Hypertension in chronic kidney disease: navigating the evidence

Vascular endothelial growth factor B-mediated fatty acid flux in the adipose-kidney axis contributes to lipotoxicity in diabetic kidney disease

A common observation in diabetic kidney disease is lipid accumulation, but the mechanism(s) underlying this pathology is unknown. Inhibition of Vascular endothelial growth factor B (VEGF-B) signaling was shown to prevent glomerular lipid accumulation and ameliorated diabetic kidney disease in experimental models. Here, we examined kidney biopsies from patients with Type 2 (84 %) and Type 1 diabetes (16 %), combined with data mining of RNA-seq dataset analyses in patients with diabetic kidney disease. In glomeruli, mesangial cell-derived VEGF-B expression was increased, and glomerular lipid accumulation positively correlated with impaired kidney function. Tubular lipid accumulation also associated with kidney dysfunction but was independent of tubular-derived VEGF-B expression. In vitro, the uptake of the fatty acid analogue, BODIPY-FA, was quantified. VEGF-B treatment increased BODIPY-FA uptake in endothelial cells, whilst pre-incubation with neutralizing antibodies against VEGF-B and its receptor VEGFR1 abolished this uptake. Transcriptome analyses of kidney and white adipose tissue from diabetic macaques showed that VEGF-B expression was higher in white adipose tissue than in kidney, and expression of VEGF-B was increased in white adipose tissue from patients with diabetic kidney disease. Analyzes in diabetic transgenic mice demonstrated that expression of VEGF-B in adipocytes determined the lipolytic activity, dyslipidemia, kidney lipid accumulation and the development of diabetic kidney disease. Overall, VEGF-B is a regulator of kidney lipotoxicity in diabetic kidney disease, by controlling white adipose tissue lipolysis as well as endothelial fatty acid transport in glomeruli. Our data propose that assessment of kidney lipid accumulation, and VEGF-B expression can serve as biomarkers for early diabetic kidney disease.

Sympathetic transduction to blood pressure in patients with chronic kidney disease

PURPOSE

Patients with chronic kidney disease (CKD) are more than twice as likely to die from a cardiovascular event than those with normal kidney function. Although CKD may increase resting sympathetic activity, quantification of resting sympathetic outflow alone does not account for the ensuing vasoconstriction, and blood pressure (BP) change (i.e., sympathetic transduction). Patients with CKD have been reported to exhibit elevated α-adrenergic receptor sensitivity, which may predispose this population to greater sympathetic transduction. We tested the hypothesis that patients with CKD have augmented sympathetic transduction to BP.

METHODS

In 16 patients with CKD, 17 bodyweight-matched (BWM) controls, and 11 lean controls of a similar age muscle sympathetic nerve activity (MSNA) and beat-to-beat BP were continuously recorded during quiet supine rest. Signal averaging was used to quantify changes in mean arterial pressure (MAP) and total vascular conductance (TVC) following spontaneous bursts of MSNA.

RESULTS

Peak increases in MAP following MSNA bursts were not different among patients with CKD and the control groups (CKD: 2.3 ± 1.1 mmHg; BWM controls: 2.1 ± 1.0 mmHg; lean controls: 1.7 ± 0.9 mmHg; P = 0.28). Likewise, nadir reductions in TVC following all bursts of MSNA were not different among patients with CKD and either control group (P = 0.69). Both patients with CKD and controls had graded increases in MAP and decreases in TVC with increasing burst size, which were not different among groups (all P > 0.05).

CONCLUSION

In summary, these data indicate that patients with CKD do not have augmented sympathetic transduction to BP.

How PPAR-alpha mediated inflammation may affect the pathophysiology of chronic kidney disease

Chronic kidney disease (CKD) is a major risk factor for death in adults. Inflammation plays a role in the pathogenesis of CKD, but the mechanisms are poorly understood. Peroxisome proliferator-activated receptor alpha (PPAR-α) is a nuclear receptor and one of the three members (PPARα, PPARβ/δ, and PPARγ) of the PPARs that plays an important role in ameliorating pathological processes that accelerate acute and chronic kidney disease. Although other PPARs members are well studied, the role of PPAR-α is not well described and its role in inflammation-mediated chronic disease is not clear. Herein, we review the role of PPAR-α in chronic kidney disease with implications for the immune system.

An In Silico Modelling Approach to Predict Hemodynamic Outcomes in Diabetic and Hypertensive Kidney Disease

Early diagnosis of kidney disease remains an unmet clinical challenge, preventing timely and effective intervention. Diabetes and hypertension are two main causes of kidney disease, can often appear together, and can only be distinguished by invasive biopsy. In this study, we developed a modelling approach to simulate blood velocity, volumetric flow rate, and pressure wave propagation in arterial networks of ageing, diabetic, and hypertensive virtual populations. The model was validated by comparing our predictions for pressure, volumetric flow rate and waveform-derived indexes with in vivo data on ageing populations from the literature. The model simulated the effects of kidney disease, and was calibrated to align quantitatively with in vivo data on diabetic and hypertensive nephropathy from the literature. Our study identified some potential biomarkers extracted from renal blood flow rate and flow pulsatility. For typical patient age groups, resistive index values were 0.69 (SD 0.05) and 0.74 (SD 0.02) in the early and severe stages of diabetic nephropathy, respectively. Similar trends were observed in the same stages of hypertensive nephropathy, with a range from 0.65 (SD 0.07) to 0.73 (SD 0.05), respectively. Mean renal blood flow rate through a single diseased kidney ranged from 329 (SD 40, early) to 317 (SD 38, severe) ml/min in diabetic nephropathy and 443 (SD 54, early) to 388 (SD 47, severe) ml/min in hypertensive nephropathy, showing potential as a biomarker for early diagnosis of kidney disease. This modelling approach demonstrated its potential application in informing biomarker identification and facilitating the setup of clinical trials.

Effect of SDF-1 and CXCR4 gene variants on the development of diabetic kidney disease

Diabetic kidney disease (DKD) is the gradual loss of renal function occurring in patients with diabetes. Stromal cell-derived factor-1 (SDF-1, encoded by SDF-1 gene) is a chemokine that binds to its receptor, CXCR4, to mediate many aspects of renal biology. To test the potential impact of SDF-1/CXCR4 gene variations on the risk for DKD, single-nucleotide polymorphisms (SNPs) of SDF-1/CXCR4 genes were genotyped in 388 DKD patients and 335 DKD-free diabetic controls. Among 6 SNPs examined, we demonstrated that rs1801157 of SDF-1 gene was associated with an increased risk for DKD (GA vs GG, AOR=2.252, p=0.035; GA+AA vs GG, AOR=2.156, p=0.036). Further stratification revealed that the correlation of rs1801157 with DKD was particularly detected in diabetic patients with early CKD but not in those with severe renal impairment. Instead, another SNP of SDF-1 gene, rs266085, was found in association with the advanced form of DKD (TC vs TT, AOR=2.106, p=0.027; TC+CC vs TT, AOR=2.130, p=0.019), indicating differential impacts of SDF-1 gene polymorphisms on the progressive loss of renal function in diabetic patients. Moreover, preliminary survey of public gene expression datasets showed that rs1801157 and rs266085 modulated SDF-1 expression in many human tissues, and SDF-1/CXCR4 levels were elevated in renal tissues of DKD patients. These data suggest that allele-specific expression of SDF-1 gene may influence DKD progression.

Association of long noncoding RNA GAS5 gene polymorphism with progression of diabetic kidney disease

Diabetic kidney disease (DKD) is a common microvascular complication of diabetes, whose complex etiology involves a genetic component. Growth arrest-specific 5 (GAS5), a long noncoding RNA (lncRNA) gene, has been recently shown to regulate renal fibrosis. Here, we aimed to explore the potential role of GAS5 gene polymorphisms in the predisposition to DKD. One single-nucleotide (rs55829688) and one insertion/deletion polymorphism (rs145204276) of GAS5 gene were surveyed in 778 DKD cases and 788 DKD-free diabetic controls. We demonstrated that diabetic subjects who are heterozygous at rs55829688 (TC; AOR, 1.737; 95% CI, 1.028-2.937; p=0.039) are more susceptible to advanced DKD but not early-staged DKD, as compared to diabetic subjects who are homozygous for the major allele of rs55829688 (TT). Carriers of at least one minor allele (C) of rs55829688 (TC and CC; AOR, 1.317; 95% CI, 1.023-1.696; p=0.033) more frequently suffer from advanced DKD than do those homozygotes for the major allele (TT). Furthermore, in comparison to those who do not carry the minor allele of rs55829688 (TT), advanced DKD patients possessing at least one minor allele of rs55829688 (TC and CC) exhibited a lower glomerular filtration rate, revealing an impact of rs55829688 on renal co-morbidities of diabetes. In conclusion, our data indicate an association of GAS5 gene polymorphisms with the progression of DKD.

Evidence for a relationship between genetic polymorphisms of the L-DOPA transporter LAT2/4F2hc and risk of hypertension in the context of chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) and hypertension are chronic diseases affecting a large portion of the population frequently coexistent and interdependent. The inability to produce/use adequate renal dopamine may contribute to the development of hypertension and renal dysfunction. The heterodimeric amino acid transporter LAT2/4F2hc (SLC7A8/SLC3A2 genes) promotes the uptake of L-DOPA, the natural precursor of dopamine. We examined the plausibility that SLC7A8/SLC3A2 gene polymorphisms may contribute to hypertensive CKD by affecting the L-DOPA uptake.

METHODS

421 subjects (203 men and 218 women, mean age of 78.9 ± 9.6 years) were recruited and divided in four groups according to presence/absence of CKD, defined as reduced estimated glomerular filtration rate (eGFR < 60 ml/min/m2) calculated using the creatinine-based Berlin Initiative Study-1 (BIS1) equation, and to presence/absence of hypertension (systolic blood pressure ≥ 140 and/or diastolic blood pressure ≥ 90 mmHg). Subjects were analysed for selected SNPs spanning the SLC7A8 and SLC3A2 loci by Sequenom MassARRAY iPLEX platform.

RESULTS

The most significant SNP at the SLC3A2 (4F2hc) locus was rs2282477-T/C, with carriers of the C-allele having a lower chance to develop hypertension among CKD affected individuals [OR = 0.33 (CI 0.14-0.82); p = 0.016]. A similar association with hypertensive CKD was found for the SLC7A8 (LAT2) rs3783436-T/C, whose C-allele resulted associated with decreased risk of hypertension among subjects affected by CKD [OR = 0.56 (95% CI 0.35-0.90; p = 0.017]. The two variants were predicted to be potentially functional.

CONCLUSIONS

The association between SLC3A2 and SLC7A8 variants to hypertension development in patients with renal failure could be linked to changes in L-DOPA uptake and consequently dopamine synthesis. Although the associations do not survive correction for Bonferroni multiple testing, and additional research is needed, our study opens new avenues for future basic and translational research in the field of hypertensive CKD.

The feasibility, efficacy, and safety of RDN procedure using CO2 angiography through radial artery in severe chronic kidney disease patients

The recent evidence regarding the effectiveness of renal denervation (RDN) in blood pressure control is becoming increasingly substantial. However, many studies have excluded populations with severely impaired kidney function, even though these individuals have a higher prevalence of hypertension compared to the general population, and controlling their blood pressure is more challenging. The effectiveness and safety of RDN in patients with severe chronic kidney disease (CKD) lack strong evidence support. Concerns about worsening kidney function still exist, particularly in patients with CKD stage 5. We conducted an observational study involving 10 patients who were using at least 3 different antihypertensive medications and had an estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m2 but had not undergone dialysis. For these patients, we performed RDN via the radial artery approach, with the assistance of carbon dioxide (CO2) angiography. Utilizing this approach, the systolic 24-hour ambulatory blood pressure monitoring did not exhibit a significant decrease at 3 months; however, a significant reduction was observed at 6 months after RDN. We also minimized contrast agent usage, observed no kidney function decline 3 months post-RDN, and experienced no vascular-related complications. Using the radial artery approach and CO2 angiography assistance for RDN may be an effective and safe blood pressure control method for patients with severe kidney impairment.

Temporal trends in hypertension related end stage renal disease mortality rates: an analysis of gender, race/ethnicity, and geographic disparities in the United States

Background

According to one USA Renal Data System report, 57% of end-stage renal disease (ESRD) cases are attributed to hypertensive and diabetic nephropathy. Yet, trends in hypertension related ESRD mortality rates in adults ≥ 35 years of age have not been studied.

Objectives

The aim of this retrospective study was to analyze the different trends hypertension related ESRD death rates among adults in the United States.

Methods

Death records from the CDC (Centers for Disease Control and Prevention Wide-Ranging OnLine Data for Epidemiologic Research) database were analyzed from 1999 to 2020 for hypertension related ESRD mortality in adults ≥ 35 years of age. Age-Adjusted mortality rates (AAMRs) per 100,000 persons and annual percent change (APC) were calculated and stratified by year, sex, race/ethnicity, place of death, and geographic location.

Results

Hypertension-related ESRD caused a total of 721,511 deaths among adults (aged ≥ 35 years) between 1999 and 2020. The overall AAMR for hypertension related ESRD deaths in adults was 9.70 in 1999 and increased all the way up to 43.7 in 2020 (APC: 9.02; 95% CI: 8.19-11.04). Men had consistently higher AAMRs than woman during the analyzed years from 1999 (AAMR men: 10.8 vs women: 9) to 2020 (AAMR men: 52.2 vs women: 37.2). Overall AAMRs were highest in Non-Hispanic (NH) Black or African American patients (45.7), followed by NH American Indian or Alaska Natives (24.7), Hispanic or Latinos (23.4), NH Asian or Pacific Islanders (19.3), and NH White patients (15.4). Region-wise analysis also showed significant variations in AAMRs (overall AAMR: West 21.2; South: 21; Midwest: 18.3; Northeast: 14.2). Metropolitan areas had slightly higher AAMRs (19.1) than nonmetropolitan areas (19). States with AAMRs in 90th percentile: District of Columbia, Oklahoma, Mississippi, Tennessee, Texas, and South Carolina, had roughly double rates compared to states in 10th percentile.

Conclusions

Overall hypertension related ESRD AAMRs among adults were seen to increase in almost all stratified data. The groups associated with the highest death rates were NH Black or African Americans, men, and populations in the West and metropolitan areas of the United States. Strategies and policies targeting these at-risk groups are required to control the rising hypertension related ESRD mortality.

Dapagliflozin-entresto protected kidney from renal hypertension via downregulating cell-stress signaling and upregulating SIRT1/PGC-1α/Mfn2-medicated mitochondrial homeostasis

This study tested whether combined dapagliflozin and entresto would be superior to mere one therapy on protecting the residual renal function and integrity of kidney parenchyma in hypertensive kidney disease (HKD) rat. In vitro results showed that the protein expressions of oxidative-stress/mitochondrial-damaged (NOX-1/NOX-2/oxidized-protein/cytosolic-cytochrome-C)/apoptotic (mitochondrial-Bax/cleaved caspeases 3, 9)/cell-stress (p-ERK/p-JNK/p-p38) biomarkers were significantly increased in H2O2-treated NRK-52E cells than those of controls that were reversed by dapagliflozin or entresto treatment. Adult-male SD rats (n = 50) were equally categorized into group 1 (sham-operated-control), group 2 (HKD by 5/6 nephrectomy + DOCA-salt/25 mg/kg/subcutaneous injection/twice weekly), group 3 (HKD + dapagliflozin/orally, 20 mg/kg/day for 4 weeks since day 7 after HKD induction), group 4 (HKD + entresto/orally, 100 mg/kg/day for 4 weeks since day 7 after HKD induction), and group 5 (HKD + dapagliflozin + entresto/the procedure and treatment strategy were identical to groups 2/3/4). By day 35, circulatory levels of blood-urine-nitrogen (BUN)/creatinine and urine protein/creatinine ratio were lowest in group 1, highest in group 2, and significantly lower in group 5 than in groups 3/4, but no difference between groups 3/4. Histopathological findings showed the kidney injury score/fibrotic area/cellular expressions of oxidative-stress/kidney-injury-molecule (8-OHdG+/KIM-1+) exhibited an identical trend, whereas the cellular expressions of podocyte components (synaptopodin/ZO-1/E-cadherin) exhibited an opposite pattern of BUN level among the groups. The protein expressions of oxidative stress/mitochondrial-damaged (NOX-1/NOX-2/oxidized protein/cytosolic-cytochrome-C/cyclophilin-D)/apoptotic (mitochondrial-Bax/cleaved-caspase 3)/mitochondrial-fission (PINK1/Parkin/p-DRP1)/autophagic (LC3BII/LC3BI ratio, Atg5/beclin-1)/MAPK-family (p-ERK/p-JNK/p-p38) biomarkers displayed a similar pattern, whereas the protein expression of mitochondria-biogenesis signaling (SIRT1/PGC-1α-Mfn2/complex I-V) displayed an opposite pattern of BUN among the groups. In conclusion, combined dapagliflozin-entresto therapy offered additional benefits on protecting the residual kidney function and architectural integrity in HKD rat.

The Role of Plant-Based Diets in Preventing and Mitigating Chronic Kidney Disease: More Light than Shadows

Chronic kidney disease (CKD) is a non-communicable disease that affects >10% of the general population worldwide; the number of patients affected by CKD is increasing due in part to the rise in risk factors such as obesity, hypertension, and diabetes mellitus. As many studies show, diet can be an important tool for preventing and mitigating the onset of non-communicable diseases. Plant-based diets (PBDs) are those that emphasize the consumption of plant foods and may or may not include small or moderate amounts of animal foods. Recently, these diets have received increasing interest because they have been associated with favourable effects on health and also appear to protect against the development and progression of CKD. PBDs, which are associated with protein restrictions, seem to offer adjunctive advantages in patients with chronic kidney disease, as compared to conventional low-protein diets that include animal proteins. The principal aims of this review are to provide a comprehensive overview of the existing literature regarding the role of plant-based diets and low-protein, plant-based diets in the context of chronic kidney disease. Moreover, we try to clarify the definition of plant-based diets, and then we analyse possible concerns about the use of PBDs in patients with chronic kidney disease (nutritional deficiency and hyperkalaemia risk). Finally, we offer some strategies to increase the nutritional value of plant-based low-protein diets. In the Materials and Methods section, many studies about plant-based diets and low-protein plant-based diets (e.g., the very-low-protein diet and vegan low-protein diet, LPD) in chronic kidney disease were considered. In the Results and Conclusion section, current data, most from observational studies, agree upon the protective effect of plant-based diets on kidney function. Moreover, in patients with advanced CKD, low-protein plant-based options, especially a very-low-protein diet supplemented with heteroanalogues (VLPDs), compared to a conventional LPD appear to offer adjunctive advances in terms of delaying dialysis and mitigating metabolic disturbances. However, further studies are necessary to better investigate the possible metabolic and cardiovascular advantages of plant-based LPDs versus conventional LPDs.

Association between environmental chemical exposure and albumin-to-creatinine ratio is modified by hypertension status in women of reproductive age

Chemicals have been identified as a potential risk factor of renal dysfunction. However, studies that consider both multiple chemicals and non-chemical risk factors, such as hypertension, are rare. In this study, we assessed the associations between exposure to several chemicals, including major metals, phthalates, and phenolic compounds, and the albumin-to-creatinine ratio (ACR). A group of Korean adult women in reproductive age (n = 438, aged between 20 and 49 years), who had previously been studied for association of several organic chemicals, was chosen for this purpose. We constructed multivariable linear regression models for individual chemicals and weighted-quantile sum (WQS) mixtures, by hypertension status. Among the study population, approximately 8.5% of the participants exhibited micro/macro-albuminuria (ACR ≥30 mg/g), and 18.5% and 3.9% exhibited prehypertension and hypertension, respectively. Blood cadmium and lead levels showed a stronger association with ACR only among women with prehypertension or hypertension. Among organic chemicals, depending on the statistial model, benzophenone-1 (BP-1) and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) showed a significant association regardless of hypertension status, but most associations disappeared in the (pre)hypertensive group. These findings clearly indicate that hypertension status can modify and may potentiate the association of environmental chemicals with ACR. Our observations suggest that low-level environmental pollutant exposure may have potential adverse effects on kidney function among general adult women. Considering the prevalence of prehypertension in the general population, efforts to reduce exposure to cadmium and lead are necessary among adult women to minimize the risk of adverse kidney function.

Burden of Hypertensive Crisis in Patients With End-Stage Kidney Disease on Maintenance Dialysis: Insights From United States Renal Data System Database

BACKGROUND

There is paucity of information on the incidence, clinical characteristics, admission trends, and outcomes of hypertensive crisis (HTN-C) in patients with end-stage kidney disease (ESKD) who are on maintenance dialysis.

METHODS

We conducted a retrospective observational study of HTN-C admissions in patients with end-stage kidney disease using the United States Renal Data System. We identified patients with end-stage kidney disease aged ≥18 years on dialysis and were hospitalized for HTN-C from January 2006 to August 2015.

RESULTS

A total of 54 483 patients with end-stage kidney disease were hospitalized for HTN-C during the study period. After study exclusions, 37 214 patients were included in the analysis. A majority of patients were Black, there were more women than men and the South region of the country accounted for a great majority of patients. During the study period, hospitalization rates increased from 1060 per 100 000 beneficiary years to 1821 (P_trend<0.0001). Overall, in-hospital mortality, 30-day, and 1-year mortality were 0.6%, 2.3%, and 21.8%, respectively, and 30-day readmission rate was 31.1%. During the study period, most study outcomes showed a significant decreasing trend (in-hospital mortality 0.6%-0.5%, 30-day mortality 2.4%-1.9%, 1-year mortality 23.9%-19.7%, P_trend<0.0001 for all).

CONCLUSIONS

Hospitalizations for HTN-C have increased consistently during the decade studied. Although temporal trends showed improving mortality and readmission rates, the absolute rates were still high with 1 in 3 patients readmitted within 30 days and 1 in 5 patients dying within 1 year of index hospitalization.

Chronic kidney disease and its association with cataracts-A cross-sectional and longitudinal study

Introduction

We aim to explore the association between chronic kidney disease (CKD) and cataracts.

Methods

A total of 121,380 participants with adequate information collected from 29 community-based recruitment centers since 2008 were analyzed. The association between CKD and self-reported diagnosed cataracts was examined in a cross-sectional cohort and was validated in a longitudinal cohort of 25,263 participants without cataracts at baseline.

Results and discussion

Of all participants, cataracts occurred in 503/1,947 (26%) and 10,464/119,433 (9%) subjects in the CKD and non-CKD groups, respectively. Multivariate logistic regression showed that CKD was significantly associated with a higher prevalence of self-reported diagnosed cataracts. In the validation cohort, a higher incidence of cataracts was also noted in the CKD group (65/317, 21%) compared to the non-CKD group (1,964/24,252, 8%) during a mean 47-month follow-up. After adjusting for confounders, subjects with CKD had a 1.498-fold higher risk of incident cataracts than those without CKD (95% confidence interval = 1.114 to 2.013, p value = 0.007). We found that CKD was associated with a higher prevalence of cataracts as well as incident cataracts, which suggests CKD patients and their primary physicians should be aware of this disease and can provide a clue for further exploration of the possible mechanisms and treatments.

Associations between APOL1 genetic variants and blood pressure in African American mothers and children from a U.S. pregnancy cohort: Modification by air pollution exposures

INTRODUCTION

Carriage of high-risk APOL1 genetic variants is associated with increased risks for kidney diseases in people of African descent. Less is known about the variants' associations with blood pressure or potential moderators.

METHODS

We investigated these associations in a pregnancy cohort of 556 women and 493 children identified as African American. Participants with two APOL1 risk alleles were defined as having the high-risk genotype. Blood pressure in both populations was measured at the child's 4-6 years visit. We fit multivariate linear and Poisson regressions and further adjusted for population stratification to estimate the APOL1-blood pressure associations. We also examined the associations modified by air pollution exposures (particulate matter ≤2.5 μ m in aerodynamic diameter [PM2.5] and nitrogen dioxide) and explored other moderators such as health conditions and behaviors.

RESULTS

Neither APOL1 risk alleles nor risk genotypes had a main effect on blood pressure in mothers or children. However, each 2-μg/m3 increase of four-year average PM2.5 was associated with a 16.3 (95%CI: 5.7, 26.9) mmHg higher diastolic blood pressure in mothers with the APOL1 high-risk genotype, while the estimated effect was much smaller in mothers with the low-risk genotype (i.e., 2.9 [95%CI: -3.1, 8.8] mmHg; Pinteraction = 0.01). Additionally, the associations of APOL1 risk alleles and the high-risk genotype with high blood pressure (i.e., SBP and/or DBP ≥ 90th percentile) were stronger in girls vs. boys (Pinteraction = 0.02 and 0.005, respectively).

CONCLUSION

This study sheds light on the distribution of high blood pressure by APOL1 genetic variants and informs regulatory policy to protect vulnerable population subgroups.

Design and rationale of GUARDD-US: A pragmatic, randomized trial of genetic testing for APOL1 and pharmacogenomic predictors of antihypertensive efficacy in patients with hypertension

RATIONALE AND OBJECTIVE

APOL1 risk alleles are associated with increased cardiovascular and chronic kidney disease (CKD) risk. It is unknown whether knowledge of APOL1 risk status motivates patients and providers to attain recommended blood pressure (BP) targets to reduce cardiovascular disease.

STUDY DESIGN

Multicenter, pragmatic, randomized controlled clinical trial.

SETTING AND PARTICIPANTS

6650 individuals with African ancestry and hypertension from 13 health systems.

INTERVENTION

APOL1 genotyping with clinical decision support (CDS) results are returned to participants and providers immediately (intervention) or at 6 months (control). A subset of participants are re-randomized to pharmacogenomic testing for relevant antihypertensive medications (pharmacogenomic sub-study). CDS alerts encourage appropriate CKD screening and antihypertensive agent use.

OUTCOMES

Blood pressure and surveys are assessed at baseline, 3 and 6 months. The primary outcome is change in systolic BP from enrollment to 3 months in individuals with two APOL1 risk alleles. Secondary outcomes include new diagnoses of CKD, systolic blood pressure at 6 months, diastolic BP, and survey results. The pharmacogenomic sub-study will evaluate the relationship of pharmacogenomic genotype and change in systolic BP between baseline and 3 months.

RESULTS

To date, the trial has enrolled 3423 participants.

CONCLUSIONS

The effect of patient and provider knowledge of APOL1 genotype on systolic blood pressure has not been well-studied. GUARDD-US addresses whether blood pressure improves when patients and providers have this information. GUARDD-US provides a CDS framework for primary care and specialty clinics to incorporate APOL1 genetic risk and pharmacogenomic prescribing in the electronic health record.

TRIAL REGISTRATION

ClinicalTrials.govNCT04191824.

Socioeconomic inequalities in prevalence, awareness, treatment and control of hypertension: evidence from the PERSIAN cohort study

BACKGROUND

Elevated blood pressure is associated with cardiovascular disease, stroke and chronic kidney disease. In this study, we examined the socioeconomic inequality and its related factors in prevalence, Awareness, Treatment and Control (ATC) of hypertension (HTN) in Iran.

METHOD

The study used data from the recruitment phase of The Prospective Epidemiological Research Studies in IrAN (PERSIAN). A sample of 162,842 adults aged >  = 35 years was analyzed. HTN was defined according to the Joint National Committee)JNC-7(. socioeconomic inequality was measured using concentration index (Cn) and curve.

RESULTS

The mean age of participants was 49.38(SD =  ± 9.14) years and 44.74% of the them were men. The prevalence of HTN in the total population was 22.3%(95% CI: 20.6%; 24.1%), and 18.8%(95% CI: 16.8%; 20.9%) and 25.2%(95% CI: 24.2%; 27.7%) in men and women, respectively. The percentage of awareness treatment and control among individuals with HTN were 77.5%(95% CI: 73.3%; 81.8%), 82.2%(95% CI: 70.2%; 81.6%) and 75.9%(95% CI: 70.2%; 81.6%), respectively. The Cn for prevalence of HTN was -0.084. Two factors, age (58.46%) and wealth (32.40%), contributed most to the socioeconomic inequality in the prevalence of HTN.

CONCLUSION

The prevalence of HTN was higher among low-SES individuals, who also showed higher levels of awareness. However, treatment and control of HTN were more concentrated among those who had higher levels of SES, indicating that people at a higher risk of adverse event related to HTN (the low SES individuals) are not benefiting from the advantage of treatment and control of HTN. Such a gap between diagnosis (prevalence) and control (treatment and control) of HTN needs to be addressed by public health policymakers.

Pharmacogenomics of Hypertension in CKD: The CKD-PGX Study

Background

Patients with CKD often have uncontrolled hypertension despite polypharmacy. Pharmacogenomic drug-gene interactions (DGIs) may affect the metabolism or efficacy of antihypertensive agents. We report changes in hypertension control after providing a panel of 11 pharmacogenomic predictors of antihypertensive response.

Methods

A prospective cohort with CKD and hypertension was followed to assess feasibility of pharmacogenomic testing implementation, self-reported provider utilization, and BP control. The analysis population included 382 subjects with hypertension who were genotyped for cross-sectional assessment of DGIs, and 335 subjects followed for 1 year to assess systolic BP (SBP) and diastolic BP (DBP).

Results

Most participants (58%) with uncontrolled hypertension had a DGI reducing the efficacy of one or more antihypertensive agents. Subjects with a DGI had 1.85-fold (95% CI, 1.2- to 2.8-fold) higher odds of uncontrolled hypertension, as compared with those without a DGI, adjusted for race, health system (safety-net hospital versus other locations), and advanced CKD (eGFR <30 ml/min). CYP2C9-reduced metabolism genotypes were associated with losartan response and uncontrolled hypertension (odds ratio [OR], 5.2; 95% CI, 1.9 to 14.7). CYP2D6-intermediate or -poor metabolizers had less frequent uncontrolled hypertension compared with normal metabolizers taking metoprolol or carvedilol (OR, 0.55; 95% CI, 0.3 to 0.95). In 335 subjects completing 1-year follow-up, SBP (-4.0 mm Hg; 95% CI, 1.6 to 6.5 mm Hg) and DBP (-3.3 mm Hg; 95% CI, 2.0 to 4.6 mm Hg) were improved. No significant difference in SBP or DBP change were found between individuals with and without a DGI.

Conclusions

There is a potential role for the addition of pharmacogenomic testing to optimize antihypertensive regimens in patients with CKD.

Renin-Angiotensin System Induced Secondary Hypertension: The Alteration of Kidney Function and Structure

Long-term hypertension is known as a major risk factor for cardiovascular and chronic kidney disease (CKD). The Renin-angiotensin system (RAS) plays a key role in hypertension pathogenesis. Angiotensin II (Ang II) enhancement in Ang II-dependent hypertension leads to progressive CKD and kidney fibrosis. In the two-kidney one-clip model (2K1C), more renin is synthesized in the principal cells of the collecting duct than juxtaglomerular cells (JGCs). An increase of renal Ang I and Ang II levels and a decrease of renal cortical and medullary Ang 1–7 occur in both kidneys of the 2K1C hypertensive rat model. In addition, the activity of the angiotensin-converting enzyme (ACE) increases, while ACE2's activity decreases in the medullary region of both kidneys in the 2K1C hypertensive model. Also, the renal prolyl carboxypeptidase (PrCP) expression and its activity reduce in the clipped kidneys. The imbalance in the production of renal ACE, ACE2, and PrCP expression causes the progression of renal injury. Intrarenal angiotensinogen (AGT) expression and urine AGT (uAGT) excretion rates in the unclipped kidney are greater than the clipped kidney in the 2K1C hypertensive rat model. The enhancement of Ang II in the clipped kidney is related to renin secretion, while the elevation of intrarenal Ang II in the unclipped kidney is related to stimulation of AGT mRNA and protein in proximal tubule cells by a direct effect of systemic Ang II level. Ang II-dependent hypertension enhances macrophages and T-cell infiltration into the kidney which increases cytokines, and AGT synthesis in proximal tubules is stimulated via cytokines. Accumulation of inflammatory cells in the kidney aggravates hypertension and renal damage. Moreover, Ang II-dependent hypertension alters renal Ang II type 1 & 2 receptors (AT₁R & AT₂R) and Mas receptor (MasR) expression, and the renal interstitial fluid bradykinin, nitric oxide, and cGMP response to AT₁R, AT₂R, or BK B₂-receptor antagonists. Based on a variety of sources including PubMed, Google Scholar, Scopus, and Science-Direct, in the current review, we will discuss the role of RAS-induced secondary hypertension on the alteration of renal function.

Association of morning blood pressure surge with chronic kidney disease progression in patients with chronic kidney disease and hypertension

Blood pressure (BP) usually rise from being asleep to awake, which is named the morning blood pressure surge (MBPS). Researches have reported that elevated MBPS was related with CV events, incident CKD in hypertensive patients. However, there have been no studies that have investigated the association between MBPS and renal or heart outcomes in patients with CKD and hypertension, in these patients, the MBPS is much lower because of high prevalence of night hypertension and reduced BP dipping. In this prospective two-center observational study, we enrolled patients with CKD and hypertension and the 24 h ambulatory blood pressure monitoring (ABPM) was conducted in all patients. Time to total mortality, CKD progression and CV events was recorded; Finally, a total of 304 patients were enrolled and 94 (30.9%) of them had elevated MBPS. After a follow-up for median 30 months, 23 (7.6%), 34 (11.2%), and 95 (31.3%) patients occurred death, CKD progression and new-onset CV events, respectively. The Cox regression analysis suggested the elevated MBPS was a strong predictor of CKD progression (HR 2.35, 95%CI 1.2 -4.63, p = .013), independent of morning BP, while no associations were found between elevated MBPS and CV events (HR 1.02, 95%CI 0.66 -1.57), as well as death (HR 1.08, 95%CI 0.46 -2.55). In conclusion, we provided the first evidence that elevated MBPS was an important risk factor of CKD progression in patients with CKD and hypertension. Appropriate evaluation and management of MBPS may be helpful to postpone CKD progression.

Determinants of hypertension among patients with type 2 diabetes mellitus on follow-up at Tikur Anbessa Specialized Hospital, Addis Ababa: A case-control study

INTRODUCTION

Hypertension (HTN) in patients with diabetes mellitus (DM) is a common problem that increases the risk of mortality and morbidity, and lowers the quality of life. Despite the disproportionately high burden of HTN in DM patients, determinants for the comorbidity have not been sufficiently explored. Therefore, this study aimed to identify the determinants of HTN among patients with type 2 diabetes mellitus on follow-up at Tikur Anbessa Specialized Hospital.

METHODS AND MATERIALS

We conducted a hospital-based unmatched case-control study at Tikur Anbessa Specialized Hospital on 386 randomly selected patients with type 2 diabetes on follow-up (200 cases and 186 controls). We collected data by using a structured interviewer-administered questionnaire and data extraction form. To identify determinants of hypertension, a multivariable binary logistic regression was fitted, and the findings are presented using adjusted odds ratio (AOR) with 95% confidence interval (CI).

RESULTS

The mean reported age (±SD) of the cases and the controls was 60.3 (±9.9) and 55.3 (±11.3) years, respectively. The eight identified independent determinants of hypertension with AOR [95% CI] were obesity: 2.82 [1.43, 5.57], sedentary activity of ≥4hrs/day: 1.75 [1.10, 2.79], higher stress score: 1.05 [1.01, 1.10], serum creatinine above 1.1 mg/dl: 2.35 [1.13, 4.91], age: 1.05 [1.02, 1.08], being government employee as compared to private workers: 2.18 [1.06, 4.50] and family history of hypertension: 2.11 [1.26, 3.54]. Further, interaction of diabetes duration with insulin use: 1.03 [1.01, 1.07] was also a significant predictor of HTN among DM patients.

CONCLUSION

The finding calls for interventions for mitigating these determinants. Further research is needed to examine the interaction between diabetes duration and insulin use.

An Evaluation of Socio-Demographic and Risk Factor Profile in End-Stage Renal Disease Patients: A Cross-Sectional Assessment

Background The global incidence and prevalence of chronic kidney disease (CKD) is skyrocketing. In Asia, the prevalence of CKD varies from 10%-18%. However, as Asia is largely populated by developing countries with nascent health care systems, there is a dearth of research and data. It is estimated that a large number of cases go unreported. As a result, the exact disease burden remains unclear. The knowledge about risk factors and their proportionate role in CKD is indispensable in regards to patient management and care.  Objective The early recognition of the most important risk factors for end-stage renal disease (ESRD) is key to early diagnosis, successful treatment, and general heightened awareness regarding CKD. In developing countries, the provision of medical services, in general, and nephrological services, in particular, is wholly inadequate. The insufficiency of solid and regularly updated data compounds the problem. This research study aims to partake in catering to that need. Methodology A structured questionnaire was used to obtain quantitative and categorical data from 119 ESRD patients in the nephrology ward, Allied Hospital, Faisalabad through non-probability sampling. Socio-demographic profile of the patients and information regarding the presence or absence of risk factors were collected. The resulting dataset was analyzed using R version 3.6.3 (R Foundation for Statistical Computing, Vienna, Austria) for data visualization and descriptive analysis. Results The most common age group for ESRD presentation was 46-60 years (52.1%). Among the 119 ESRD patients, the most frequent risk factor was hypertension with 85.7% of the patients presenting with the condition, followed by diabetes mellitus (DM) in 54.6%, renal calculi in 28.6%, glomerulonephritis (GN) in 31.1%, Family history of CKD in 24.4%, and polycystic kidney disease (PKD) in 5% of the patients. Gender-wise distribution of the patients shows that the proportion of patients with hypertension, renal calculi, and family history of CKD varied very little among the two groups. Conclusion In conclusion, our study has reinforced the existing body of knowledge and brought some fresh evidence regarding the prevalence of risk factors in ESRD to light. Hypertension and DM, together, represent the vast majority of cases with ESRD. However, hypertension far outpaces DM as the leading risk factor. Nephrolithiasis was also present in a considerable minority, with a figure much higher than previously reported. Finally, a relatively younger age group (45-60 years) formed the majority of the ESRD patients which is a concerning development. It points to early progression of CKD to ESRD. Long-term adequate control of these risk factors limits disease progression.

Risk factors for hypertensive crisis in adult patients: a systematic review

OBJECTIVE

The objective of this review was to examine the best available evidence on the risk factors for hypertensive crisis in adult patients with hypertension.

INTRODUCTION

Hypertensive crisis is an acute severe elevation in blood pressure, which can present as hypertensive urgency or emergency. In contrast to hypertensive urgency, which is a markedly elevated blood pressure without acute target organ damage, hypertensive emergency is associated with equally high blood pressure in the presence of potentially life-threatening target organ damage, such as myocardial infarction, stroke, pulmonary edema, or acute kidney injury. Hypertensive crisis results in adverse clinical outcomes and high utilization of health care.

INCLUSION CRITERIA

This review considered studies of non-modifiable factors (age, sex, ethnicity) and modifiable factors such as socioeconomic factors (lack of medical insurance, lack of access to medical care), adherence to medical therapies, presence of comorbidities (diabetes, hyperlipidemia, coronary artery disease, history of stroke, chronic kidney disease, congestive heart failure), and substance abuse in persons of either sex, older than 18 years with a diagnosis of hypertension.

METHODS

A search of four databases, seven gray literature sites, and relevant organizational websites revealed 11,387 titles. After duplicates were removed, 9183 studies were screened by the title and abstract for eligibility. Forty full-text articles were retrieved, and each was assessed for eligibility. Twenty-one articles were excluded. The remaining 19 full-text studies were critically appraised and included in this review.

RESULTS

The risk of hypertensive crisis was higher in patients with a history of comorbid cardiovascular conditions, such as chronic kidney disease (odds ratio [OR] 2.899, 95% confidence interval [CI] 1.32, 6.364), coronary artery disease (OR 1.654, 95% CI 1.232, 2.222), or stroke (OR 1.769, 95% CI 1.218, 2.571). Patients with hypertensive emergency had higher mean systolic blood pressure (mean difference [MD] 2.413, 95% CI 0.477, 4.350) and diastolic blood pressure (MD 2.043, 95% CI 0.624, 3.461). Hypertensive emergency was more common in men (OR 1.390, 95% CI 1.207,1.601), older patients (MD 5.282, 95% CI 3.229, 7.335), and those with diabetes (OR 1.723, 95% CI 1.485, 2.000) and hyperlipidemia (OR 2.028, 95% CI 1.642, 2.505). Non-adherence to antihypertensive medications (OR 0.939, 95% CI 0.647,1.363) and hypertensive diagnosis unawareness (OR 0.807, 95% CI 0.564, 1.154) did not increase the risk of hypertensive emergency.

CONCLUSIONS

Comorbid cardiac, renal, and cerebral comorbidities (coronary artery disease, congestive heart failure, cerebrovascular disease, and chronic kidney disease) increase the risk of hypertensive crisis. The risk of hypertensive crisis is higher in patients with unhealthy alcohol and recreational drug use. Systolic and diastolic blood pressure are marginally higher in patients with hypertensive emergency compared to patients with hypertensive urgency. Since these differences are small and not clinically significant, clinicians should rely on other symptoms and signs to differentiate between hypertensive urgency and hypertensive emergency. The risk of hypertensive emergency is higher in older adults. The coexistence of diabetes, hyperlipidemia, and chronic kidney disease increases the risk of hypertensive emergency.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO (CRD42019140093).

Hypercholesterolemia in Progressive Renal Failure Is Associated with Changes in Hepatic Heparan Sulfate - PCSK9 Interaction

BACKGROUND

Dyslipidemia is an important risk factor in CKD. The liver clears triglyceride-rich lipoproteins (TRL) via LDL receptor (LDLR), LDLR-related protein-1 (LRP-1), and heparan sulfate proteoglycans (HSPGs), mostly syndecan-1. HSPGs also facilitate LDLR degradation by proprotein convertase subtilisin/kexin type 9 (PCSK9). Progressive renal failure affects the structure and activity of hepatic lipoprotein receptors, PCSK9, and plasma cholesterol.

METHODS

Uninephrectomy- and aging-induced CKD in normotensive Wistar rats and hypertensive Munich-Wistar-Frömter (MWF) rats.

RESULTS

Compared with 22-week-old sex- and strain-matched rats, 48-week-old uninephrectomized Wistar-CKD and MWF-CKD rats showed proteinuria, increased plasma creatinine, and hypercholesterolemia (all P<0.05), which were most apparent in hypertensive MWF-CKD rats. Hepatic PCSK9 expression increased in both CKD groups (P<0.05), with unusual sinusoidal localization, which was not seen in 22-week-old rats. Heparan sulfate (HS) disaccharide analysis, staining with anti-HS mAbs, and mRNA expression of HS polymerase exostosin-1 (Ext-1), revealed elongated HS chains in both CKD groups. Solid-phase competition assays showed that the PCSK9 interaction with heparin-albumin (HS-proteoglycan analogue) was critically dependent on polysaccharide chain length. VLDL binding to HS from CKD livers was reduced (P<0.05). Proteinuria and plasma creatinine strongly associated with plasma cholesterol, PCSK9, and HS changes.

CONCLUSIONS

Progressive CKD induces hepatic HS elongation, leading to increased interaction with PCSK9. This might reduce hepatic lipoprotein uptake and thereby induce dyslipidemia in CKD. Therefore, PCSK9/HS may be a novel target to control dyslipidemia.

Chronic kidney disease in adrenal disorders

PURPOSE OF REVIEW

This review will focus on hypertension due to underlying adrenal disorders in chronic kidney disease (CKD). Diagnosis of adrenal hypertension and particularly primary aldosteronism (PA) in CKD is frequently not pursued. We outline limitations that advanced kidney disease poses on the diagnostic work up of these disorders and provide a framework for approaching CKD patients suspected of having an adrenal disorder. Recognition of these disorders is important as they are often underdiagnosed which leads to poorer outcomes.

RECENT FINDINGS

Adrenal disease associated with hypertension in CKD is most commonly due to PA whereas pheochromocytoma and Cushing's disease are important but less common. Diagnosis of these diseases is important as their identification leads to better blood pressure control and can possibly mitigate the risk of progression of CKD. Work up and treatment of PA has been shown to be safe and is associated with less antihypertensive medication requirement for the associated hypertension and slower progression of CKD.

SUMMARY

This chapter summarizes the importance of recognizing adrenal hypertension in CKD and reinforces the need for physicians to pursue these diagnoses in CKD patients as this is safe and improves both BP control and delays progression of CKD.

Is the risk of cardiovascular disease increased in living kidney donors? A Danish population-based cohort study

Reduced renal function is associated with cardiovascular disease (CVD); however, how living donor nephrectomy affects the risk of CVD remains controversial. We conducted a nationwide cohort study including living kidney donors in Denmark from 1996 to 2018 to assess the risk of hypertension, atrial fibrillation/flutter (AF), major adverse cardiovascular events (MACE; composite of myocardial infarction, ischemic stroke, and death) and death after living kidney donation. As comparisons we identified: a cohort of healthy individuals from the general population and an external blood donor cohort. We followed kidney donors (1,103 when compared with the general population cohort; 1,007 when compared with blood donors) for a median of 8 years. Kidney donors had an increased risk of initiating treatment for hypertension when compared with blood donors (standardized incidence ratio [SIR], 1.40; 95% confidence interval [CI], 1.17-1.66) but they did not have increased risk of MACE neither when compared with the general population cohort (hazard ratio, 0.68; 95% CI, 0.52-0.89) nor with blood donors (SIR, 1.17; 95% CI, 0.88-1.55). Neither did they have increased risks of AF and death. Thus, living kidney donation may be associated with increased risk of hypertension; however, we did not identify increased risks of CVD or death.

SARS-CoV-2 Viral Entry Proteins in Hyperandrogenemic Female Mice: Implications for Women with PCOS and COVID-19

SARS-CoV-2, the causative agent of COVID-19, infects host cells using the angiotensin I converting enzyme 2 (ACE2) as its receptor after priming by host proteases, including TMPRSS2. COVID-19 affects multiple organ systems, and male patients suffer increased severity and mortality. Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder in reproductive-age women and is characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. PCOS is associated with obesity and cardiometabolic comorbidities, both being risk factors associated with severe COVID-19 pathology. We hypothesize that elevated androgens in PCOS regulate SARS-CoV-2 entry proteins in multiple tissues increasing the risk for this population. Female mice were treated with dihydrotestosterone (DHT) for 90 days. Body composition was measured by EchoMRI. Fasting glucose was determined by an enzymatic method. mRNA and protein levels of ACE2, Tmprss2, Cathepsin L, Furin, Tmprss4, and Adam17 were quantified by RT-qPCR, Western-blot, or ELISA in tissues, serum, and urine. DHT treatment increased body weight, fat and lean mass, and fasting glucose. Ace2 mRNA was upregulated in the lung, cecum, heart, and kidney, while downregulated in the brain by DHT. ACE2 protein was upregulated by DHT in the small intestine, heart, and kidney. The SARS-CoV-2 priming proteases Tmprss2, Cathepsin L, and Furin mRNA were upregulated by DHT in the kidney. ACE2 sheddase Adam17 mRNA was upregulated by DHT in the kidney, which corresponded with increased urinary ACE2 in DHT treated mice. Our results highlight the potential for increased cardiac, renal, and gastrointestinal dysfunction in PCOS women with COVID-19.

Association between estimated glomerular filtration rate and clinical outcomes in ischemic stroke patients with high-grade carotid artery stenosis

Background

Chronic kidney disease has been identified as a risk factor affecting stroke prognosis. High-grade carotid artery stenosis (CAS) is associated with distal hemodynamic compromise. The association between the estimated glomerular filtration rate (eGFR) and ischemic stroke (IS) outcome in patients with high-grade CAS remains unclear. We aimed to investigate the association between eGFR and outcomes of acute IS patients with high-grade CAS.

Methods

From January 1, 2007 to April 30, 2012, we enrolled 372 acute IS patients with high-grade CAS and prospectively observed them for 5 years. The eGFR on admission was assessed using the Modification of Diet in Renal Disease Study equation. Demographic features, vascular risk factors, comorbidities, and outcomes were compared between different eGFR levels.

Results

Among 372 individuals, 76 (20.4%) had an eGFR < 45, 65 (17.5%) had an eGFR between 45 and 59, and 231 (62.1%) had an eGFR ≥60 mL/min/1.73 m². Compared to other groups, in the eGFR < 45 mL/min/1.73 m² group, the prevalence rates of hypertension, diabetes mellitus, coronary artery disease, congestive heart failure, valvular heart disease, and gout were significantly higher (P = 0.013, P = 0.030, P = 0.001, P < 0.001, P = 0.043, and P < 0.001, respectively). Patients with eGFR < 45 mL/min/1.73 m² demonstrated lower hemoglobin and total cholesterol levels compared with other groups (P < 0.001 and P = 0.048). The blood potassium and uric acid levels were significantly higher in patients with eGFR < 45 mL/min/1.73 m² (P < 0.001 and P < 0.001). The multivariate Cox proportional hazards model indicated that eGFR < 45 mL/min/1.73 m² was a significant risk factor for 5-year all-cause mortality in IS patients with high-grade CAS after adjusting for these variables (hazard ratio = 2.05; 95% CI = 1.31–3.21; P = 0.002).

Conclusions

eGFR < 45 mL/min/1.73 m² was associated with an increased risk of 5-year all-cause mortality in acute IS patients with high-grade CAS. Whether aggressive treatment of chronic kidney disease in IS patients with high-grade CAS can improve stroke outcomes should be confirmed in future studies.

Prevalence of Mildly Reduced Estimated GFR by Height- or Age-Related Equations in Young People With Obesity and Its Association with Cardiometabolic Risk Factors

OBJECTIVE

To compare the prevalence of mildly reduced estimated glomerular filtration rate (MRGFR) (eGFR >60 and < 90 mL/min/1.73 m²), calculated by two creatinine-based equations, and its association with cardiometabolic risk factors (CMRF) in youth with overweight (OW)/obesity (OB).

METHODS

This is a multicenter cross-sectional study involving university and non-university hospital pediatrics departments. We enrolled 3,118 youth with OW/OB (5-14 years) and 286 healthy normal weight (NW) youth. eGFR was calculated using bedside Schwartz equation (eGFRBSE) and Full Age Spectrum equation (eGFRFAS). In OW/OB group we analyzed the association between eGFR calculated by both equations and CMRF. Uric acid (UA) and birth weight were available in 2,135 and in 1,460 youth.

RESULTS

The prevalence of MRGFR was 3.8% in NW versus 7.8% in OW/OB (P = .016) by eGFRBSE, and 8.7% in NW versus 19.4% in OW/OB (P < .0001) by eGFRFAS. eGFRBSE and eGFRFAS identified 242 and 605 young people with OW/OB with MRGFR, respectively. Individuals with MRGFR according with both equations showed lower birth weight, younger age, higher BMI-SDS, non-high-density lipoprotein-cholesterol and UA as compared to those with normal eGFR. To examine whether the eGFRFAS was associated with a worse CMR profile also in the range of normal eGFRBSE, we reclassified young people with normal eGFRBSE (n = 2,876) according with eGFRFAS. Out of youth with normal eGFRBSE, 366 (12.7%) presented MRGFR by eGFRFAS and had lower age, higher BMI-SDS, BP and UA than the remaining youth reclassified as normal eGFRFAS.

CONCLUSION

MRGFR is associated with an altered CMR profile in a large sample of young people with overweight (OW)/obesity (OB). The eGFRFAS equation identifies a higher prevalence of youth with MRGFR, compared to eGFRBSE equation.

Rice bran modulates renal disease risk factors in animals submitted to high sugar-fat diet

Introduction:

Obesity, diabetes, and hypertension are common risk factors for chronic kidney disease (CKD). CKD arises due to many pathological insults, including inflammation and oxidative stress, which affect renal function and destroy nephrons. Rice bran (RB) is rich in vitamins and minerals, and contains significant amount of antioxidants. The aim of this study was to evaluate the preventive effect of RB on renal disease risk factors.

Methods:

Male Wistar rats (±325 g) were divided into two experimental groups to received a high sugar-fat diet (HSF, n = 8) or high sugar-fat diet with rice bran (HSF + RB, n = 8) for 20 weeks. At the end, renal function, body composition, metabolic parameters, renal inflammatory and oxidative stress markers were analyzed.

Results:

RB prevented obesity [AI (HSF= 9.92 ± 1.19 vs HSF + RB= 6.62 ± 0.78)], insulin resistance [HOMA (HSF= 83 ± 8 vs. HSF + RB= 42 ± 11)], dyslipidemia [TG (HSF= 167 ± 41 vs. HSF + RB=92 ± 40)], inflammation [TNF-α (HSF= 80 ± 12 vs. HSF + RB=57 ± 14), IL-6 (903 ± 274 vs. HSF + RB=535 ± 277)], oxidative stress [protein carbonylation (HSF= 3.38 ± 0.18 vs. HSF + RB=2.68 ± 0.29), RAGE (HSF=702 ± 36 vs. RSF + RB=570 ± 190)], and renal disease [protein/creatinine ratio (HSF=1.10 ± 0.38 vs. HSF + RB=0.49 ± 0.16)].

Conclusion:

In conclusion, rice bran prevented renal disease by modulating risk factors.

Genomics, Proteomics and Metabolomics Approaches for Predicting Diabetic Nephropathy in Type 2 Diabetes Mellitus Patients

BACKGROUND

There is a continuous rise in the prevalence of type 2 diabetes mellitus (T2DM) worldwide and most patients are unaware of the presence of this chronic disease at the early stages. T2DM is associated with complications related to long-term damage and failure of multiple organ systems caused by vascular changes associated with glycated end products, oxidative stress, mild inflammation, and neovascularization. Among the most frequent complications of T2DM observed in about 20-40% of T2DM patients is diabetes nephropathy (DN).

METHODS

A literature search was made in view of highlighting the novel applications of genomics, proteomics and metabolomics, as the new prospective strategy for predicting DN in T2DM patients.

RESULTS

The complexity of DN requires a comprehensive and unbiased approach to investigate the main causes of disease and identify the most important mechanisms underlying its development. With the help of evolving throughput technology, rapidly evolving information can now be applied to clinical practice.

DISCUSSION

DN is also the leading cause of end-stage renal disease and comorbidity independent of T2DM. In terms of the comorbidity level, DN has many phenotypes; therefore, timely diagnosis is required to prevent these complications. Currently, urine albumin-to-creatinine ratio and estimated glomerular filtration rate (eGFR) are gold standards for assessing glomerular damage and changes in renal function. However, GFR estimation based on creatinine is limited to hyperfiltration status; therefore, this makes albuminuria and eGFR indicators less reliable for early-stage diagnosis of DN.

CONCLUSION

The combination of genomics, proteomics, and metabolomics assays as suitable biological systems can provide new and deeper insights into the pathogenesis of diabetes, as well as discover prospects for developing suitable and targeted interventions.

Linking chronic kidney disease and Parkinson's disease: a literature review

Chronic kidney disease (CKD) has been typically implicated in cardiovascular risk, considering the function the kidney has related to blood pressure, vitamin D, red blood cell metabolism, and electrolyte and acid-base regulation. However, neurological consequences are also attributed to this disease. Among these, recent large epidemiological studies have demonstrated an increased risk for Parkinson's disease (PD) in patients with CKD. Multiple studies have evaluated individually the association of blood pressure, vitamin D, and red blood cell dysmetabolism with PD, however, no study has reviewed the potential mechanisms related to these components in context of CKD and PD. In this review, we explored the association of CKD and PD and linked the components of the former to propose potential pathways explaining a future increased risk for PD, where renin-angiotensin system, oxidative stress, and inflammation have a main role. Potential preventive and therapeutic interventions based on these associations are also explored. More preclinical studies are needed to confirm the potential link of CKD conditions and future PD risk, whereas more interventional studies targeting this association are warranted to confirm their potential benefit in PD.

Pre-hospital predictors of an adverse outcome among patients with dyspnoea as the main symptom assessed by pre-hospital emergency nurses - a retrospective observational study

Background

Dyspnoea is one of the most common reasons for patients contacting emergency medical services (EMS). Pre-hospital Emergency Nurses (PENs) are independently responsible for advanced care and to meet these patients individual needs. Patients with dyspnoea constitute a complex group, with multiple different final diagnoses and with a high risk of death. This study aimed to describe on-scene factors associated with an increased risk of a time-sensitive final diagnosis and the risk of death.

Methods

A retrospective observational study including patients aged ≥16 years, presenting mainly with dyspnoea was conducted. Patients were identified thorough an EMS database, and were assessed by PENs in the south-western part of Sweden during January to December 2017. Of 7260 missions (9% of all primary missions), 6354 were included. Among those, 4587 patients were randomly selected in conjunction with adjusting for unique patients with single occasions. Data were manually collected through both EMS- and hospital records and final diagnoses were determined through the final diagnoses verified in hospital records. Analysis was performed using multiple logistic regression and multiple imputations.

Results

Among all unique patients with dyspnoea as the main symptom, 13% had a time-sensitive final diagnosis. The three most frequent final time-sensitive diagnoses were cardiac diseases (4.1% of all diagnoses), infectious/inflammatory diseases (2.6%), and vascular diseases (2.4%). A history of hypertension, renal disease, symptoms of pain, abnormal respiratory rate, impaired consciousness, a pathologic ECG and a short delay until call for EMS were associated with an increased risk of a time-sensitive final diagnosis. Among patients with time-sensitive diagnoses, approximately 27% died within 30 days. Increasing age, a history of renal disease, cancer, low systolic blood pressures, impaired consciousness and abnormal body temperature were associated with an increased risk of death.

Conclusions

Among patients with dyspnoea as the main symptom, age, previous medical history, deviating vital signs, ECG pattern, symptoms of pain, and a short delay until call for EMS are important factors to consider in the prehospital assessment of the combined risk of either having a time-sensitive diagnosis or death.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12873-020-00384-1.

Collecting duct cells show differential retinoic acid responses to acute versus chronic kidney injury stimuli

Retinoic acid (RA) activates RA receptors (RAR), resulting in RA response element (RARE)-dependent gene expression in renal collecting duct (CD). Emerging evidence supports a protective role for this activity in acute kidney injury (AKI) and chronic kidney disease (CKD). Herein, we examined this activity in RARE-LacZ transgenic mice and by RARE-Luciferase reporter assays in CD cells, and investigated how this activity responds to neurotransmitters and mediators of kidney injury. In RARE-LacZ mice, Adriamycin-induced heavy albuminuria was associated with reduced RA/RAR activity in CD cells. In cultured CD cells, RA/RAR activity was repressed by acetylcholine, albumin, aldosterone, angiotensin II, high glucose, cisplatin and lipopolysaccharide, but was induced by aristolochic acid I, calcitonin gene-related peptide, endothelin-1, gentamicin, norepinephrine and vasopressin. Compared with age-matched normal human CD cells, CD-derived renal cystic epithelial cells from patients with autosomal recessive polycystic kidney disease (ARPKD) had significantly lower RA/RAR activity. Synthetic RAR agonist RA-568 was more potent than RA in rescuing RA/RAR activity repressed by albumin, high glucose, angiotensin II, aldosterone, cisplatin and lipopolysaccharide. Hence, RA/RAR  in CD cells is a convergence point of regulation by neurotransmitters and mediators of kidney injury, and may be a novel therapeutic target.

Sonographic assessment of kidneys in patients with hypertension co-existed with diabetes mellitus and ischemic heart disease

Background

Hypertension is one of the major world health problems. Ultrasonography plays a useful role in the assessment of morphologicalchanges at the kidneys in hypertensive patients.

Aim

To assess sonographic findings of the kidneys in hypertensive patients' co-morbidities with type 2 diabetes mellitus and ischemic heart disease (IDH).

Materials and Methods

This was a prospective cross-sectional study involved 100 participants with primary hypertension selected by a method of simple convenient sampling. The patients were examined using ultrasonography to assess the sonographic findings of the kidneys. The renal length, corticomedullary differentiation (CMD), and renal artery diameters were assessed. Statistical Package for the Social Sciences (SPSS version 23.0) was used in data analysis.

Results

The length of the right kidney was 8.9850 ± 1.01 cm and 9.48 ± 0.98 cm for the left kidney. Among the hypertensive patients, the incidence of hypertension was highest in housewives (27%) and students (23%) as compared with the other groups. The sonographic findings were 18% affected with simple renal cysts, 7% poor CMD, and the majority had normal kidneys. Significant correlation was found between age and sonographic findings of kidneys (r = 0.21, P value = 0.033).

Conclusion

Simple renal cysts, poor CMD, and stenosis of renal arteries were most common sonographic findings in hypertension. Simple renal cystshad a significant association with hypertension.

A metabolic handbook for the COVID-19 pandemic

For infectious-disease outbreaks, clinical solutions typically focus on efficient pathogen destruction. However, the COVID-19 pandemic provides a reminder that infectious diseases are complex, multisystem conditions, and a holistic understanding will be necessary to maximize survival. For COVID-19 and all other infectious diseases, metabolic processes are intimately connected to the mechanisms of disease pathogenesis and the resulting pathology and pathophysiology, as well as the host defence response to the infection. Here, I examine the relationship between metabolism and COVID-19. I discuss why preexisting metabolic abnormalities, such as type 2 diabetes and hypertension, may be important risk factors for severe and critical cases of infection, highlighting parallels between the pathophysiology of these metabolic abnormalities and the disease course of COVID-19. I also discuss how metabolism at the cellular, tissue and organ levels might be harnessed to promote defence against the infection, with a focus on disease-tolerance mechanisms, and speculate on the long-term metabolic consequences for survivors of COVID-19.

Adipose Mesenchymal Cells-Derived EVs Alleviate DOCA-Salt-Induced Hypertension by Promoting Cardio-Renal Protection

Hypertension is a long-term condition that can increase organ susceptibility to insults and lead to severe complications such as chronic kidney disease (CKD). Extracellular vesicles (EVs) are cell-derived membrane structures that participate in cell-cell communication by exporting encapsulated molecules to target cells, regulating physiological and pathological processes. We here demonstrate that multiple administration of EVs from adipose-derived mesenchymal stromal cells (ASC-EVs) in deoxycorticosterone acetate (DOCA)-salt hypertensive model can protect renal tissue by maintaining its filtration capacity. Indeed, ASC-EVs downregulated the pro-inflammatory molecules monocyte chemoattracting protein-1 (MCP-1) and plasminogen activating inhibitor-1 (PAI1) and reduced recruitment of macrophages in the kidney. Moreover, ASC-EVs prevented cardiac tissue fibrosis and maintained blood pressure within normal levels, thus demonstrating their multiple favorable effects in different organs. By applying microRNA (miRNA) microarray profile of the kidney of DOCA-salt rats, we identified a selective miRNA signature associated with epithelial-mesenchymal transition (EMT). One of the key pathways found was the axis miR-200-TGF-β, that was significantly altered by EV administration, thereby affecting the EMT signaling and preventing renal inflammatory response and fibrosis development. Our results indicate that EVs can be a potent therapeutic tool for the treatment of hypertension-induced CKD in cardio-renal syndrome.

Diet and Kidney Function: a Literature Review

PURPOSE OF REVIEW

The burden of chronic kidney disease (CKD) is increasing worldwide. For CKD prevention, it is important to gain insight in commonly consumed foods and beverages in relation to kidney function.

RECENT FINDINGS

We included 21 papers of prospective cohort studies with 3-24 years of follow-up. We focused on meat, fish, dairy, vegetables, fruit, coffee, tea, soft drinks, and dietary patterns. There was convincing evidence that a healthy dietary pattern may lower CKD risk. Plant-based foods, coffee, and dairy may be beneficial. Unhealthy diets and their components, such as red (processed) meat and sugar-sweetened beverages, may promote kidney function loss. For other foods and beverages, associations with CKD were neutral and/or the number of studies was too limited to draw conclusions. Healthy dietary patterns are associated with a lower risk of CKD. More research is needed into the effects of specific food groups and beverages on kidney function.

The risk of urinary tract infection in vegetarians and non-vegetarians: a prospective study

Urinary tract infection (UTI) is caused principally by ascending Escherichia coli infection via an intestine-stool-urethra route. Recent studies found that the strains of E. coli causing UTIs, called extra-intestinal pathogenic E. coli (ExPEC), were distinct from the intestinal pathogenic strains and normal commensal strains. Further analysis found the meat including poultry and pork is the major reservoir for ExPECs. Vegetarians avoid meat and should theoretically have less exposure to ExPEC. However, no study thus far has examined whether vegetarian diets reduce the risk of UTI. Our aim was to examine the association between vegetarian diet and UTI risk in a Taiwanese Buddhist population. We prospectively followed 9724 Buddhists free of UTI from 2005 to 2014. During the 10-year follow-up, 661 incident UTI cases were confirmed. Diet was assessed through a food frequency questionnaire. Cox regression was used to evaluate the prospective association between a vegetarian diet on risk of UTI while adjusting for age, sex, educational level, alcohol-drinking, smoking, hypertension, diabetes mellitus, hyperlipidemia, and disease conditions predisposing to UTIs. Overall, vegetarian diet was associated with 16% lower hazards (hazard ratio [HR]: 0.84, 95% confidence interval [CI]: 0.71-0.99). In subgroup analysis, the protective association between vegetarian diet and UTI is observed mainly in the female (HR: 0.82, 95% CI: 0.69-0.99), never smokers (HR: 0.80, 95% CI: 0.67-0.95), and for uncomplicated UTI (HR: 0.81, 95% CI: 0.68-0.98).

Diabetic kidney diseases revisited: A new perspective for a new era

BACKGROUND

Globally, diabetic kidney disease (DKD) is the leading cause of end-stage renal disease. As the most common microvascular complication of diabetes, DKD is a thorny, clinical problem in terms of its diagnosis and management. Intensive glucose control in DKD could slow down but not significantly halt disease progression. Revisiting the tremendous advances that have occurred in the field would enhance recognition of DKD pathogenesis as well as improve our understanding of translational science in DKD in this new era.

SCOPE OF REVIEW

In this review, we summarize advances in the understanding of the local microenvironmental changes in diabetic kidneys and discuss the involvement of genetic and epigenetic factors in the pathogenesis of DKD. We also review DKD prevalence changes and analyze the challenges in optimizing the diagnostic approaches and management strategies for DKD in the clinic. As we enter the era of 'big data', we also explore the possibility of linking systems biology with translational medicine in DKD in the current healthcare system.

MAJOR CONCLUSION

Newer understanding of the structural changes of diabetic kidneys and mechanisms of DKD pathogenesis, as well as emergent research technologies will shed light on new methods of dealing with the existing clinical challenges of DKD.

Elevation of serum adiponectin in mildly decreased glomerular filtration rate

Background

Adiponectin secreted by adipocytes plays a key role in insulin sensitivity, anti-inflammation, and antiatherosclerosis. It is involved in several conditions including obesity, type 2 diabetes mellitus, cardiovascular disease, and chronic kidney disease (CKD). Glomerular filtration rate is monitored to indicate the kidney function and CKD progression.

Objective

To assess the serum adiponectin levels in individuals with normal and mildly decreased glomerular filtration rate, analyze the association of serum adiponectin with various physical and biological parameters, and test whether serum adiponectin is the risk factor of mildly decreased glomerular filtration rate.

Methods

This cross-sectional study was conducted in 172 individuals with 35–60 years of age. Serum samples were collected and divided into two groups, based on estimated glomerular filtration rate (eGFR): 90 with normal eGFR (G1, eGFR ≥90 mL/min/1.73 m2) and 82 with mildly decreased eGFR (G2, eGFR = 60–89 mL/min/1.73 m2). Anthropometric data were recorded. Serum adiponectin was measured by enzyme-linked immunosorbent assay.

Results

Serum adiponectin levels were significantly increased in individuals with mildly decreased eGFR (G2), compared to G1 (8.23 ± 3.26 µg/mL and 6.57 ± 3.24 µg/mL, respectively; P = 0.001). Serum adiponectin was positively associated with age and high-density lipoprotein cholesterol but negatively associated with weight, body mass index, triglyceride, and waist and hip circumferences. Univariate analysis showed that serum adiponectin was significantly correlated with mildly decreased eGFR; however, when adjusting for confounding factors, there were no correlations. Furthermore, multivariate regression analysis showed that individuals at the age of 46–55 years (4.0; 95% CI: 1.9–8.3) and > 55 years (11.4; 95% CI: 3.7–35.5) were significantly correlated with mildly decreased eGFR.

Conclusions

Serum adiponectin was significantly elevated in individuals with mildly decreased eGFR and may be a modulation factor, but was not an independent risk factor for mildly kidney damage. Further study is needed to clarify its potential benefits as monitoring biomarker for CKD progression.

Association Between Hypertension and Kidney Function Decline: The Atherosclerosis Risk in Communities (ARIC) Study

RATIONALE & OBJECTIVE

The relationship between hypertension, antihypertension medication use, and change in glomerular filtration rate (GFR) over time among individuals with preserved GFR requires investigation.

STUDY DESIGN

Observational study.

SETTING & PARTICIPANTS

14,854 participants from the Atherosclerosis Risk in Communities (ARIC) Study.

PREDICTORS

Baseline hypertension status (1987-1989) was categorized according to the 2017 American College of Cardiology/American Heart Association Clinical Practice Guideline as normal blood pressure, elevated blood pressure, stage 1 hypertension, stage 2 hypertension without medication, or stage 2 hypertension with medication.

OUTCOMES

Slope of estimated GFR (eGFR) at 5 study visits over 30 years.

ANALYTICAL APPROACH

Mixed models with random intercepts and random slopes were fit to evaluate the association between baseline hypertension status and slope of eGFR.

RESULTS

At baseline, 13.2%, 7.3%, and 19.4% of whites and 15.8%, 14.9%, and 39.9% of African Americans had stage 1 hypertension, stage 2 hypertension without medication, and stage 2 hypertension with medication. Compared with those with normal blood pressure, the annual eGFR decline was greater in people with higher blood pressure (whites: elevated blood pressure, -0.11mL/min/1.73m2; stage 1 hypertension, -0.15mL/min/1.73m2; stage 2 hypertension without medication, -0.36mL/min/1.73m2; stage 2 hypertension with medication, -0.17mL/min/1.73m2; African Americans: elevated blood pressure, -0.21mL/min/1.73m2; stage 1 hypertension, -0.16mL/min/1.73m2; stage 2 hypertension without medication, -0.50mL/min/1.73m2; stage 2 hypertension with medication, -0.16mL/min/1.73m2). The 30-year predicted probabilities of developing chronic kidney disease stage G3a+with normal blood pressure, elevated blood pressure, stage 1 hypertension, stage 2 hypertension without medication, or stage 2 hypertension with medication among whites were 54.4%, 61.6%, 64.7%, 78.1%, and 70.9%, respectively, and 55.4%, 62.8%, 60.9%, 76.1%, and 66.6% among African Americans.

LIMITATIONS

Slope estimated using a maximum of 5 eGFR assessments; differential loss to follow-up.

CONCLUSIONS

Compared to normotension, baseline hypertension status was associated with faster kidney function decline over 30-year follow-up in a general population cohort. This difference was attenuated among people using antihypertensive medications.

Relationship of reduced glomerular filtration rate with alterations in plasma free amino acids and uric acid evaluated in healthy control and hypertensive subjects

The potential association between altered levels of plasma free amino acids (PFAAs) and uric acid (UA) with estimated glomerular filtration rate (eGFR) remains unknown among patients with hypertension. A total of 2804 healthy controls and 2455 hypertensive patients were included in the current analysis. eGFR was defined as reduced when it was <60 ml/min/1.73 m². The associations between reduced eGFR and individual PFAAs and UA in the healthy control and hypertension groups were explored by logistic regression analyses adjusted for potential confounding variables. Results show that UA had a significant positive association with reduced eGFR in both healthy control and hypertension groups (P < 0.001). Among the PFAAs, citrulline, glycine and phenylalanine showed significant positive associations with reduced eGFR in both healthy control (P < 0.01 to 0.001) and hypertension (P < 0.001) groups. Moreover, alanine, asparagine and methionine achieved significant positive associations with reduced eGFR only in the hypertension group (P < 0.01 to 0.001). Conversely, serine showed significant inverse associations with reduced eGFR in the hypertension group only (P < 0.001). Our findings provide first evidence for a strong relationship between distinct patterns of PFAAs and elevated UA with reduced eGFR in hypertension. The findings may appear useful in developing effective strategies for the prevention or early detection and treatment of declined kidney function in hypertension.

Use of renal risk drugs in a nation-wide Polish older adult population: an analysis of PolSenior database

BACKGROUND

Numerous medications should be avoided, or require dose adjustment in subjects with impaired kidney function. We aimed to assess the prevalence of potentially inappropriate use of renal risk drugs in a nation-wide, community-dwelling Polish older adult population.

METHODS

We analysed regular intake of 38 medications that should be avoided, requiring dose modification, increase the risk of pre-renal kidney injury, or may cause potassium retention in subjects with moderately to severely impaired renal function in the PolSenior data base (N = 4514, mean age 76 ± 11 yrs). Kidney function was assessed with short Modification of Diet in Renal Disease formula estimated glomerular filtration rate (sMDRD) and Cockcroft-Gault creatinine clearance (CC).

RESULTS

There were 855 (19%) individuals with sMDRD < 60 ml/min/1.73m2, and 1734 (38%) with CC <  60 ml/min. Among drugs that should be avoided, spironolactone (20.4% of patients as classified by sMDRD and 17.5% by CC), non-steroidal anti-inflammatory drugs (13.4 and 11.3%), hydrochlorothiazide (11.1 and 11.0%), and metformin (6.9 and 8.2%) were most frequently used. The most frequently used drugs requiring dose modification were piracetam (13.9% by sMDRD, and 11.9% by CC), digoxin (8.3 and 8.8%), and gliclazide (6.8 and 5.9%). Classification of a drug use as 'appropriate' or 'inappropriate' was discordant depending on the method of kidney function assessment (sMDRD or CC) in up to 30%. Subgroups with sMDRD < 60 ml/min/1.73m2 and with CC <  60 ml/min were taking ≥2 drugs increasing the risk of pre-renal kidney injury more frequently than individuals with better kidney function (46.6 vs. 23.1 and 33.0% vs. 24.4%, respectively). There were 24.7% of individuals with sMDRD < 60 ml/min/1.73m2 and 18.0% with CC <  60 ml/min taking 2 or more drugs increasing serum potassium level. The proportion of subjects with hyperkalaemia increased with the number of such drugs.

CONCLUSIONS

Use of drugs that should be avoided or require dose adjustment due to renal impairment, and potentially inappropriate drug combinations is a common problem in older adults in Poland. Assessment of kidney function with sMDRD may result in overlooking of requirements for dose adjustment formulated based on creatinine clearance.

TRIAL REGISTRATION

Not applicable.

Apparent Treatment-Resistant Hypertension and Cardiovascular Risk in Hemodialysis Patients: Ten-Year Outcomes of the Q-Cohort Study

There has been limited data discussing the relationship between apparent treatment-resistant hypertension (ATRH) and cardiovascular disease risk in patients receiving maintenance hemodialysis. We analyzed data for 2999 hypertensive patients on maintenance hemodialysis. ATRH was defined as uncontrolled blood pressure despite the use of three or more classes of antihypertensive medications, or four or more classes of antihypertensive medications regardless of blood pressure level. We examined the relationships between ATRH and cardiovascular events using a Cox proportional hazards model. The proportion of participants with ATRH was 18.0% (539/2999). During follow-up (median: 106.6 months, interquartile range: 51.3-121.8 months), 931 patients experienced cardiovascular events including coronary heart disease (n = 424), hemorrhagic stroke (n = 158), ischemic stroke (n = 344), and peripheral arterial disease (n = 242). Compared with the non-ATRH group, the ATRH group showed a significant increased risk of developing cardiovascular disease (hazard ratio [HR]: 1.27; 95% confidence interval [CI]: 1.08-1.49), coronary heart disease (HR: 1.28; 95% CI: 1.01-1.62), ischemic stroke (HR: 1.31; 95% CI: 1.01-1.69), and peripheral arterial disease (HR: 1.42; 95% CI: 1.06-1.91) even after adjusting for potential confounders. This study demonstrated that ATRH was significantly associated with increased cardiovascular risk in hemodialysis patients.

Trans-ethnic kidney function association study reveals putative causal genes and effects on kidney-specific disease aetiologies

Chronic kidney disease (CKD) affects ~10% of the global population, with considerable ethnic differences in prevalence and aetiology. We assemble genome-wide association studies of estimated glomerular filtration rate (eGFR), a measure of kidney function that defines CKD, in 312,468 individuals of diverse ancestry. We identify 127 distinct association signals with homogeneous effects on eGFR across ancestries and enrichment in genomic annotations including kidney-specific histone modifications. Fine-mapping reveals 40 high-confidence variants driving eGFR associations and highlights putative causal genes with cell-type specific expression in glomerulus, and in proximal and distal nephron. Mendelian randomisation supports causal effects of eGFR on overall and cause-specific CKD, kidney stone formation, diastolic blood pressure and hypertension. These results define novel molecular mechanisms and putative causal genes for eGFR, offering insight into clinical outcomes and routes to CKD treatment development.

Estimated glomerular filtration rate (eGFR) is a measure of kidney function used to define chronic kidney disease. Here, Morris et al. perform trans-ethnic genome-wide meta-analyses for eGFR in 312,468 individuals and identify novel loci and downstream putative causal genes.

Role of Toxic Elements in Chronic Kidney Disease

BACKGROUND

The kidney is central to many complex pathways in the body and kidney injury can precipitate multiple negative clinical outcomes. The resultant effect on nutrition and elemental body burden is bi-directional, confounding the very complex pathways that maintain homeostasis. These elemental changes themselves increase the risk of nutritional and biochemical disturbances.

OBJECTIVES

The aim of the present study was to describe how toxic elements interface with complications of chronic kidney disease (CKD).

METHODS

The present review included studies focusing on the molecular mechanisms induced by exposure to elements with known nephrotoxic effects and associated health complications in CKD patients.

DISCUSSION

Many non-essential elements have nephrotoxic activity. Chronic injury can involve direct tubular damage, activation of mediators of oxidative stress, genetic modifications that predispose poor cardiovascular outcomes, as well as competitive uptake and element mobilization with essential elements, found to be deficient in CKD. Cardiovascular disease is the most common cause of mortality among CKD patients. Oxidative stress, a common denominator of both deficient and excess element body constitution, underlies many pathological derivatives of chronic kidney disease. Bone disorders, hematological dysfunction and dysregulation of acid-base balance are also prevalent in kidney patients. The largest contribution of toxic element body burden results from environmental exposure and lifestyle practices. However, standard medical therapies may also potentiate toxic element accumulation and re-injury of vulnerable tissue.

CONCLUSIONS

For CKD patients, the cumulative effect of toxic elements persists throughout the disease and potentiates complications of CKD. Medical management should be coordinated between a medical team, dietitians and clinical researchers to mitigate those harmful effects.

COMPETING INTERESTS

The authors declare no competing financial interests.