Hypokalemia, its contributing factors and renal outcomes in patients with chronic kidney disease

Real-World Evidence on Levetiracetam-Induced Hypokalemia: An Active Comparator Cohort Study

BACKGROUND

Levetiracetam is an anti-seizure medication (ASM) with an established safety profile. However, a potential safety signal of hypokalemia following levetiracetam use was published in the World Health Organization newsletter.

OBJECTIVE

To investigate the possible causal association between the use of levetiracetam and the development of hypokalemia.

METHOD

This was a new-user, active-comparator retrospective cohort study using Real-world Evidence Research Network data at the Saudi Food and Drug Authority from 2016 to 2022. Adults (≥ 18 years old) with an incident prescription for either levetiracetam or carbamazepine were followed for up to 6 months from the prescription date. Hypokalemia was ascertained by using diagnostic code (i.e., E87.6) or by serum potassium level below 3.5 mmol/L. A Cox proportional hazards model, adjusted with stabilized inverse probability of treatment weight, was fitted to compare the hazard of hypokalemia between levetiracetam and carbamazepine exposed patients.

RESULTS

A total of 8,982 patients entered the study cohort. The incidence rate of hypokalemia was 303 cases per 10,000 patient-years in the levetiracetam-exposed cohort compared to 57 cases per 10,000 patient-years among carbamazepine users. Compared to carbamazepine users, patients exposed to levetiracetam had an adjusted hazard ratio related to induced hypokalemia of 1.99 (95% confidence interval, 0.88-4.49). Results of sensitivity analyses were comparable to the main analysis.

CONCLUSION

The hazard ratio for hypokalemia with the use of levetiracetam versus carbamazepine was statistically comparable. However, the potential association between levetiracetam use and hypokalemia cannot be ruled out given the elevated hazard ratios from the main and sensitivity analyses. Further studies may provide a more precise assessment of this association.

Disorders of Potassium

Abnormalities in serum potassium are commonly encountered in patients presenting to the emergency department. A variety of acute and chronic causes can lead to life-threatening illness in both hyperkalemia and hypokalemia. Here we summarize the relevant causes, risks, and treatment options for these frequently encountered disorders.

Novel Approaches in Chronic Renal Failure without Renal Replacement Therapy: A Review

Chronic kidney disease (CKD) is characterized by renal parenchymal damage leading to a reduction in the glomerular filtration rate. The inflammatory response plays a pivotal role in the tissue damage contributing to renal failure. Current therapeutic options encompass dietary control, mineral salt regulation, and management of blood pressure, blood glucose, and fatty acid levels. However, they do not effectively halt the progression of renal damage. This review critically examines novel therapeutic avenues aimed at ameliorating inflammation, mitigating extracellular matrix accumulation, and fostering renal tissue regeneration in the context of CKD. Understanding the mechanisms sustaining a proinflammatory and profibrotic state may offer the potential for targeted pharmacological interventions. This, in turn, could pave the way for combination therapies capable of reversing renal damage in CKD. The non-replacement phase of CKD currently faces a dearth of efficacious therapeutic options. Future directions encompass exploring vaptans as diuretics to inhibit water absorption, investigating antifibrotic agents, antioxidants, and exploring regenerative treatment modalities, such as stem cell therapy and novel probiotics. Moreover, this review identifies pharmaceutical agents capable of mitigating renal parenchymal damage attributed to CKD, targeting molecular-level signaling pathways (TGF-β, Smad, and Nrf2) that predominate in the inflammatory processes of renal fibrogenic cells.

Personalised recommendations for hospitalised patients with Acute Kidney Injury using a Kidney Action Team (KAT-AKI): protocol and early data of a randomised controlled trial

INTRODUCTION

Although studies have examined the utility of clinical decision support tools in improving acute kidney injury (AKI) outcomes, no study has evaluated the effect of real-time, personalised AKI recommendations. This study aims to assess the impact of individualised AKI-specific recommendations delivered by trained clinicians and pharmacists immediately after AKI detection in hospitalised patients.

METHODS AND ANALYSIS

KAT-AKI is a multicentre randomised investigator-blinded trial being conducted across eight hospitals at two major US hospital systems planning to enrol 4000 patients over 3 years (between 1 November 2021 and 1 November 2024). A real-time electronic AKI alert system informs a dedicated team composed of a physician and pharmacist who independently review the chart in real time, screen for eligibility and provide combined recommendations across the following domains: diagnostics, volume, potassium, acid-base and medications. Recommendations are delivered to the primary team in the alert arm or logged for future analysis in the usual care arm. The planned primary outcome is a composite of AKI progression, dialysis and mortality within 14 days from randomisation. A key secondary outcome is the percentage of recommendations implemented by the primary team within 24 hours from randomisation. The study has enrolled 500 individuals over 8.5 months. Two-thirds were on a medical floor at the time of the alert and 17.8% were in an intensive care unit. Virtually all participants were recommended for at least one diagnostic intervention. More than half (51.6%) had recommendations to discontinue or dose-adjust a medication. The median time from AKI alert to randomisation was 28 (IQR 15.8-51.5) min.

ETHICS AND DISSEMINATION

The study was approved by the ethics committee of each study site (Yale University and Johns Hopkins institutional review board (IRB) and a central IRB (BRANY, Biomedical Research Alliance of New York). We are committed to open dissemination of the data through clinicaltrials.gov and sharing of data on an open repository as well as publication in a peer-reviewed journal on completion.

TRIAL REGISTRATION NUMBER

NCT04040296.

Association between Hypokalemia and Albuminuria in a Japanese General Population

INTRODUCTION

Hypokalemia is associated with an increased risk of chronic kidney disease (CKD) and is a risk factor for mortality. Albuminuria is an early manifestation of CKD. We investigated the association between hypokalemia and the prevalence of albuminuria in a Japanese general population.

METHODS

We analyzed the data of 18,289 subjects who underwent annual health checkups in 2018. We categorized them into four groups according to their concentration of serum potassium (sK) and performed a multivariate logistic regression analysis to determine the association between hypokalemia and the prevalence of albuminuria in this population. Hypokalemia was defined as having an sK = 3.1-3.5 mEq/L. After dividing the subjects into those with/without renal dysfunction, those with/without hypertension, and those with/without hyperglycemia, we examined the association between hypokalemia and albuminuria in each group.

RESULTS

Compared to the subjects with sK = 4.1-4.5 mEq/L, the subjects with hypokalemia had a significantly high prevalence of albuminuria: multivariable-adjusted odds ratio (OR) = 2.70 (95% confidence interval [CI] 1.84-3.96). The subgroup analyses showed the following multivariable-adjusted ORs (95% CIs) of the subjects: without renal dysfunction, 3.08 (2.00-4.73); with renal dysfunction, 2.05 (0.89-4.69); without hypertension, 2.89 (1.36-6.16); with hypertension, 2.60 (1.67-4.04); without hyperglycemia, 2.49 (1.62-3.84); and with hyperglycemia, 3.55 (1.43-8.79).

CONCLUSIONS

Hypokalemia was significantly associated with the high prevalence of albuminuria in general population. Regardless of the presence/absence of renal dysfunction, hypertension, or hyperglycemia, hypokalemia was positively associated with the prevalence of albuminuria, and the associations were significant except for the subjects with renal dysfunction.

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.

Immediate and Delayed Response of Simulated Human Atrial Myocytes to Clinically-Relevant Hypokalemia

Although plasma electrolyte levels are quickly and precisely regulated in the mammalian cardiovascular system, even small transient changes in K⁺, Na⁺, Ca²⁺, and/or Mg²⁺ can significantly alter physiological responses in the heart, blood vessels, and intrinsic (intracardiac) autonomic nervous system. We have used mathematical models of the human atrial action potential (AP) to explore the electrophysiological mechanisms that underlie changes in resting potential (V_r) and the AP following decreases in plasma K⁺, [K⁺]_o, that were selected to mimic clinical hypokalemia. Such changes may be associated with arrhythmias and are commonly encountered in patients (i) in therapy for hypertension and heart failure; (ii) undergoing renal dialysis; (iii) with any disease with acid-base imbalance; or (iv) post-operatively. Our study emphasizes clinically-relevant hypokalemic conditions, corresponding to [K⁺]_o reductions of approximately 1.5 mM from the normal value of 4 to 4.5 mM. We show how the resulting electrophysiological responses in human atrial myocytes progress within two distinct time frames: (i) Immediately after [K⁺]_o is reduced, the K⁺-sensing mechanism of the background inward rectifier current (I_K1) responds. Specifically, its highly non-linear current-voltage relationship changes significantly as judged by the voltage dependence of its region of outward current. This rapidly alters, and sometimes even depolarizes, V_r and can also markedly prolong the final repolarization phase of the AP, thus modulating excitability and refractoriness. (ii) A second much slower electrophysiological response (developing 5-10 minutes after [K⁺]_o is reduced) results from alterations in the intracellular electrolyte balance. A progressive shift in intracellular [Na⁺]_i causes a change in the outward electrogenic current generated by the Na⁺/K⁺ pump, thereby modifying V_r and AP repolarization and changing the human atrial electrophysiological substrate. In this study, these two effects were investigated quantitatively, using seven published models of the human atrial AP. This highlighted the important role of I_K1 rectification when analyzing both the mechanisms by which [K⁺]_o regulates V_r and how the AP waveform may contribute to "trigger" mechanisms within the proarrhythmic substrate. Our simulations complement and extend previous studies aimed at understanding key factors by which decreases in [K⁺]_o can produce effects that are known to promote atrial arrhythmias in human hearts.

Potassium Metabolism and Management in Patients with CKD

Potassium (K), the main cation inside cells, plays roles in maintaining cellular osmolarity and acid-base equilibrium, as well as nerve stimulation transmission, and regulation of cardiac and muscle functions. It has also recently been shown that K has an antihypertensive effect by promoting sodium excretion, while it is also attracting attention as an important component that can suppress hypertension associated with excessive sodium intake. Since most ingested K is excreted through the kidneys, decreased renal function is a major factor in increased serum levels, and target values for its intake according to the degree of renal dysfunction have been established. In older individuals with impaired renal function, not only hyperkalemia but also hypokalemia due to anorexia, K loss by dialysis, and effects of various drugs are likely to develop. Thus, it is necessary to pay attention to K management tailored to individual conditions. Since abnormalities in K metabolism can also cause lethal arrhythmia or sudden cardiac death, it is extremely important to monitor patients with a high risk of hyper- or hypokalemia and attempt to provide early and appropriate intervention.

Serum potassium and outcomes in heart failure with preserved ejection fraction: a post-hoc analysis of the PARAGON-HF trial

AIMS

The relationship between serum potassium concentration and outcomes in patients with heart failure and preserved ejection fraction (HFpEF) is not well-established. The aim of this study was to explore the association between serum potassium and clinical outcomes in the PARAGON-HF trial in which 4822 patients with HFpEF were randomised to treatment with sacubitril/valsartan or valsartan.

METHODS AND RESULTS

The relationship between serum potassium concentrations and the primary study composite outcome of total (first and recurrent) heart failure hospitalisations and cardiovascular death was analysed. Hypo-, normo-, and hyperkalaemia were defined as serum potassium <4 mmol/L, 4-5 mmol/L and >5 mmol/L, respectively. Both screening and time-updated potassium (categorical and continuous spline-transformed) were studied. Patient mean age was 73 years and 52% were women. Patients with higher baseline potassium more often had an ischaemic aetiology and diabetes and mineralocorticoid receptor antagonist treatment. Compared with normokalaemia, both time-updated (but not screening) hypo- and hyperkalaemia were associated with a higher risk of the primary outcome [adjusted hazard ratio (HR) for hypokalaemia 1.55, 95% confidence interval (CI) 1.30-1.85; P < 0.001, and for hyperkalaemia HR 1.21, 95% CI 1.02-1.44; P = 0.025]. Hypokalaemia had a stronger association with a higher risk of all-cause, cardiovascular and non-cardiovascular death than hyperkalaemia. The association of hypokalaemia with increased risk of all-cause and cardiovascular death was most marked in participants with impaired kidney function (interaction P < 0.05). Serum potassium did not significantly differ between sacubitril/valsartan and valsartan throughout the follow-up.

CONCLUSIONS

Both hypo- and hyperkalaemia were associated with heart failure hospitalisation but only hypokalaemia was associated with mortality, especially in the context of renal impairment. Hypokalaemia was as strongly associated with death from non-cardiovascular causes as with cardiovascular death. Collectively, these findings suggest that potassium disturbances are a more of a marker of HFpEF severity rather than a direct cause of death.

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.

Acute Kidney Injury Impacts on Hypokalemia Associated with Yokukansan Preparation: A Retrospective Observational Study

The time course of acute kidney injury and hypokalemia remains unelucidated. We investigated whether altered renal function impacts hypokalemia and clinical predictors for acute kidney injury in patients who used Yokukansan preparation. We performed a secondary analysis of retrospective observational cohort data from adult patients who started Yokukansan preparation. The study was conducted from June 2015 to May 2019 at Tokyo Women's Medical University, Medical Center East. The effect of acute kidney injury (>1.5-fold increase from baseline serum creatinine level) or renal function recovery on hypokalemia (serum potassium level <3.0 mEq/L) was investigated. The clinical predictors for acute kidney injury were determined using a multivariate Cox proportional hazard analysis. Out of 258 patients, 12 patients had both outcomes, and all but one patient experienced in the order of acute kidney injury and hypokalemia. Excluding one patient, hypokalemia occurred in 11/34 (32%) patients after acute kidney injury and 27/223 (12%) patients without acute kidney injury (p = 0.005). Hypokalemia occurred in 9/25 (36%) of acute kidney injury with recovery, 2/9 (22%) of acute kidney injury without recovery, and 27/223 (12%) of no acute kidney injury (p = 0.014). Patients with acute kidney injury showed a late onset of hypokalemia compared with those without acute kidney injury (p = 0.001). In 258 patients, multivariate Cox proportional hazard analysis showed that high systolic blood pressure and mean arterial pressure increased the risk of acute kidney injury. Clinicians should remember that hypokalemia developed after acute kidney injury while Yokukansan preparation treatment.

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.

Geriatric Patients Are at a High Risk of Hypokalemia Associated with Yokukansan Preparation: A Retrospective Cohort Study

Although hypokalemia is an adverse effect of Yokukansan preparation, especially in geriatric patients, its association with age is unclear. We investigated whether age is a risk factor for hypokalemia. This single-center retrospective cohort study, conducted at Tokyo Women's Medical University, Medical Center East between June 2015 and May 2019, included patients who received the Yokukansan preparation. The primary outcome was hypokalemia (serum potassium level: < 3.0 mEq/L). A multivariate Cox proportional hazard model was used to determine risk factors, hazard ratio (HR) and 95% confidence interval (95% CI). The cut-off age was also examined. Of 665 patients (median age: 78 years; interquartile range: 68-84 years), 55 (8.3%) developed hypokalemia associated with Yokukansan preparation. Risk factors for hypokalemia were age (HR: 1.013, 95% CI: 1.006-1.021, p < 0.001), dementia (HR: 0.500, 95% CI: 0.357-0.682, p < 0.001), serum albumin level (HR: 0.754, 95% CI: 0.669-0.850, p < 0.001), and daily Yokukansan preparation dose ≥ 7.5 g (HR: 1.446, 95% CI: 1.144-1.850, p = 0.002). The cut-off ages were >75 and >80 years but not 65 years and >70 years. Clinicians should assess risk factors and monitor serum potassium levels to avoid hypokalemia associated with the Yokukansan preparation.

Pharmacodynamic effects of the K+ binder patiromer in a novel chronic hyperkalemia model in spontaneously hypertensive rats

Currently described hyperkalemia (HK) animal models are typically acute and cause significant distress and mortality to the animals, warranting new approaches for studying chronic HK in a more appropriate clinical setting. Using the spontaneously hypertensive rat (SHR) model as a more relevant disease template, as well as surgical (unilateral nephrectomy), dietary (3% potassium [K+ ] supplementation), and pharmacological (amiloride) interventions, we were able to stably induce HK on a chronic basis for up to 12 weeks to serum K+ elevations between 8 and 9 mmol/L, with minimal clinical stress to the animals. Short-term proof-of-concept and long-term chronic studies in hyperkalemic SHRs showed concomitant increases in serum aldosterone, consistent with the previously reported relationship between serum K+ and aldosterone. Treatment with the K+ binder patiromer demonstrated that the disease model was responsive to pharmacological intervention, with significant abrogation in serum K+ , as well as serum aldosterone to levels near baseline, and this was consistent in both short-term and long-term 12-week chronic studies. Our results demonstrate the feasibility of establishing a chronic HK disease state, and this novel HK animal model may be suitable for further evaluating the effects of long-term, K+ -lowering therapies on effects such as renal fibrosis and end-organ damage.

Klotho-beta and fibroblast growth factor 19 expression correlates with early recurrence of resectable hepatocellular carcinoma

BACKGROUND AND AIMS

Fibroblast growth factor 19 (FGF19) and fibroblast growth factor receptor 4 (FGFR4) signalling play critical roles in hepatocarcinogenesis. This study explored the potential of FGF19- and FGFR4-related biomarkers in predicting early tumour recurrence (ETR) and survival in patients with resectable hepatocellular carcinoma (HCC).

METHODS

We examined the mRNA expressions of FGF19, FGFR4, klotho-beta (KLB), cyclin D1 (CCND1) and FGF4 in 151 surgically resected, primary unifocal HCCs through quantitative real-time polymerase chain reaction. Generalized additive models were fitted to detect nonlinear effects of continuous covariates and define thresholds of biomarker expressions. Univariate and multivariate analyses were performed to evaluate prognostic values of these biomarkers for tumour recurrence and patient survival.

RESULTS

Overexpression of FGF19, FGFR4, KLB, CCND1 and FGF4 mRNA was detected in 40%, 32%, 26%, 15% and 35% of 151 tumours respectively. ETR was the strongest prognostic factor predicting worse overall survival (hazard ratio [HR], 5.678; 95% confidence interval, 3.7-8.713; P < 0.001). Furthermore, we revealed that mRNA expression levels of KLB (HR, 3.857; P = 0.021) and FGF19 (HR, 3.248; P = 0.017) were significantly associated with the occurrence of ETR.

CONCLUSIONS

Frequent overexpression of FGF19/FGFR4-related biomarkers was detected in resectable HCC. Expression levels of KLB and FGF19 may determine patient survival outcomes through their effects on ETR.

Association of hyperkalemia with clinical outcomes in advanced chronic kidney disease

INTRODUCTION

Patients with advanced chronic kidney disease (CKD) are at greatest risk of hyperkalemia (HK). The relationship between HK and negative outcomes (mortality or progression of renal insufficiency) in non-dialysis dependent CKD patients is controversial.

AIMS

To determine the incidence, prevalence, and factors related with HK in a cohort of CKD patients, and its relationship with mortality, hospitalization rate, CKD progression, and dialysis initiation.

MATERIAL AND METHODS

A retrospective, observational study in an incident cohort of adult patients with stage 4 or 5 CKD not on dialysis. Inclusion criteria were: having at least three consecutive estimated glomerular filtration rate (eGFR) measurements in a follow-up period >3 months. Decline in renal function was estimated as the slope of the individual linear regression line of eGFR over follow-up time. HK was defined as serum K levels ≥5.5 meq/l. Associations of HK with outcomes were adjusted for major confounding variables in the multivariate analysis.

RESULTS

The study group consisted of 1079 patients (574 males, mean age: 65±14 years) with mean baseline eGFR 14.8±4.5 ml/min/1,73 m². Mean follow-up time was 15 months with a median of 7 serum sample determinations per patient. HK was observed at baseline in 26% of patients; in at least one serum sample during the individual follow-up period in 68%; or chronically (>50% of samples) in 33% of patients. By multivariate logistic regression, the best determinants of chronic HK were: male sex (OR = 1.529; 95% CI [1.154-2.025], p = .003), serum bicarbonate (OR = 0.863 [0.829-0.900], p <.0001), diuretic treatment (OR = 0.743 [0.556-0.992], p = .044), and angiotensin converting enzyme inhibitor and/or angiotensin receptor blockers (OR = 4.412 [2.915-6.678], p <.0001). Patients whose serum K levels were in the upper quartile showed a significantly faster CKD progression (-4.05±5.22 vs. -2.69±5.61 ml/min/1.73 m²/year, p <.0001), and more frequent dialysis initiation (63% vs. 57%, p = .115), though lower mortality (9% vs. 17%, p = .003) and hospitalization rates (2.68±5.94 vs. 3.16±6.77 days per year, p = .301) than the other study patients. However, in the multivariate analysis, average serum K levels were not independently associated with the clinical outcomes investigated.

CONCLUSION

HK is a common biochemical finding in non-dialysis dependent CKD patients, mainly associated with prescribed medication. However, HK was not independently associated with major negative clinical outcomes.

Competing-Risk Analysis of Death and End Stage Kidney Disease by Hyperkalaemia Status in Non-Dialysis Chronic Kidney Disease Patients Receiving Stable Nephrology Care

Hyperkalaemia burden in non-dialysis chronic kidney disease (CKD) under nephrology care is undefined. We prospectively followed 2443 patients with two visits (referral and control with 12-month interval) in 46 nephrology clinics. Patients were stratified in four categories of hyperkalaemia (serum potassium, sK ≥ 5.0 mEq/L) by sK at visit 1 and 2: Absent (no-no), Resolving (yes-no), New Onset (no-yes), Persistent (yes-yes). We assessed competing risks of end stage kidney disease (ESKD) and death after visit 2. Age was 65 ± 15 years, eGFR 35 ± 17 mL/min/1.73 m², proteinuria 0.40 (0.14–1.21) g/24 h. In the two visits sK was 4.8 ± 0.6 and levels ≥6 mEq/L were observed in 4%. Hyperkalaemia was absent in 46%, resolving 17%, new onset 15% and persistent 22%. Renin-angiotensin-system inhibitors (RASI) were prescribed in 79% patients. During 3.6-year follow-up, 567 patients reached ESKD and 349 died. Multivariable competing risk analysis (sub-hazard ratio-sHR, 95% Confidence Interval-CI) evidenced that new onset (sHR 1.34, 95% CI 1.05–1.72) and persistent (sHR 1.27, 95% CI 1.02–1.58) hyperkalaemia predicted higher ESKD risk versus absent, independently from main determinants of outcome including eGFR change. Conversely, no effect on mortality was observed. Results were confirmed by testing sK as continuous variable. Therefore, in CKD under nephrology care, mild-to-moderate hyperkalaemia status is common (37%) and predicts per se higher ESKD risk but not mortality.

Association of Low Serum Potassium Levels and Risk for All-Cause Mortality in Patients With Chronic Kidney Disease: A Systematic Review and Meta-Analysis

Dyskalemia is a risk factor for mortality in patients without CKD, but the effect of hypokalemia in patients with CKD remains uncertain. PubMed, Embase, Cochrane, and Ovid databases were searched from inception to December 31, 2017 for studies that reported all-cause and cardiovascular mortality or events in patients with CKD (any stage). Pooled hazard ratios (HR) and corresponding 95% CI were calculated. A total of 11 clinical studies enrolling 57 234 subjects with CKD were included in the meta-analysis. Compared with control serum potassium (SK) levels, low SK (SK <4.0 mEq/L) was associated with higher risk of all-cause mortality in a random-effects model (HR = 1.57; 95% CI: 1.25-1.97). Moderate low SK (<3.5 mEq/L) increased risk of all-cause mortality by 105%. Mild low SK (3.5~4.0 mEq/L) also increased all-cause mortality risk (HR = 1.18, 95% CI: 1.11-1.26). Low SK was also associated with increased cardiovascular mortality (HR = 1.40, 95% CI: 1.22-1.62) and ESRD risk (HR = 1.35, 95% CI: 1.18-1.54). SK <4.0 mEq/L was associated with higher mortality risk in CKD patients, especially in those with SK <3.5 mEq/L. Additional prospective studies will be necessary to explore this relationship, as well as whether correcting hypokalemia decreases mortality in patients with CKD.

Acid-Base and Electrolyte Disorders in Patients with and without Chronic Kidney Disease: An Update

Kidneys play a pivotal role in the maintenance and regulation of acid-base and electrolyte homeostasis, which is the prerequisite for numerous metabolic processes and organ functions in the human body. Chronic kidney diseases compromise the regulatory functions, resulting in alterations in electrolyte and acid-base balance that can be life-threatening. In this review, we discuss the renal regulations of electrolyte and acid-base balance and several common disorders including metabolic acidosis, alkalosis, dysnatremia, dyskalemia, and dysmagnesemia. Common disorders in chronic kidney disease are also discussed. The most recent and relevant advances on pathophysiology, clinical characteristics, diagnosis, and management of these conditions have been incorporated.

Association of plasma potassium with mortality and end-stage kidney disease in patients with chronic kidney disease under nephrologist care - The NephroTest study

BACKGROUND

Low and high blood potassium levels are common and were both associated with poor outcomes in patients with chronic kidney disease (CKD). Whether such relationships may be altered in CKD patients receiving optimized nephrologist care is unknown.

METHODS

NephroTest is a hospital-based prospective cohort study that enrolled 2078 nondialysis patients (mean age: 59 ± 15 years, 66% men) in CKD stages 1 to 5 who underwent repeated extensive renal tests including plasma potassium (PK) and glomerular filtration rate (GFR) measured (mGFR) by 51Cr-EDTA renal clearance. Test reports included a reminder of recommended targets for each abnormal value to guide treatment adjustment. Main outcomes were cardiovascular (CV) and all-cause mortality before end-stage kidney disease (ESKD), and ESKD.

RESULTS

At baseline, median mGFR was 38.4 mL/min/1.73m2; prevalence of low PK (<4 mmol/L) was 26.5%, and of high PK (>5 mmol/L) 6.4%; 74.4% of patients used angiotensin converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB). After excluding 137 patients with baseline GFR < 10 mL/min/1.73m2 or lost to follow-up, 459 ESKD events and 236 deaths before ESKD (83 CV deaths) occurred during a median follow-up of 5 years. Compared to patients with PK within [4, 5] mmol/L at baseline, those with low PK had hazard ratios (HRs) [95% CI] for all-cause and CV mortality before ESKD, and for ESKD of 0.82 [0.58-1.16], 1.01 [0.52-1.95], and 1.14 [0.89-1.47], respectively, with corresponding figures for those with high PK of 0.79 [0.48-1.32], 1.5 [0.69-3.3], and 0.92 [0.70-1.21]. Considering time-varying PK did not materially change these findings, except for the HR of ESKD associated with high PK, 1.39 [1.09-1.78]. Among 1190 patients with at least two visits, PK had normalized at the second visit in 39.9 and 54.1% respectively of those with baseline low and high PK. Among those with low PK that normalized, ARB or ACEi use increased between the visits (68.3% vs 81.8%, P < .0001), and among those with high PK that normalized, potassium-binding resin and bicarbonate use increased (13.0% vs 37.0%, P < .001, and 4.4% vs 17.4%, P = 0.01, respectively) without decreased ACEi or ARB use.

CONCLUSION

In these patients under nephrology care, neither low nor high PK was associated with excess mortality.

Association of Serum Potassium with All-Cause Mortality in Patients with and without Heart Failure, Chronic Kidney Disease, and/or Diabetes

BACKGROUND

The relationship between serum potassium, mortality, and conditions commonly associated with dyskalemias, such as heart failure (HF), chronic kidney disease (CKD), and/or diabetes mellitus (DM) is largely unknown.

METHODS

We reviewed electronic medical record data from a geographically diverse population (n = 911,698) receiving medical care, determined the distribution of serum potassium, and the relationship between an index potassium value and mortality over an 18-month period in those with and without HF, CKD, and/or DM. We examined the association between all-cause mortality and potassium using a cubic spline regression analysis in the total population, a control group, and in HF, CKD, DM, and a combined cohort.

RESULTS

27.6% had a potassium <4.0 mEq/L, and 5.7% had a value ≥5.0 mEq/L. A U-shaped association was noted between serum potassium and mortality in all groups, with lowest all-cause mortality in controls with potassium values between 4.0 and <5.0 mEq/L. All-cause mortality rates per index potassium between 2.5 and 8.0 mEq/L were consistently greater with HF 22%, CKD 16.6%, and DM 6.6% vs. controls 1.2%, and highest in the combined cohort 29.7%. Higher mortality rates were noted in those aged ≥65 vs. 50-64 years. In an adjusted model, all-cause mortality was significantly elevated for every 0.1 mEq/L change in potassium <4.0 mEq/L and ≥5.0 mEq/L. Diuretics and renin-angiotensin-aldosterone system inhibitors were related to hypokalemia and hyperkalemia respectively.

CONCLUSION

Mortality risk progressively increased with dyskalemia and was differentially greater in those with HF, CKD, or DM.

Race, Serum Potassium, and Associations With ESRD and Mortality

BACKGROUND

Recent studies suggest that potassium levels may differ by race. The basis for these differences and whether associations between potassium levels and adverse outcomes differ by race are unknown.

STUDY DESIGN

Observational study.

SETTING & PARTICIPANTS

Associations between race and potassium level and the interaction of race and potassium level with outcomes were investigated in the Racial and Cardiovascular Risk Anomalies in Chronic Kidney Disease (RCAV) Study, a cohort of US veterans (N=2,662,462). Associations between African ancestry and potassium level were investigated in African Americans in the Atherosclerosis Risk in Communities (ARIC) Study (N=3,450).

PREDICTORS

Race (African American vs non-African American and percent African ancestry) for cross-sectional analysis; serum potassium level for longitudinal analysis.

OUTCOMES

Potassium level for cross-sectional analysis; mortality and end-stage renal disease for longitudinal analysis.

RESULTS

The RCAV cohort was 18% African American (N=470,985). Potassium levels on average were 0.162mmol/L lower in African Americans compared with non-African Americans, with differences persisting after adjustment for demographics, comorbid conditions, and potassium-altering medication use. In the ARIC Study, higher African ancestry was related to lower potassium levels (-0.027mmol/L per each 10% African ancestry). In both race groups, higher and lower potassium levels were associated with mortality. Compared to potassium level of 4.2mmol/L, mortality risk associated with lower potassium levels was lower in African Americans versus non-African Americans, whereas mortality risk associated with higher levels was slightly greater. Risk relationships between potassium and end-stage renal disease were weaker, with no difference by race.

LIMITATIONS

No data for potassium intake.

CONCLUSIONS

African Americans had slightly lower serum potassium levels than non-African Americans. Consistent associations between potassium levels and percent African ancestry may suggest a genetic component to these differences. Higher and lower serum potassium levels were associated with mortality in both racial groups.

Plasma potassium, diuretic use and risk of developing chronic kidney disease in a predominantly White population

Objective

Both hypokalemia and hyperkalemia are associated with disease progression in patients with chronic kidney disease (CKD). It is unclear whether similar associations are present in the general population. Our aim was to examine the association of plasma potassium with risk of developing CKD and the role of diuretics in this association in a population-based cohort.

Research design and methods

We studied 5,130 subjects free of CKD at baseline of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study, a prospective, population-based cohort of Dutch men and women aged 28–75 years. Hypokalemia was defined as plasma potassium <3.5 mmol/L, and hyperkalemia as plasma potassium ≥5.0 mmol/L. Risk of CKD was defined as de novo development of eGFR <60 ml/min/1.73m² and/or albuminuria >30 mg/24h.

Results

Mean baseline plasma potassium was 4.4±0.3 mmol/L. The prevalences of hypokalemia and hyperkalemia were 0.5% and 3.8%, respectively; 3.0% of the subjects used diuretics. During a median follow-up of 10.3 years (interquartile range: 6.3–11.4 years), 753 subjects developed CKD. The potassium-CKD association was modified by diuretic use (P_interaction = 0.02). Both hypokalemia without (HR, 7.74, 95% CI, 3.43–17.48) or with diuretic use (HR, 4.32, 95% CI, 1.77–10.51) were associated with an increased CKD risk as compared to plasma potassium 4.0–4.4 mmol/L without diuretic use. Plasma potassium concentrations ≥3.5 mmol/L were associated with an increased CKD risk among subjects using diuretics (P_trend = 0.01) but not among subjects not using diuretics (P_trend = 0.74).

Conclusion

In this population-based cohort, hypokalemia was associated with an increased CKD risk, regardless of diuretic use. In the absence of hypokalemia, plasma potassium was not associated with an increased CKD risk, except among subjects using diuretics.

Glycosuria and Renal Outcomes in Patients with Nondiabetic Advanced Chronic Kidney Disease

Sodium glucose cotransporter 2 inhibitors have shown a potential for renoprotection beyond blood glucose lowering. Glycosuria in nondiabetic patients with chronic kidney disease (CKD) is sometimes noted. Whether glycosuria in CKD implies a channelopathy or proximal tubulopathy is not known. The consequence of glycosuria in CKD is also not studied. We performed a cross-sectional study for the association between glycosuria and urine electrolyte excretion in 208 nondiabetic patients. Fractional excretion (FE) of glucose >4% was 3.4%, 6.3% and 62.5% in CKD stage 3, 4 and 5, respectively. These patients with glycosuria had higher FE sodium, FE potassium, FE uric acid, UPCR, and urine NGAL-creatinine ratio. We conducted a longitudinal study for the consequence of glycosuria, defined by dipstick, in 769 nondiabetic patients with stage 4-5 CKD. Glycosuria was associated with a decreased risk for end-stage renal disease (adjusted hazard ratio: 0.77; CI = 0.62-0.97; p = 0.024) and for rapid renal function decline (adjusted odds ratio: 0.63; CI = 0.43-0.95; p = 0.032); but glycosuria was not associated with all-cause mortality or cardiovascular events. The results were consistent in the propensity-score matched cohort. Glycosuria is associated with increased fractional excretion of electrolytes and is related to favorable renal outcomes in nondiabetic patients with stage 5 CKD.

Non-obvious correlations to disease management unraveled by Bayesian artificial intelligence analyses of CMS data

OBJECTIVE

Given the availability of extensive digitized healthcare data from medical records, claims and prescription information, it is now possible to use hypothesis-free, data-driven approaches to mine medical databases for novel insight. The goal of this analysis was to demonstrate the use of artificial intelligence based methods such as Bayesian networks to open up opportunities for creation of new knowledge in management of chronic conditions.

MATERIALS AND METHODS

Hospital level Medicare claims data containing discharge numbers for most common diagnoses were analyzed in a hypothesis-free manner using Bayesian networks learning methodology.

RESULTS

While many interactions identified between discharge rates of diagnoses using this data set are supported by current medical knowledge, a novel interaction linking asthma and renal failure was discovered. This interaction is non-obvious and had not been looked at by the research and clinical communities in epidemiological or clinical data. A plausible pharmacological explanation of this link is proposed together with a verification of the risk significance by conventional statistical analysis.

CONCLUSION

Potential clinical and molecular pathways defining the relationship between commonly used asthma medications and renal disease are discussed. The study underscores the need for further epidemiological research to validate this novel hypothesis. Validation will lead to advancement in clinical treatment of asthma & bronchitis, thereby, improving patient outcomes and leading to long term cost savings. In summary, this study demonstrates that application of advanced artificial intelligence methods in healthcare has the potential to enhance the quality of care by discovering non-obvious, clinically relevant relationships and enabling timely care intervention.

Perioperative Concerns for Profound Metabolic Alkalosis During Kidney Transplantation: A Case Report

Introduction

Profound metabolic alkalosis is an uncommon consideration for the anesthetic management of kidney transplantation. Serum total carbon dioxide content and complex electrolyte abnormalities might be important diagnostic clues for the presence of metabolic alkalosis in the absence of arterial blood gas analysis.

Case Presentation

A 34-year-old female visited Gachon University Gil Medical Center, Incheon, South Korea during year 2015. She experienced aggravated renal function due to chronic hypokalemia and severe hypochloremic metabolic alkalosis, induced by laxative abuse, and underwent ABO incompatible kidney transplantation. Serum total carbon dioxide content remained high (about 60 mEq/L) over eight months of monthly follow-up prior to kidney transplantation.

Conclusions

The authors described their anesthetic experience of profound metabolic alkalosis with complex electrolyte abnormalities and provided a review of relevant literature.

Serum Potassium, Mortality, and Kidney Outcomes in the Atherosclerosis Risk in Communities Study

OBJECTIVES

To investigate the association between serum potassium, mortality, and kidney outcomes in the general population and whether potassium-altering medications modify these associations.

PATIENTS AND METHODS

We studied 15,539 adults in the Atherosclerosis Risk in Communities Study. Cox proportional hazard regression was used to investigate the association of serum potassium at baseline (1987-1989), evaluated categorically (hypokalemia, <3.5 mmol/L; normokalemia, ≥3.5 and <5.5 mmol/L; hyperkalemia, ≥5.5 mmol/L) and continuously using linear spline terms (knots at 3.5 and 5.5 mmol/L), with mortality, sudden cardiac death, incident chronic kidney disease, and end-stage renal disease. The end date of follow-up for all outcomes was December 31, 2012. We also evaluated whether classes of potassium-altering medications modified the association between serum potassium and adverse outcomes.

RESULTS

Overall, 413 (2.7%) of the participants had hypokalemia and 321 (2.1%) had hyperkalemia. In a fully adjusted model, hyperkalemia was significantly associated with mortality (hazard ratio, 1.24; 95% CI, 1.04-1.49) but not sudden cardiac death, chronic kidney disease, or end-stage renal disease. Hypokalemia as a categorical variable was not associated with any outcome; however, associations of hypokalemia with all-cause mortality and kidney outcomes were observed among those who were not taking potassium-wasting diuretics (all P for interaction, <.001).

CONCLUSIONS

Higher values of serum potassium were associated with a higher risk of mortality in the general population. Lower levels of potassium were associated with adverse kidney outcomes and mortality among participants not taking potassium-wasting diuretics.

Mechanism of Action and Pharmacology of Patiromer, a Nonabsorbed Cross-Linked Polymer That Lowers Serum Potassium Concentration in Patients With Hyperkalemia

Hyperkalemia is a potentially life-threatening condition, and patients who have chronic kidney disease, who are diabetic, or who are taking renin-angiotensin-aldosterone system inhibitors are at increased risk. Therapeutic options for hyperkalemia tend to have limited effectiveness and can be associated with serious side effects. Colonic potassium secretion can increase to compensate when urinary potassium excretion decreases in patients with renal impairment, but this adaptation is insufficient and hyperkalemia still results. Patiromer is a novel, spherical, nonabsorbed polymer designed to bind and remove potassium, primarily in the colon, thereby decreasing serum potassium in patients with hyperkalemia. Patiromer has been found to decrease serum potassium in patients with hyperkalemia having chronic kidney disease who were on renin-angiotensin-aldosterone system inhibitors. Results of nonclinical studies and an early phase clinical study are reported here. Two studies with radiolabeled drug, one in rats and the other in dogs, confirmed that patiromer was not absorbed into the systemic circulation. Results of an in vitro study showed that patiromer was able to bind 8.5 to 8.8 mEq of potassium per gram of polymer at a pH similar to that found in the colon and had a much higher potassium-binding capacity compared with other resins, including polystyrene sulfonate. In a study in hyperkalemic rats, a decrease in serum potassium was observed via an increase in fecal potassium excretion. In a clinical study in healthy adult volunteers, a significant increase in fecal potassium excretion and a significant decrease in urinary potassium excretion were observed. Overall, patiromer is a high-capacity potassium binder, and the chemical and physical characteristics of patiromer may lead to good clinical efficacy, tolerability, and patient acceptance.

Association between Serum Potassium and Outcomes in Patients with Reduced Kidney Function

BACKGROUND AND OBJECTIVES

Patients with CKD are more likely than others to have abnormalities in serum potassium (K(+)). Aside from severe hyperkalemia, the clinical significance of K(+) abnormalities is not known. We sought to examine the association of serum K(+) with mortality and hospitalization rates within narrow eGFR strata to understand how the burden of hyperkalemia varies by CKD severity. Associations were examined between serum K(+) and discontinuation of medications that block the renin-angiotensin-aldosterone system (RAAS), which are known to increase serum K(+).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A cohort of patients with CKD (eGFR<60 ml/min per 1.73 m(2)) with serum K(+) data were studied (n=55,266) between January 1, 2009, and June 30, 2013 (study end). Serum K(+), eGFR, and covariates were considered on a time-updated basis. Mortality, major adverse cardiovascular events (MACE), hospitalization, and discontinuation of RAAS blockers were considered per time at risk.

RESULTS

During the study, serum K(+) levels of 5.5-5.9 and ≥6.0 mEq/L were most prevalent at lower eGFR: they were present, respectively, in 1.7% and 0.2% of patient-time for eGFR of 50-59 ml/min per 1.73 m(2) versus 7.6% and 1.8% of patient-time for eGFR<30 ml/min per 1.73 m(2). Serum K(+) level <3.5 mEq/L was present in 1.2%-1.4% of patient-time across eGFR strata. The median follow-up time was 2.76 years. There was a U-shaped association between serum K(+) and mortality; pooled adjusted incidence rate ratios were 3.05 (95% confidence interval, 2.53 to 3.68) and 3.31 (95% confidence interval, 2.52 to 4.34) for K(+) levels <3.5 mEq/L and ≥6.0 mEq/L, respectively. Within eGFR strata, there were U-shaped associations of serum K(+) with rates of MACE, hospitalization, and discontinuation of RAAS blockers.

CONCLUSIONS

Both hyperkalemia and hypokalemia were independently associated with higher rates of death, MACE, hospitalization, and discontinuation of RAAS blockers in patients with CKD who were not undergoing dialysis. Future studies are needed to determine whether interventions targeted at maintaining normal serum K(+) improve outcomes in this population.

Clinical perspectives on the rationale for potassium supplementation

Hypokalemia is a common electrolyte disturbance, observed in > 20% of hospitalized patients. Hypokalemia, although not formally defined, is generally considered to be when serum potassium levels fall below the normal value of 3.6 mmol/L. In contrast to other electrolytes, potassium is primarily an intracellular ion: only 2% of all potassium in the body is present in the extracellular fluid, so a small decrease in serum potassium may represent a significant decrease in intracellular potassium. Individuals with mildly decreased potassium levels (3.0-3.5 mmol/L) may be asymptomatic, but patients with more pronounced decreases may report symptoms including muscle weakness, fatigue, and constipation. Very low serum potassium levels (≤ 2.5 mmol/L) can lead to muscle necrosis, paralysis, cardiac arrhythmias, and impaired respiration, which can be life-threatening. Absent comprehensive and robust treatment guidelines, strategies for the prevention or treatment of hypokalemia, such as how to diagnose hypokalemia, when to treat patients, what dosage regimen of potassium supplementation to use and for how long, are often based on the experience of the physician and empirical evidence. However, proper evaluation and treatment of hypokalemia in patients is essential because of associated morbidities. Because small potassium deficits in serum represent large body losses, potassium repletion requires substantial and prolonged supplementation. For patients with known risk factors for hypokalemia (e.g. hypertension, heart failure, or diabetes), careful monitoring is crucial to avoid the adverse sequelae associated with potassium deficits and to ensure that adequate and timely preventive measures can be taken. In this review, we provide practical insights into the etiology, differential diagnosis, and treatment of hypokalemia, including treatment strategies for patients with known risk factors.

CKD of unknown origin in Central America: the case for a Mesoamerican nephropathy

An epidemic of chronic kidney disease of unknown origin has emerged in the last decade in Central America and has been named Mesoamerican nephropathy. This form of chronic kidney disease is present primarily in young male agricultural workers from communities along the Pacific coast, especially workers in the sugarcane fields. In general, these men have a history of manual labor under very hot conditions in agricultural fields. Clinically, they usually present with normal or mildly elevated systemic blood pressure, asymptomatic yet progressive reduction in estimated glomerular filtration rate, low-grade non-nephrotic proteinuria, and often hyperuricemia and or hypokalemia. Diabetes is absent in this population. Kidney biopsies that have been performed show a chronic tubulointerstitial disease with associated secondary glomerulosclerosis and some signs of glomerular ischemia. The cause of the disease is unknown; this article discusses and analyzes some of the etiologic possibilities currently under consideration. It is relevant to highlight that recurrent dehydration is suggested in multiple studies, a condition that possibly could be exacerbated in some cases by other conditions, including the use of nonsteroidal anti-inflammatory agents. At present, Mesoamerican nephropathy is a medical enigma yet to be solved.