistical analyses were performed using the RevMan software, which is available free from the Cochrane Collaboration.

RESULTS

Seven trials involving 1277 patients were identified, and the randomized controlled trials (RCTs) and non-randomized controlled trials (non-RCTs) were classified into two groups. Taking at least one blood pressure-lowering medication at bedtime was not shown to reduce total death (P=0.056) or cardiovascular death (P=0.059) but was shown to reduce total events (P<0.001) and major cardiovascular events (P<0.001) in both RCTs and non-RCTs. Compared with a morning dosing regimen, taking antihypertensive drug in the evening significantly lowered nighttime systolic blood pressure (SBP) (P<0.0001) and diastolic blood pressure (P<0.05) in patients in the RCTs but did not affect blood pressure in patients in the non-RCTs (P<0.05). There is limited evidence from one non-RCT that taking an antihypertensive drug (benazepril 10 mg) in the evening did not increase adverse events (P=0.72) or withdrawals due to adverse events (P=0.64).

CONCLUSIONS

A regimen of antihypertensive drugs in the evening should be considered for CKD patients with hypertension to lower nighttime blood pressure and help prevent total events and cardiovascular mortality. More studies are needed to verify the results of this study.

Estimation of total glomerular number using an integrated disector method in embryonic and postnatal kidneys

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) are a polymorphic group of clinical disorders comprising the major cause of renal failure in children. Included within CAKUT is a wide spectrum of developmental malformations ranging from renal agenesis, renal hypoplasia and renal dysplasia (maldifferentiation of renal tissue), each characterized by varying deficits in nephron number. First presented in the Brenner Hypothesis, low congenital nephron endowment is becoming recognized as an antecedent cause of adult-onset hypertension, a leading cause of coronary heart disease, stroke, and renal failure in North America. Genetic mouse models of impaired nephrogenesis and nephron endowment provide a critical framework for understanding the origins of human kidney disease. Current methods to quantitate nephron number include (i) acid maceration (ii) estimation of nephron number from a small number of tissue sections (iii) imaging modalities such as MRI and (iv) the gold standard physical disector/fractionator method. Despite its accuracy, the physical disector/fractionator method is rarely employed because it is labour-intensive, time-consuming and costly to perform. Consequently, less rigourous methods of nephron estimation are routinely employed by many laboratories. Here we present an updated, digitized version of the physical disector/fractionator method using free open source Fiji software, which we have termed the integrated disector method. This updated version of the gold standard modality accurately, rapidly and cost-effectively quantitates nephron number in embryonic and post-natal mouse kidneys, and can be easily adapted for stereological measurements in other organ systems.

Feline CKD: Diagnosis, staging and screening - what is recommended?

PRACTICAL RELEVANCE

Feline chronic kidney disease (CKD) is frequently encountered by veterinarians. Timely diagnosis and staging may facilitate the initiation of adequate therapy and improve the prognosis for patients.

CLINICAL CHALLENGES

Feline CKD is diagnosed based on the presence of compatible clinical signs and renal azotaemia, which implies that urinalysis (particularly urine specific gravity) is mandatory to confirm the diagnosis. Although the diagnosis of advanced feline CKD and associated complications is usually straightforward, based on complete blood and urine examination, all routine blood and urine tests have their limitations in detecting early CKD. Therefore, diagnosing early or non-azotaemic CKD is much more challenging. Although determination of glomerular filtration rate (GFR) would be ideal to identify early kidney dysfunction, practical limitations hamper its routine use in clinical practice.

PATIENT GROUP

CKD is typically a disease of aged cats, but may affect cats of all ages. Conclusive breed and sex predispositions for feline CKD are not reported.

AUDIENCE

This review is directed at practising veterinarians and provides an overview of the required diagnostic tests, the classification system established by the International Renal Interest Society, and the importance of and possible techniques for early detection of CKD.

EVIDENCE BASE

Staging of cats with CKD is essential as it directs management and provides a prognostic guide. Given that diagnosis at early disease stages is associated with more prolonged survival times, simple, inexpensive and accurate methods for early CKD diagnosis are needed. Techniques currently under investigation include limited sampling strategies to estimate GFR, clearance marker cut-off concentrations to identify cats with low GFR, new indirect GFR markers and urinary biomarkers.

High-fat-diet-induced obesity causes an inflammatory and tumor-promoting microenvironment in the rat kidney

Obesity and concomitant comorbidities have emerged as public health problems of the first order. For instance, obese individuals have an increased risk for kidney cancer. However, direct mechanisms linking obesity with kidney cancer remain elusive. We hypothesized that diet-induced obesity (DIO) promotes renal carcinogenesis by inducing an inflammatory and tumor-promoting microenvironment. We compared chow-fed lean Wistar rats with those that were sensitive (DIOsens) or partially resistant (DIOres) to DIO to investigate the impact of body adiposity versus dietary nutrient overload in the development of renal preneoplasia and activation of tumor-promoting signaling pathways. Our data clearly show a correlation between body adiposity, the severity of nephropathy, and the total number and incidence of preneoplastic renal lesions. However, similar plasma triglyceride, plasma free fatty acid and renal triglyceride levels were found in chow-fed, DIOres and DIOsens rats, suggesting that lipotoxicity is not a critical contributor to the renal pathology. Obesity-related nephropathy was further associated with regenerative cell proliferation, monocyte infiltration and higher renal expression of monocyte chemotactic protein-1 (MCP-1), interleukin (IL)-6, IL-6 receptor and leptin receptor. Accordingly, we observed increased signal transducer and activator of transcription 3 (STAT3) and mammalian target of rapamycin (mTOR) phosphorylation in tubules with preneoplastic phenotypes. In summary, our results demonstrate that high body adiposity induces an inflammatory and proliferative microenvironment in rat kidneys that promotes the development of preneoplastic lesions, potentially via activation of the STAT3 and mTOR signaling pathways.