A Randomized Trial of Distal Diuretics versus Dietary Sodium Restriction for Hypertension in Chronic Kidney Disease

Mechanisms of Antihypertensive Effect of Chlorthalidone in Advanced Chronic Kidney Disease: A Causal Mediation Analysis

Key Points

Chlorthalidone reduces the amount of fluid and the BP, but fluid volume reduction is not the cause of lowering of BP. It is not volume loss but the response to volume loss such as the synthesis of substances that lower BP is important.

Background

Chlorthalidone (CTD) in a chronic kidney disease randomized trial demonstrated a robust reduction in systolic BP in stage 4 CKD. In this study, we explore the mechanisms underlying the antihypertensive effect of CTD.

Methods

In this prespecified analysis, we analyzed the contributions of baseline levels of 24-hour urinary sodium and aldosterone and the changes from baseline to 4 weeks in the multiple mediators reflecting volume status in a causal mediation analysis framework. Baseline levels of these mediators served as covariates. No power calculation for this analysis was performed.

Results

Of the 160 patients randomized, 140 (87.5%) were included in this analysis. Compared with placebo, CTD within 4 weeks reduced weight −1.5% (95% confidence interval [CI], −2.2 to −0.7) and volume −1.4% (95% CI, −2.2 to −0.6), stimulated plasma renin 40.5% (95% CI, 25.4% to 57.4%) and serum aldosterone 40.2% (95% CI, 11.7% to 76%), and reduced plasma N -terminal pro-B-type natriuretic peptide levels −19.4% (95% CI, −33.8% to −1.9%). Mediation analysis revealed the following results: for weight change, the total effect on systolic BP was −10.8 mm Hg (95% CI, −16 to −5.7), of which weight change (indirect effect) accounted for −0.9 mm Hg (95% CI, −4.2 to 2.5) and BP change independent of weight (direct effect) accounted for −10 mm Hg (−15.7 to −4.2). Thus, the percent mediation was 8.1% (95% CI, −22.4 to 38.5). Baseline excretion of 24-hour sodium or aldosterone or any of the changes in the above mediators examined accounted for <2 mm Hg BP drop and were not significant for any of the mediators.

Conclusions

CTD improved BP control among patients with advanced CKD independent of baseline urinary sodium, aldosterone, weight loss, or changes in the renin-angiotensin system or N -terminal pro-B-type natriuretic peptide.

Clinical Trial registry name and registration number:

CTD in chronic kidney disease ClinicalTrials.gov number: NCT02841280 .

Amiloride versus furosemide for the treatment of edema in patients with nephrotic syndrome: A pilot study (AMILOR)

AIM

In rodent models of nephrotic syndrome (NS), edema formation was prevented by blockade of the epithelial sodium channel ENaC with amiloride. However, apart from case reports, there is no evidence favoring ENaC blockade in patients with NS.

METHODS

The monocentric randomized controlled AMILOR study investigated the antiedematous effect of amiloride (starting dose 5 mg/day, max. 15 mg/day) in comparison to standard therapy with the loop diuretic furosemide (40 mg/day, max. 120 mg/day) over 16 days. Overhydration (OH) was measured by bioimpedance spectroscopy (BCM, Fresenius). Depending on the OH response, diuretic dose was adjusted on days 2, 5, 8 and 12, and if necessary, hydrochlorothiazide (HCT) was added from d8 (12.5 mg/day, max. 25 mg/day). The primary endpoint was the decrease in OH on d8. The study was terminated prematurely due to insufficient recruitment and a low statistical power due to a low actual effect size.

RESULTS

Median baseline OH was +26.4 (interquartile range 15.5-35.1)% extracellular water (ECW) in the amiloride arm and + 27.9 (24.1-29.4)% ECW in the furosemide arm and decreased by 1.95 (0.80-6.40) and 5.15 (0.90-8.30)% ECW after 8 days, respectively, and by 10.10 (1.30-14.40) and 7.40 (2.80-10.10)% ECW after 16 days, respectively. OH decrease on d8 and d16 was not significantly different between both arms.

CONCLUSION

The AMILOR study is the first randomized controlled pilot study suggesting a similar antiedematous effect as furosemide. Further studies are required to better define the role of amiloride in NS (EudraCT 2019-002607-18).

The Effect of Thiazide Diuretics on Urinary Prostaglandin E2 Excretion and Serum Sodium in the General Population

CONTEXT

Thiazide-induced hyponatremia is one of the most common forms of hyponatremia, but its pathogenesis is incompletely understood. Recent clinical data suggest links with prostaglandin E2 (PGE2) and a single nucleotide polymorphism (SNP) in the prostaglandin transporter gene (SLCO2A1), but it is unknown if these findings also apply to the general population.

OBJECTIVE

To study the associations between serum sodium, thiazide diuretics, urinary excretions of PGE2 and its metabolite (PGEM), and the rs34550074 SNP in SLCO2A1 in the general population.

DESIGN

Prospective population-based cohort study (Rotterdam Study).

SETTING

General population.

PARTICIPANTS

2,178 participants (65% female, age 64 ± 8 years).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Serum sodium levels.

RESULTS

Higher urinary PGE2 excretion was associated with lower serum sodium: difference in serum sodium for each two-fold higher PGE2 -0.19 mmol/l (95%CI -0.31 to -0.06), PGEM -0.29 mmol/l (95%CI -0.41 to -0.17). This association was stronger in thiazide users (per two-fold higher PGE2 -0.73 vs. -0.12 mmol/l and PGEM -0.6 vs. -0.25 mmol/l, p for interaction < 0.05 for both). A propensity score matching analysis of thiazide vs. non-thiazide users yielded similar results. The SNP rs34550074 was not associated with lower serum sodium or higher urinary PGE2 or PGEM excretion in thiazide or non-thiazide users.

CONCLUSIONS

Serum sodium is lower in people with higher urinary PGE2 and PGEM excretion and this association is stronger in thiazide users. This suggests that PGE2-mediated water reabsorption regulates serum sodium, which is relevant for the pathogenesis of hyponatremia in general and thiazide-induced hyponatremia in specific.

Combined eutexia and amorphization for simultaneous enhancement of dissolution rate of triamterene and hydrochlorothiazide: preparation of orodispersible tablets

BACKGROUND

Triamterene is an oral antihypertensive drug with dissolution-limited poor bioavailability. It can be used as monotherapy or in fixed dose combination with hydrochlorothiazide which also suffers from poor dissolution. Moreover, co-processing of drugs in fixed dose combination can alter their properties. Accordingly, pre-formulation studies should investigate the effect of co-processing and optimize the dissolution of drugs before and after fixed dose combination. This is expected to avoid deleterious interaction (if any) and to hasten the biopharmaceutical properties.

OBJECTIVE

Accordingly, the aim of this work was to optimize the dissolution rate of triamterene alone and after fixed dose combination with hydrochlorothiazide.

METHODOLOGY

Triamterene was subjected to dry co-grinding with xylitol, HPMC-E5 or their combination. The effect of co-grinding with hydrochlorothiazide was also tested in absence and presence of xylitol and HPMC-E5. The products were assessed using Fourier-transform infrared (FTIR), differential scanning calorimetry, X-ray powder diffraction (XRPD), in addition to dissolution studies. Optimum formulations were fabricated as oral disintegrating tablets (ODT).Results: Co-processing of triamterene with xylitol formed eutectic system which hastened dissolution rate. HPMC-E5 resulted in partial amorphization and improved triamterene dissolution. Co-grinding with both materials combined their effects. Co-processing of triamterene with hydrochlorothiazide resulted in eutexia but the product was slowly dissolving due to aggregation. This problem was vanished in presence of HPMC-E5 and xylitol. Compression of the optimum formulation into ODT underwent fast disintegration and liberated acceptable amounts of both drugs.

CONCLUSION

The study introduced simple co-processing with traditional excipients for development of ODT of triamterene and hydrochlorothiazide.

Danger-associated metabolites trigger metaflammation: A crowbar in cardiometabolic diseases

Cardiometabolic diseases (CMDs) are characterized by a series of metabolic disorders and chronic low-grade inflammation. CMDs contribute to a high burden of mortality and morbidity worldwide. Host-microbial metabolic regulation that triggers metaflammation is an emerging field of study that promotes a new perspective for perceiving cardiovascular risks. The term metaflammation denotes the entire cascade of immune responses activated by a new class of metabolites known as "danger-associated metabolites" (DAMs). It is being proposed by the present review for the first time. We summarize current studies covering bench to bedside aspects of DAMs to better understand CMDs in the context of DAMs. We have focused on the involvement of DAMs in the pathophysiological development of CMDs, including the disruption of immune homeostasis and chronic inflammation-triggered damage leading to CMD-related adverse events, as well as emerging therapeutic approaches for targeting DAM metabolism in CMDs.

What is central to renal nutrition: protein or sodium intake?

Historically, nutrition intervention has been primarily focused on limiting kidney injury, reducing generation of uraemic metabolites, as well as maintaining nutrition status and preventing protein-energy wasting in patients with chronic kidney disease (CKD). This forms an important rationale for prescribing restricted protein diet and restricted salt diet in patients with CKD. However, evidence supporting a specific protein intake threshold or salt intake threshold remains far from compelling. Some international or national guidelines organizations have provided strong or 'level 1' recommendations for restricted protein diet and restricted salt diet in CKD. However, it is uncertain whether salt or protein restriction plays a more central role in renal nutrition management. A key challenge in successful implementation or wide acceptance of a restricted protein diet and a restricted salt diet is patients' long-term dietary adherence. These challenges also explain the practical difficulties in conducting randomized trials that evaluate the impact of dietary therapy on patients' outcomes. It is increasingly recognized that successful implementation of a restricted dietary prescription or nutrition intervention requires a highly personalized, holistic care approach with support and input from a dedicated multidisciplinary team that provides regular support, counselling and close monitoring of patients. With the advent of novel drug therapies for CKD management such as sodium-glucose cotransporter-2 inhibitors or non-steroidal mineralocorticoid receptor antagonist, it is uncertain whether restricted protein diet and restricted salt diet may still be necessary and have incremental benefits. Powered randomized controlled trials with novel design are clearly indicated to inform clinical practice on recommended dietary protein and salt intake threshold for CKD in this new era.

Prostaglandin E2, Osmoregulation, and Disease Progression in Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Prostaglandin E2 (PGE2) plays a physiological role in osmoregulation, a process that is affected early in autosomal dominant polycystic kidney disease (ADPKD). PGE2 has also been implicated in the pathogenesis of ADPKD in preclinical models, but human data are limited. Here, we hypothesized that urinary PGE2 excretion is associated with impaired osmoregulation, disease severity, and disease progression in human ADPKD.

METHODS

Urinary excretions of PGE2 and its metabolite (PGEM) were measured in a prospective cohort of patients with ADPKD. The associations between urinary PGE2 and PGEM excretions, markers of osmoregulation, eGFR and height-adjusted total kidney volume were assessed using linear regression models. Cox regression and linear mixed models were used for the longitudinal analysis of the associations between urinary PGE2 and PGEM excretions and disease progression defined as 40% eGFR loss or kidney failure, and change in eGFR over time. In two intervention studies, we quantified the effect of starting tolvaptan and adding hydrochlorothiazide to tolvaptan on urinary PGE2 and PGEM excretions.

RESULTS

In 562 patients with ADPKD (61% female, eGFR 63±28 ml/min per 1.73 m 2 ), higher urinary PGE2 or PGEM excretions were independently associated with higher plasma copeptin, lower urine osmolality, lower eGFR, and greater total kidney volume. Participants with higher baseline urinary PGE2 and PGEM excretions had a higher risk of 40% eGFR loss or kidney failure (hazard ratio, 1.28; 95% confidence interval [CI], 1.13 to 1.46 and hazard ratio, 1.50; 95% CI, 1.26 to 1.80 per two-fold higher urinary PGE2 or PGEM excretions) and a faster change in eGFR over time (-0.39 [95% CI, -0.59 to -0.20] and -0.53 [95% CI, -0.75 to -0.31] ml/min per 1.73 m 2 per year). In the intervention studies, urinary PGEM excretion was higher after starting tolvaptan, while urinary PGE2 excretion was higher after adding hydrochlorothiazide to tolvaptan.

CONCLUSIONS

Higher urinary PGE2 and PGEM excretions in patients with ADPKD are associated with impaired osmoregulation, disease severity, and progression.

Thiazide and thiazide-like diuretics are associated with improved cardiovascular and renal outcomes in patients with chronic kidney disease

Introduction

Hypervolemia is a prevalent comorbidity of chronic kidney disease (CKD) patients. Thiazide diuretics (THZ) are the most common treatment for volume overload and hypertension (HTN). This study examines the association between THZ usage and clinical outcomes among CKD patients in a nationwide cohort.

Method

The total number of patients in the study was 24,312. After matching with one non-user randomly selected from the CKD population, we identified 8501 patients in the THZ and the comparison cohorts. Cox proportional hazards regression analysis was conducted to estimate the associations of THZ on the incidence of all-cause mortality, end-stage renal disease (ESRD), congestive heart failure (CHF), acute myocardial infarction (AMI), peripheral arterial occlusive disease (PAOD), and stroke.

Results

The all-cause mortality rate was significantly lower in THZ users than in non-users (hazard ratio [HR] = 0.65, 95% confidence interval [CI] = 0.60- 0.71). The THZ usage was associated with a lower incidence of ESRD, AMI, PAOD, and stroke (P<0.05). In subgroup analysis, some significant clinical outcomes were related with CKD stages 3 and 4 (P<0.05); however, there were no clinical associations in CKD stage 5. In further THZ subtype analysis, there were clinical associations with fewer deaths, ESRD, AMI, and PAOD accompanying chlorthalidone treatment. Moreover, the indapamide prescription was linked to lower mortality, ESRD, AMI, and PAOD prevalence. However, there were significantly greater incidences of ESRD, CHF, and AMI in the metolazone users.

Conclusion

THZ usage is associated with lower mortality and incidence of ESRD, AMI, PAOD, and stroke s in patients with CKD stages 3 and 4.

Amiloride evokes significant natriuresis and weight loss in kidney transplant recipients with and without albuminuria

Albuminuria in kidney transplant recipients (KTRs) is associated with hypertension and aberrant glomerular filtration of serine proteases that may proteolytically activate the epithelial Na+ channel (ENaC). The present nonrandomized, pharmacodynamic intervention study aimed to investigate if inhibition of ENaC increases Na+ excretion and reduces extracellular volume in KTRs dependent on the presence of albuminuria. KTRs with and without albuminuria (albumin-to-creatinine ratio > 300 mg/g, n = 7, and <30 mg/g, n = 7, respectively) were included and ingested a diet with fixed Na+ content (150 mmol/day) for 5 days. On the last day, amiloride at 10 mg was administered twice. Body weight, 24-h urine electrolyte excretion, body water content, and ambulatory blood pressure as well as plasma renin, angiotensin II, and aldosterone concentrations were determined before and after amiloride. Amiloride led to a significant decrease in body weight, increase in 24-h urinary Na+ excretion, and decrease in 24-h urinary K+ excretion in both groups. Urine output increased in the nonalbuminuric group only. There was no change in plasma renin, aldosterone, and angiotensin II concentrations after amiloride, whereas a significant decrease in nocturnal systolic blood pressure and increase in 24-h urine aldosterone excretion was observed in albuminuric KTRs only. There was a significant correlation between 24-h urinary albumin excretion and amiloride-induced 24-h urinary Na+ excretion. In conclusion, ENaC activity contributes to Na+ and water retention in KTRs with and without albuminuria. ENaC is a relevant pharmacological target in KTRs; however, larger and long-term studies are needed to evaluate whether the magnitude of this effect depends on the presence of albuminuria.NEW & NOTEWORTHY Amiloride has a significant natriuretic effect in kidney transplant recipients (KTRs) that relates to urinary albumin excretion. The epithelial Na+ channel may be a relevant direct pharmacological target to counter Na+ retention and hypertension in KTRs. Epithelial Na+ channel blockers should be further investigated as a mean to mitigate Na+ and water retention and to potentially obtain optimal blood pressure control in KTRs.

Estimated 24-h urinary sodium excretion and risk of end-stage kidney disease

The association between sodium intake and long-term kidney disease endpoints is debated and yet to be proven. We aimed to investigate the associations of estimated 24-h urinary sodium excretion, reflecting daily sodium intake, with the incidence of end-stage kidney disease (ESKD). In this prospective cohort study including 444,375 UK Biobank participant, 865 (0.2%) ESKD events occurred after median follow-up of 12.7 years. For every 1 g increment in estimated 24-h urinary sodium excretion, multivariable-adjusted hazard ratio for incident ESKD was 1.09 (95% confidence interval 0.94-1.26). Nonlinear associations were not detected with restricted cubic splines. The null findings were confirmed by a series of sensitivity analyses, which attenuated potential bias from measurement errors of the exposure, regression dilution, reverse causality, and competing risks. In conclusion, there is insufficient evidence that estimated 24-h urinary sodium excretion is associated with the incidence of ESKD.

Efficacy of tolvaptan in postoperative volume therapy for acute Stanford type A aortic dissection

BACKGROUND

Despite the increasing application of tolvaptan in cardiac surgery, there is no information on the use of tolvaptan in Stanford patients with type A aortic dissection. This study aimed to evaluate the postoperative clinical effects of tolvaptan in patients with type A aortic dissection  after tafter surgery.

METHODS

A retrospective analysis was performed on 45 patients treated for type A aortic dissection in our hospital from 2018 to 2020. These included 21 patients who were treated with tolvaptan (Group T) and 24 patients who received traditional diuretics (Group L). The hospital's electronic health records were used to obtain perioperative data.

RESULTS

Group T did not differ significantly from Group L in terms of the duration of mechanical ventilation, postoperative blood required, length of catecholamine use, or the amount of intravenous diuretic drugs administered (all P > 0.05). The development of postoperative atrial fibrillation was significantly less in the tolvaptan group (P = 0.023). The urine volumes and change in body weight loss were slightly higher in group T than in group L but the differences were non-significant (P > 0.05). Serum potassium, creatinine, and urea nitrogen levels did not differ between the groups in the week after surgery, At the same time, sodium was significantly higher in the Group T group on day 7 after transfer from the ICU (P = 0.001). In Group L, sodium levels were also elevated by day 7 (P = 0.001). On days 3 and 7, serum creatinine and urea nitrogen levels increased in both groups (both P < 0.05).

CONCLUSIONS

Both tolvaptan and traditional diuretics were found to be effective and safe for patients with acute Stanford type A aortic dissection. Moreover, tolvaptan may be associated with reducing the incidence of postoperative atrial fibrillation.

Dietary sodium restriction prevents vascular endothelial growth factor inhibitor-induced hypertension

BACKGROUND

Vascular endothelial growth factor inhibitors (VEGFIs) are effective anticancer agents which often induce hypertension. VEGFI-induced hypertension is sodium-sensitive in animal studies. Therefore, the efficacy of dietary sodium restriction (DSR) to prevent VEGFI-induced hypertension in cancer patients was studied.

METHODS

Cancer patients with VEGFI-induced hypertension (day mean >135/85 mmHg or a rise in systolic and/or diastolic BP ≥ 20 mmHg) were treated with DSR (aiming at <4 g salt/day). The primary endpoint was the difference in daytime mean arterial blood pressure (MAP) increase between the treatment cycle with and without DSR.

RESULTS

During the first VEGFI treatment cycle without DSR, mean daytime MAP increased from 95 to 110 mmHg. During the subsequent treatment cycle with DSR, mean daytime MAP increased from 94 to 102 mmHg. Therefore, DSR attenuated the increase in mean daytime MAP by 7 mmHg (95% CI 1.3-12.0, P = 0.009). DSR prevented the rise in the endothelin-1/renin ratio that normally accompanies VEGFI-induced hypertension (P = 0.020) and prevented the onset of proteinuria: 0.15 (0.10-0.25) g/24 h with DSR versus 0.19 (0.11-0.32) g/24 h without DSR; P = 0.005.

DISCUSSION

DSR significantly attenuated VEGFI induced BP rise and proteinuria and thus is an effective non-pharmacological intervention.

The World Hypertension League Science of Salt: a regularly updated systematic review of salt and health outcomes studies (Sept 2019 to Dec 2020)

The World Hypertension League Science of Salt health outcomes review series highlights high-quality publications relating to salt intake and health outcomes. This review uses a standardised method, outlined in previous reviews and based on methods developed by WHO, to identify and critically appraise published articles on dietary salt intake and health outcomes. We identified 41 articles published between September 2019 to December 2020. Amongst these, two studies met the pre-specified methodological quality criteria for critical appraisal. They were prospective cohort studies and examined physical performance and composite renal outcomes as health outcomes. Both found an association between increased/higher sodium intake and poorer health outcomes. Few studies meet criteria for high-quality methods. This review adds further evidence that dietary salt reduction has health benefits and strengthens evidence relating to health outcomes other than blood pressure and cardiovascular disease. We observe that most studies on dietary sodium do not have adequate methodology to reliably assess sodium intake and its association with health outcomes.

Applications of cardiac biomarkers in chronic kidney disease

PURPOSE OF REVIEW

Cardiovascular disease is the leading cause of death in individuals with chronic kidney disease (CKD). The mechanisms connecting CKD and cardiovascular disease are complex, and serum biomarkers can help improve our understanding. Nt-proBNP and troponin have documented success as biomarkers to diagnose and provide mechanistic insights in non-CKD populations. The purpose of this review is to summarize evidence suggesting efficacy and potential for clinical application of Nt-proBNP and troponin in individuals with CKD.

RECENT FINDINGS

Our understanding of how Nt-proBNP and Troponin should be interpreted in those with CKD is evolving. Although both biomarkers are in part cleared by the kidney, elevated levels predominantly reflect cardiovascular disease. Both Nt-proBNP and troponin are associated with risk for future cardiovascular events in CKD. Determining CKD-specific cutoffs and using biomarkers to guide therapy remains under active investigation.

SUMMARY

Of the many serum biomarkers under investigation, Nt-proBNP and troponin best meet the criteria for effective biomarkers in CKD. Assays are widely available and proven to be accurate in CKD populations. Nt-proBNP and troponin deserve special focus in ongoing research of cardiovascular risk reduction in CKD, especially to identify patients at the highest risk, suggest targetable mechanisms and assess treatment efficacy.

Thiazide diuretics are back in CKD: the case of chlorthalidone

Sodium and volume excess is the fundamental risk factor underlying hypertension in chronic kidney disease (CKD) patients, who represent the prototypical population characterized by salt-sensitive hypertension. Low salt diets and diuretics constitute the centrepiece for blood pressure control in CKD. In patients with CKD stage 4, loop diuretics are generally preferred to thiazides. Furthermore, thiazide diuretics have long been held as being of limited efficacy in this population. In this review, by systematically appraising published randomized trials of thiazides in CKD, we show that this class of drugs may be useful even among people with advanced CKD. Thiazides cause a negative sodium balance and reduce body fluids by 1-2 l within the first 2-4 weeks and these effects go along with improvement in hypertension control. The recent CLICK trial has documented the antihypertensive efficacy of chlorthalidone, a long-acting thiazide-like diuretic, in stage 4 CKD patients with poorly controlled hypertension. Overall, chlorthalidone use could be considered in patients with treatment-resistant hypertension when spironolactone cannot be administered or must be withdrawn due to side effects. Hyponatremia, hypokalaemia, volume depletion and acute kidney injury are side effects that demand a vigilant attitude by physicians prescribing these drugs. Well-powered randomized trials assessing hard outcomes are still necessary to more confidently recommend the use of these drugs in advanced CKD.

Revisiting diuretic choice in chronic kidney disease

PURPOSE OF REVIEW

Existing guidelines offer little direction about the use of thiazide and loop diuretics in patients with chronic kidney disease (CKD). This review summarizes recent studies impacting indications and safety considerations for these agents in patients with CKD.

RECENT FINDINGS

Chlorthalidone reduces blood pressure compared to placebo in patients with advanced CKD, challenging the belief that thiazide diuretics lose efficacy at lower glomerular filtration rates (GFR). Existing studies show no clear impact of thiazide or loop diuretic use on kidney or cardiovascular outcomes in patients with CKD. Sodium-glucose co-transporter type 2 (SGLT2) inhibitors have diuretic effects, but concomitant use of a diuretic does not diminish the preventive benefits of these agents against acute kidney injury (AKI). Despite theoretical concerns, thiazide diuretics likely do not worsen circulating vasopressin levels or cyst progression in polycystic kidney disease and may be useful for alleviating polyuria from tolvaptan. Diuretics cause multiple adverse effects, including electrolyte abnormalities, hemodynamic-mediated decrease in estimated GFR, and AKI.

SUMMARY

Recent evidence supports expanded indications for diuretics in patients with kidney disease, including chlorthalidone for hypertension in advanced CKD. Monitoring electrolytes and estimated GFR is critical to ensure patient safety when prescribing these agents for patients with CKD.

Effect of Tolvaptan in Patients with Chronic Kidney Disease Stage G5, and Impact of Concomitant Use of Thiazide Diuretics: A Retrospective Cohort Study

BACKGROUND

The diuretic effect of tolvaptan, a vasopressin V2 receptor antagonist, in patients with severe renal dysfunction remains poorly characterized. Thiazide diuretics reduce urinary volume (UV) in patients with nephrogenic diabetes insipidus, which lacks V2 receptor function.

OBJECTIVE

This retrospective study investigated the acute urinary effects of tolvaptan in patients with stage G5 chronic kidney disease and congestive heart failure (CHF), and the impact of thiazide diuretics on the urinary effects of tolvaptan.

METHODS

UVs 24 h before and after tolvaptan administration and 30-day dialysis initiation rate were compared between patients with and without thiazide diuretic administration.

RESULTS

Thiazide diuretics were used in 26 of the 106 recruited patients (age 73.4 ± 13.0 years; estimated glomerular filtration rate 8.07 ± 3.13 mL/min/1.73 m²). The pre- and post-tolvaptan 24-h UVs were significantly higher in patients not administered thiazide diuretics (1043.4 ± 645.6 vs. 1422.2 ± 774.0 mL/day; p < 0.001) than in those administered thiazide diuretics (1177.3 ± 686.5 vs. 1173.1 ± 629.1 mL/day; p = 0.93). In a multivariate regression model, thiazide diuretic use was significantly associated with decreased 24-h UV (β coefficient - 486.7, 95% confidence interval [CI] - 674.5 to - 298.8); increased urine osmolality (β coefficient 37.7, 95% CI 17.1-58.4); increased body weight (β coefficient 0.62, 95% CI 0.31-0.92); and increased 30-day dialysis initiation rate (odds ratio 3.40, 95% CI 1.18-9.82) after tolvaptan administration.

CONCLUSIONS

Tolvaptan exhibited significant diuretic effects in patients with CHF, including those with severe renal dysfunction, which were diminished with concomitant thiazide diuretic use.

Effects of a remote patient monitoring system for patients on automated peritoneal dialysis: a randomized crossover controlled trial

Purpose

Remote patient monitoring (RPM) has contributed to improved patient-centered outcomes and prognosis in patients with end-stage renal disease on automated peritoneal dialysis (APD). However, evidence from prospective trials is lacking.

Methods

The participants (n = 15; median age: 65 years; males: 10; peritoneal dialysis vintage: 6.4 ± 3.5 years) randomly received APD therapy using the Kaguya® APD system either with or without the connective use of the cloud-based RPM software Sharesource® for 12 weeks. The primary outcome was patient satisfaction assessed using a modified nine-item Treatment Satisfaction Questionnaire for Medication (TSQM-9) questionnaire. The secondary outcomes were healthcare resource consumption, the health-related quality of life (HRQOL) subscales assessed with the Kidney Disease Quality of Life-Short Form questionnaire, and clinical laboratory parameters.

Results

Significant improvements were observed in the TSQM-9 subscales of Effectiveness (64.4 ± 18.8 vs. 57.8 ± 18.8; P = 0.006) and Convenience (76.3 ± 15.4 vs. 63.3 ± 17.3; P < 0.001) in patients on Sharesource®. Moreover, Sharesource® reduced the total amount of healthcare resource consumption (0.80 ± 1.32 vs. 1.87 ± 2.39 times/12 weeks; P = 0.02) and consultation time during regular monthly visits (813 ± 269 vs. 1024 ± 292 s; P < 0.001). A significant increase in ultrafiltration volume was found associated with more frequent modification of APD prescription in patients with Sharesource®. Sharesource® also improved the HRQOL subscale of General Health and Vitality.

Conclusion

Sharesource® can improve patient-centered outcomes in patients on APD while reducing the treatment burden for both patients and medical staff.

Trial registration: The study was registered in the Japan Registry of Clinical Trials (jRCT Number: jRCTs032190005).

Supplementary Information

The online version contains supplementary material available at 10.1007/s11255-022-03178-5.

Update in Hypertension

The treatment of elevated blood pressure (BP) can improve cardiovascular (CV) event rates. Current BP targets depend on expected CV event rates in individuals as assessed by concurrent medical conditions and other risk factors. Importantly, the means by which BP is measured has evolved. This evolution is driven by recognition that techniques different than routine office BP measurements can provide a better assessment of future CV risk.

A multiple 24-hour urine collection study indicates that kidney function decline is related to urinary sodium and potassium excretion in patients with chronic kidney disease

Multiple 24-hour urine collections are necessary to adequately assess sodium and potassium intake. Here, we assessed kidney function decline for four years after baseline in relation to seven-time averaged 24-hour urinary sodium and potassium excretion (UNaV, UKV), their UNaV/UKV ratio, and their categorical combination in outpatients with chronic kidney disease (CKD). This retrospective cohort study was based on 240 outpatients with baseline CKD stages 3-5, baseline age 20 years or more (median age 72.0 years), and a median follow-up (with interquartile range) of 2.9 (1.4-4.0) years. Outcome was the percentage change in annual slope of estimated glomerular filtration rate (delta eGFR per year). In linear mixed models, percentage changes in delta eGFR per year were -3.26% (95% confidence interval -5.85 to -0.60), +5.20% (2.34 to 8.14), and -5.20% (-7.64 to -2.69), respectively, per one standard deviation increase in the seven-time averaged UNaV and UKV, and their UNaV/UKV ratio. Additionally, percentage changes per year in delta eGFR per year were -16.27% (-23.57 to -8.27) in the middle-to-high UNaV and low UKV group, compared with the low UNaV and middle-to high UKV group. Thus, our study reinforces the observation of opposite associations between GFR decline and urinary excretion rates of sodium (positive) and potassium (negative), respectively. Whether changes in dietary sodium and potassium intake slow GFR decline still requires further study.

Lifestyle interventions for preventing and ameliorating CKD in primary and secondary care

PURPOSE OF REVIEW

Despite the growth in chronic kidney disease (CKD) epidemics, evidence-based lifestyle recommendations for primary prevention of CKD are limited by reliance on observational studies and predominantly pilot clinical trials.

RECENT FINDINGS

Emerging data have shown lifestyle modification strategies for primary CKD prevention with the most evidence favoring a healthy dietary pattern (rich in fruit, vegetables, potassium and have a higher plant-based to animal protein ratio), and diet low in sodium, being physically active, avoiding tobacco smoking, moderating alcohol consumption and maintaining a healthy body weight. The way these behavioral interventions can be implemented in practice should consider their synergistic benefit as well as mechanisms to facilitate long-term behavior change. Sustaining long-term behavior change remains a challenge in practice, particularly due to a lack of healthcare resources and behavior relapse. Some suggestions to mitigate this include ensuring adequate time is spent in intervention codesign and planning, utilizing adaptive trial/intervention designs with regular intervention tailoring for intervention dose, intensity, duration, and modality.

SUMMARY

A number of modifiable lifestyle behaviors consistently associate with developing CKD in the community. The current evidence base, despite its inherent limitations, may inform both public health recommendations and clinical practice.

Impact of Dietary Sodium Reduction on the Development of Obesity and Type 2 Diabetes in db/db Mice

The impact of dietary sodium reduction on mouse models of type 2 diabetes is not well understood. Therefore, we analyzed the effect of a low-salt diet on obesity and parameters of type 2 diabetes in db/db mice. Five-week-old male db/db and lean db/m mice were fed a normal salt (0.19% Na⁺, NS) or a low-salt diet (<0.03% Na⁺, LS) for 5 weeks. Body and organ weight and parameters of glucose and insulin tolerance were analyzed. Plasma levels of steroids were determined by liquid chromatography tandem mass spectrometry. Body weight, glucose, and insulin tolerance were not affected by LS. The amount of gonadal adipose tissue showed a trend to be increased by LS whereas liver, pancreas, kidney, heart, and adrenal weight remained unaffected. LS reduced urinary sodium-to-creatinine ratio but did not affect plasma Na⁺ levels in both genotypes. Plasma and urinary potassium-to-creatinine ratio did not differ in all groups of mice. Aldosterone as a major determinant of changes in dietary sodium remained unaffected by LS in db/db mice as well as further investigated steroid hormones. The present study showed reduced sodium-to-creatinine ratio, but no additional effects of dietary sodium reduction on major metabolic parameters and steroid levels in obese and hyper-glycemic db/db mice.

Comparison of Clinical Outcomes and Safety Associated With Chlorthalidone vs Hydrochlorothiazide in Older Adults With Varying Levels of Kidney Function

IMPORTANCE

Thiazide diuretics are commonly prescribed for the treatment of hypertension, a disease highly prevalent among older individuals and in those with chronic kidney disease. How specific thiazide diuretics compare in regard to safety and clinical outcomes in these populations remains unknown.

OBJECTIVE

To compare safety and clinical outcomes associated with chlorthalidone or hydrochlorothiazide use among older adults with varying levels of kidney function.

DESIGN, SETTING, AND PARTICIPANTS

This population-based retrospective cohort study was conducted in Ontario, Canada, from 2007 to 2015. Participants included adults aged 66 years or older who initiated chlorthalidone or hydrochlorothiazide during this period. Data were analyzed from December 2019 through September 2020.

EXPOSURES

New chlorthalidone users were matched 1:4 with new hydrochlorothiazide users by a high-dimensional propensity score. Time-to-event models accounting for competing risks examined the associations between chlorthalidone vs hydrochlorothiazide use and the outcomes of interest overall and within estimated glomerular filtration rate (eGFR) categories (≥60, 45-59, and <45 mL/min/1.73 m2).

MAIN OUTCOMES AND MEASURES

The outcomes of interest were adverse kidney events (ie, eGFR decline ≥30%, dialysis, or kidney transplantation), cardiovascular events (composite of myocardial infarction, coronary revascularization, heart failure, or atrial fibrillation), all-cause mortality, and electrolyte anomalies (ie, sodium or potassium levels outside reference ranges).

RESULTS

After propensity score matching, the study cohort included 12 722 adults (mean [SD] age, 74 [7] years; 7063 [56%] women; 5659 [44%] men; mean [SD] eGFR, 69 [19] mL/min/1.73 m2), including 2936 who received chlorthalidone and 9786 who received hydrochlorothiazide. Chlorthalidone use was associated with a higher risk of eGFR decline of 30% or greater (hazard ratio [HR], 1.24 [95% CI, 1.13-1.36]) and cardiovascular events (HR, 1.12 [95% CI, 1.04-1.22]) across all eGFR categories compared with hydrochlorothiazide use. Chlorthalidone use was also associated with a higher risk of hypokalemia compared with hydrochlorothiazide use, which was more pronounced among those with higher eGFR (eGFR ≥60 mL/min/1.73 m2: HR, 1.86 [95% CI, 1.67-2.08]; eGFR 45-59 mL/min/1.73 m2: HR, 1.57 [95% CI, 1.25-1.96]; eGFR <45 mL/min/1.73 m2: HR, 1.10 [95% CI, 0.84-1.45]; P for interaction = .001). No significant differences were observed between chlorthalidone and hydrochlorothiazide for dialysis or kidney transplantation (HR, 1.44 [95% CI, 0.88-2.36]), all-cause mortality (HR, 1.10 [95% CI, 0.93-1.29]), hyperkalemia (HR, 1.05 [95% CI, 0.79-1.39]), or hyponatremia (HR, 1.14 [95% CI, CI 0.98-1.32]).

CONCLUSIONS AND RELEVANCE

This cohort study found that among older adults, chlorthalidone use was associated with a higher risk of eGFR decline, cardiovascular events, and hypokalemia compared with hydrochlorothiazide use. The excess risk of hypokalemia with chlorthalidone was attenuated in participants with reduced kidney function. Placed in context with prior observational studies comparing the safety and clinical outcomes associated with thiazide diuretics, these results suggest that there is no evidence to prefer chlorthalidone over hydrochlorothiazide.

Chronic kidney disease

Chronic kidney disease is a progressive disease with no cure and high morbidity and mortality that occurs commonly in the general adult population, especially in people with diabetes and hypertension. Preservation of kidney function can improve outcomes and can be achieved through non-pharmacological strategies (eg, dietary and lifestyle adjustments) and chronic kidney disease-targeted and kidney disease-specific pharmacological interventions. A plant-dominant, low-protein, and low-salt diet might help to mitigate glomerular hyperfiltration and preserve renal function for longer, possibly while also leading to favourable alterations in acid-base homoeostasis and in the gut microbiome. Pharmacotherapies that alter intrarenal haemodynamics (eg, renin-angiotensin-aldosterone pathway modulators and SGLT2 [SLC5A2] inhibitors) can preserve kidney function by reducing intraglomerular pressure independently of blood pressure and glucose control, whereas other novel agents (eg, non-steroidal mineralocorticoid receptor antagonists) might protect the kidney through anti-inflammatory or antifibrotic mechanisms. Some glomerular and cystic kidney diseases might benefit from disease-specific therapies. Managing chronic kidney disease-associated cardiovascular risk, minimising the risk of infection, and preventing acute kidney injury are crucial interventions for these patients, given the high burden of complications, associated morbidity and mortality, and the role of non-conventional risk factors in chronic kidney disease. When renal replacement therapy becomes inevitable, an incremental transition to dialysis can be considered and has been proposed to possibly preserve residual kidney function longer. There are similarities and distinctions between kidney-preserving care and supportive care. Additional studies of dietary and pharmacological interventions and development of innovative strategies are necessary to ensure optimal kidney-preserving care and to achieve greater longevity and better health-related quality of life for these patients.

Altered dietary salt intake for people with chronic kidney disease

BACKGROUND

Evidence indicates that reducing dietary salt may reduce the incidence of heart disease and delay decline in kidney function in people with chronic kidney disease (CKD). This is an update of a review first published in 2015.

OBJECTIVES

To evaluate the benefits and harms of altering dietary salt for adults with CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 6 October 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials comparing two or more levels of salt intake in adults with any stage of CKD.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for eligibility, conducted risk of bias evaluation and evaluated confidence in the evidence using GRADE. Results were summarised using random effects models as risk ratios (RR) for dichotomous outcomes or mean differences (MD) for continuous outcomes, with 95% confidence intervals (CI).

MAIN RESULTS

We included 21 studies (1197 randomised participants), 12 in the earlier stages of CKD (779 randomised participants), seven in dialysis (363 randomised participants) and two in post-transplant (55 randomised participants). Selection bias was low in seven studies, high in one and unclear in 13. Performance and detection biases were low in four studies, high in two, and unclear in 15. Attrition and reporting biases were low in 10 studies, high in three and unclear in eight. Because duration of the included studies was too short (1 to 36 weeks) to test the effect of salt restriction on endpoints such as death, cardiovascular events or CKD progression, changes in salt intake on blood pressure and other secondary risk factors were examined. Reducing salt by mean -73.51 mmol/day (95% CI -92.76 to -54.27), equivalent to 4.2 g or 1690 mg sodium/day, reduced systolic/diastolic blood pressure by -6.91/-3.91 mm Hg (95% CI -8.82 to -4.99/-4.80 to -3.02; 19 studies, 1405 participants; high certainty evidence). Albuminuria was reduced by 36% (95% CI 26 to 44) in six studies, five of which were carried out in people in the earlier stages of CKD (MD -0.44, 95% CI -0.58 to -0.30; 501 participants; high certainty evidence). The evidence is very uncertain about the effect of lower salt intake on weight, as the weight change observed (-1.32 kg, 95% CI -1.94 to -0.70; 12 studies, 759 participants) may have been due to fluid volume, lean tissue, or body fat. Lower salt intake may reduce extracellular fluid volume in the earlier stages of CKD (-0.87 L, 95% CI -1.17 to -0.58; 3 studies; 187 participants; low certainty evidence). The evidence is very uncertain about the effect of lower salt intake on reduction in antihypertensive dose (RR 2.45, 95% CI 0.98 to 6.08; 8 studies; 754 participants). Lower salt intake may lead to  symptomatic hypotension (RR 6.70, 95% CI 2.40 to 18.69; 6 studies; 678 participants; moderate certainty evidence). Data were sparse for other types of adverse events.

AUTHORS' CONCLUSIONS

We found high certainty evidence that salt reduction reduced blood pressure in people with CKD, and albuminuria in people with earlier stage CKD in the short-term. If such reductions could be maintained long-term, this effect may translate to clinically significant reductions in CKD progression and cardiovascular events. Research into the long-term effects of sodium-restricted diet for people with CKD is warranted.

Acute decrease of urine calcium by amiloride in healthy volunteers under high sodium diet

BACKGROUND

Amiloride is a competitive blocker of the epithelial sodium channel (ENaC) in the renal collecting duct. It is a less potent diuretic than thiazides or loop diuretics, but is often used in association for its potassium-sparing profile. Whether amiloride has hypocalciuric effect similar to thiazides remains unclear. Animal studies and experiments on cell lines suggested that amiloride increases calcium reabsorption in the distal nephron, but human studies are scarce.

METHODS

We performed a post hoc analysis of a study with 48 healthy males (age, 23.2 ± 3.9 years) who were assigned to a high sodium (Na)/low potassium (K) diet for 7 days before receiving 20 mg of amiloride p.o. Urinary excretions of electrolytes were measured at 3 and 6 hours afterward; we calculated the relative changes in urinary excretion rates after amiloride administration.

RESULTS

The high Na/low K diet led to an expected suppression of plasma renin and aldosterone. Amiloride showed a mild natriuretic effect associated with a decreased kaliuresis. Urinary calcium excretion dropped substantially (by 80%) 3 hours after amiloride administration and remained low at the 6th hour. At the same time, fractional excretion of lithium decreased by a third, reflecting an increased proximal tubular reabsorption.

CONCLUSION

During a high Na/low K diet, amiloride had a strong acute hypocalciuric effect, most probably mediated by increased proximal calcium reabsorption, even though distal effect cannot be excluded. Further studies should establish if chronic amiloride or combined amiloride/thiazide treatment may decrease calciuria more efficiently and be useful in preventing kidney stones.

Dietary salt modifies the blood pressure response to renin-angiotensin inhibition in experimental chronic kidney disease

Chronic kidney disease contributes to hypertension, but the mechanisms are incompletely understood. To address this, we applied the 5/6th nephrectomy rat model to characterize hypertension and the response to dietary salt and renin-angiotensin inhibition. 5/6th nephrectomy caused low-renin, salt-sensitive hypertension with hyperkalemia and unsuppressed aldosterone. Compared with sham rats, 5/6th nephrectomized rats had lower Na⁺/H⁺ exchanger isoform 3, Na⁺-K⁺-2Cl^- cotransporter, Na⁺-Cl^- cotransporter, α-epithelial Na⁺ channel (ENaC), and Kir4.1 levels but higher serum and glucocorticoid-regulated kinase 1, prostasin, γ-ENaC, and Kir5.1 levels. These differences correlated with plasma renin, aldosterone, and/or K⁺. On a normal-salt diet, adrenalectomy (0 ± 9 mmHg) and spironolactone (-11 ± 10 mmHg) prevented a progressive rise in blood pressure (10 ± 8 mmHg), and this was enhanced in combination with losartan (-41 ± 12 and -43 ± 9 mmHg). A high-salt diet caused skin Na⁺ and water accumulation and aggravated hypertension that could only be attenuated by spironolactone (-16 ± 7 mmHg) and in which the additive effect of losartan was lost. Spironolactone also increased natriuresis, reduced skin water accumulation, and restored vasorelaxation. In summary, in the 5/6th nephrectomy rat chronic kidney disease model, salt-sensitive hypertension develops with a selective increase in γ-ENaC and despite appropriate transporter adaptations to low renin and hyperkalemia. With a normal-salt diet, hypertension in 5/6th nephrectomy depends on angiotensin II and aldosterone, whereas a high-salt diet causes more severe hypertension mediated through the mineralocorticoid receptor.NEW & NOTEWORTHY Chronic kidney disease (CKD) causes salt-sensitive hypertension, but the interactions between dietary salt and the renin-angiotensin system are incompletely understood. In rats with CKD on a normal-salt diet targeting aldosterone, the mineralocorticoid receptor (MR) and especially angiotensin II reduced blood pressure. On a high-salt diet, however, only MR blockade attenuated hypertension. These results reiterate the importance of dietary salt restriction to maintain renin-angiotensin system inhibitor efficacy and specify the MR as a target in CKD.

How Do I Manage Hypertension in Patients with Advanced Chronic Kidney Disease Not on Dialysis? Perspectives from Clinical Practice

In the general population, the prevalence of moderate and severe chronic kidney disease (CKD) is usually below 5% but this figure is often higher in specific groups of patients such as those with type 2 diabetes. Patients with advanced CKD (CKD stage 3b and 4) are at high or very high cardiovascular risk, and their risk of progressing towards end-stage kidney disease (CKD stage 5) and the need of renal replacement therapy are elevated. Hypertension is a major cause of poor cardiovascular and renal outcomes in severe CKD. Therefore, an adequate control of blood pressure (BP) is mandatory. However, normalizing BP is often challenging in these patients because the clinical management of hypertension in advanced CKD is not well defined and rarely supported by large randomized controlled trials. In the present review, we discuss the characteristics of hypertension in advanced CKD, excluding dialysis, and its management integrating data from recent clinical studies and a pragmatic approach enriched by a long-standing clinical experience.

Volume Balance in Chronic Kidney Disease: Evaluation Methodologies and Innovation Opportunities

BACKGROUND

Patients affected by chronic kidney disease are at a risk of cardiovascular morbidity and mortality. Body fluids unbalance is one of the main characteristics of this condition, as fluid overload is highly prevalent in patients affected by the cardiorenal syndrome.

SUMMARY

We describe the state of the art and new insights into body volume evaluation. The mechanisms behind fluid balance are often complex, mainly because of the interplay of multiple regulatory systems. Consequently, its management may be challenging in clinical practice and even more so out-of-hospital. Availability of novel technologies offer new opportunities to improve the quality of care and patients' outcome. Development and validation of new technologies could provide new tools to reduce costs for the healthcare system, promote personalized medicine, and boost home care. Due to the current COVID-19 pandemic, a proper monitoring of chronic patients suffering from fluid unbalances is extremely relevant. Key Message: We discuss the main mechanisms responsible for fluid overload in different clinical contexts, including hemodialysis, peritoneal dialysis, and heart failure, emphasizing the potential impact provided by the implementation of the new technologies.

Salt-sensitive hypertension in chronic kidney disease: distal tubular mechanisms

Chronic kidney disease (CKD) causes salt-sensitive hypertension that is often resistant to treatment and contributes to the progression of kidney injury and cardiovascular disease. A better understanding of the mechanisms contributing to salt-sensitive hypertension in CKD is essential to improve these outcomes. This review critically explores these mechanisms by focusing on how CKD affects distal nephron Na+ reabsorption. CKD causes glomerulotubular imbalance with reduced proximal Na+ reabsorption and increased distal Na+ delivery and reabsorption. Aldosterone secretion further contributes to distal Na+ reabsorption in CKD and is not only mediated by renin and K+ but also by metabolic acidosis, endothelin-1, and vasopressin. CKD also activates the intrarenal renin-angiotensin system, generating intratubular angiotensin II to promote distal Na+ reabsorption. High dietary Na+ intake in CKD contributes to Na+ retention by aldosterone-independent activation of the mineralocorticoid receptor mediated through Rac1. High dietary Na+ also produces an inflammatory response mediated by T helper 17 cells and cytokines increasing distal Na+ transport. CKD is often accompanied by proteinuria, which contains plasmin capable of activating the epithelial Na+ channel. Thus, CKD causes both local and systemic changes that together promote distal nephron Na+ reabsorption and salt-sensitive hypertension. Future studies should address remaining knowledge gaps, including the relative contribution of each mechanism, the influence of sex, differences between stages and etiologies of CKD, and the clinical relevance of experimentally identified mechanisms. Several pathways offer opportunities for intervention, including with dietary Na+ reduction, distal diuretics, renin-angiotensin system inhibitors, mineralocorticoid receptor antagonists, and K+ or H+ binders.

Dietary potassium and the kidney: lifesaving physiology

Potassium often has a negative connotation in Nephrology as patients with chronic kidney disease (CKD) are prone to develop hyperkalaemia. Approaches to the management of chronic hyperkalaemia include a low potassium diet or potassium binders. Yet, emerging data indicate that dietary potassium may be beneficial for patients with CKD. Epidemiological studies have shown that a higher urinary potassium excretion (as proxy for higher dietary potassium intake) is associated with lower blood pressure (BP) and lower cardiovascular risk, as well as better kidney outcomes. Considering that the composition of our current diet is characterized by a high sodium and low potassium content, increasing dietary potassium may be equally important as reducing sodium. Recent studies have revealed that dietary potassium modulates the activity of the thiazide-sensitive sodium-chloride cotransporter in the distal convoluted tubule (DCT). The DCT acts as a potassium sensor to control the delivery of sodium to the collecting duct, the potassium-secreting portion of the kidney. Physiologically, this allows immediate kaliuresis after a potassium load, and conservation of potassium during potassium deficiency. Clinically, it provides a novel explanation for the inverse relationship between dietary potassium and BP. Moreover, increasing dietary potassium intake can exert BP-independent effects on the kidney by relieving the deleterious effects of a low potassium diet (inflammation, oxidative stress and fibrosis). The aim of this comprehensive review is to link physiology with clinical medicine by proposing that the same mechanisms that allow us to excrete an acute potassium load also protect us from hypertension, cardiovascular disease and CKD.