Association of hypo- and hyperkalemia with disease progression and mortality in males with chronic kidney disease: the role of race

The burden of hyperkalaemia on hospital healthcare resources

Hyperkalaemia is associated with prolonged hospital admission and worse mortality. Hyperkalaemia may also necessitate clinical consults, therapies for hyperkalaemia and high-dependency bed utilisation. We evaluated the 'hidden' human and organisational resource utilisation for hyperkalaemia in hospitalised patients. This was a single-centre, observational cohort study (Jan 2017-Dec 2020) at a tertiary-care hospital. The CogStack system (data processing and analytics platform) was used to search unstructured and structured data from individual patient records. Association between potassium and death was modelled using cubic spline regression, adjusted for age, sex, and comorbidities. Cox proportional hazards estimated the hazard of death compared with normokalaemia (3.5-5.0 mmol/l). 129,172 patients had potassium measurements in the emergency department. Incidence of hyperkalaemia was 85.7 per 1000. There were 49,011 emergency admissions. Potassium > 6.5 mmol/L had 3.9-fold worse in-hospital mortality than normokalaemia. Chronic kidney disease was present in 21% with potassium 5-5.5 mmol/L and 54% with potassium > 6.5 mmol/L. For diabetes, it was 20% and 32%, respectively. Of those with potassium > 6.5 mmol/L, 29% had nephrology review, and 13% critical care review; in this group 22% transferred to renal wards and 8% to the critical care unit. Dialysis was used in 39% of those with peak potassium > 6.5 mmol/L. Admission hyperkalaemia and hypokalaemia were independently associated with reduced likelihood of hospital discharge. Hyperkalaemia is associated with greater in-hospital mortality and reduced likelihood of hospital discharge. It necessitated significant utilisation of nephrology and critical care consultations and greater likelihood of patient transfer to renal and critical care.

Hyperkalemia Burden and Treatment Pathways in Patients with CKD: Findings From the DISCOVER CKD Retrospective Cohort

Key Points

Hyperkalemia (HK) is associated with increased comorbidity burden in patients with CKD. Reducing serum potassium levels after HK episodes helps continuation of renin-angiotensin-aldosterone system inhibitor treatment. In Japan, HK treatment pathways are more heterogeneous and potassium binders are more commonly prescribed compared with the United Kingdom.

Background

This analysis used retrospective data from the DISCOVER CKD observational study (NCT04034992 ) to describe the burden of and treatment pathways for hyperkalemia (HK) in patients with CKD.

Methods

Data were extracted from the following databases: UK Clinical Practice Research Datalink (2008–2019) and Japan Medical Data Vision (2008–2017). Patients with CKD (two eGFR measures <75 ml/min per 1.73 m2 recorded ≥90 days apart) and HK (at least two serum potassium [sK+] measures >5.0 mmol/L) were compared with patients without HK (sK+ <5.0 mmol/L); HK index event was the second sK+ measurement. Outcomes included baseline characteristics and treatment pathways for key medications (renin-angiotensin-aldosterone system inhibitors [RAASi], diuretics and potassium [K+] binders).

Results

In the UK Clinical Practice Research Datalink, 37,713 patients with HK and 142,703 patients without HK were included for analysis (HK prevalence 20.9%). In the Japan Medical Data Vision, 5924 patients with HK and 74,272 patients without HK were included for analysis (HK prevalence 7.4%). In both databases, median eGFR was lower and comorbidities such as hypertension, heart failure, type 2 diabetes, and AKI were more prevalent among patients with versus without HK, and most patients were taking RAASi at the time of HK index. Treatment pathways were more heterogeneous in Japan; <0.2% of patients with CKD and HK in the United Kingdom initiated K+ binders within 3 months of HK index versus 18.7% in Japan. The proportions of patients with CKD and HK who stopped treatment with diuretics, K+ binders, and RAASi during follow-up were 48.7%, 76.5%, and 50.6%, respectively, in the United Kingdom, and 22.9%, 53.6%, and 29.2%, respectively, in Japan.

Conclusions

HK was associated with increased comorbidity burden in patients with CKD. Variations in treatment pathways between the United Kingdom and Japan reflect the previous lack of a standardized approach to HK management in CKD.

Hyperkalemia Recurrence and Its Association With Race and Ethnicity in United States Veterans: A Retrospective Cohort Study

INTRODUCTION

Information on whether race and ethnicity are associated with a greater risk of recurrent hyperkalemia is limited. The aim of this study was to examine the association between race or ethnicity and recurrent hyperkalemia in a population of US veterans.

METHODS

This retrospective study used the US Veterans Affairs database to identify adults (aged ≥18 years) with at least one serum potassium measurement during the study period who ever experienced hyperkalemia (serum potassium > 5.0 mmol/L). The proportion of patients with hyperkalemia recurrence (≥1 subsequent event) within one year was determined for different race and ethnicity groups. The association between patient race and ethnicity and the risk of hyperkalemia recurrence within one year after the index hyperkalemia event was analyzed using competing risk regression.

RESULTS

Among a total of 1,493,539 veterans with incident hyperkalemia (median age (interquartile range): 61.0 years (54.0, 71.0)), recurrence within one year occurred in 19.1% of Black, 16.0% of Native Hawaiian/other Pacific Islander, 15.1% of White, 14.9% of American Indian/Alaska Native, and 13.1% of Asian patient groups. Recurrent hyperkalemia occurred in 18.1% of Hispanic and 15.6% of non-Hispanic patient groups. In a fully-adjusted regression model, recurrent hyperkalemia risk was significantly higher in Black versus White patient groups (subhazard ratio (sHR), 1.17; 95% confidence interval (CI), 1.16-1.19; p< 0.0001) and in Hispanic versus non-Hispanic patient groups (sHR, 1.30; 95% CI, 1.28-1.33; p< 0.0001).

DISCUSSION/CONCLUSION

Among US veterans with incident hyperkalemia, the risk of recurrent hyperkalemia was higher in Black and Hispanic patient groups. This information may be useful for health system screenings to risk stratify patient groups and both guide the frequency of serum potassium monitoring and better understand the root causes of group differences.

Recommendations for the management of hyperkalemia in patients receiving renin-angiotensin-aldosterone system inhibitors

Hyperkalemia is common in clinical practice and can be caused by medications used to treat cardiovascular diseases, particularly renin-angiotensin-aldosterone system inhibitors (RAASis). This narrative review discusses the epidemiology, etiology, and consequences of hyperkalemia, and recommends strategies for the prevention and management of hyperkalemia, mainly focusing on guideline recommendations, while recognizing the gaps or differences between the guidelines. Available evidence emphasizes the importance of healthcare professionals (HCPs) taking a proactive approach to hyperkalemia management by prioritizing patient identification and acknowledging that hyperkalemia is often a long-term condition requiring ongoing treatment. Given the risk of hyperkalemia during RAASi treatment, it is advisable to monitor serum potassium levels prior to initiating these treatments, and then regularly throughout treatment. If RAASi therapy is indicated in patients with cardiorenal disease, HCPs should first treat chronic hyperkalemia before reducing the dose or discontinuing RAASis, as reduction or interruption of RAASi treatment can increase the risk of adverse cardiovascular and renal outcomes or death. Moreover, management of hyperkalemia should involve the use of newer potassium binders, such as sodium zirconium cyclosilicate or patiromer, as these agents can effectively enable optimal RAASi treatment. Finally, patients should receive education regarding hyperkalemia, the risks of discontinuing their current treatments, and need to avoid excessive dietary potassium intake.

Long-term Patiromer Use and Outcomes Among US Veterans With Hyperkalemia and CKD: A Propensity-Matched Cohort Study

Rationale & Objective

Patiromer is a potassium binder approved for the long-term management of hyperkalemia. Although patiromer use among patients with advanced chronic kidney disease (CKD) has been shown to reduce the discontinuation of renin-angiotensin-aldosterone system inhibition therapy, it remains unclear whether patiromer can improve clinical outcomes. The aim of this study was to examine the association of long-term patiromer use with clinical outcomes among hyperkalemic patients with CKD.

Study Design

This was a longitudinal observational study.

Setting & Participants

We evaluated a national cohort of 854,217 US Veterans who had at least 1 serum potassium measurement of ≥5.1 mEq/L and were treated at US Department of Veterans Affairs health care facilities between January 2016 and September 2019.

Exposure

The exposure was long-term patiromer use.

Outcomes

The outcomes were as follows: (1) composite endpoint of kidney failure with replacement therapy (KFRT) or all-cause death and (2) all-cause death including the post-KFRT period.

Analytical Approach

Cox proportional Fine-Gray subdistribution hazard models were used in a propensity-matched cohort.

Results

Among 2,004 patients who ever used patiromer during the study period (0.2% of the cohort), 666 met the criteria for long-term patiromer use. We matched 308 long-term patiromer users to 308 nonusers based on propensity scores. The median estimated glomerular filtration rate was 23.5 mL/min/1.73m2, and the median potassium level was 5.2 mEq/L. Approximately 45% were on renin-angiotensin system inhibitor(s) at baseline. During follow-up, 93 patients developed KFRT, and 134 patients died. Long-term patiromer users, when compared to nonusers, experienced a 26% lower risk of the composite outcome (HR, 0.74; 95% CI, 0.53-1.01; P = 0.06) and a 41% lower risk of all-cause mortality (HR, 0.59; 95% CI, 0.41-0.84; P = 0.003).

Limitations

The study cohort included mostly male veterans with relatively short follow-up periods.

Conclusions

Long-term patiromer use was associated with a lower risk of all-cause mortality among patients with CKD and hyperkalemia. Long-term potassium binder use for hyperkalemia may improve clinical outcomes in CKD.

Plain-Language Summary

Hyperkalemia is a common complication of chronic kidney disease (CKD) and can result in the discontinuation of renin-angiotensin-aldosterone system inhibition therapy, a cornerstone of CKD management. Patiromer is a new potassium binder approved for the long-term management of hyperkalemia, but it remains unclear whether patiromer can improve clinical outcomes. We examined a cohort of US Veterans with hyperkalemia between January 2016 and September 2019 and found that patiromer use was uncommon for treating hyperkalemia during this study period. We then matched 308 long-term patiromer users and 308 nonusers based on propensity scores. Long-term patiromer users, when compared to nonusers, experienced a 26% lower risk of the composite outcome and a 41% lower risk of all-cause mortality. These findings indicate that long-term potassium binder use for hyperkalemia may improve clinical outcomes in CKD.

Cost-effectiveness analysis of sodium zirconium cyclosilicate for treating hyperkalemia among Chinese patients

Objectives

Hyperkalemia most commonly develops in chronic kidney disease (CKD) or heart failure (HF) patients. Sodium zirconium cyclosilicate (SZC) is a new selective potassium (K+) binder for treating hyperkalemia. The aim of this study was to evaluate the cost-effectiveness of SZC vs. usual care for the treatment of hyperkalemia among CKD patients or HF patients in China.

Methods

Individual patient microsimulation models were constructed to simulate a CKD cohort until the initiation of renal replacement therapy (RRT) and a HF cohort across the lifetime horizon. K+ levels were based on two phase 3 clinical trials. Health state utility and event incidence rates were retrieved from literature. Drug costs and healthcare utilization costs were obtained from negotiated price, literature, and expert interviews. Costs and quality-adjusted life-years (QALYs) were both discounted at 5%. The main outcomes were overall costs, QALYs, and incremental cost-effectiveness ratio (ICER). The willingness-to-pay (WTP) threshold in China is CNY 80,976-242,928/QALY, which is one to three times the gross domestic product per capita. Sensitivity analyses were performed to characterize the models' uncertainty.

Results

In the HF cohort, the base case results revealed that SZC was associated with 2.86 QALYs and the total cost was CNY 92671.58; usual care was associated with 1.81 QALYs and CNY 54101.26. In the CKD cohort, SZC was associated with 3.23 QALYs and CNY 121416.82 total cost; usual care was associated with 2.91 QALYs and CNY 111464.57. SZC resulted in an ICER of CNY 36735.87/QALY for the HF cohort and CNY 31181.55/QALY for the CKD cohort, respectively. The one-way and probability sensitivity analyses found that the results were robust.

Conclusion

SZC is a cost-effective treatment compared to usual care in HF and CKD patients. SZC is an important novel treatment option for managing patients with hyperkalemia in China.

Clinical outcomes by serum potassium levels for patients hospitalized for heart failure: Secondary analysis of data from the China National Heart Failure Registry

BACKGROUND

Dyskalemia is a mortality risk factor in patients with heart failure (HF).

HYPOTHESIS

We described the prevalence of dyskalemia, and clinical outcomes by serum potassium (sK) levels, in Chinese patients hospitalized for HF.

METHODS

In this secondary analysis of the prospective China National Heart Failure Registry, adult patients hospitalized between January 1, 2013 and June 30, 2015 who had at least one baseline sK measurement were followed for up to 3 years after discharge. The use of renin-angiotensin-aldosterone system inhibitors at baseline and clinical outcomes during follow-up were compared among sK groups.

RESULTS

Among 6950 patients, 5529 (79.6%) had normokalemia (sK >3.5-5.0 mmol/L), 1113 (16.0%) had hypokalemia (sK 0-3.5 mmol/L), and 308 (4.4%) had hyperkalemia (sK >5.0 mmol/L). Baseline characteristics that were most common in patients with hyperkalemia than those with hypo- and normokalemia included older age, HF with reduced ejection fraction, New York Heart Association Class III/IV status, hypertension, and chronic kidney disease. Use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) differed across sK groups (p = .0001); reported in 64.1%, 63.4%, and 54.5% of patients with hypo-, normo-, and hyperkalemia, respectively. Overall, 26.6%, 28.6%, and 36.0% of patients with hypo-, normo-, and hyperkalemia had rehospitalization for worsened HF, or cardiovascular mortality; p = .0057 for between-group comparison.

CONCLUSIONS

Patients with hyperkalemia received ACEIs or ARBs for HF treatment at baseline less frequently than those with hypo- or normokalemia, and had worse prognoses. This warrants further investigation into effective hyperkalemia management in HF.

Efficacy and Safety of Sodium-Glucose Cotransporter-2 Inhibitors in Nondiabetic Patients with Chronic Kidney Disease: A Review of Recent Evidence

Background

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) were initially developed as glucose-lowering agents in patients with type-2 diabetes. However, available data from clinical trials and meta-analyses suggest that SGLT2i have pleiotropic benefits in reducing mortality and delaying the progression of chronic kidney disease (CKD) in both diabetic and nondiabetic patients. Thus, we herein review the current evidence regarding the efficacy and safety of SGLT2i in patients with nondiabetic CKD and appraise the recently reported clinical trials that might facilitate the management of CKD in routine clinical practice.

Summary

The benefits of SGLT2i on nondiabetic CKD are multifactorial and are mediated by a combination of mechanisms. The landmark DAPA-CKD trial revealed that dapagliflozin administered with renin-angiotensin system blockade drugs reduced the risk of a sustained decline (at least 50%) in the estimated glomerular filtration rate, end-stage kidney disease, or death from cardiorenal causes. The recent EMPA-KIDNEY trial showed that empagliflozin therapy led to a lower risk of progression of kidney disease or death from cardiovascular causes. These benefits were consistent in patients with and without diabetes. Moreover, a meta-analysis of DAPA-HF and EMPEROR-Reduced trials confirmed reductions in the combined risk of cardiovascular death or worsening heart failure including composite renal endpoint.

Key Messages

Considering the robust data available from DAPA-CKD, EMPA-KIDNEY, and other trials such as EMPEROR-Preserved, DIAMOND that included nondiabetic patients, it may be necessary to update current guidelines to include SGLT2i as a first-line therapy for CKD and reevaluate current CKD therapeutic approaches.

Daptomycin-Induced Severe Hyperkalemia With Normal Creatine Kinase in a Patient With Methicillin-Resistant Staphylococcus aureus Osteomyelitis

We report a case of an asymptomatic 60-year-old female who presented to the emergency department due to a home health measured serum potassium of 7.7 mmol/L (normal range: 3.6-5.0 mmol/L) and was admitted for severe hyperkalemia. She was recently started on a low dose of daily intravenous daptomycin to treat methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis of her sacral decubitus ulcers. Laboratory results showed normal creatine kinase (CK). Her elevated serum potassium levels reversed throughout her hospital stay and remained within normal range after daptomycin discontinuation, establishing a temporal relationship between daptomycin and hyperkalemia. To our knowledge, no other cases report daptomycin-induced severe hyperkalemia in the absence of rhabdomyolysis. Our case emphasizes the importance of considering hyperkalemia as an adverse effect of daptomycin, especially in elderly hospitalized patients.

Factors associated with kalemia in renal disease

BACKGROUND

International recommendations promote a strict potassium diet in order to avoid hyperkalemia in chronic kidney disease (CKD) patients. However, the efficiency of such a dietary recommendation has never been demonstrated. The objectives of this study were to define the relationship between kalemia, dietary potassium intake estimated by kaliuresis and renal function, and to define the factors associated with kalemia in patients using artificial intelligence.

METHODS

To this extent, data from patients followed in a nephrology unit, included in the UniverSel study and whose kalemia (measured on the day of urine collection; n = 367) were analyzed.

RESULTS

The patients included had a wide range of estimated glomerular filtration rate (eGFR), but few had stage 5 CKD. Kalemia was negatively and linearly correlated to eGFR (P < .001) but was not correlated to kaliuresis (P = .55). Kaliuresis was not correlated to eGFR (P = .08). Factors associated with kalemia were analyzed using a Bayesian network. The five variables most associated with kalemia were, in descending order, eGFR, original nephropathy, age, diabetes and plasma bicarbonate level.

CONCLUSION

The results of this study do not support a strict dietary potassium control to regulate kalemia in stage 1-4 CKD patients.

Hyperkalemia in CKD: an overview of available therapeutic strategies

Hyperkalemia (HK) is a life-threatening condition that often occurs in patients with chronic kidney disease (CKD). High serum potassium (sKsK) is responsible for a higher risk of end-stage renal disease, arrhythmias and mortality. This risk increases in patients that discontinue cardio-nephroprotective renin-angiotensin-aldosterone system inhibitor (RAASi) therapy after developing HK. Hence, the management of HK deserves the attention of the clinician in order to optimize the therapeutic strategies of chronic treatment of HK in the CKD patient. The adoption in clinical practice of the new hypokalaemic agents patiromer and sodium zirconium cyclosilicate (SZC) for the prevention and chronic treatment of HK could allow patients, suffering from heart failure and chronic renal failure, to continue to benefit from RAASi therapy. We have updated a narrative review of the clear variables, correct definition, epidemiology, pathogenesis, etiology and classifications for HK among non-dialysis CKD (ND CKD) patients. Furthermore, by describing the prognostic impact on mortality and on the progression of renal damage, we want to outline the strategies currently available for the control of potassium (K+) plasma levels.

TRPV4 expression in the renal tubule is necessary for maintaining whole body K+ homeostasis

The Ca2+-permeable transient receptor potential vanilloid type 4 (TRPV4) channel serves as the sensor of tubular flow, thus being well suited to govern mechanosensitive K+ transport in the distal renal tubule. Here, we directly tested whether the TRPV4 function is significant in affecting K+ balance. We used balance metabolic cage experiments and systemic measurements with different K+ feeding regimens [high (5% K+), regular (0.9% K+), and low (<0.01% K+)] in newly created transgenic mice with selective TRPV4 deletion in the renal tubule (TRPV4fl/fl-Pax8Cre) and their littermate controls (TRPV4fl/fl). Deletion was verified by the absence of TRPV4 protein expression and lack of TRPV4-dependent Ca2+ influx. There were no differences in plasma electrolytes, urinary volume, and K+ levels at baseline. In contrast, plasma K+ levels were significantly elevated in TRPV4fl/fl-Pax8Cre mice on high K+ intake. K+-loaded knockout mice exhibited lower urinary K+ levels than TRPV4fl/fl mice, which was accompanied by higher aldosterone levels by day 7. Moreover, TRPV4fl/fl-Pax8Cre mice had more efficient renal K+ conservation and higher plasma K+ levels in the state of dietary K+ deficiency. H+-K+-ATPase levels were significantly increased in TRPV4fl/fl-Pax8Cre mice on a regular diet and especially on a low-K+ diet, pointing to augmented K+ reabsorption in the collecting duct. Consistently, we found a significantly faster intracellular pH recovery after intracellular acidification, as an index of H+-K+-ATPase activity, in split-opened collecting ducts from TRPV4fl/fl-Pax8Cre mice. In summary, our results demonstrate an indispensable prokaliuretic role of TRPV4 in the renal tubule in controlling K+ balance and urinary K+ excretion during variations in dietary K+ intake. NEW & NOTEWORTHY The mechanoactivated transient receptor potential vanilloid type 4 (TRPV4) channel is expressed in distal tubule segments, where it controls flow-dependent K+ transport. Global TRPV4 deficiency causes impaired adaptation to variations in dietary K+ intake. Here, we demonstrate that renal tubule-specific TRPV4 deletion is sufficient to recapitulate the phenotype by causing antikaliuresis and higher plasma K+ levels in both states of K+ load and deficiency.

A cost-effectiveness analysis of patiromer in the UK: evaluation of hyperkalaemia treatment and lifelong RAASi maintenance in chronic kidney disease patients with and without heart failure

BACKGROUND

Chronic kidney disease (CKD) patients with and without heart failure (HF) often present with hyperkalaemia (HK) leading to increased risk of hospitalisations, cardiovascular related events and cardiovascular-related mortality. Renin-angiotensin-aldosterone system inhibitor (RAASi) therapy, the mainstay treatment in CKD management, provides significant cardiovascular and renal protection. Nevertheless, its use in the clinic is often suboptimal and treatment is frequently discontinued due to its association with HK. We evaluated the cost-effectiveness of patiromer, a treatment known to reduce potassium levels and increase cardiorenal protection in patients receiving RAASi, in the UK healthcare setting.

METHODS

A Markov cohort model was generated to assess the pharmacoeconomic impact of patiromer treatment in regulating HK in patients with advanced CKD with and without HF. The model was generated to predict the natural history of both CKD and HF and quantify the costs and clinical benefits associated with the use of patiromer for HK management from a healthcare payer's perspective in the UK.

RESULTS

Economic evaluation of patiromer use compared to standard of care (SoC) resulted in increased discounted life years (8.93 versus 8.67) and increased discounted quality-adjusted life years (QALYs) (6.36 versus 6.16). Furthermore, patiromer use resulted in incremental discounted cost of £2,973 per patient and an incremental cost-effectiveness ratio (ICER) of £14,816 per QALY gained. On average, patients remained on patiromer therapy for 7.7 months, and treatment associated with a decrease in overall clinical event incidence and delayed CKD progression. Compared to SoC, patiromer use resulted in 218 fewer HK events per 1,000 patients, when evaluating potassium levels at the 5.5-6 mmol/l; 165 fewer RAASi discontinuation episodes; and 64 fewer RAASi down-titration episodes. In the UK, patiromer treatment was predicted to have a 94.5% and 100% chance of cost-effectiveness at willingness-to-pay thresholds (WTP) of £20,000/QALY and £30,000/QALY, respectively.

CONCLUSION

This study highlights the value of both HK normalisation and RAASi maintenance in CKD patients with and without HF. Results support the guidelines which recommend HK treatment, e.g., patiromer, as a strategy to enable the continuation of RAASi therapy and improve clinical outcomes in CKD patients with and without HF.

Clinicopathological Features of Gitelman Syndrome with Proteinuria and Renal Dysfunction

INTRODUCTION

Gitelman syndrome (GS) is a rare renal tubular salt-wasting disorder. Besides kidney electrolyte loss, proteinuria and renal dysfunction were also observed. However, their incidence, risk factors, pathological features, and prognosis were unclear.

METHODS

We retrospectively reviewed 116 GS patients and analyzed their clinical, genetic, and pathological characteristics. We also systematically reviewed articles on GS with proteinuria and renal dysfunction.

RESULTS

Twenty-three GS patients had proteinuria (69.6%) and renal dysfunction (43.5%) with a mean age of 35.3 ± 13.2 years, and 65.2% were male. Compared to patients without proteinuria or renal dysfunction, these patients had elevated plasma angiotensin II level (440.2 ± 351.7 vs. 253.2 ± 187.4 pg/mL, p = 0.031) and three times higher incidence of diabetes. The renal pathology of nine biopsied patients indicated hypertrophy of the juxtaglomerular apparatus (100%), chronic tubulointerstitial changes (66.7%), intrarenal vascular changes (66.7%), and glomerulopathy (55.6%). More extensive renin staining was observed in patients with GS than in the control group with glomerular minor lesion (p < 0.001). During a median of 85 months (range, 11-205 months) of follow-up for 19 out of the 23 GS-renal patients, the renal function was generally stable, except one died of cancer and one developed end-stage renal disease because of concomitant membranous nephropathy and IgA nephropathy.

CONCLUSION

Proteinuria and renal dysfunction were more common than expected and might indicate glomerulopathy and vascular lesions besides a tubulointerstitial injury in GS. Renal function may maintain stable with effective therapy in most cases.

Mediation of serum albumin in the association of serum potassium with mortality in Chinese dialysis patients: a prospective cohort study

BACKGROUND

The clinical importance of hypokalemia is likely underrecognized in Chinese dialysis patients, and whether its clinical effect was mediated by serum albumin is not fully elucidated. This study aimed to explore the association between serum potassium and mortality in dialysis patients of a Chinese nationwide multicenter cohort, taking albumin as a consideration.

METHODS

This was a prospective nation-wide multicenter cohort study. Restricted cubic splines were used to test the linearity of serum potassium and relationships with all-cause (AC) and cardiovascular (CV) mortality and a subsequent two-line piecewise linear model was fitted to approach the nadir. A mediation analysis was performed to examine relations of albumin to potassium and mortalities.

RESULTS

A total of 10,027 patients were included, of whom 6605 were peritoneal dialysis and 3422 were hemodialysis patients. In the overall population, the mean age was 51.7 ± 14.8 years, 55.3%(5546/10,027) were male, and the median dialysis vintage was 13.60 (4.70, 39.70) months. Baseline serum potassium was 4.30 ± 0.88 mmol/L. After a median follow-up period of 26.87 (14.77, 41.50) months, a U-shape was found between potassium and mortality, and a marked increase in risk at lower potassium but a moderate elevation in risk at higher potassium were observed. The nadir for AC mortality risk was estimated from piecewise linear models to be a potassium concentration of 4.0 mmol/L. Interestingly, the significance of the association between potassium and mortality was attenuated when albumin was introduced into the extended adjusted model. A subsequent significant mediation by albumin for potassium and AC and CV mortalities were found ( P < 0.001 for both), indicating that hypokalemia led to higher mortality mediated by low serum albumin, which was a surrogate of poor nutritional status and inflammation.

CONCLUSIONS

Associations between potassium and mortalities were U-shaped in the overall population. The nadir for AC mortality risk was at a potassium of 4.0 mmol/L. Serum albumin mediated the association between potassium and AC and CV mortalities.

Hyperkalemia and the Use of New Potassium Binders a Single Center Experience from Vestfold Norway (The PotBind Study)

Purpose

Hyperkalemia is a common metabolic complication of chronic kidney disease (CKD) and is associated with several serious adverse events. We aimed to treat/prevent hyperkalemia using the new of potassium-binders, allowing maintained renin-angiotensin-aldosterone system inhibitors (RAASi) treatment in proteinuric CKD and/or congestive heart failure (CHF) patients.

Patients and Methods

We conducted a retrospective cohort study in long-term users of potassium binders for chronic hyperkalemia. Patients aged 18 years and older, treated with potassium-binders and who met the reimbursement criteria and indication for RAASi treatment were included.

Results

Fifty-seven percent of the patients were males and mean age was 65 years. During the study period, no patients were admitted to hospital due to hyperkalemia after initiation of potassium binders. Potassium maximum values were significantly lower after treatment. Few patients reported major side effects, and discontinuation was mostly due to normokalemia. We found no significant changes in bicarbonate, serum creatinine or GFR stage after starting potassium binder treatment. All patients on RAASi treatment before initiating potassium-binders were retained on RAASi treatment.

Conclusion

New potassium binders in clinical practice are an easy and safe treatment with few side effects and good tolerance, that significantly lowers the risk of hyperkalemia. Furthermore, and most importantly, patients can be maintained on RAASi treatment.

Assessing potassium levels in critically ill patients with heart failure: application of a group-based trajectory model

AIMS

Abnormalities in potassium homeostasis are frequently seen in hospitalized patients. A poor outcome in heart failure (HF) has been linked to both hypokalaemia and hyperkalaemia. The studies on the connection between variations in potassium levels and all-cause mortality remain scarce. We delineated trajectories of potassium levels and investigated the association of these trajectories with all-cause mortality of critically ill patients with HF.

METHODS AND RESULTS

A retrospective analysis of blood potassium levels (9 times) in patients with HF after being admitted to the intensive care unit (ICU). Potassium levels were divided into three groups according to the first serum potassium level in ICU and thereafter categorized as follows: hypokalaemia group (n = 336) (<3.5 mmol/L), normal blood potassium-level group (n = 3322) (3.5-5.0 mmol/L), and hyperkalaemia group (n = 395) (>5.0 mmol/L). According to the group-based trajectory modelling (GBTM), the hyperkalaemia group and the normal blood potassium-level group can be divided into three trajectory groups: the low-level stable group, the medium-level stable group, and the high-level decline group. The hypokalaemia group can be divided into two trajectory groups: the low-level rise group and the high-level rise group. A total of 4053 HF patients were included (mean age 71.81 ± 13.12 years, 54.90% males, 45.10% females). After adjusting for possible confounding variables, in the hyperkalaemia group, the low-level stable group had lower 28 day [high-level decline group vs. low-level stable group hazard ratio (HR), 95% confidence interval (CI): 2.917, 1.555-5.473; P < 0.05] and 365 day (high-level decline group vs. low-level stable group HR, 95% CI: 2.854, 1.820-4.475; P < 0.05) all-cause mortality. In the normal blood potassium-level group, the medium-level stable group had lower 28 day (medium-level stable group vs. low-level stable group HR, 95% CI: 0.776, 0.657-0.918; P < 0.05) and 365 day (medium-level stable group vs. low-level stable group HR, 95% CI: 0.827, 0.733-0.934; P < 0.05) all-cause mortality. In the hypokalaemia group, the cumulative survival of the high-level rise group and the low-level rise group did not differ significantly.

CONCLUSIONS

Critically ill patients with HF have blood potassium trajectories. And the trajectories are associated with all-cause mortality for hyperkalaemia and normal blood potassium-level patients. GBTM is a granular method to describe the evolution of blood potassium, which may increase the current knowledge of blood potassium-level adjustment.

The Influence of the Severity of Early Chronic Kidney Disease on Oxidative Stress in Patients with and without Type 2 Diabetes Mellitus

Early Chronic Kidney Disease (CKD) is a condition that tends to progress to End-Stage Kidney Disease (ESKD). Early diagnosis of kidney disease in the early stages can reduce complications. Alterations in renal function represent a complication of diabetes mellitus (DM). The mechanisms underlying the progression of CKD in diabetes could be associated with oxidative and inflammatory processes. This study aimed to evaluate the state of inflammation and oxidative stress (OS) on the progression of CKD in the early stages in patients with and without type 2 diabetes mellitus (T2DM). An analytical cross-sectional study was carried out in patients with CKD in early stages (1, 2, 3) with and without T2DM. The ELISA method determined the expression of pro-inflammatory cytokines IL-6 and TNF-α as well as lipoperoxides (LPO), nitric oxide (NO), and superoxide dismutase activity (SOD). Colorimetric methods determined glutathione peroxidase (GPx) and total antioxidant capacity (TAC). Patients with CKD and T2DM had significantly decreased antioxidant defenses for SOD (p < 0.01), GPx (p < 0.01), and TAC (p < 0.01) compared to patients without T2DM. Consequently, patients with T2DM had higher concentrations of oxidant markers, NO (p < 0.01), inflammation markers, IL-6 (p < 0.01), and TNF-α than patients without T2DM. CKD stages were not related to oxidative, antioxidant, and inflammatory marker outcomes in T2DM patients. Patients without T2DM presented an increase in SOD (p = 0.04) and a decrease in NO (p < 0.01) when the stage of CKD increased. In conclusion, patients with T2DM present higher levels of oxidative and inflammatory markers accompanied by a decrease in antioxidant defense. However, these oxidative status markers were associated with CKD stage progression in patients without T2DM. Thus, NO and SOD markers could help detect the early stages of CKD in patients who have not yet developed metabolic comorbidities such as T2DM.

The Cost Effectiveness of Patiromer for the Treatment of Hyperkalaemia in Patients with Chronic Kidney Disease with and without Heart Failure in Ireland

BACKGROUND AND OBJECTIVE

Hyperkalaemia can be a life-threatening condition, particularly in patients with advanced chronic kidney disease with and without heart failure. Renin-angiotensin-aldosterone system inhibitor therapy offers cardiorenal protection in chronic kidney disease and heart failure; however, it may also cause hyperkalaemia subsequently resulting in down-titration or discontinuation of treatment. Hence, there is an unmet need for hyperkalaemia treatment in patients with chronic kidney disease with and without heart failure to enable renin-angiotensin-aldosterone system inhibitor use in this patient population. In this study, we develop a de novo disease progression and cost-effectiveness model to evaluate the clinical and economic outcomes associated with the use of patiromer for the treatment of hyperkalaemia in patients with chronic kidney disease with and without heart failure.

METHODS

A Markov model was developed using data from the OPAL-HK trial to assess the health economic impact of patiromer therapy in comparison to standard of care in controlling hyperkalaemia in patients with advanced chronic kidney disease with and without heart failure in the Irish setting. The model was designed to predict the natural history of chronic kidney disease and heart failure and quantify the costs and benefits associated with the use of patiromer for hyperkalaemia management over a lifetime horizon from a payer perspective.

RESULTS

Treatment with patiromer was associated with an increase in discounted life-years (8.62 vs 8.37) and an increase in discounted quality-adjusted life-years (6.15 vs 5.95). Incremental discounted costs were predicted at €4979 per patient, with an incremental cost-effectiveness ratio of €25,719 per quality-adjusted life-year gained. Patients remained taking patiromer treatment for an average of 7.7 months, with treatment associated with reductions in the overall clinical event incidence and a delay in chronic kidney disease progression. Furthermore, patiromer was associated with lower overall rates of hospitalisation, major adverse cardiovascular events, dialysis, renin-angiotensin-aldosterone system inhibitor discontinuation episodes and renin-angiotensin-aldosterone system inhibitor down-titration episodes. At a willingness-to-pay threshold of €45,000 per quality-adjusted life-year in Ireland, treatment with patiromer was estimated to have a 100% chance of cost effectiveness compared with standard of care.

CONCLUSIONS

This study has demonstrated an economic case for the reimbursement of patiromer for the treatment of hyperkalaemia in patients with chronic kidney disease with and without heart failure in Ireland. Patiromer was estimated to improve life expectancy and quality-adjusted life expectancy, whilst incurring marginal additional costs when compared with current standard of care. Results are predominantly attributed to the ability of patiromer to enable the continuation of renin-angiotensin-aldosterone system inhibitor treatment whilst also reducing potassium levels.

Potassium Derangements: A Pathophysiological Review, Diagnostic Approach, and Clinical Management

Potassium is an essential cation critical in fluid and electrolyte balance, acid–base regulation, and neuromuscular functions. The normal serum potassium is kept within a narrow range of 3.5–5.2 meq/L while the intracellular concentration is approximately 140–150 meq/L. The total body potassium is about 45–55 mmol/kg; thus, a 70 kg male has an estimated ~136 g and 60 kg female has ~117 g of potassium. In total, 98% of the total body potassium is intracellular. Skeletal muscle contains ~80% of body potassium stores. The ratio of intracellular to extracellular potassium concentration (Ki/Ke) maintained by Na+/K+ ATPase determines the resting membrane potential. Disturbances of potassium homeostasis lead to hypo- and hyperkalemia, which if severe, can be life-threatening. Prompt diagnosis and management of these problems are important.

The "FIFTY SHADOWS" of the RALES Trial: Lessons about the Potential Risk of Dietary Potassium Supplementation in Patients with Chronic Kidney Disease

Hyperkalaemia (HK) is one of the most common electrolyte disorders and a frequent reason for nephrological consultations. High serum potassium (K+) levels are associated with elevated morbidity and mortality, mainly due to life-threatening arrhythmias. In the majority of cases, HK is associated with chronic kidney disease (CKD), or with the use of renin-angiotensin-aldosterone system inhibitors (RAASis) and/or mineral corticoid antagonists (MRAs). These drugs represent the mainstays of treatment in CKD, HF, diabetes, hypertension, and even glomerular diseases, in consideration of their beneficial effect on hard outcomes related to cardiovascular events and CKD progression. However, experiences in relation to the Randomised Aldactone Evaluation Study (RALES) cast a long shadow that extends to the present day, since the increased risk for HK remains a major concern. In this article, we summarise the physiology of K+ homeostasis, and we review the effects of dietary K+ on blood pressure and cardiovascular risk in the general population and in patients with early CKD, who are often not aware of this disease. We conclude with a note of caution regarding the recent publication of the SSaSS trial and the use of salt substitutes, particularly in patients with a limited capacity to increase K+ secretion in response to an exogenous load, particularly in the context of "occult" CKD, HF, and in patients taking RAASis and/or MRAs.

Chronic Hyperkaliemia in Chronic Kidney Disease: An Old Concern with New Answers

Increasing potassium intake ameliorates blood pressure (BP) and cardiovascular (CV) prognoses in the general population; therefore the World Health Organization recommends a high-potassium diet (90–120 mEq/day). Hyperkalaemia is a rare condition in healthy individuals due to the ability of the kidneys to effectively excrete dietary potassium load in urine, while an increase in serum K⁺ is prevalent in patients with chronic kidney disease (CKD). Hyperkalaemia prevalence increases in more advanced CKD stages, and is associated with a poor prognosis. This scenario generates controversy on the correct nutritional approach to hyperkalaemia in CKD patients, considering the unproven link between potassium intake and serum K⁺ levels. Another concern is that drug-induced hyperkalaemia leads to the down-titration or withdrawal of renin-angiotensin system inhibitors (RASI) and mineralocorticoids receptors antagonists (MRA) in patients with CKD, depriving these patients of central therapeutic interventions aimed at delaying CKD progression and decreasing CV mortality. The new K⁺-binder drugs (Patiromer and Sodium-Zirconium Cyclosilicate) have proven to be adequate and safe therapeutic options to control serum K⁺ in CKD patients, enabling RASI and MRA therapy, and possibly, a more liberal intake of fruit and vegetables.

Association of serum potassium with decline in residual kidney function in incident hemodialysis patients

BACKGROUND

Hyperkalemia is associated with kidney function decline in patients with non-dialysis dependent chronic kidney disease, but this relationship is unclear for residual kidney function among hemodialysis (HD) patients.

METHODS

We conducted a retrospective cohort study of 6655 patients who started HD from January 2007 to December 2011 and who had data on renal urea clearance (KRU). Serum potassium levels were stratified into four groups (i.e. ≤4.0, >4.0 to ≤ 4.5, >4.5 to ≤ 5.0, >5.0 mEq/L) and 1-year KRU slope for each group was estimated by a linear mixed-effects model.

RESULTS

Higher serum potassium was associated with greater decline in KRU, and the greatest decrease in KRU (-0.20, 95% CI -0.50, -0.06) was observed for baseline potassium > 5.0 mEq/L in the fully adjusted model. Mediation analysis showed that KRU slope mediated 1.78% of the association between serum potassium and mortality.

CONCLUSIONS

In conclusion, hyperkalemia is associated with decline in residual kidney function amongst incident HD patients. These findings may have important clinical implications in the management of hyperkalemia in advanced CKD if confirmed in additional studies including clinical trials.

Epidemiology of hyperkalemia in CKD patients under nephrological care: a longitudinal study

Hyperkalemia is a potential life-threatening condition among chronic kidney disease (CKD) patients. Available estimates of the burden of this alteration in CKD are mainly derived from large administrative databases. Since K measurements in patients in these databases are often dictated by clinical reasons, longitudinal studies including pre-planned measurements of potassium independently of clinical complication/symptoms may produce more reliable estimates of the frequency and the risk factors underlying hyperkalemia in CKD patients. We estimated the prevalence and the incidence of hyperkalemia in a longitudinal study in 752 stages 2-5 CKD patients lasting 3 years and including up to seven pre-planned assessment of key biochemical measurements including K. At baseline, 203 out of 752 patients (27%) had serum K > 5.0 mM/L and 33% had acidosis (HCO₃ ≤ 22 mmol/L). Among those without hyperkalemia at baseline (n = 549), 284 patients developed this alteration across the 3-year follow-up. The point prevalence of hyperkalemia rose from 27% (baseline) to 30% (last visit) (P = 0.001). In a multivariate model, hyperkalemia at baseline [odds ratio (OR):7.29, 95% CI 5.65-9.41, P < 0.001], venous bicarbonate levels [OR (1 mmol/l): 0.92, 0.89-0.96, P < 0.001], eGFR [OR (1 ml/min/1.73m²): 0.98, 0.97-0.99, P < 0.001], use of ACE inhibitors (OR: 1.68, 1.28-2.19, P < 0.001) and angiotensin II antagonists (OR: 1.30, 1.01-1.68, P = 0.045) were related to hyperkalemia over time. Of note, venous bicarbonate levels emerged as an independent risk factor of hyperkalemia over time also in a separate analysis of patients with and without hyperkalemia at baseline. In a cohort of CKD patients including pre-planned measurements of K, 27% of patients had hyperkalemia. Metabolic acidosis and the use of drugs interfering with renin-angiotensin system were the strongest modifiable risk factors for this potentially life-threatening alteration in CKD in longitudinal analyses in the whole study cohort and in patients developing de novo hyperkalemia over time.

Association between serum potassium and risk of all-cause mortality among chronic kidney diseases patients: A systematic review and dose-response meta-analysis of more than one million participants

We aimed to perform a meta-analysis, using prospective cohort studies, to test the association between serum potassium and all-cause mortality among chronic kidney diseases (CKD) patients. A systematic search was performed using PubMed-MEDLINE and Scopus, up to July 2020. Prospective cohort studies which reported risk estimates of all-cause mortality in CKD patients with different serum potassium levels were included in the present meta-analysis. Thirteen studies were included in the analysis. A nonlinear dose-response meta-analysis suggested that there is a J-shaped association between serum potassium levels and the risk of all-cause mortality, with a nadir at serum potassium of 4.5 mmol/L. Subgroup analyses indicated that the strength and shape of the association between serum potassium and all-cause mortality may be influenced by age. Our meta-analysis provides supportive evidence that there is a J-shape association between serum potassium and all-cause mortality among CKD patients.

Development of a preoperative index-based nomogram for the prediction of hypokalemia in patients with pituitary adenoma: a retrospective cohort study

Objective

To develop and validate a preoperative index-based nomogram for the prediction of hypokalemia in patients with pituitary adenoma (PA).

Methods

This retrospective cohort study included 205 patients with PAs between January 2013 and April 2020 in the Sun Yat-sen Memorial Hospital, Guangzhou, China. The patients were randomly classified into either a training set (N = 143 patients) and a validation set (N = 62 patients) at a ratio of 7:3. Variables, which were identified by using the LASSO regression model were included for the construction of a nomogram, and a logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) in the training set. The area under the curve (AUC) was used to evaluate the performance of the nomogram for predicting hypokalemia. Multivariate logistic regression analysis with a restricted cubic spline analysis was conducted to identify a potential nonlinear association between the preoperative index and hypokalemia.

Results

The incidence of hypokalemia was 38.05%. Seven preoperative indices were identified for the construction of the nomogram: age, type of PA, weight, activated partial thromboplastin time, urea, eosinophil percentage, and plateletocrit. The AUCs of the nomogram for predicting hypokalemia were 0.856 (95% CI [0.796–0.915]) and 0.652 (95% CI [0.514–0.790]) in the training and validation sets, respectively. Restricted cubic splines demonstrated that there was no nonlinear association between hypokalemia and the selected variables.

Conclusion

In this study, we constructed a preoperative indices-based nomogram that can assess the risk of hypokalemia after the surgical treatment of pituitary adenomas. This nomogram may also help to identify high risk patients who require close monitoring of serum potassium.

Race-Specific Comparisons of Antihypertensive and Metabolic Effects of Hydrochlorothiazide and Chlorthalidone

BACKGROUND

Chlorthalidone is recommended over hydrochlorothiazide (HCTZ) as the preferred thiazide, but the supporting evidence is not robust at routinely used doses, or in whites vs blacks, in whom differences in response to thiazides are well known. We compare the efficacy and safety of HCTZ and chlorthalidone as first-line therapies for white and black hypertensive patients.

METHODS

We compared treatment-related outcomes between the HCTZ arm (12.5 mg for 2-3 weeks; 25 mg for additional 6 weeks) of the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR, n = 376) and chlorthalidone arm (15 mg for 2 weeks; 25 mg for additional 6 weeks) of PEAR-2 (n = 326) clinical trials, in 17-65-year-old mild-moderate uncomplicated hypertensive whites and blacks.

RESULTS

Mean systolic/diastolic blood pressure (SBP/DBP) reduction with HCTZ vs chlorthalidone: 8 ± 8/4 ± 5 vs 12 ± 9/7 ± 5 mm Hg in whites (P < 10^-6 SBP and DBP); 12 ± 10/7 ± 6 vs 15 ± 10/9 ± 6 in blacks (P = .008 SBP, P = .054 DBP). Treatment with HCTZ vs chlorthalidone in whites resulted in significantly fewer patients achieving target BP (<140/90 mm Hg) (44% vs 57%, P = .018) and clinical response rate (≥10 mm Hg DBP reduction); and significantly higher nonresponse rate (<6 mm Hg DBP reduction); but no significant differences in rates among blacks (eg, target-BP rate: 56% vs 63%, P = .31). HCTZ treatment led to significantly lower rates of hypokalemia and hyperuricemia in whites and blacks, vs chlorthalidone, and significantly lower odds of requiring potassium supplementation among blacks (odds ratio 0.16; 95% confidence interval, 0.07-0.37; P = 3.4e^-7).

CONCLUSION

Compared with HCTZ, chlorthalidone showed greater blood pressure lowering and adverse metabolic effects in whites, but similar blood pressure lowering and greater adverse effects in blacks; suggesting that the recent guideline recommendations to choose chlorthalidone over HCTZ may not be warranted in blacks.

Reduced alternative insulin dosing in hyperkalemia: A meta-analysis of effects on hypoglycemia and potassium reduction

STUDY OBJECTIVE

Recent studies have identified that reduced alternative intravenous insulin doses, such as 5 units or 0.1 units/kg, may reduce the risk of hypoglycemia compared to standard doses of 10 units in patients treated for hyperkalemia. However, some studies suggest that these alternative doses may reduce the ability to lower serum potassium. This study was performed to determine the impact of alternative insulin dosing on hypoglycemia and potassium reduction in patients with hyperkalemia.

DESIGN

Meta-analysis.

DATA SOURCE

PubMed/MEDLINE, CENTRAL, Ovid, and ClinicalTrials.gov were searched from inception through November 2020.

PATIENTS

Patients treated with standard (10 units) or alternative (<10 units) insulin dosing strategies for hyperkalemia. Only studies that evaluated hypoglycemia (serum glucose <70 mg/dl), severe hypoglycemia (serum glucose <50 mg/dl), and potassium reduction post-treatment were included in the meta-analysis. All articles were assessed for bias using the Cochrane Risk of Bias Assessment Tool and Newcastle-Ottawa scales for randomized prospective trials and retrospective trials, respectively.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Ten retrospective cohort studies (n = 3437) were included and had low- or moderate-risk of bias. Alternative insulin dosing strategies included 5 units, 0.1 units/kg, and <10 units. Alternative dosing had lower pooled odds of hypoglycemia (odds ratio [OR] 0.55, 95% confidence interval [CI] 0.43-0.69, I²  = 8%) and severe hypoglycemia (OR 0.41, 95% CI 0.27-0.64, I²  = 0%). No difference in potassium reduction was detected (mean difference -0.02 mmol/L, 95% CI -0.11-0.07, I²  = 53%).

CONCLUSIONS

Alternative insulin dosing strategies for hyperkalemia management resulted in less hypoglycemia and severe hypoglycemia without compromising potassium reduction compared to standard dose. Prospective studies are needed to confirm these findings.

Current Management of Hyperkalemia in Non-Dialysis CKD: Longitudinal Study of Patients Receiving Stable Nephrology Care

Background: No study has explored the limitations of current long-term management of hyperkalemia (HK) in outpatient CKD clinics. Methods: We evaluated the association between current therapeutic options and control of serum K (sK) during 12-month follow up in ND-CKD patients stratified in four groups by HK (sK ≥ 5.0 mEq/L) at baseline and month 12: Absent (no-no), Resolving (yes-no), New Onset (no-yes), Persistent (yes-yes). Results: We studied 562 patients (age 66.2 ± 14.5 y; 61% males; eGFR 39.8 ± 21.8 mL/min/1.73 m², RAASI 76.2%). HK was “absent” in 50.7%, “resolving” in 15.6%, “new onset” in 16.6%, and “persistent” in 17.1%. Twenty-four hour urinary measurements testified adherence to nutritional recommendations in the four groups at either visit. We detected increased prescription from baseline to month 12 of bicarbonate supplements (from 5.0 to 14.1%, p < 0.0001), K-binders (from 2.0 to 7.7%, p < 0.0001), and non-K sparing diuretics (from 34.3 to 41.5%, p < 0.001); these changes were consistent across groups. Similar results were obtained when using higher sK level (≥5.5 mEq/L) to stratify patients. Mixed-effects regression analysis showed that higher sK over time was associated with eGFR < 60, diabetes, lower serum bicarbonate, lower use of non-K sparing diuretics, bicarbonate supplementation, and K-binder use. Treatment-by-time interaction showed that sK decreased in HK patients given bicarbonate (p = 0.003) and K-binders (p = 0.005). Conclusions: This observational study discloses that one-third of ND-CKD patients under nephrology care remain with or develop HK during a 12-month period despite low K intake and increased use of sK-lowering drugs.

Diuretic-induced hypokalaemia: an updated review

Diuretic-induced hypokalaemia is a common and potentially life-threatening adverse drug reaction in clinical practice. Previous studies revealed a prevalence of 7%-56% of hypokalaemia in patients taking thiazide diuretics. The clinical manifestations of hypokalaemia due to diuretics are non-specific, varying from asymptomatic to fatal arrhythmia. Diagnosis of hypokalaemia is based on the level of serum potassium. ECG is useful in identifying the more severe consequences. A high dosage of diuretics and concomitant use of other drugs that increase the risk of potassium depletion or cardiac arrhythmias can increase the risk of cardiovascular events and mortality. Thiazide-induced potassium depletion may cause dysglycaemia. The risk of thiazide-induced hypokalaemia is higher in women and in black people. Reducing diuretic dose and potassium supplementation are the most direct and effective therapies for hypokalaemia. Combining with a potassium-sparing diuretic or blocker of the renin-angiotensin system also reduces the risk of hypokalaemia. Lowering salt intake and increasing intake of vegetables and fruits help to reduce blood pressure as well as prevent hypokalaemia.

Association between wide QRS pulseless electrical activity and hyperkalemia in cardiac arrest patients

AIM

We evaluated the relationship between hyperkalemia and wide QRS complex in patients with pulseless electrical activity (PEA) cardiac arrest.

METHODS

This was a single-center, retrospective observational study of patients over the age of 18 treated for cardiac arrest at a tertiary referral hospital whose initial electrocardiogram rhythm was PEA from February 2010 to December 2019. Wide QRS PEA was defined as a QRS interval of 120 ms or more. Hyperkalemia was defined as serum potassium level > 5.5 mmol/L. The primary outcome was hyperkalemia. Multivariable logistic regression analysis was used to evaluate the relationship between wide QRS and hyperkalemia.

RESULTS

Among 617 patients, we analyzed 111 episodes in the wide QRS group and 506 episodes in the narrow QRS group. The potassium level in the wide QRS group was significantly higher than in the narrow QRS group (5.4 mmol/L, IQR 4.4-6.7 vs. 4.6 mmol/L, IQR 4.0-5.6, P < 0.001). Among all patients, 49.6% (n = 55/111) in the wide QRS group had hyperkalemia, which was significantly higher than the 26.7% (n = 135/506) in the narrow QRS group (P < 0.001). In multivariable logistic regression analysis, wide QRS PEA was significantly associated with hyperkalemia (odds ratio = 2.86, 95% confidence interval: 1.80-4.53, P < 0.001).

CONCLUSIONS

Wide QRS PEA as an initial cardiac rhythm was significantly associated with hyperkalemia in cardiac arrest patients.

Association between serum potassium levels and adverse outcomes in chronic kidney disease: the Fukushima CKD cohort study

BACKGROUND

Serum potassium disorders, commonly observed in chronic kidney disease (CKD), are reportedly associated with higher mortality, but their impact on renal outcomes is still controversial.

METHODS

The present study used the longitudinal data of the Fukushima CKD cohort study to investigate the relationships between hypokalemia and hyperkalemia and adverse outcomes such as renal outcomes and all-cause mortality in Japanese patients with non-dialysis-dependent CKD. The study involved 1330 CKD patients followed-up for 2.8 years. The primary endpoint of the present study was a kidney event, defined as a combination of doubling of baseline serum creatinine and end-stage kidney disease.

RESULTS

Hyperkalemia (≥ 5.0 mmol/L) was noted in 10.6% and hypokalemia (< 4.0 mmol/L) in 16.4% of the study population. Significant U-shaped associations were observed between potassium levels and both kidney events and all-cause mortality on univariate Cox regression analyses. After adjustment for covariates, both hypokalemia and hyperkalemia were significantly associated with an increased risk of kidney events, with the lowest risk at a serum potassium of 4.0-4.4 mmol/L. Compared with a reference level of 4.0-4.4 mmol/L, the adjusted hazard ratio for kidney events was 2.49 (1.33-4.66) for serum potassium < 4.0 mmol/L, 1.72 (1.00-2.96) for 4.5-4.9 mmol/L, and 2.16 (1.15-4.06) for ≥ 5.0 mmol/L. There was no significant association between serum potassium levels and mortality after multivariate adjustment.

CONCLUSION

Hypokalemia and hyperkalemia were associated with an increased risk of CKD progression, but not with mortality in Japanese patients with non-dialysis-dependent CKD.

Abnormalities of Potassium in Heart Failure: JACC State-of-the-Art Review

Potassium (K⁺) is the most abundant cation in humans and is essential for normal cellular function. Alterations in K⁺ regulation can lead to neuromuscular, gastrointestinal, and cardiac abnormalities. Dyskalemia (i.e., hypokalemia and hyperkalemia) in heart failure is common because of heart failure itself, related comorbidities, and medications. Dyskalemia has important prognostic implications. Hypokalemia is associated with excess morbidity and mortality in heart failure. The lower the K⁺ levels, the higher the risk, starting at K⁺ levels below approximately 4.0 mmol/l, with a steep risk increment with K⁺ levels <3.5 mmol/l. Hyperkalemia (>5.5 mmol/l) has also been associated with increased risk of adverse events; however, this association is prone to reverse-causation bias as stopping renin angiotensin aldosterone system inhibitor therapy in the advent of hyperkalemia likely contributes the observed risk. In this state-of-the-art review, practical and easy-to-implement strategies to deal with both hypokalemia and hyperkalemia are provided as well as guidance for the use of potassium-binders.

Risk factors associated with disturbances of calcium homeostasis after initiation of a phosphate-restricted diet in cats with chronic kidney disease

BACKGROUND

Dietary phosphate restriction improves survival in cats with chronic kidney disease (CKD). However, feeding a phosphate-restricted diet may disrupt calcium homeostasis leading to hypercalcemia in some cats.

OBJECTIVES

To identify risk factors associated with increasing plasma total calcium (tCa) concentration after transition to a phosphate-restricted diet and to explore its role in CKD-mineral and bone disorder (CKD-MBD) in cats.

ANIMALS

Seventy-one geriatric (≥9 years) euthyroid client-owned cats with International Renal Interest Society (IRIS) stage 2 to 3 azotemic CKD.

METHODS

Retrospective cross-sectional cohort study. Changes in plasma tCa concentration in the first 200 days of diet transition were assessed using linear regression. Binary logistic regressions were performed to identify risk factors for increasing calcium concentration. Changes in clinicopathological variables associated with CKD-MBD over time were explored using linear mixed model and generalized linear mixed model analyses.

RESULTS

Lower baseline plasma potassium (odds ratio [OR] = 1.19 per 0.1 mmol/L decrease; P = .003) and phosphate (OR = 1.15 per 0.1 mmol/L decrease; P = .01) concentrations remained independent risk factors for increasing plasma tCa concentration. Plasma creatinine (β = .069 ± .029 mg/dL; P = .02), symmetric dimethylarginine (β = .64 ± .29 μg/dL; P = .03), phosphate (β = .129 ± .062 mg/dL; P = .04), and ln[FGF23] (β = .103 ± .035 pg/mL; P = .004) concentrations had significantly increased rates of change in cats with increasing plasma tCa concentration over time.

CONCLUSION AND CLINICAL IMPORTANCE

Lower plasma potassium or phosphate concentrations or both at the time of transition of cats with CKD to a phosphate-restricted diet are independently associated with increased risk of an increase in plasma tCa concentration. Increasing plasma tCa concentration is associated with progression of CKD.

Serum potassium in chronic kidney disease: prevalence, patient characteristics and clinical outcomes

BACKGROUND & AIMS

Abnormalities in serum potassium are a well-known complication of chronic kidney disease (CKD), but little is known about their impact on inpatient outcomes. To better understand the role of dyskalaemia in hospital in-patients, we assessed the epidemiology of potassium disorders among CKD patients, and the association between admission potassium and inpatient mortality or intensive care unit (ICU) requirement.

METHODS

This retrospective hospital-based cohort study (n = 11 156) included patients with eGFR<60 mL/min/1.73m² admitted to Austin Health between 2014 and 2018 and who had an admission potassium value. Dialysis patients or those with a renal transplant were excluded. Multivariate logistic analysis was conducted to identify factors associated with hyperkalaemia (≥5.5 mmol/L) and hypokalaemia (<3.5 mmol/L). Odds ratios for inpatient mortality and ICU admission between potassium categories were obtained by multivariate regression with adjustments for demographics, renal function and comorbidities.

RESULTS

Hyperkalaemia and hypokalaemia were present in 6.86% and 2.94% of hospital admissions, respectively. In multivariate regression male sex, lower eGFR, diabetes and cardiac failure were associated with higher odds of hyperkalaemia. Thiazide diuretics, loop diuretics, infectious disease and endocrine pathology were associated with higher odds of hypokalaemia. A U-shaped association was noted between potassium and inpatient mortality. Potassium <4.0 mmol/L and ≥ 5.0 mmol/L was associated with increased mortality. Only patients with potassium ≥5.5 mmol/L had increased ICU admission risk.

CONCLUSION

Derangements in potassium frequently occur in CKD inpatients and are independently associated with higher mortality and ICU requirement. Further studies are required to determine whether interventions to maintain normokalaemia improve outcomes in this population. This article is protected by copyright. All rights reserved.

Serum potassium in the PARADIGM-HF trial

Aims

The associations between potassium level and outcomes, the effect of sacubitril–valsartan on potassium level, and whether potassium level modified the effect of sacubitril–valsartan in patients with heart failure and a reduced ejection fraction were studied in PARADIGM‐HF. Several outcomes, including cardiovascular death, sudden death, pump failure death, non‐cardiovascular death and heart failure hospitalization, were examined.

Methods and results

A total of 8399 patients were randomized to either enalapril or sacubitril–valsartan. Potassium level at randomization and follow‐up was examined as a continuous and categorical variable (≤3.5, 3.6–4.0, 4.1–4.9, 5.0–5.4 and ≥5.5 mmol/L) in various statistical models. Hyperkalaemia was defined as K⁺ ≥5.5 mmol/L and hypokalaemia as K⁺ ≤3.5 mmol/L. Compared with potassium 4.1–4.9 mmol/L, both hypokalaemia [hazard ratio (HR) 2.40, 95% confidence interval (CI) 1.84–3.14] and hyperkalaemia (HR 1.42, 95% CI 1.10–1.83) were associated with a higher risk for cardiovascular death. However, potassium abnormalities were similarly associated with sudden death and pump failure death, as well as non‐cardiovascular death and heart failure hospitalization. Sacubitril–valsartan had no effect on potassium overall. The benefit of sacubitril–valsartan over enalapril was consistent across the range of baseline potassium levels.

Conclusions

Although both higher and lower potassium levels were independent predictors of cardiovascular death, potassium abnormalities may mainly be markers rather than mediators of risk for death.

Longer Predialysis ACEi/ARB Utilization Is Associated With Reduced Postdialysis Mortality

BACKGROUND

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ACEi/ARB) improve predialysis outcomes; however, ACEi/ARB are underused in patients transitioning to dialysis. We examined the association of different patterns of predialysis ACEi/ARB use with postdialysis survival and whether potentially modifiable adverse events are associated with lower predialysis ACEi/ARB use.

METHODS

This was a historic cohort study of 34,676 US veterans with, and 10,690 without, ACEi/ARB exposure in the 3-year predialysis period who subsequently transitioned to dialysis between 2007 and 2014. Associations of different patterns of predialysis ACEi/ARB use with postdialysis all-cause mortality and with predialysis acute kidney injury and hyperkalemia events were examined using multivariable adjusted regression analyses.

RESULTS

The mean age of the cohort was 70 years, 98% were males and 27% were African Americans. Compared to ACEi/ARB nonuse, continuous ACEi/ARB use was associated with lower postdialysis all-cause mortality (adjusted hazard ratio [aHR]; 95% confidence interval [95% CI] 0.87; 0.83-0.92). In analyses modeling the duration of predialysis ACEi/ARB use, ACEi/ARB use of 50%-74% and ≥75% were associated with lower mortality compared to nonuse (adjusted hazard ratio, 95% confidence interval 0.96, 0.92-0.99 and 0.91; 0.88-0.94, respectively), whereas no increase in postdialysis survival was observed with shorter predialysis ACEi/ARB use. Predialysis acute kidney injury was associated with shorter duration (<50%) of ACEi/ARB use and hyperkalemia was associated with interrupted and ACEi/ARB use of <75%.

CONCLUSIONS

Longer predialysis ACEi/ARB exposure was associated with lower postdialysis mortality. Prospective studies are needed to evaluate the benefits of strategies enabling uninterrupted predialysis ACEi/ARB use.

A method comparison study of a point-of-care blood gas analyser with a laboratory auto-analyser for the determination of potassium concentrations during hyperkalaemia in patients with kidney disease

Introduction

Hyperkalaemia is a common electrolyte disorder that may cause life-threatening cardiac arrythmias. We aimed to determine the agreement of potassium concentrations between GEM premier 3500 point-of-care blood gas analyser (POC-BGA) and Roche Cobas 6000 c501 auto-analyser in patients with hyperkalaemia.

Methods

A prospective, cross-sectional study of all consecutive adult patients referred to the Renal Unit with a serum potassium concentration ≥ 5.5 mmol/L was performed. A total of 59 paired venous blood samples were included in the final statistical analysis. Passing-Bablok regression and Bland Altman analysis were used to compare the two methods.

Results

The median laboratory auto-analyser potassium concentration was 6.1 (5.9-7.1) mmol/L as compared to the POC-BGA potassium concentration of 5.7 (5.5-6.8) mmol/L with a mean difference of - 0.43 mmol/L and 95% upper and lower limits of agreement of 0.35 mmol/L and - 1.21 mmol/L, respectively. Regression analysis revealed proportional systematic error. Test for linearity did not indicate significant deviation (P = 0.297).

Conclusion

Although regression analysis indicated proportional systematic error, on Bland Altman analysis, the mean difference appeared to remain relatively constant across the potassium range that was evaluated. Therefore, in patients presenting to the emergency department with a clinical suspicion of hyperkalaemia, POC-BGA potassium concentrations may be considered a surrogate for laboratory auto-analyser measurements once clinicians have been cautioned about this difference.

Predictors of Hyperkalemia and Hypokalemia in Individuals with Diabetes: a Classification and Regression Tree Analysis

BACKGROUND

Both hyperkalemia and hypokalemia can lead to cardiac arrhythmias and are associated with increased mortality. Information on the predictors of potassium in individuals with diabetes in routine clinical practice is lacking.

OBJECTIVE

To identify predictors of hyperkalemia and hypokalemia in adults with diabetes.

DESIGN

Retrospective cohort study, with classification and regression tree (CART) analysis.

PARTICIPANTS

321,856 individuals with diabetes enrolled in four large integrated health care systems from 2012 to 2013.

MAIN MEASURES

We used a single serum potassium result collected in 2012 or 2013. Hyperkalemia was defined as a serum potassium ≥ 5.5 mEq/L and hypokalemia as < 3.5 mEq/L. Predictors included demographic factors, laboratory measurements, comorbidities, medication use, and health care utilization.

KEY RESULTS

There were 2556 hypokalemia events (0.8%) and 1517 hyperkalemia events (0.5%). In univariate analyses, we identified concordant predictors (associated with increased probability of both hyperkalemia and hypokalemia), discordant predictors, and predictors of only hyperkalemia or hypokalemia. In CART models, the hyperkalemia "tree" had 5 nodes and a c-statistic of 0.76. The nodes were defined by prior potassium results and eGFRs, and the 5 terminal "leaves" had hyperkalemia probabilities of 0.2 to 7.2%. The hypokalemia tree had 4 nodes and a c-statistic of 0.76. The hypokalemia tree included nodes defined by prior potassium results, and the 4 terminal leaves had hypokalemia probabilities of 0.3 to 17.6%. Individuals with a recent potassium between 4.0 and 5.0 mEq/L, eGFR ≥ 45 mL/min/1.73m², and no hypokalemia in the previous year had a < 1% rate of either hypokalemia or hyperkalemia.

CONCLUSIONS

The yield of routine serum potassium testing may be low in individuals with a recent serum potassium between 4.0 and 5.0 mEq/L, eGFR ≥ 45 mL/min/1.73m², and no recent history of hypokalemia. We did not examine the effect of recent changes in clinical condition or medications on acute potassium changes.

Postdischarge Health Care Costs and Readmission in Patients With Hyperkalemia-Related Hospitalizations

Introduction

Limited evidence is available regarding the postdischarge economic and readmission burdens of hyperkalemia.

Methods

Using the IBM MarketScan Commercial and Medicare-Supplemental Claims database (January 1, 2010–December 31, 2014), adult patients with a hospitalization with a hyperkalemia diagnosis (ICD-9-CM 276.7, hyperkalemia cohort) were 1:1 matched with patients with a hospitalization without evidence of hyperkalemia (nonhyperkalemia cohort) on age, chronic kidney disease stage, heart failure, dialysis, renin-angiotensin-aldosterone system inhibitor use, and major diagnostic categories of the hospitalization. All-cause health care costs and health care resource utilization measures were compared between cohorts during the 1-year postdischarge period. Postdischarge readmission and length of stay (LOS) were compared between hyperkalemia-related hospitalizations from the hyperkalemia cohort and matched hospitalizations unrelated to hyperkalemia from the nonhyperkalemia cohort.

Results

Patients with hyperkalemia-related hospitalizations (n = 4426) incurred $30,379 (95% confidence interval, $25,423–$35,335) higher 1-year total all-cause costs ($68,861 vs. $38,482) and had higher rates of inpatient admissions (1.0 vs. 0.4), emergency department visits (2.0 vs. 1.2), and outpatient visits (49.6 vs. 39.1) than the nonhyperkalemia cohort during the 1-year postdischarge study period (all P < 0.001). Hyperkalemia-related hospitalizations (n = 5377) were associated with significantly higher readmission rates (within 30 days: 0.15 vs. 0.09; 60 days: 0.25 vs. 0.16; 90 days: 0.36 vs. 0.23; all P < 0.001), longer LOS per readmission (8.1 vs. 7.1 days), and longer total inpatient days (10.5 vs. 5.8 days) compared with hospitalizations unrelated to hyperkalemia (all P < 0.001). Similar trends were observed across comorbidity subgroups.

Conclusion

Hyperkalemia-related hospitalizations were associated with significant economic and readmission burdens during the 1-year postdischarge period.

Ethnic minority disparities in progression and mortality of pre-dialysis chronic kidney disease: a systematic scoping review

Background

There are a growing number of studies on ethnic differences in progression and mortality for pre-dialysis chronic kidney disease (CKD), but this literature has yet to be synthesised, particularly for studies on mortality.

Methods

This scoping review synthesized existing literature on ethnic differences in progression and mortality for adults with pre-dialysis CKD, explored factors contributing to these differences, and identified gaps in the literature. A comprehensive search strategy using search terms for ethnicity and CKD was taken to identify potentially relevant studies. Nine databases were searched from 1992 to June 2017, with an updated search in February 2020.

Results

8059 articles were identified and screened. Fifty-five studies (2 systematic review, 7 non-systematic reviews, and 46 individual studies) were included in this review. Most were US studies and compared African-American/Afro-Caribbean and Caucasian populations, and fewer studies assessed outcomes for Hispanics and Asians. Most studies reported higher risk of CKD progression in Afro-Caribbean/African-Americans, Hispanics, and Asians, lower risk of mortality for Asians, and mixed findings on risk of mortality for Afro-Caribbean/African-Americans and Hispanics, compared to Caucasians. Biological factors such as hypertension, diabetes, and cardiovascular disease contributed to increased risk of progression for ethnic minorities but did not increase risk of mortality in these groups.

Conclusions

Higher rates of renal replacement therapy among ethnic minorities may be partly due to increased risk of progression and reduced mortality in these groups. The review identifies gaps in the literature and highlights a need for a more structured approach by researchers that would allow higher confidence in single studies and better harmonization of data across studies to advance our understanding of CKD progression and mortality.

The Associations of Diuretics and Laxatives Use with Cardiovascular Mortality. An Individual Patient-Data Meta-analysis of Two Large Cohort Studies

Purpose

To investigate the associations of diuretics overall, non-potassium-sparing diuretics in specific, and laxative use with cardiovascular mortality (CVM) in subjects with antihypertensive treatment.

Methods

Analyses included 4253 participants, aged 50 to 75 years, from the German ESTHER cohort and 105,359 participants, aged 50 to 69 years, from the UK Biobank. Cox proportional hazard regression models were applied in both studies, and then results were pooled using random-effects model meta-analyses.

Results

During 14 and 7 years of follow-up, 476 and 1616 CVM cases were observed in the ESTHER study and the UK Biobank, respectively. Compared to non-users, a 1.6-fold (hazard ratio [95% confidence interval] 1.57 [1.29; 1.90]), a 1.4-fold (1.39 [1.26; 1.53]), and no statistically significantly increased (1.13 [0.94; 1.36]) CVM were observed in users of diuretics overall, non-potassium-sparing diuretics in specific, and laxatives, respectively. Concurrent use of non-potassium-sparing diuretics and laxatives was associated with a 2-fold increased CVM (2.05 [1.55; 2.71]) when compared to users of neither diuretics nor laxatives. However, a test for interaction slightly missed statistical significance (p = 0.075).

Conclusions

These consistent results from two large cohort studies imply that more research is needed on the safety of diuretics in routine care. Although not statistically significant in this study, a drug-drug interaction of non-potassium-sparing diuretics and laxatives appears plausible. Physicians and pharmacists are advised to clarify additional laxative use in users of non-potassium-sparing diuretics and inform about the risk of concurrent use. Moreover, closer potassium monitoring intervals (e.g., every 3 months) might be indicated in concurrent users to prevent fatal cardiovascular events.

Electronic supplementary material

The online version of this article (10.1007/s10557-019-06894-w) contains supplementary material, which is available to authorized users.

Comparative Study of Constipation Exacerbation by Potassium Binders Using a Loperamide-Induced Constipation Model

Patients on dialysis are frequently administered high doses of potassium binders such as calcium polystyrene sulfonate (CPS) and sodium polystyrene sulfonate (SPS), which exacerbate constipation. Here, we compare the degree of constipation induced by CPS and SPS using a loperamide-induced constipation model to identify the safer potassium binder. Constipation model was created by twice-daily intraperitoneal administration (ip) of loperamide hydrochloride (Lop; 1 mg/kg body weight) in rats for 3 days. Rats were assigned to a control group, Lop group, Lop + CPS group or Lop + SPS group, and a crossover comparative study was performed. Defecation status (number of feces, feces wet weight, fecal water content and gastrointestinal transit time (GTT)) was evaluated. In the Lop + CPS group, GTT was significantly longer, and fecal water content was reduced. In the Lop + SPS group—although the fecal water content and GTT were unaffected—the number of fecal pellets and the fecal wet weight improved. Thus, SPS was less likely to cause constipation exacerbation than CPS. Considering the high frequency of constipation in dialysis patients with hyperkalemia, preferentially administering SPS over CPS may prevent constipation exacerbation.

Prevalence of Hypokalemia and Primary Aldosteronism in 5100 Patients Referred to a Tertiary Hypertension Unit

Primary aldosteronism (PA) was considered a rare disorder almost always associated with hypokalemia. The widespread screening of patients with hypertension unveiled an increased prevalence of PA with normokalemic hypertension the prevailing phenotype. Many studies have reported the prevalence of hypokalemia in patients with PA; conversely, the prevalence of PA in patients with hypokalemia is unknown. In this retrospective observational study, we define the prevalence of hypokalemia in referred patients with hypertension and the prevalence of PA in patients with hypokalemia and hypertension. Hypokalemia was present in 15.8% of 5100 patients with hypertension, whereas 76.9% were normokalemic, and 7.3% hyperkalemic. The prevalence of PA in patients with hypokalemia was 28.1% and increased with decreasing potassium concentrations up to 88.5% of patients with spontaneous hypokalemia and potassium concentrations <2.5 mmol/L. A multivariate regression analysis demonstrated the association of hypokalemia with the occurrence of cardiovascular events independent of PA diagnosis. An association of PA with the occurrence of cardiovascular events and target organ damage independent of hypokalemia was also demonstrated. In conclusion, our results confirm that PA is a frequent cause of secondary hypertension in patients with hypokalemia, and the presence of hypertension and spontaneous hypokalemia are strong indications for PA diagnosis. Finally, we show that PA and hypokalemia are associated with an increased risk of cardiovascular events.

Should we eat more potassium to better control blood pressure in hypertension?

Changes in lifestyle and nutrition are recommended as the first-step approach to the management of hypertension by all national and international guidelines. Today, when considering nutritional factors in hypertension, almost all the attention is focused on the reduction of salt intake to improve blood pressure (BP) control. Changes in potassium intake are only briefly evoked in guidelines. Few physicians actually think about proposing to eat more foods that are high in potassium (fruits, vegetables, nuts) to better control BP. Yet, during the last 40 years, increasing evidence has accumulated demonstrating that increasing potassium intake, either with food products or with supplements, is associated with significant reductions of both systolic and diastolic BP. The hypotensive effect of potassium is particularly marked in patients with hypertension and in subjects with a very high sodium intake, suggesting that potassium counterbalances the effects of sodium. In addition, several meta-analyses have now confirmed that high potassium intake reduces the risk of stroke by ∼ 25%. Finally, increasing potassium in the diet may perhaps be beneficial for some renal patients, as post hoc analyses have suggested that a high potassium intake may retard the decline of renal function in patients with early chronic kidney disease (CKD) stages. However, high potassium intake may be risky and sometimes even dangerous in hypertensive patients with CKD stages 3-5, specifically diabetics. In this context, however, as the level of evidence remains low, more prospective clinical studies are needed. The goal of this review is to discuss the actual evidence that supports the recommendation to eat more potassium in order to better control BP in essential hypertension and to review the restrictions in CKD patients with hypertension.

Hyperkalemia in chronic kidney disease

Hyperkalemia is a frequent finding in patients with chronic kidney disease (CKD). This increase in serum potassium levels is associated with decreased renal ion excretion, as well as the use of medications to reduce the progression of CKD or to control associated diseases such as diabetes mellitus and heart failure. Hyperkalemia increases the risk of cardiac arrhythmia episodes and sudden death. Thus, the control of potassium elevation is essential for reducing the mortality rate in this population. Initially, the management of hyperkalemia includes orientation of low potassium diets and monitoring of patients' adherence to this procedure. It is also important to know the medications in use and the presence of comorbidities to guide dose reduction or even temporary withdrawal of any of the potassium retention-related drugs. And finally, the use of potassium binders is indicated in both acute episodes and chronic hyperkalemia.

The Economic Implications of Hyperkalemia in a Medicaid Managed Care Population

BACKGROUND

Hyperkalemia, defined as a serum potassium level >5 mEq/L that results from multiple mechanisms, is a serious medical condition that can lead to life-threatening arrhythmias and sudden cardiac death. The coexistence of cardiac and renal diseases (ie, cardiorenal syndrome) significantly increases the complexity of care, but its economic impact is not well-characterized in this understudied Medicaid managed care population with hyperkalemia.

OBJECTIVE

To calculate the economic impact of hyperkalemia on patients with cardiorenal syndrome in a Medicaid managed care population in the United States using real-world data.

METHODS

In this retrospective cohort study, we used a proprietary Medicaid managed care database from 1 southern state. The total study population included 3563 patients, including 973 patients with hyperkalemia and 2590 controls (without hyperkalemia), who were matched based on age, comorbidities, and Medicaid eligibility status and duration, during a 30-month period between 2013 and 2016. The inclusion criteria for the hyperkalemia cohort were age ≥18 years, Medicaid-only insurance status, coded cardiorenal diagnosis, and a claim for hyperkalemia during the study period. The cost was determined using paid claims data.

RESULTS

The mean healthcare costs (medical and pharmacy per member per year [PMPY] for patients with hyperkalemia was higher than that for the control cohort without hyperkalemia ($56,002 vs $23,653, respectively). These cost differences were driven by medical costs accrued in the hyperkalemia and in the control cohorts ($49,648 and $18,399 PMPY, respectively). Two of the largest drivers of the medical cost variance were inpatient costs ($33,116 vs $10,629 PMPY for the hyperkalemia and control cohorts, respectively) and dialysis costs ($2716 vs $810 PMPY, respectively). The medical loss ratios were 552% for the hyperkalemia cohort and 260% for the control cohort. Both cohorts had revenue deficits to the health plan, but the hyperkalemia cohort had double the medical loss ratio compared with the control cohort.

CONCLUSIONS

The findings from this Medicaid managed care population suggest that hyperkalemia increases healthcare utilization and costs, which were primarily driven by the costs associated with inpatient care and dialysis. Our findings demonstrate that the Medicaid beneficiaries who have cardiorenal comorbidities accrue high costs to the Medicaid health plan, and these costs are even higher if a hyperkalemia diagnosis is present. The very high medical loss ratio for the hyperkalemia cohort in our analysis indicates that enhanced monitoring and management of patients with hyperkalemia should be considered.