The effect of antihypertensive drugs on chronic kidney disease: a comprehensive review

A glycopolymersome strategy for 'drug-free' treatment of diabetic nephropathy

Diabetic nephropathy is a severe complication of diabetes. Treatment of diabetic nephropathy is an important challenge due to persistent hyperglycemia and elevated levels of reactive oxygen species (ROS) in the kidney. Herein, we designed a glycopolymersome that can treat type 2 diabetic nephropathy by effectively inhibiting hyperglycemia and ROS-associated diabetic nephropathy pathogenesis. The glycopolymersome is self-assembled from phenylboronic acid derivative-containing copolymer, poly(ethylene oxide)45-block-poly[(aspartic acid)13-stat-glucosamine24-stat-(phenylboronic acid)18-stat-(phenylboronic acid pinacol ester)3] [PEO45-b-P(Asp13-stat-GA24-stat-PBA18-stat-PAPE3)]. PBA segment can reversibly bind blood glucose or GA segment for long-term regulation of blood glucose levels; PAPE segment can scavenge excessive ROS for renoprotection. In vitro studies confirmed that the glycopolymersomes exhibit efficient blood glucose responsiveness within 2 h and satisfactory ROS-scavenging ability with 500 μM H2O2. Moreover, the glycopolymersomes display long-acting regulation of blood glucose levels in type 2 diabetic nephropathy mice within 32 h. Dihydroethidium staining revealed that these glycopolymersomes reduced ROS to normal levels in the kidney, which led to 61.7% and 76.6% reduction in creatinine and urea levels, respectively, along with suppressing renal apoptosis, collagen accumulation, and glycogen deposition in type 2 diabetic nephropathy mice. Notably, the polypeptide-based glycopolymersome was synthesized by ring-opening polymerization (ROP) of N-carboxyanhydrides (NCAs), thereby exhibiting favorable biodegradability. Overall, we proposed a new glycopolymersome strategy for 'drug-free' treatment of diabetic nephropathy, which could be extended to encompass the design of various multifunctional nanoparticles targeting diabetes and its associated complications.

Predictors of chronic kidney disease survival in type 2 diabetes: a 12-year retrospective cohort study utilizing estimated glomerular filtration rate

Predicting the course of kidney disease in individuals with both type 1 and type 2 diabetes mellitus (DM) is a significant clinical and policy challenge. In several regions, DM is now the leading cause of end-stage renal disease. The aim of this study to identify both modifiable and non-modifiable risk factors, along with clinical markers and coexisting conditions, that increase the likelihood of stage 3-5 chronic kidney disease (CKD) development in individuals with type 2 DM in the United Arab Emirates (UAE). This was a single-center retrospective cohort study based on data derived from electronic medical records of UAE patients with DM who were registered at outpatient clinics at Tawam Hospital in Al Ain, UAE, between January 2011 and December 2021. Type 2 DM patients aged ≥ 18 years who had serum HbA1c levels ≥ 6.5% were included in the study. Patients with type 1 DM, who had undergone permanent renal replacement therapy, who had under 1 year of follow-up, or who had missing or incomplete data were excluded from the study. Factors associated with diabetic patients developing stage 3-5 CKD were identified through Cox regression analysis and a fine and gray competing risk model to account for competing events that could potentially hinder the development of CKD. A total of 1003 patients were recruited for the study. The mean age of the study cohort at baseline was 70.6 ± 28.2 years. Several factors were found to increase the risk of developing stage 3-5 CKD: advancing age (HR 1.005, 95% CI 1.002-1.009, p = 0.026), a history of hypertension (HR 1.69, 95% CI 1.032-2.8, p = 0.037), a history of heart disease (HR 1.49, 95% CI 1.16-1.92, p = 0.002), elevated levels of serum creatinine (HR 1.006, 95% CI 1.002-1.010, p = 0.003), decreased levels of estimated glomerular filtration rate (eGFR) (HR 0.943, 95% CI, 0.938-0.947; p < 0.001), and the use of beta-blockers (HR 139, 95% CI 112-173, p = 0.003). Implementing preventative measures, initiating early interventions, and developing personalized care plans tailored to address specific risk factors are imperative for reducing the impact of CKD. Additionally, the unforeseen findings related to eGFR highlight the ongoing need for research to deepen our understanding of the complexities of kidney disease.

Risk Factors of Chronic Kidney Disease Progression: Between Old and New Concepts

Chronic kidney disease (CKD) is a condition characterized by the gradual loss of kidney function over time and it is a worldwide health issue. The estimated frequency of CKD is 10% of the world's population, but it varies greatly on a global scale. In absolute terms, the staggering number of subjects affected by various degrees of CKD is 850,000,000, and 85% of them are in low- to middle-income countries. The most important risk factors for chronic kidney disease are age, arterial hypertension, diabetes, obesity, proteinuria, dyslipidemia, and environmental risk factors such as dietary salt intake and a more recently investigated agent: pollution. In this narrative review, we will focus by choice just on some risk factors such as age, which is the most important non-modifiable risk factor, and among modifiable risk factors, we will focus on hypertension, salt intake, obesity, and sympathetic overactivity.

Trajectories of kidney function and risk of mortality

BACKGROUND

We aimed to identify patterns within the rate of kidney function decline, determinants of these patterns and their association with all-cause mortality risk in the general population.

METHODS

Participants aged ≥ 45 years with at least one assessment of creatinine-based estimated glomerular filtration rate (eGFR) taken between 1997 and 2018 were selected from a population-based cohort study. Analyses were performed using several distinct latent class trajectory modelling methods. Cumulative incidences were calculated with 45 years of age as the starting point.

RESULTS

In 12 062 participants (85 922 eGFR assessments, mean age 67.0 years, 58.7% women, median follow-up 9.6 years), four trajectories of eGFR change with age were identified: slow eGFR decline [rate of change in mL/min/1.73 m2 per year (RC), -0.9; 95% CI, -0.9 to -0.9; reference group], intermediate eGFR decline (RC, -2.5; 95% CI, -2.7 to -2.5) and fast eGFR decline (RC, -4.3; 95% CI, -4.4 to -4.1), and an increase/stable eGFR (RC, 0.3; 95% CI, 0.3 to 0.4). Women were more likely to have an increase/stable eGFR [odds ratio (OR), 1.94; 95% CI, 1.53 to 2.46] whereas men were more likely to have a fast eGFR decline (OR, 1.86; 95% CI, 1.33 to 2.60). Participants with diabetes, cardiovascular disease (CVD) or hypertension were more likely to have an intermediate or fast eGFR decline. All-cause mortality risks (cumulative incidence at age of 70 years) were 32.3% (95% CI, 21.4 to 47.9, slow eGFR decline), 6.7% (95% CI, 3.5 to 12.4, intermediate eGFR decline), 68.8% (95% CI, 44.4 to 87.8, fast eGFR decline) and 9.5% (95% CI, 5.5 to 15.7, increase/stable eGFR).

CONCLUSION

Sex, hypertension, diabetes and CVD were identified as trajectory membership determinants. Having fast eGFR decline was associated with the highest risk of all-cause mortality, highlighting the need for extensive monitoring and prevention of kidney function decline in individuals at risk of having fast eGFR decline.

A novel prognostic nomogram predicts premature failure of kidney allografts with IgA nephropathy recurrence

BACKGROUND

Recurrence of immunoglobulin A nephropathy (IgAN) limits graft survival in kidney transplantation. However, predictors of a worse outcome are poorly understood.

METHODS

Among 442 kidney transplant recipients (KTRs) with IgAN, 83 (18.8%) KTRs exhibited biopsy-proven IgAN recurrence between 1994 and 2020 and were enrolled in the derivation cohort. A multivariable Cox model predicting allograft loss based on clinical data at the biopsy and a web-based nomogram were developed. The nomogram was externally validated using an independent cohort (n = 67).

RESULTS

Patient age <43 years {hazard ratio [HR] 2.20 [95% confidence interval (CI) 1.41-3.43], P < .001}, female gender [HR 1.72 (95% CI 1.07-2.76), P = .026] and retransplantation status [HR 1.98 (95% CI 1.13-3.36), P = .016] were identified as independent risk factors for IgAN recurrence. Patient age <43 years [HR 2.77 (95% CI 1.17-6.56), P = .02], proteinuria >1 g/24 hours [HR 3.12 (95% CI 1.40-6.91), P = .005] and C4d positivity [HR 2.93 (95% CI 1.26-6.83), P = .013] were found to be associated with graft loss in patients with IgAN recurrence. A nomogram predicting graft loss was constructed based on clinical and histological variables, with a C statistic of 0.736 for the derivation cohort and 0.807 for the external validation cohort.

CONCLUSIONS

The established nomogram identified patients with recurrent IgAN at risk for premature graft loss with good predictive performance.

Assessment of common risk factors of diabetes and chronic kidney disease: a Mendelian randomization study

Background

The increasing prevalence of diabetes and its significant impact on mortality and morbidity rates worldwide has led to a growing interest in understanding its common risk factors, particularly in relation to chronic kidney disease (CKD). This research article aims to investigate the shared risk factors between type 1 diabetes (T1D), type 2 diabetes (T2D), and CKD using a Mendelian randomization (MR) design.

Methods

The study utilized genome-wide association study (GWAS) datasets for T1D, T2D, and CKD from the FinnGen research project. GWAS summary statistics datasets for 118 exposure traits were obtained from the IEU OpenGWAS database. MR analyses were conducted to examine the causal relationships between exposure traits and each of the three outcomes. Multiple methods, including inverse-variance weighted, weighted median, and MR-Egger, were employed for the MR studies.

Results

Phenome-wide MR analyses revealed that eosinophil percentage exhibited a significant and suggestive causal association with T1D and CKD, respectively, suggesting its potential as a shared risk factor for T1D and CKD. For T2D, 34 traits demonstrated significant associations. Among these 34 traits, 14 were also significantly associated with CKD, indicating the presence of common risk factors between T2D and CKD, primarily related to obesity, height, blood lipids and sex hormone binding globulin, blood pressure, and walking pace.

Conclusion

This research has uncovered the eosinophil percentage as a potential common risk factor for both T1D and CKD, while also identifying several traits, such as obesity and blood lipids, as shared risk factors for T2D and CKD. This study contributes to the understanding of the common risk factors between diabetes and CKD, emphasizing the need for targeted interventions to reduce the risk of these diseases.

Risk factors for heart, cerebrovascular, and kidney diseases: evaluation of potential side effects of medications to control hypertension, hyperglycemia, and hypercholesterolemia

Background

Heart disease (HD), cerebrovascular disease (CBD), and kidney disease (KD) are serious diseases worldwide. These diseases constitute the leading causes of death worldwide and are costly to treat. An analysis of risk factors is necessary to prevent these diseases.

Data and Methods

Risk factors were analyzed using data from 2,837,334, 2,864,874, and 2,870,262 medical checkups obtained from the JMDC Claims Database. The side effects of medications used to control hypertension (antihypertensive medications), hyperglycemia (antihyperglycemic medications), and hypercholesterolemia (cholesterol medications), including their interactions, were also evaluated. Logit models were used to calculate the odds ratios and confidence intervals. The sample period was from January 2005 to September 2019.

Results

Age and history of diseases were found to be very important factors, and the risk of having diseases could be almost doubled. Urine protein levels and recent large weight changes were also important factors for all three diseases and made the risks 10%-30% higher, except for KD. For KD, the risk was more than double for individuals with high urine protein levels. Negative side effects were observed with antihypertensive, antihyperglycemic, and cholesterol medications. In particular, when antihypertensive medications were used, the risks were almost doubled for HD and CBD. The risk would be triple for KD when individuals were taking antihypertensive medications. If they did not take antihypertensive medications and took other medications, these values were lower (20%-40% for HD, 50%-70% for CBD, and 60%-90% for KD). The interactions between the different types of medications were not very large. When antihypertensive and cholesterol medications were used simultaneously, the risk increased significantly in cases of HD and KD.

Conclusion

It is very important for individuals with risk factors to improve their physical condition for the prevention of these diseases. Taking antihypertensive, antihyperglycemic, and cholesterol medications, especially antihypertensive medications, may be serious risk factors. Special care and additional studies are necessary to prescribe these medications, particularly antihypertensive medications.

Limitations

No experimental interventions were performed. As the dataset was comprised of the results of health checkups of workers in Japan, individuals aged 76 and above were not included. Since the dataset only contained information obtained in Japan and the Japanese are ethnically homogeneous, potential ethnic effects on the diseases were not evaluated.

Associations of urinary orosomucoid, N-acetyl-β-D-glucosaminidase, and albumin with blood pressure and hypertension after 7 years. The Tromsø Study

Purpose: Subclinical chronic kidney disease is known to exacerbate hypertension and progression of kidney damage. In order to initiate timely interventions, early biomarkers for this vicious circle are needed. Our aim was to describe the cross-sectional associations of urinary orosomucoid and urinary N-acetyl-β-D-glucosaminidase (NAG) with blood pressure and the longitudinal associations of urinary orosomucoid and NAG to hypertension after 7 years, and to compare the strength of these associations to the urinary albumin excretion (UAE).Material and methods: The Tromsø Study is a population-based, prospective study of inhabitants of the municipality of Tromsø, Northern Norway. Morning spot urine samples were collected on three consecutive days in the Tromsø 6 survey (2007-2008). We assessed the cross-sectional associations of urinary orosomucoid, NAG and UAE with blood pressure in Tromsø 6. In a cohort of participants attending Tromsø 6 and Tromsø 7 (2015-2016), we studied whether urinary biomarkers were longitudinally associated with hypertension.Results: A total of 7197 participants with a mean age of 63.5 years (SD 9.2), and a mean blood pressure of 141/78 mmHg (SD 23.0/10.6), were included in the study. Orosomucoid and UAE, but not NAG, was significantly associated with systolic and diastolic blood pressure in all the crude and multivariable cross-sectional analyses. Orosomucoid had consistently, although marginally, stronger associations with blood pressure. Incident hypertension at follow-up (Tromsø 7) was consistently significantly associated with urinary orosomucoid, but not urinary NAG or UAE. However, the standardized regression coefficients for orosomucoid were only marginally stronger than the standardized regression coefficients for ACR.Conclusion: In a cohort from the general population urine orosomucoid had a stronger cross-sectional association with blood pressure than UAE. After 7 years, urine orosomucoid showed the strongest association with incident hypertension. There were varying and weak associations between U-NAG, blood pressure and hypertension.

[Effect of modification of antihypertensive medications on the association of nitrogen dioxide long-term exposure and chronic kidney disease]

OBJECTIVE

To investigate the potential effect of modification of antihypertensive medications on the association of nitrogen dioxide (NO₂) long-term exposure and chronic kidney disease (CKD).

METHODS

Data of the national representative sample of adult population from the China National Survey of Chronic Kidney Disease (2007-2010) were included in the analyses, and exposure data of NO₂ were collected and matched. Generalized mixed-effects models were used to analyze the associations between NO₂ and CKD, stratified by the presence of hypertension and taking antihypertensive medications. The stratified exposure-response curves of NO₂ and CKD were fitted using the natural spine smoothing function. The modifying effects of antihypertensive medications on the association and the exposure-response curve of NO₂ and CKD were analyzed.

RESULTS

Data of 45 136 participants were included, with an average age of (49.5±15.3) years. The annual average exposure concentration of NO₂ was (7.2±6.4) μg/m³. Altogether 6 517 (14.4%) participants were taking antihypertensive medications, and 4 833 (10.7%) participants were identified as having CKD. After adjustment for potential confounders, in the hypertension population not using antihypertensive medications, long-term exposure to NO₂ was associated with a significant increase risk of CKD (OR: 1.38, 95%CI: 1.24-1.54, P < 0.001); while in the hypertension population using antihypertensive medications, no significant association between long-term exposure to NO₂ and CKD (OR: 0.96, 95%CI: 0.86-1.07, P=0.431) was observed. The exposure-response curve of NO₂ and CKD suggested that there was a non-linear trend in the association between NO₂ and CKD. The antihypertension medications showed significant modifying effects both on the association and the exposure-response curve of NO₂ and CKD (interaction P < 0.001).

CONCLUSION

The association between long-term exposure to NO₂ and CKD was modified by antihypertensive medications. Taking antihypertensive medications may mitigate the effect of long-term exposure to NO₂ on CKD.

Factors Associated with Antiretroviral Therapy Toxicity Out-Comes in Patients with and without Hypertension

BACKGROUND

Negative effects of antiretroviral therapy (ART) drugs on HIV/AIDS patients are one of the major health issues in the therapeutic treatment of this communicable disease. This holds particularly for people living with HIV (PLHIV) who might have a non-communicable disease (like hypertension), which also requires a lifetime treatment. In this study, we investigated the association between hypertension and other possible factors on ART toxicity markers in patients with hypertension, compared to those without hypertension.

METHODS

This retrospective longitudinal study reviewed chronic patient files of 525 patients (of which 222 were hypertensive) who satisfied the inclusion criteria and were on ART at a hospital in central Eswatini. Specific levels of estimated glomerular filtration (eGFR), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were used as drug toxicity markers. To analyze the longitudinal data between the exposure of interest and outcome variables, a Generalized Estimated Equation method was employed.

RESULTS

Participants with hypertension had decreased eGFR compared to those without hypertension (β = -2.22; p-value = 0.03). There was no significant association between ALT, AST and hypertension (p-value = 0.34 and 0.20, respectively). Factors that were found to have a significant association with ART toxicity markers included age, sex, ART duration, hypertension treatment and time of study. The eGFR was found to be significantly increasing over the study period (p-value < 0.001) for all participants. The significance was consistent in both hypertensive and non-hypertensive participants independently (p-value = 0.002 and <0.001, respectively). The overall trends of ALT and AST over time were also significant (p-value = 0.003 and <0.001, respectively).

CONCLUSIONS

Patients with hypertension had decreased eGFR, and there was a significant association of eGFR with time of the study. Special attention, therefore, to monitor calamities which are indicated by a decrease of eGFR (like renal impairment) should be given in PLHIV on ART with hypertension, especially more so if they were on ART for longer time.

Cardiovascular disease protein biomarkers are associated with kidney function: The Framingham Heart Study

Background

Biomarkers common to chronic kidney disease (CKD) and cardiovascular disease (CVD) may reflect early impairments underlying both diseases.

Methods

We evaluated associations of 71 CVD-related plasma proteins measured in 2,873 Framingham Heart Study (FHS) Offspring cohort participants with cross-sectional continuous eGFR and with longitudinal change in eGFR from baseline to follow-up (ΔeGFR). We also evaluated the associations of the 71 CVD proteins with the following dichotomous secondary outcomes: prevalent CKD stage ≥3 (cross-sectional), new-onset CKD stage ≥3 (longitudinal), and rapid decline in eGFR (longitudinal). Proteins significantly associated with eGFR and ΔeGFR were subsequently validated in 3,951 FHS Third Generation cohort participants and were tested using Mendelian randomization (MR) analysis to infer putatively causal relations between plasma protein biomarkers and kidney function.

Results

In cross-sectional analysis, 37 protein biomarkers were significantly associated with eGFR at FDR<0.05 in the FHS Offspring cohort and 20 of these validated in the FHS Third Generation cohort at p<0.05/37. In longitudinal analysis, 27 protein biomarkers were significantly associated with ΔeGFR at FDR<0.05 and 12 of these were validated in the FHS Third Generation cohort at p<0.05/27. Additionally, 35 protein biomarkers were significantly associated with prevalent CKD, five were significantly associated with new-onset CKD, and 17 were significantly associated with rapid decline in eGFR. MR suggested putatively causal relations of melanoma cell adhesion molecule (MCAM; -0.011±0.003 mL/min/1.73m², p = 5.11E-5) and epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1; -0.006±0.002 mL/min/1.73m², p = 0.0001) concentration with eGFR.

Discussion/conclusions

Eight protein biomarkers were consistently associated with eGFR in cross-sectional and longitudinal analysis in both cohorts and may capture early kidney impairment; others were implicated in association and causal inference analyses. A subset of CVD protein biomarkers may contribute causally to the pathogenesis of kidney impairment and should be studied as targets for CKD treatment and early prevention.

Effects of diuretics furosemide and hydrochlorothiazide on CKD-MBD: A prospective randomized study

Although diuretics are often prescribed to control fluid overload, they can change Chronic kidney disease-mineral and bone disorder (CKD-MBD) parameters. Previous studies have shown an association between diuretic prescription and changes in both calciuria and parathormone levels. However, the causal relationship could not be confirmed. In addition, the effects of diuretics on bone mineral density and turnover markers are yet to be established. To evaluate the effects of diuretics on CKD-MBD, we have performed a prospective randomized trial comparing hydrochlorothiazide with furosemide in a stage 3CKD population followed for 1 year. Furosemide increased bone remodeling and parathormone levels, whereas hydrochlorothiazide attenuated parathyroid hormone rise and decreased bone turnover markers.

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Diuretics may change parathormone (PTH), although a randomized trial was missing.

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Patients with CKD were randomized to either Furosemide or Hydrochlorothiazide.

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Furosemide increased PTH levels, CTx and P1NP.

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Hydrochlorothiazide attenuated PTH rise and decreased CTx and P1NP.

1,3-Butanediol attenuates hypertension and suppresses kidney injury in female rats

Thirty-seven million people in the United States are estimated to have chronic kidney disease (CKD). Hypertension (HTN) is the second leading risk factor for developing kidney disease. A recent study reported that increasing levels of β-hydroxybutyrate levels by administration of its precursor, 1,3-butanediol, decreased salt-induced HTN in male Dahl salt-sensitive (S) rats. The effect of 1,3-butanediol on hypertensive kidney disease in female rats or the absence of high salt has not been investigated. This study tested the hypothesis that 1,3-butanediol attenuates HTN and the progression of CKD in female S-SHR(11) rats. The S-SHR(11) strain is a congenic rat strain generated from genetic modification of the Dahl S rat, previously characterized as a model of accelerated renal disease. Rats received 1,3-butanediol (20% via drinking water) or control for 10 wk and were maintained on a 0.3% NaCl rodent diet (n = 12-14 rats/group). Blood pressure was measured after 6 and 9 wk of treatment by tail-cuff plethysmography; after 10 wk, urine and tissues were collected. Activity of the treatment was confirmed by measuring plasma β-hydroxybutyrate levels, which were greater in the treated group. The 1,3-butanediol-treated group had lower systolic blood pressure, proteinuria, plasma creatinine, and renal fibrosis after 9 wk of treatment compared with controls. The treated group had significantly smaller spleens and increased the renal anti-inflammatory molecules interleukin-10 and granulocyte-macrophage colony-stimulating factor, suggesting reduced inflammation. The present data demonstrate that 1,3-butanediol lowers blood pressure and renal injury in female rats and could be a novel nutritional intervention for the treatment of CKD.

Effect of imidazoline-1 receptor agonists on renal dysfunction in rats associated with chronic, sequential fructose and ethanol administration

Insulin resistance and chronic alcoholism are risk factors for renal dysfunction. This study investigated the therapeutic effects of two imidazoline-1 receptor (I1R) agonists on renal dysfunction in rats after chronic, sequential fructose and ethanol administration. Daily drinking water was supplemented with fructose (10%, w/v) for 12 weeks and then with ethanol (20%, v/v) for another 8 weeks. Rats were treated with rilmenidine and clonidine in the last two weeks of the study. Blood glucose and serum insulin (sIns) levels, lipid profiles, kidney function and renal histopathology were evaluated at the end of the experiment. Additionally, renal gene expression of nischarin, phosphatidylcholine-specific phospholipase C (PC-PLC) and prostaglandin E2 (PGE2) were measured. Renal levels of superoxide dismutase (SOD), malondialdehyde (MDA), myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS) and total NO (tNO) were detected, and we determined the relative renal gene expression levels of alpha smooth muscle actin (α-SMA), hydroxyproline, interleukin 10 (IL-10), tumour necrosis factor alpha (TNF-α) and caspase-3. The results showed significant deterioration of blood glucose, sIns, lipid profiles, kidney function and renal histopathology in fructose/ethanol-fed rats. Additionally, markers of inflammation, fibrosis, apoptosis and oxidative stress were upregulated. The administration of rilmenidine or clonidine significantly improved blood glucose and sIns levels and reduced renal dysfunction. Our work showed that chronic, sequential fructose and ethanol administration induced fasting hyperglycaemia and renal impairment, and these effects were ameliorated by I1R agonists.

Antihypertensive therapy prescribing patterns and correlates of blood pressure control among hypertensive patients with chronic kidney disease

We used electronic health records (EHRs) data from 5658 ambulatory chronic kidney disease (CKD) patients with hypertension and prescribed antihypertensive therapy to examine antihypertensive drug prescribing patterns, blood pressure (BP) control, and risk factors for resistant hypertension (RHTN) in a real-world setting. Two-thirds of CKD patients and three-fourths of those with proteinuria were prescribed guideline-recommended renoprotective agents including an angiotensin-converting enzyme inhibitor (ACEI) or an angiotensin receptor blocker (ARB); however, one-third were not prescribed an ACEI or ARB. CKD patients, particularly those with stages 1-2 CKD, who were prescribed regimens including beta-blocker (BB) + diuretic or ACEI/ARB + BB + diuretic were more likely to have controlled BP (<140/90 mm Hg) compared to those prescribed other combinations. Risk factors for RHTN included African American race and major comorbidities. Clinicians may use these findings to tailor antihypertensive therapy to the needs of each patient, including providing CKD stage-specific treatment, and better identify CKD patients at risk of RHTN.

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).

Angiotensin Converting Enzyme Inhibitors and Angiotensin Receptor Blockers: A Promising Medication for Chronic Obstructive Pulmonary Disease?

Chronic obstructive pulmonary disease (COPD) is a complex disorder that primarily affects the lungs and is characterized not only by local pulmonary, but also by systemic inflammation which promotes the development of extrapulmonary and cardiovascular co-morbidities. Angiotensin converting enzyme (ACE) inhibitors and ARBs (angiotensin receptor blockers) are widely used drugs in the treatment of cardiovascular diseases, with growing evidence suggesting potential benefits in COPD patients. The purpose of this review is to describe the correlation of renin-angiotensin system (RAS) with COPD pathophysiology and to present the latest data regarding the potential role of RAS blockers in COPD.

Combined Inhibition of Soluble Epoxide Hydrolase and Renin-Angiotensin System Exhibits Superior Renoprotection to Renin-Angiotensin System Blockade in 5/6 Nephrectomized Ren-2 Transgenic Hypertensive Rats with Established Chronic Kidney Disease

BACKGROUND/AIMS

We found recently that increasing renal epoxyeicosatrienoic acids (EETs) levels by blocking soluble epoxide hydrolase (sEH), an enzyme responsible for EETs degradation, shows renoprotective actions and retards the progression of chronic kidney disease (CKD) in Ren-2 transgenic hypertensive rats (TGR) after 5/6 renal ablation (5/6 NX). This prompted us to examine if additional protection is provided when sEH inhibitor is added to the standard renin-angiotensin system (RAS) blockade, specifically in rats with established CKD.

METHODS

For RAS blockade, an angiotensin-converting enzyme inhibitor along with an angiotensin II type receptor blocker was used. RAS blockade was compared to sEH inhibition added to the RAS blockade. Treatments were initiated 6 weeks after 5/6 NX in TGR and the follow-up period was 60 weeks.

RESULTS

Combined RAS and sEH blockade exhibited additional positive impact on the rat survival rate, further reduced albuminuria, further reduced glomerular and tubulointerstitial injury, and attenuated the decline in creatinine clearance when compared to 5/6 NX TGR subjected to RAS blockade alone. These additional beneficial actions were associated with normalization of the intrarenal EETs deficient and a further reduction of urinary angiotensinogen excretion.

CONCLUSION

This study provides evidence that addition of pharmacological inhibition of sEH to RAS blockade in 5/6 NX TGR enhances renoprotection and retards progression of CKD, notably, when applied at an advanced stage.

Role of mesenchymal stem cells versus angiotensin converting enzyme inhibitor in kidney repair

AIM

The current study sought to clarify the role of bone marrow derived mesenchymal stem cells (BM-MSCs) and adipose tissue derived mesenchymal stem cells (AD-MSCs) in repressing nephropathy in the experimental model. Moreover, the aim of this work was extended to compare between stem cells role and angiotensin converting enzyme inhibitor in kidney repair.

METHODS

Isolation and preparation of MSCs culture, flow cytometry using CD34, CD44 and CD105 cell surface markers, biochemical analyses for determination of serum creatinine, urea, transforming growth factor β (TGF-β), cystatin C (CYS-C) and urinary N-Acetyl-ß-D-Glucosaminidase (UNAG), and histopathological investigation of kidney tissue sections were performed.

RESULTS

The results of the present study revealed that single intravenous infusion of MSCs either derived from bone marrow or adipose tissue was able to enhance renal reparative processes through significantly decreased serum creatinine, urea, TGF-β and CYS-C levels as well as UNAG level and significantly increase glomerular filtration rate. Additionally, the histopathological investigations of kidney tissues showed that MSCs have significant regenerative effects as evidenced by the decrease in focal inflammatory cells infiltration, focal interstitial nephritis and congested glomeruli as well as degenerated tubules.

CONCLUSION

The current data provided distinct evidence about the favourable impact of AD-MSCs and BM-MSCs in attenuation of cyclosporine-induced nephropathy in rats through their ability to promote functional and structural kidney repair via transdifferentiation.

The dilemma of dual renin-angiotensin system blockade in chronic kidney disease: why beneficial in animal experiments but not in the clinic?

Drugs interfering with the renin-angiotensin-aldosterone system (RAAS) improved the prognosis in patients with hypertension, heart failure, diabetes and chronic kidney disease. However, combining different drugs brought no further benefit while increasing the risk of hyperkalemia, hypotension and acute renal failure. This was so with combining angiotensin converting enzyme inhibitors (ACEi) and angiotensin II receptors type 1 antagonists (ARB). Dissimilarly, in animal disease models this dual therapy proved clearly superior to single drug treatment and became the optimal standard regime for comparison with other treatments. This review analyzes the causes of the discrepancy of effects of the dual therapy between animal experiments versus clinical studies, and is focused on the outcomes in chronic kidney disease. Discussed is the role of species differences in RAAS, of the variability of the disease features in humans versus relative stability in animals, of the genetic uniformity in the animals but not in humans, and of the biased publication habits of experimental versus clinical studies. We attempt to understand the causes and reconcile the discordant findings and suggest to what extent dual RAAS inhibition should be continued in animal experiments and why its application in the clinics should be limited to strictly selected groups of patients.

Blood pressure and antihypertensive medication profile in a multiethnic Asian population of stable chronic kidney disease patients

INTRODUCTION

Clinical practice guidelines recommend different blood pressure (BP) goals for chronic kidney disease (CKD) patients. Usage of antihypertensive medication and attainment of BP targets in Asian CKD patients remain unclear. This study describes the profile of antihypertensive agents used and BP components in a multiethnic Asian population with stable CKD.

METHODS

Stable CKD outpatients with variability of serum creatinine levels < 20%, taken > 3 months apart, were recruited. Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using automated manometers, according to practice guidelines. Serum creatinine was assayed and the estimated glomerular filtration rate (GFR) calculated using the CKD Epidemiology Collaboration equation. BP and antihypertensive medication profile was examined using univariate analyses.

RESULTS

613 patients (55.1% male; 74.7% Chinese, 6.4% Indian, 11.4% Malay; 35.7% diabetes mellitus) with a mean age of 57.8 ± 14.5 years were recruited. Mean SBP was 139 ± 20 mmHg, DBP was 74 ± 11 mmHg, serum creatinine was 166 ± 115 µmol/L and GFR was 53 ± 32 mL/min/1.73 m(2). At a lower GFR, SBP increased (p < 0.001), whereas DBP decreased (p = 0.0052). Mean SBP increased in tandem with the number of antihypertensive agents used (p < 0.001), while mean DBP decreased when ≥ 3 antihypertensive agents were used (p = 0.0020).

CONCLUSION

Different targets are recommended for each BP component in CKD patients. A majority of patients cannot attain SBP targets and/or exceed DBP targets. Research into monitoring and treatment methods is required to better define BP targets in CKD patients.

Neprilysin is a Mediator of Alternative Renin-Angiotensin-System Activation in the Murine and Human Kidney

Cardiovascular and renal pathologies are frequently associated with an activated renin-angiotensin-system (RAS) and increased levels of its main effector and vasoconstrictor hormone angiotensin II (Ang II). Angiotensin-converting-enzyme-2 (ACE2) has been described as a crucial enzymatic player in shifting the RAS towards its so-called alternative vasodilative and reno-protective axis by enzymatically converting Ang II to angiotensin-(1-7) (Ang-(1-7)). Yet, the relative contribution of ACE2 to Ang-(1-7) formation in vivo has not been elucidated. Mass spectrometry based quantification of angiotensin metabolites in the kidney and plasma of ACE2 KO mice surprisingly revealed an increase in Ang-(1-7), suggesting additional pathways to be responsible for alternative RAS activation in vivo. Following assessment of angiotensin metabolism in kidney homogenates, we identified neprilysin (NEP) to be a major source of renal Ang-(1-7) in mice and humans. These findings were supported by MALDI imaging, showing NEP mediated Ang-(1-7) formation in whole kidney cryo-sections in mice. Finally, pharmacologic inhibition of NEP resulted in strongly decreased Ang-(1-7) levels in murine kidneys. This unexpected new role of NEP may have implications for the combination therapy with NEP-inhibitors and angiotensin-receptor-blockade, which has been shown being a promising therapeutic approach for heart failure therapy.

Nighttime Systolic Blood-Pressure Load Is Correlated with Target-Organ Damage Independent of Ambulatory Blood-Pressure Level in Patients with Non-Diabetic Chronic Kidney Disease

Background

The impacts of blood pressure (BP) load on target-organ damage in patients with chronic kidney disease (CKD) are largely unclear. We examined whether BP load is correlated with target-organ damage (TOD) in Chinese CKD patients independent of BP level.

Methods

We recruited 1219 CKD patients admitted to our hospital division in this cross-sectional study. The TOD were measured by estimated glomerular filtration rate (eGFR), proteinuria, left ventricular mass index (LVMI) and carotid intima-media thickness (cIMT) in this study. Univariate and multivariate linear analyses were used to evaluate the relationship between systolic blood pressure (SBP) load, diastolic blood pressure (DBP) load and these renal, cardiovascular parameters.

Results

In multivariable-adjusted models, BP load and ambulatory BP levels both independently correlated with LVMI, eGFR and proteinuria in all groups of CKD patients (p<0.05), 24-h SBP correlated with cIMT only in non-diabetic CKD patients without hypertension (p<0.05), while nighttime SBP load was associated with cIMT only in non-diabetic CKD patients (p<0.05). Furthermore, nighttime SBP load additionally increased coefficient of determination (R²) and correlated with LVMI, proteinuria in non-diabetic CKD patients without hypertension (R² = 0.034, P<0.001 and R² = 0.012, P = 0.006 respectively) and LVMI, cIMT, eGFR in non-diabetic CKD patients with hypertension (R²>0.008, P<0.05) in multivariable-adjusted model which already including the 24-h BP. BP load did not refine this correlation based on the 24-h BP level in diabetic CKD patients.

Conclusion

Night-time SBP load was correlated with TOD in patients with non-diabetic chronic kidney disease independent of BP level.

Inhibition of soluble epoxide hydrolase is renoprotective in 5/6 nephrectomized Ren-2 transgenic hypertensive rats

1. The aim of the present study was to test the hypothesis that increasing kidney tissue concentrations of epoxyeicosatrienoic acids (EETs) by preventing their degradation to the biologically inactive dihydroxyeicosatrienoic acids (DHETEs) using blockade of soluble epoxide hydrolase (sEH) would attenuate the progression of chronic kidney disease (CKD).

2. Ren-2 transgenic rats (TGR) after 5/6 renal mass reduction (5/6 NX) served as a model of CKD associated with angiotensin (Ang) II-dependent hypertension. Soluble epoxide hydrolase was inhibited using cis-4-[4-(3-adamantan-1-yl-ureido)cyclohexyloxy]benzoic acid (c-AUCB; 3 mg/L drinking water) for 20 weeks after 5/6 NX. Sham-operated normotensive transgene-negative Hannover Sprague-Dawley (HanSD) rats served as controls.

3. When applied in TGR subjected to 5/6 NX, c-AUCB treatment improved survival rate, prevented the increase in blood pressure, retarded the progression of cardiac hypertrophy, reduced proteinuria and the degree of glomerular and tubulointerstitial injury and reduced glomerular volume. All these organ-protective actions were associated with normalization of the intrarenal EETs : DHETEs ratio, an index of the availability of biologically active EETs, to levels observed in sham-operated HanSD rats. There were no significant concurrent changes of increased intrarenal AngII content.

4. Together, these results show that 5/6 NX TGR exhibit a profound deficiency of intrarenal availability of active epoxygenase metabolites (EETs), which probably contributes to the progression of CKD in this model of AngII-dependent hypertension, and that restoration of intrarenal availability of EETs using long-term c-AUCB treatment exhibits substantial renoprotective actions.

The Effect of Chinese rhubarb, Rheum officinale, with and without benazepril on the progression of naturally occurring chronic kidney disease in cats

Background

Renal fibrosis is common in progressive kidney disease. Transforming growth factors β (TGF‐β) are important mediators of all types of fibrosis, including renal fibrosis. Chinese rhubarb has been shown to have antifibrotic properties in part because of inhibition of TGF‐β and has slowed the progression of kidney disease in rodent models.

Hypothesis

That administration of a Chinese rhubarb supplement will slow the progression of chronic kidney disease (CKD) in cats and the concurrent administration of Chinese rhubarb and benazepril will be more effective than either alone.

Animals

Twenty‐nine client‐owned cats with naturally occurring IRIS Stage 2 or early Stage 3 CKD and without comorbidity such as cancer, urinary tract obstruction, urinary tract infection, poorly controlled hyperthyroidism, or systemic hypertension were enrolled in the study.

Methods

A randomized, positive‐controlled, prospective study was performed. Cats received Chinese rhubarb, benazepril, or both in addition to standard treatment for CKD. Repeated measures ANOVA was used to assess changes in serum creatinine concentration, body weight, hematocrit, urine protein: urine creatinine ratio (UPC), and systemic arterial blood pressure over time between and within treatment groups over an average of 22 months.

Results

No significant differences were detected in serum creatinine concentration, body weight, hematocrit, UPC, and systemic arterial pressure over time between or within treatment groups.

Conclusions and Clinical Importance

This study failed to detect a significant difference in the progression of CKD in cats treated with Chinese rhubarb, benazepril, or both. Further study in specific subsets of cats with CKD is warranted.

Beta-Blockers in the Management of Hypertension and/or Chronic Kidney Disease

This minireview provides current summaries of beta-blocker use in the management of hypertension and/or chronic kidney disease. Accumulated evidence suggests that atenolol is not sufficiently effective as a primary tool to treat hypertension. The less-than-adequate effect of beta-blockers in lowering the blood pressure and on vascular protection, and the unfavorable effects of these drugs, as compared to other antihypertensive agents, on the metabolic profile have been pointed out. On the other hand, in patients with chronic kidney disease, renin-angiotensin system blockers are the drugs of first choice for achieving the goal of renal protection. Recent studies have reported that vasodilatory beta-blockers have adequate antihypertensive efficacy and less harmful effects on the metabolic profile, and also exert beneficial effects on endothelial function and renal protection. However, there is still not sufficient evidence on the beneficial effects of the new beta-blockers.

Addition of ET(A) receptor blockade increases renoprotection provided by renin-angiotensin system blockade in 5/6 nephrectomized Ren-2 transgenic rats

AIMS

There is evidence that in addition to hypertension and hyperactivity of the renin-angiotensin system (RAS), enhanced intrarenal activity of endothelin (ET) system contributes to the pathophysiology and progression of chronic kidney disease (CKD). This prompted us to examine if this progression would be alleviated by addition of type A ET receptor (ETA) blockade to the standard blockade of RAS.

MAIN METHODS

Ren-2 transgenic rats (TGR) after 5/6 renal ablation (5/6 NX) served as a model of CKD. For RAS inhibition a combination of angiotensin-converting enzyme inhibitor (trandolapril, 6 mg/L drinking water) and angiotensin II type 1 receptor blocker (losartan, 100 mg/L drinking water) was used. Alternatively, ETA receptor blocker (atrasentan, 5 mg·kg(-1)·day(-1) in drinking water) was added to the combined RAS blockade. The follow-up period was 44 weeks after 5/6 NX, and the rats' survival rate, systolic blood pressure (SBP), proteinuria and indices of renal glomerular damage were evaluated.

KEY FINDINGS

The survival rate was at first improved, by either therapeutic regime, however, the efficiency of RAS blockade alone considerably decreased 36 weeks after 5/6 NX: final survival rate of 65% was significantly lower than 91% achieved with combined RAS and ETA receptor blockade. SBP was not affected by the addition of ETA blockade while proteinuria and renal glomerular damage were further reduced.

SIGNIFICANCE

Our data show that a combined RAS and ETA receptor blockade exhibits additional beneficial effects on survival rate and the progression of CKD in 5/6 NX TGR, as compared with RAS inhibition alone.

Reversed dipper blood-pressure pattern is closely related to severe renal and cardiovascular damage in patients with chronic kidney disease

BACKGROUND

A non-dipper blood pressure (BP) pattern is very common in chronic kidney disease (CKD) patients and affects the progression and development of cardiovascular disease. However, data on the reversed dipper BP pattern on target-organ damage in Chinese CKD patients are lacking.

METHODS

A total of 540 CKD patients were enrolled. Ambulatory blood pressure monitoring (ABPM), clinical BP, ultrasonographic assessment and other clinical data were collected. Univariate and multivariate analyses were used to ascertain the relationship between ABPM results and clinical parameters.

RESULTS

A total of 21.9% CKD patients had a reversed dipper BP pattern, 42% of patients had a non-dipper BP pattern and 36.1% of patients had a dipper BP pattern. Patients with reversed dipper BP pattern had the worst renal function and most severe cardiovascular damages among these CKD patients (p<0.05). The estimated glomerular filtration rate (eGFR) and left ventricular mass index (LVMI) correlated significantly with the rate of decline of nocturnal BP. A reversed dipper BP pattern was an independent factor affecting kidney damage and left ventricular hypertrophy. Age, lower hemoglobin level, higher 24-h systolic BP from ABPM, and higher serum phosphate levels were independent associated with a reversed dipper BP pattern after multivariate logistic regression analyses.

CONCLUSION

The reversed dipper BP pattern is closely related to severe renal damage and cardiovascular injuries in CKD patients, and special attention should be given to these CKD patients.