Kidney function decline associated with proton pump inhibitors: results from the ELSA-Brasil cohort

OBJECTIVE

Investigate the longitudinal association of use and time of use of proton pump inhibitors (PPI) with incidence of chronic kidney disease (CKD) and kidney function change.

METHODS

Prospective study with 13,909 participants from baseline (2008-2010) and second wave (2012-2014) of the ELSA-Brasil (mean interval between visits = 3.9 years (1.7-6.0)). Participants answered about use and time use of the PPI in the two weeks prior the interview. Renal function was assessed by glomerular filtration rate estimated by the Collaboration Equation for the Epidemiology of Chronic Kidney Disease. Values below 60ml/min/1.73 m² in wave 2 were considered incident CKD. Associations between PPI use and time of use at baseline and incident CKD and decline in renal function were estimated, respectively, by logistic regression and linear models with mixed effects, after adjusting for confounders.

RESULTS

After adjustments, PPI users for more than six months had an increased risk of CKD compared to non-users. Compared to non-users, users PPIs for up to six months and above six months had greater decline in kidney function over time.

CONCLUSION

This cohort of adults and elderly, after a mean interval of 3.9 years, PPI use and initial duration were associated with kidney function change between visits.

Renal medicine in the intensive care unit: a narrative review

Kidney disease, both acute and chronic, is commonly encountered on the intensive care unit. Due to the role the kidneys play in whole body homeostasis, it follows that their dysfunction has wide-ranging implications and can affect prescribing and therapeutic management. This narrative review discusses the pathophysiology of acute kidney injury and chronic kidney disease, and how this relates to critically unwell patients. We cover several aspects of the management of renal dysfunction on the critical care unit, exploring some of the recurrent themes within the literature, including type and timing of kidney replacement therapy, management of acute kidney injury, as well as discussing how novel biomarkers for acute kidney injury may help to identify patients suffering from acute kidney injury as well as risk stratifying these patients. We discuss how early involvement of specialist nephrology services can improve outcomes in patients with kidney disease as well as offer valuable diagnostic and specialist management advice, particularly for patients with established end stage kidney disease and patients who are already known to nephrology services. We also explore some of the ongoing research questions that need to be answered within this arena.

Regulation of Mitochondrial Homeostasis and Nrf2 in Kidney Disease: Timing Is Critical

Abnormal regulation of mitochondrial homeostasis plays a critical role in the progression of renal disease. Recent studies have shown that activation of nuclear factor erythroid 2-related factor 2 (Nrf2) has time-dependent protective effects, which can be explained by the differing regulation of mitochondrial homeostasis during the various stages of kidney disease. In this review, we summarize the mechanisms whereby mitochondrial homeostasis is regulated and the nature of the dysregulation of mitochondrial homeostasis in renal disease. In addition, we summarize the dual roles of Nrf2 in kidney disease by discussing the studies that have shown the importance of the timing of its activation in the regulation of mitochondrial homeostasis. This should provide a theoretical basis for therapeutic strategies aimed at activating Nrf2 in kidney disease.

Frequency and Predictors of Acute Kidney Injury in Patients With Acute Coronary Syndrome in a Tertiary Care Hospital: A Retrospective Study

Introduction

Acute kidney injury (AKI) is a complex condition marked by rapid deterioration of renal function (within hours or days), with clinical symptoms ranging from a minor rise in serum creatinine to anuric renal failure needing renal replacement therapy. AKI is one of the complications of acute coronary syndrome (ACS). This study aims to determine the frequency of AKI among patients with ACS and identify its predictors.

Method

This study is a retrospective observational study conducted at the Dow University of Health Sciences, a tertiary care hospital located in Karachi, Pakistan. This study was conducted from January 2020 to June 2021. All patients aged 18-75 years admitted with ACS and admitted for more than 48 hours were included in the study. A pre-set questionnaire was used to collect data from the hospital management information system (HMIS).

Results

The frequency of AKI among patients with ACS was 24.18%. The factors associated with AKI among patients with ACS on multivariable logistic regression included the age of patients (odds ratio (OR) = 1.04, p-value = 0.018), having diabetes mellitus (OR = 2.33, p-value = 0.031), admission Killip ≥ II (OR = 2.12, p-value = 0.041), previous history of myocardial infarction (MI) (OR = 3.64, p-value = 0.001), baseline glomerular filtration rate (GFR) (OR = 0.94, p-value = 0.001), in-hospital ejection fraction (EF) (OR = 0.93, p-value = 0.001), and serum creatinine at admission (OR = 1.02, p-value = 0.001).

Conclusion

Age, comorbidities including diabetes mellitus and previous history of MI, admission Killip ≥ II, baseline GFR, in-hospital EF, and serum creatinine level at admission are significant independent predictors of AKI in patients with ACS.

(-)-α-Bisabolol as a protective agent against epithelial renal cytotoxicity induced by amphotericin B

INTRODUCTION

Amphotericin B (AmB), used for systemic fungal infections, has a limited clinical application because of its high nephrotoxicity. Natural antioxidant and anti-inflammatory substances have been widely studied for protection against drug-induced nephrotoxicity. α-Bisabolol (BIS) has demonstrated a nephroprotective effect on both in vitro and in vivo models.

AIMS

The aim of this work was to evaluate the effect of BIS against AmB-induced nephrotoxicity in vitro.

MATERIAL AND METHODS

LLC-MK2 cells were pre- and post-treated with non-toxic BIS concentrations and/or AmB IC50 (13.97 μM). Cell viability was assessed by MTT [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)] assay. Flow cytometry analyses were used to assess cell death mechanism, production of reactive oxidative stress (ROS) and mitochondrial transmembrane potential. Kidney Injury Molecule-1 (KIM-1) levels were measured via ELISA.

KEY FINDINGS

The present work showed that BIS pretreatment (125; 62.5 and 31.25 μM) increased cell viability when compared to the group treated only with AmB IC50. AmB treatment induced both necrosis (7-AAD-labeled cells) and late apoptosis (AnxV-labeled). BIS was able to prevent the occurrence of these events. These effects were associated with a decrease of ROS accumulation, improving transmembrane mitochondrial potential and protecting against tubular cell damage, highlighted by the inhibition of KIM-1 release after BIS treatment.

SIGNIFICANCE

BIS presented a potential effect on model of renal cytotoxicity induced by AmB, bringing perspectives for the research of new nephroprotective agents.

Polypharmacy and bone fracture risk in patients with type 2 diabetes: The Fukuoka Diabetes Registry

AIMS

To prospectively investigate the association between the number of prescribed drugs and the fracture risk in patients with type 2 diabetes.

METHODS

Japanese participants with type 2 diabetes (n = 4,706; 2,755 men, 1,951 postmenopausal women; mean age, 66 years) were followed for a median of 5.3 years and grouped on the basis of the number of prescribed drugs at baseline. The main outcomes were fractures at any anatomic site and fragility fractures (fractures at hip and spine sites).

RESULTS

During follow-up, any fracture occurred in 662 participants. The overall age- and sex-adjusted fracture incidence rates per 1,000 person-years were 21.2 (0-2 drugs), 28.1 (3-5 drugs), 37.7 (6-8 drugs), and 44.0 (≥9 drugs) (p for trend < 0.001). Compared with 0-2 drugs, the multivariate-adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) for fractures were 1.34 (1.07-1.68) for 3-5 drugs, 1.76 (1.37-2.26) for 6-8 drugs, and 1.71 (1.27-2.31) in ≥ 9 drugs. The multivariate-adjusted HR (95% CI) per increment in drugs was 1.05 (1.02-1.08) (p < 0.001). Similar tendencies were observed for fragility fractures.

CONCLUSIONS

A greater number of prescribed drugs is associated with an increased bone fracture risk in patients with type 2 diabetes.

Pharmacological Management of Acute Endodontic Pain

Pain associated with infections of the tooth pulp and periapical tissues is intense and often the most common reason for patients seeking emergency dental care. Effective management of acute dental pain requires a deep understanding of pain mechanisms, which enables accurate diagnosis and definitive treatment. While drugs are only used as an adjunct to definitive dental treatment, a thorough understanding of their mechanism of action and effectiveness enables clinicians to effectively control intra-operative and post-operative pain and prevent persistent pain. This review describes how pain is detected, processed, and perceived. It also provides information on evidence-based strategies on the use of different classes of drugs to effectively manage endodontic pain.

The clinicopathological features of drug-induced acute kidney injury-a single-center retrospective analysis

Background

This study aimed to analyze changes to the drug spectrum and clinicopathological features of drug-induced acute kidney injury (AKI) with recent medication habits changes.

Methods

A retrospective analysis of the characteristics of patients diagnosed with drug-induced AKI from January 2012 to October 2016 period at the First Affiliated Hospital of the Medical College of Zhejiang University was conducted.

Results

Between January 2012 and October 2016, 909 patients were diagnosed with AKI. Of these, 228 were diagnosed with drug-related AKI were engaged in this study, including 51 who underwent renal biopsies, 74 treated with antibacterial and antiviral drugs, and 63 who received nonsteroidal anti-inflammatory drugs (NSAIDs), and 17 who were treated with Chinese herbal medicine. AKI was most frequently associated with antibiotics and antiviral drugs, including cephalosporins, acyclovir, azithromycin, clindamycin, and levofloxacin. In those who underwent renal biopsy, 12 patients were diagnosed with allergic interstitial nephritis, 19 with interstitial nephritis, 8 with renal tubular epithelial cell injury, 2 with minimal change nephropathy, 2 with IgA nephropathy, and 2 with mild mesangial hyperplasia with glomerulosclerosis. The mean follow-up time was 437 days, ranging from 3 to 2,756 days. Among 228 patients, 165 recovered completely, 4 recovered partially, 8 did not recover, and 51 were lost to follow-up after discharge.

Conclusions

The three main contributors to drug-induced AKI were antimicrobial agents, NSAIDs, and Chinese herbal medicines. The age distribution of the three different drug-induced AKI groups was significantly different. Allergic interstitial nephritis, interstitial nephritis, and tubular epithelial cell injury were the main pathological manifestations of drug-induced AKI. The novel predictive nomogram achieved a good performance of prediction recovery within 2 weeks in drug-induced AKI patients.

Acute kidney injury pathology and pathophysiology: a retrospective review

Acute kidney injury (AKI) is the clinical term used for decline or loss of renal function. It is associated with chronic kidney disease (CKD) and high morbidity and mortality. However, not all causes of AKI lead to severe consequences and some are reversible. The underlying pathology can be a guide for treatment and assessment of prognosis. The Kidney Disease: Improving Global Outcomes guidelines recommend that the cause of AKI should be identified if possible. Renal biopsy can distinguish specific AKI entities and assist in patient management. This review aims to show the pathology of AKI, including glomerular and tubular diseases.

A Review on Drug-Induced Nephrotoxicity: Pathophysiological Mechanisms, Drug Classes, Clinical Management, and Recent Advances in Mathematical Modeling and Simulation Approaches

A variety of marketed drugs belonging to various therapeutic classes are known to cause nephrotoxicity. Nephrotoxicity can manifest itself in several forms depending on the specific site involved as well as the underlying pathophysiological mechanisms. As they often coexist with other pathophysiological conditions, the steps that can be taken to treat them are often limited. Thus, drug-induced nephrotoxicity remains a major clinical challenge. Prior knowledge of risk factors associated with special patient populations and specific classes of drugs, combined with early diagnosis, therapeutic drug monitoring with dose adjustments, as well as timely prospective treatments are essential to prevent and manage them better. Most incident drug-induced renal toxicity is reversible only if diagnosed at an early stage and treated promptly. Hence, diagnosis at an early stage is the need of the hour to counter it. Significant recent advances in the identification of novel early biomarkers of nephrotoxicity are not beyond limitations. In such a scenario, mathematical modeling and simulation (M&S) approaches may help to better understand and predict toxicities in a clinical setting. This review summarizes pathophysiological mechanisms of drug-induced nephrotoxicity, classes of nephrotoxic drugs, management, prevention, and diagnosis in clinics. Finally, it also highlights some of the recent advancements in mathematical M&S approaches that could be used to better understand and predict drug-induced nephrotoxicity.

Risk factors for high-dose methotrexate associated acute kidney injury in patients with hematological malignancies

High dose methotrexate (HDMTX)-induced acute kidney injury (AKI) is a well-known adverse event in hemato-oncology patients. Our purpose was to define factors and setup cut-offs that may help better identify patients at-risk for developing AKI following HDMTX. All consecutive patients who received MTX dose ≥1 g were retrospectively reviewed. We compared patients with or without renal toxicity. We used a logistic regression model to define baseline variables associated with AKI. Overall survival (OS) was estimated by the Kaplan-Meier method employing log-rank test. Between 2012 and 2017, 160 patients were included with a total of 265 courses. Indications included: primary central nervous system (CNS) lymphoma, CNS prophylaxis in other lymphoma types, acute lymphatic leukemia and others. Median age at diagnosis was 58 years (range, 18-84), 54% were males, median MTX dose was 1941 mg/m² (range, 743-5442) and AKI developed in 9% of drug administrations (n = 24). In univariate analysis: age > 40, LDH > 380 units/L, eGFR < 112 mL/min, albumin <3.6 mg/dL at baseline and Charlson comorbidity index (CCI) were associated with AKI. In multivariable analysis, only LDH > 380 units/L (OR = 4.1, 95% confidence interval [CI] 1.04-20.9, P = .04) and albumin levels <3.6 g/dL (OR = 4.17, 95% CI 1.04-6.5, P = .04) remained significant. In patients with AKI, median drug elimination was longer (8 days vs 5 days). In 80% of cases, the creatinine levels returned to normal within 1 month. Yet, the median survival of patients who developed AKI was 37 months, compared to 145 months in patients without AKI (Log rank = 0.015). In conclusion, LDH > 380 units/L and albumin <3.6 g/dL were the strongest factors associated with AKI in patients receiving HDMTX. Although the rise in creatinine levels was almost uniformly reversible, AKI was associated with increased mortality rates.

Effect of Renin-Angiotensin System Inhibitors on the Comparative Nephrotoxicity of NSAIDs and Opioids during Hospitalization

Background

Nonsteroidal anti-inflammatory drugs (NSAIDS) are increasingly important alternatives to opioids for analgesia during hospitalization as health systems implement opioid-minimization initiatives. Increasing NSAID use may increase AKI rates, particularly in patients with predisposing risk factors. Inconclusive data in outpatient populations suggests that NSAID nephrotoxicity is magnified by renin-angiotensin system inhibitors (RAS-I). No studies have tested this in hospitalized patients.

Methods

Retrospective, active-comparator cohort study of patients admitted to four hospitals in Philadelphia, Pennsylvania. To minimize confounding by indication, NSAIDs were compared to oxycodone, and RAS-I were compared to amlodipine. We tested synergistic NSAID+RAS-I nephrotoxicity by comparing the difference in AKI rate between NSAID versus oxycodone in patients treated with RAS-I to the difference in AKI rate between NSAID versus oxycodone in patients treated with amlodipine. In a secondary analysis, we restricted the cohort to patients with baseline diuretic treatment. AKI rates were adjusted for 71 baseline characteristics with inverse probability of treatment-weighted Poisson regression.

Results

The analysis included 25,571 patients who received a median of 2.4 days of analgesia. The overall AKI rate was 23.6 per 1000 days. The rate difference (RD) for NSAID versus oxycodone in patients treated with amlodipine was 4.1 per 1000 days (95% CI, -2.8 to 11.1), and the rate difference for NSAID versus oxycodone in patients treated with RAS-I was 5.9 per 1000 days (95% CI, 1.9 to 10.1), resulting in a nonsignificant interaction estimate: 1.85 excess AKI events per 1000 days (95% CI, -6.23 to 9.92). Analysis in patients treated with diuretics produced a higher, albeit nonsignificant, interaction estimate: 9.89 excess AKI events per 1000 days (95% CI, -5.04 to 24.83).

Conclusions

Synergistic nephrotoxicity was not observed with short-term NSAID+RAS-I treatment in the absence of concomitant diuretics, suggesting that RAS-I treatment may not be a reason to choose opioids in lieu of NSAIDs in this population. Synergistic nephrotoxicity cannot be ruled out in patients treated with diuretics.

Risk of acute kidney injury in patients with HIV receiving proton pump inhibitors

Aims/patients & methods: To evaluate the risk of acute kidney injury (AKI) in patients with HIV receiving proton pump inhibitors (PPI) a cohort study was conducted utilizing the Veterans Affairs Informatics and Computing Infrastructure (VINCI) database. Patients were followed from the index date until the earliest date of AKI, 120 days or end of study period, or death. Statistical analyses utilized a Cox proportional hazards model. Results: A total of 21,643 patients (6000 PPI and 15,643 non-PPI) met all study criteria. The PPI cohort had twice the risk of AKI compared with controls (2.12, hazard ratio: 1.46-3.1). Conclusion: A nationwide cohort study supported the relationship of an increased risk of AKI in patients receiving PPIs.

Predictors of acute kidney injury (AKI) in high-risk ST-elevation myocardial infarction (STEMI) patients: A single-center retrospective observational study

Acute kidney injury (AKI) is a frequent complication in ST-elevation myocardial infarction (STEMI) patients. Factors other than contrast exposure have been suggested as major contributors to renal dysfunction in patients undergoing primary percutaneous coronary intervention (PPCI). Our aim was to assess the incidence and risk factors of AKI in high-risk STEMI patients, mostly treated by PPCI with implemented measures to prevent contrast-induced AKI. We retrospectively analyzed data of 245 STEMI patients (165 men, mean age 63.9 ± 11.9 years) admitted to the Department of Medical Intensive Care Unit. Demographic, clinical, and mortality data were compared between AKI and non-AKI group. AKI was defined as a 1.5-fold increase in serum creatinine from baseline level within 24-48 hours. AKI developed in 34/245 (13.9%) patients. PPCI was performed in 226/245 (92.2%) of all STEMI cases, with no difference between AKI and non-AKI group. There were significant differences between AKI and non-AKI group in diabetes mellitus (41.2% vs. 20.9%), prior MI (26.5% vs. 11.8%), prior resuscitation (38.2% vs. 12.4%), admission acute heart failure [AHF] (44.1% vs. 12.8%), in-hospital AHF (70.6% vs. 17.5%), and hospital-acquired infection [HAI] (79.4% vs. 18.0%). Significantly more AKI patients had increased admission CRP ≥25 mg/L (38.2% vs. 11.8%), peak CRP ≥50 mg/L (91.2% vs. 36%), admission troponin I ≥10 mg/L (44.1% vs. 24.6%), peak troponin I ≥50 mg/L (64.7% vs. 44.1%), peak NT-proBNP ≥400 pmol/L (82.4% vs. 27.5%), and ejection fraction <45% (76.5% vs. 33.6%). Mortality was significantly increased in AKI group, including in-hospital (52.9% vs. 7.1%), 30-day (64.7% vs. 10.7%) and 6-month mortality (70.6% vs. 13.7%). Significant independent predictors of AKI were prior resuscitation (OR 4.171, 95% CI 1.088-15.998), HAI (OR 7.974, 95% CI 1.992-31.912), and peak NT-proBNP (OR 21.261, 95% CI 2.357-191.795). To reduce the risk of AKI in STEMI patients, early diagnosis and treatment of AHF and HAIs are advisable.

Association of proton pump inhibitor use with the risk of the development or progression of albuminuria among Japanese patients with diabetes: A prospective cohort study [Diabetes Distress and Care Registry at Tenri (DDCRT 16)]

AIMS

We aimed to determine the prospective association between proton pump inhibitor (PPI) use and the subsequent risk of the development or progression of albuminuria or eGFR.

METHODS

Longitudinal data of patients with diabetes were obtained from a large Japanese diabetes registry. To assess the independent correlation between PPI use and the development or progression of urine microalbuminuria, the time-varying Cox proportional hazards model was used with adjustment for potential confounders.

RESULTS

The mean patient age, body-mass index (BMI), and hemoglobin A1c (HbA1c) levels were 65.7 y, 24.5 kg/m², and 7.5% (57.9 mmol/mol), respectively. In 1711 patients without albuminuria, we observed 599 cases with development of albuminuria over median follow-up of 4.0 years, and in 1279 patients with microalbuminuria, 290 cases with urinary albuminuria progression over 4.0 years, and 257 eGFR decline cases over 3.8 years. PPI use was not associated with the development of albuminuria (HR = 0.88; 95%CI, 0.77-1.01; p = .058), progression of albuminuria (HR = 1.24; 95%CI, 0.87-1.79; p = .236), nor eGFR decline (HR = 1.05; 95%CI, 0.81-1.34; p = .973) even in a propensity score-adjusted model with time-varyingly updating PPI use information.

CONCLUSIONS

In conclusion, PPI use was not associated with the subsequent risk of development or progression of albuminuria, or eGFR decline in patients with diabetes.

[Prevention of acute kidney injury in critically ill patients : Recommendations from the renal section of the DGIIN, ÖGIAIN and DIVI]

BACKGROUND

Acute kidney injury (AKI) has both high mortality and morbidity.

OBJECTIVES

To prevent the occurrence of AKI, current recommendations from the renal section of the DGIIN (Deutschen Gesellschaft für Internistische Intensivmedizin und Notfallmedizin), ÖGIAIN (Österreichischen Gesellschaft für Internistische und Allgemeine Intensivmedizin und Notfallmedizin) and DIVI (Deutschen Interdisziplinären Vereinigung für Intensiv- und Notfallmedizin) are stated.

MATERIALS AND METHODS

The recommendations stated in this paper are based on the current Kidney Disease Improving Global Outcomes (KDIGO) guidelines, the published statements of the "Working Group on Prevention, AKI section of the European Society of Intensive Care Medicine" and the expert knowledge and clinical experience of the authors.

RESULTS

Currently there are no approved clinically effective drugs for the prevention of AKI. Therefore the mainstay of prevention is the optimization of renal perfusion by improving the mean arterial pressure (>65 mm Hg, higher target may be considered in hypertensive patients). This can be done by vasopressors, preferably norepinephrine and achieving or maintaining euvolemia. Hyperhydration that can lead to AKI itself should be avoided. In patients with maintained diuresis this can be done by diuretics that are per se no preventive drug for AKI. Radiocontrast enhanced imaging should not be withheld from patients at risk for AKI; if indicated, however, the contrast media should be limited to the smallest possible volume.

The Effects of 2'-O-Methoxyethyl Oligonucleotides on Renal Function in Humans

Systemically administered 2′-O-methoxyethyl (2′MOE) antisense oligonucleotides (ASOs) accumulate in the kidney and metabolites are cleared in urine. The effects of eleven 2′MOE ASOs on renal function were assessed in 2,435 patients from 32 phase 2 and phase 3 trials. The principle analysis was on data from 28 randomized placebo-controlled trials. Mean levels of renal parameters remained within normal ranges over time across dose groups. Patient-level meta-analyses demonstrated a significant difference between placebo-treated and 2′MOE ASO-treated patients at doses >175 mg/week in the percentage and absolute change from baseline for serum creatinine and estimated glomerular filtration rate. However, these changes were not clinically significant or progressive. No dose-related effects were observed in the incidence of abnormal renal test results in the total population of patients, or subpopulation of diabetic patients or patients with renal dysfunction at baseline. The incidence of acute kidney injury [serum creatinine ≥0.3 mg/dL (26.5 μM) increases from baseline or ≥1.5 × baseline] in 2′MOE ASO-treated patients (2.4%) was not statistically different from placebo (1.7%, P = 0.411). In conclusion, in this database, encompassing 32 clinical trials and 11 different 2′MOE ASOs, we found no evidence of clinically significant renal dysfunction up to 52 weeks of randomized-controlled treatment.

Prevention of acute kidney injury and protection of renal function in the intensive care unit: update 2017 : Expert opinion of the Working Group on Prevention, AKI section, European Society of Intensive Care Medicine

BACKGROUND

Acute kidney injury (AKI) in the intensive care unit is associated with significant mortality and morbidity.

OBJECTIVES

To determine and update previous recommendations for the prevention of AKI, specifically the role of fluids, diuretics, inotropes, vasopressors/vasodilators, hormonal and nutritional interventions, sedatives, statins, remote ischaemic preconditioning and care bundles.

METHOD

A systematic search of the literature was performed for studies published between 1966 and March 2017 using these potential protective strategies in adult patients at risk of AKI. The following clinical conditions were considered: major surgery, critical illness, sepsis, shock, exposure to potentially nephrotoxic drugs and radiocontrast. Clinical endpoints included incidence or grade of AKI, the need for renal replacement therapy and mortality. Studies were graded according to the international GRADE system.

RESULTS

We formulated 12 recommendations, 13 suggestions and seven best practice statements. The few strong recommendations with high-level evidence are mostly against the intervention in question (starches, low-dose dopamine, statins in cardiac surgery). Strong recommendations with lower-level evidence include controlled fluid resuscitation with crystalloids, avoiding fluid overload, titration of norepinephrine to a target MAP of 65-70 mmHg (unless chronic hypertension) and not using diuretics or levosimendan for kidney protection solely.

CONCLUSION

The results of recent randomised controlled trials have allowed the formulation of new recommendations and/or increase the strength of previous recommendations. On the other hand, in many domains the available evidence remains insufficient, resulting from the limited quality of the clinical trials and the poor reporting of kidney outcomes.

Long-term kidney outcomes among users of proton pump inhibitors without intervening acute kidney injury

Proton pump inhibitor (PPI) use is associated with an increased risk of acute kidney injury (AKI), incident chronic kidney disease (CKD), and progression to end-stage renal disease (ESRD). PPI-associated CKD is presumed to be mediated by intervening AKI. However, whether PPI use is associated with an increased risk of chronic renal outcomes in the absence of intervening AKI is unknown. To evaluate this we used the Department of Veterans Affairs national databases to build a cohort of 144,032 incident users of acid suppression therapy that included 125,596 PPI and 18,436 Histamine H2 receptor antagonist (H2 blockers) consumers. Over 5 years of follow-up in survival models, cohort participants were censored at the time of AKI occurrence. Compared with incident users of H2 blockers, incident users of PPIs had an increased risk of an estimated glomerular filtration rate (eGFR) under 60 ml/min/1.73m² (hazard ratio 1.19; 95% confidence interval 1.15-1.24), incident CKD (1.26; 1.20-1.33), eGFR decline over 30% (1.22; 1.16-1.28), and ESRD or eGFR decline over 50% (1.30; 1.15-1.48). Results were consistent in models that excluded participants with AKI either before chronic renal outcomes, during the time in the cohort, or before cohort entry. The proportion of PPI effect mediated by AKI was 44.7%, 45.47%, 46.00%, and 46.72% for incident eGFR under 60 ml/min/1.73m², incident CKD, eGFR decline over 30%, and ESRD or over 50% decline in eGFR, respectively. Thus, PPI use is associated with increased risk of chronic renal outcomes in the absence of intervening AKI. Hence, reliance on antecedent AKI as warning sign to guard against the risk of CKD among PPI users is not sufficient as a sole mitigation strategy.

Mitochondria Damage and Kidney Disease

The kidney is a vital organ that demands an extraordinary amount of energy to actively maintain the body's metabolism, plasma hemodynamics, electrolytes and water homeostasis, nutrients reabsorption, and hormone secretion. Kidney is only second to the heart in mitochondrial count and oxygen consumption. As such, the health and status of the energy power house, the mitochondria, is pivotal to the health and proper function of the kidney. Mitochondria are heterogeneous and highly dynamic organelles and their functions are subject to complex regulations through modulation of its biogenesis, bioenergetics, dynamics and clearance within cell. Kidney diseases, either acute kidney injury (AKI) or chronic kidney disease (CKD), are important clinical issues and global public health concerns with high mortality rate and socioeconomic burden due to lack of effective therapeutic strategies to cure or retard the progression of the diseases. Mitochondria-targeted therapeutics has become a major focus for modern research with the belief that maintaining mitochondria homeostasis can prevent kidney pathogenesis and disease progression. A better understanding of the cellular and molecular events that govern mitochondria functions in health and disease will potentially lead to improved therapeutics development.

Proton Pump Inhibitors and Risk of Incident CKD and Progression to ESRD

The association between proton pump inhibitors (PPI) use and risk of acute interstitial nephritis has been described. However, whether exposure to PPI associates with incident CKD, CKD progression, or ESRD is not known. We used Department of Veterans Affairs national databases to build a primary cohort of new users of PPI (n=173,321) and new users of histamine H₂-receptor antagonists (H₂ blockers; n=20,270) and followed these patients over 5 years to ascertain renal outcomes. In adjusted Cox survival models, the PPI group, compared with the H₂ blockers group, had an increased risk of incident eGFR<60 ml/min per 1.73 m² and of incident CKD (hazard ratio [HR], 1.22; 95% confidence interval [95% CI], 1.18 to 1.26; and HR, 1.28; 95% CI, 1.23 to 1.34, respectively). Patients treated with PPI also had a significantly elevated risk of doubling of serum creatinine level (HR, 1.53; 95% CI, 1.42 to 1.65), of eGFR decline >30% (HR, 1.32; 95% CI, 1.28 to 1.37), and of ESRD (HR, 1.96; 95% CI, 1.21 to 3.18). Furthermore, we detected a graded association between duration of PPI exposure and risk of renal outcomes among those exposed to PPI for 31-90, 91-180, 181-360, and 361-720 days compared with those exposed for ≤30 days. Examination of risk of renal outcomes in 1:1 propensity score-matched cohorts of patients taking H₂ blockers versus patients taking PPI and patients taking PPI versus controls yielded consistent results. Our results suggest that PPI exposure associates with increased risk of incident CKD, CKD progression, and ESRD.