Exposure-response analysis of the efficacy and safety of esaxerenone, a novel nonsteroidal mineralocorticoid receptor blocker, in hypertensive patients with or without diabetic kidney disease

BACKGROUND

Esaxerenone is a novel non-steroidal mineralocorticoid receptor blocker. Here, we assessed efficacy and safety exposure-response relationships of esaxerenone and its covariates and thereby justified the recommended dosage regimens, focusing on the safety benefits of up-titration regimen in patients at higher risk for increased serum potassium (sK+).

METHODS

The relationships between model-derived individual esaxerenone exposure and efficacy (blood pressure [BP]) and safety (increased sK+) were evaluated using multivariate linear regression and Cox regression analyses, respectively, using data from 1453 hypertensive patients with or without diabetic kidney disease in five clinical studies.

RESULTS

Exposure-efficacy analyses demonstrated that higher exposure was linearly associated with greater BP reduction over the investigated dose range. Exposure-safety analyses showed that higher exposure was associated with a higher risk of increased sK+ under a fixed-dosing regimen; higher baseline sK+ and lower baseline estimated glomerular filtration rate (eGFR) were influential covariates. Model-based simulations suggested that fewer occurrences of increased sK+ are expected under the up-titration regimen (from 1.25 to 5 mg) relative to the fixed-dosing regimen (5 mg) in patients with different combinations of these covariates.

CONCLUSIONS

The exposure-response analyses supported the esaxerenone recommended doses and the safety benefits of using the up-titration regimen.

Associations between serum electrolyte and short-term outcomes in patients with acute decompensated heart failure

INTRODUCTION

There is a dearth of comprehensive studies on the association between serum electrolyte and adverse short-term prognosis of Chinese patients with acute decompensated heart failure (ADHF).

PATIENTS AND METHODS

A total of 5166 patients with ADHF were divided into four serum electrolyte-related study populations (potassium (n = 5145), sodium (n = 5135), chloride (n = 4966), serum total calcium (STC) (n = 4143)) under corresponding exclusions. Different logistic regression models were utilized to gauge the association between these electrolytes or the number of electrolyte abnormalities and the risk of a composite of all-cause mortality or 30-day heart failure (HF) readmission.

RESULTS

In multivariable adjusted analysis, patients with potassium below 3.5 mmol/L (odds ratios (ORs) 1.45; 95% confidence interval (CI):1.07-1.95), 4.01-4.50 mmol/L (OR: 1.29, CI: 1.02-1.62), 4.51-5.00 mmol/L (OR: 1.43, CI: 1.08-1.90) and above 5.00 mmol/L (OR: 1.74, CI: 1.21-2.51) had an increased risk of outcome when compared with potassium at 3.50-4.00 mmol/L. Sodium levels were inversely related to the risk of a composite outcome (<130 mmol/L: OR: 2.73 (95% CI, 1.81-4.12); 130-134 mmol/L: OR, 1.97 (CI, 1.45-2.68); 135-140 mmol/L: OR, 1.45 (CI, 1.17-1.81); p for trend < 0.001) in comparison with sodium at 141-145 mmol/L. Chloride < 95 mmol/L corresponded to a higher risk of a composite outcome with an OR of 1.65 (95% CI, 1.16-2.37) in contrast to chloride levels at 101-105 mmol/L. In addition, the adjusted ORs (95% CI) for a composite outcome comparing the STC < 2.00 and 2.00-2.24 vs. 2.25-2.58 mmol/L were 0.98 (0.69-1.43) and 1.13 (0.89-1.44), respectively. Besides that, the number of electrolyte abnormalities was positively related to the risk of a composite outcome (N = 1, OR 1.40, 95% CI: 1.13-1.73; N = 2, OR 2.51, 95% CI: 1.85-3.42; N = 3, OR 2.47, 95% CI: 1.45-4.19; p for trend < 0.001) in comparison with N = 0.

CONCLUSIONS

A deviation of potassium levels from 3.50 to 4.00 mmol/L, lower sodium levels and hypochloremia were associated with poorer short-term prognosis of ADHF. Furthermore, the number of electrolyte abnormalities positively correlated with adverse short-term prognosis of patients with ADHF. Key MessagesADHF patients with baseline serum potassium at first half part of normal range (3.50-4.00 mmol/L) may herald the lowest risk of recent cardiovascular events.Serum sodium and chloride levels exhibit discrepancies in terms of risk of short-term adverse events of ADHF patients.The number of electrolyte abnormalities is a significant predictor of poor short-term prognosis in patients with ADHF.

CLINICAL TRIAL REGISTRATION URL

http://www.chictr.org.cn/showproj.aspx?proj=23139. Unique identifier: ChiCTR-POC-17014020.

Serum glucose/potassium ratio as a clinical risk factor for predicting the severity and prognosis of acute traumatic spinal cord injury

OBJECTIVE

Acute traumatic Spinal cord injury (TSCI) is a devastating event that causes severe sensory and motor impairments as well as autonomic dysfunction in patients, yet relevant clinical biomarkers have not been established. This study aimed to determine the significance of the serum glucose/potassium ratio (GPR) in evaluating TSCI severity and predicting prognosis.

METHODS

An analysis of 520 clinical records of acute TSCI patients from January 2012 to June 2022 was conducted. The relationships between serum GPR and The American Spinal Injury Association Impairment Scale (AIS) grade 6-month post-trauma prognosis and the admission AIS grade were analyzed. To evaluate the discriminatory ability, a receiver operating characteristic curve (ROC) analysis was used. All methods were performed in accordance with the relevant guidelines and regulations.

RESULTS

Based on the initial assessment of AIS grade, 256 (49.2%) patients were categorized into the severe TSCI group (AIS A-B), and there was a significant correlation between the severe TSCI group and serum GPR (p < 0.001). Serum GPR was reduced in an AIS grade-dependent manner (R = - 0.540, p < 0.001). Of the 520 patients, 262 (50.4%) patients were classified as having a poor prognosis according to the AIS grade at discharge. Serum GPR was also reduced in an AIS grade at discharge-dependent manner (R = - 0.599, p < 0.001), and was significantly higher in the poor prognosis group compared to the good prognosis group (p < 0.001). Poor prognosis was significantly associated with sex (p = 0.009), severity of TSCI (p < 0.001), location of TSCI (p < 0.001), surgical decompression (p < 0.018), body temperature (p < 0.001), heart rate (p < 0.001), systolic arterial pressure (SAP) (p < 0.001), diastolic arterial pressure (DAP) (p < 0.001), serum GPR (p < 0.001), serum glucose (p < 0.001), serum potassium (p < 0.001), and white blood cell count (p = 0.003). Multivariate logistic regression analysis showed a significant correlation between poor prognosis and serum GPR (p = 0.023). The ROC analysis showed the area under the curve of serum GPR to be a poor predictor of prognosis in TSCI patients at 0.842 (95% confidence interval, 0.808-0.875).

CONCLUSION

There was a significant relationship between serum GPR and admission injury severity and the 6-month prognosis of acute TSCI patients. Serum GPR serves as a readily available clinical risk factor for predicting the severity and 6-month prognosis of acute traumatic spinal cord injury, which holds potential clinical significance for patients with TSCI.

Efficacy and Safety of Esaxerenone in Hypertensive Patients with Diabetes Mellitus Undergoing Treatment with Sodium-Glucose Cotransporter 2 Inhibitors (EAGLE-DH)

INTRODUCTION

The EAGLE-DH study assessed the efficacy and safety of esaxerenone in hypertensive patients with diabetes mellitus receiving sodium-glucose cotransporter 2 (SGLT2) inhibitors.

METHODS

In this multicenter, open-label, prospective, interventional study, esaxerenone was started at 1.25 or 2.5 mg/day and could be gradually increased to 5 mg/day on the basis of blood pressure (BP) and serum potassium levels. Oral hypoglycemic or antihypertensive medications prior to obtaining consent was continued. Data were evaluated in the total population and creatinine-based estimated glomerular filtration rate (eGFR) subcohorts (eGFR ≥ 60 mL/min/1.73 m2 [G1-G2 subcohort] and 30 to < 60 mL/min/1.73 m2 [G3 subcohort]).

RESULTS

In total, 93 patients were evaluated (G1-G2, n = 49; G3, n = 44). Morning home systolic/diastolic BP values (SBP/DBP) were significantly reduced from baseline to week 12 (- 11.8 ± 10.8/- 5.1 ± 6.3 mmHg, both P < 0.001) and week 24 (- 12.9 ± 10.5/- 5.7 ± 6.3 mmHg, both P < 0.001). Similar results were observed in both eGFR subcohorts. The urinary albumin-to-creatinine ratio significantly decreased from baseline to week 24 in the total population (geometric percentage change, - 49.1%, P < 0.001) and in both eGFR subcohorts. The incidences of treatment-emergent adverse events (TEAEs) and drug-related TEAEs were 45.2% and 12.9%, respectively; most were mild or moderate. Serum potassium levels increased over the first 2 weeks of esaxerenone treatment, gradually decreased by week 12, and remained constant to week 24. One patient in the G1-G2 subcohort had serum potassium levels ≥ 5.5 mEq/L. No patients had serum potassium ≥ 6.0 mEq/L.

CONCLUSION

Esaxerenone effectively lowered BP, was safe, and showed renoprotective effects in hypertensive patients with diabetes mellitus receiving treatment with SGLT2 inhibitors. Esaxerenone and SGLT2 inhibitors did not interfere with either drug's efficacy and may reduce the frequency of serum potassium elevations, suggesting they are a compatible combination.

CLINICAL TRIAL REGISTRATION

jRCTs031200273.

Efficacy and safety assessment of mineralocorticoid receptor antagonists in patients with chronic kidney disease

BACKGROUND

The objective of our study is to evaluate the efficacy and safety of mineralocorticoid receptor antagonists (MRAs) and determine the optimal MRA treatment regimen in patients with chronic kidney disease (CKD).

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library from their inception to June 20, 2022. The composite kidney outcome, cardiovascular events, urinary albumin to creatinine ratio (UACR), estimated glomerular filtration rate (EGFR), serum potassium, systolic blood pressure (SBP), diastolic blood pressure (DBP), creatine and creatine clearance were included for analysis. We conducted pairwise meta-analyses and Bayesian network meta-analyses (NMA) and calculated the surface under the cumulative ranking curve (SUCRA).

RESULTS

We included 26 studies with 15,531 participants. By pairwise meta-analyses, we found that MRA treatment could significantly reduce UACR in CKD patients with or without diabetes. Notably, compared to placebo, Finerenone was associated with a lower risk of composite kidney outcome and cardiovascular events. Data from NMA demonstrated an overt UACR reduction without increasing serum potassium by Apararenone, Esaxerenone, and Finerenone in CKD patients. Spironolactone decreased SBP and DBP but elevated CKD patients' serum potassium.

CONCLUSIONS

Compared to placebo, Apararenone, Esaxerenone, and Finerenone might ameliorate albuminuria in CKD patients without causing elevated serum potassium levels. Remarkably, Finerenone conferred a cardiovascular benefit, and Spironolactone lowered blood pressure in CKD patients.

Associations between laboratory variables and clinical features in patients hospitalized with COVID-19 after non-mRNA vaccination in China: A cross-sectional study

Objectives

Based on the data during the outbreak of COVID-19 in Wuxi city in China, we explored the relationship between laboratory variables and clinical features in patients hospitalized with COVID-19 after non-mRNA vaccination, and attempted to identify the significant impact of vaccination and COVID-19 infection on humans.

Methods

A retrospective observational cohort study was carried out. Patients who received non-mRNA COVID-19 vaccines and were hospitalized with COVID-19 between June 28, 2022, and July 24, 2022 were included. The correlation between different vaccine statuses, the time to negative PCR test, and biochemical parameters were investigated.

Results

All patients had a mild COVID-19 disease. The number of vaccine doses exerted no effects on the time to negative PCR test (P = 0.559). No differences were evident among inactivated, adenoviral-vectored, and recombinant subunit vaccines in the time to negative PCR test.Patients who just received one dose had significantly lower blood glucose levels than those who received three doses (P = 0.024), whereas two doses had no effect on blood glucose levels (one dose vs. two doses, P = 0.223; two doses vs. three doses, P = 0.457).Body temperature (β = 0.168, P = 0.011) and the percentage of lymphocytes (β = -0.219, P = 0.001) were substantially correlated with the time to COVID-19 negative PCR test. The prolonged stay was linked to a rise in GOT that fell within the usual range (P = 0.025).The percentage of lymphocytes (P = 0.007) and serum potassium (P = 0.004) were concordant with the marked change in body temperature.

Conclusions

The dose and type of vaccination had no effect on the time to COVID-19 negative PCR test in patients with mild COVID-19. Comparing the first dose with the booster dose, the blood glucose levels increased within the normal range. The period at which the COVID-19 nucleic acid turned negative correlated with body temperature, the proportion of lymphocytes, GOT, and serum potassium.

Factors Associated with the Antihypertensive Effect of Esaxerenone and Serum Potassium Elevation: A Pooled Analysis of Seven Phase III Studies

INTRODUCTION

This study investigated factors associated with the antihypertensive effects of esaxerenone and the incidence of serum potassium elevation in patients with hypertension.

METHODS

Using pooled data from seven phase III studies, the study analyzed factors associated with changes in office systolic (SBP) and diastolic (DBP) blood pressure from baseline to 12 weeks, and factors associated with incidence of serum potassium levels ≥ 5.5 mEq/L in esaxerenone-treated patients.

RESULTS

Overall, 1466 and 1472 patients were included in the full analysis and safety analysis sets, respectively. Male sex (4.02/2.40 mmHg), weight ≥ 78.4 kg (4.62/2.09 mmHg), hypertension duration ≥ 10 years (2.66/1.71 mmHg), prior antihypertensive treatment (2.38/1.40 mmHg), plasma aldosterone concentration ≥ 120 pg/mL (1.66/1.17 mmHg), urinary albumin-to-creatinine ratio (UACR) ≥ 300 mg/gCr (8.94/4.85 mmHg) or 30-299 mg/gCr (5.17/4.15 mmHg), and smoking (2.62/1.27 mmHg) were associated with mean changes in SBP and DBP. Fasting blood glucose ≥ 126 mg/dL (- 2.73 mmHg) was associated with the mean change in SBP only, and older age (65-74 years, - 2.12 mmHg; and ≥ 75 years, - 3.06 mmHg) with mean change in DBP only. Factors significantly associated with incidence of serum potassium levels ≥ 5.5 mEq/L were higher baseline serum potassium (≥ 4.5 mEq/L, odds ratio [OR] 6.702); lower estimated glomerular filtration rate (≥ 90 mL/min/1.73 m², OR 0.148; 60-89 mL/min/1.73 m², OR 0.331 vs 30-59 mL/min/1.73 m², respectively); higher UACR (30-299 mg/gCr, OR 7.317); higher DBP (≥ 100 mmHg, OR 3.248); and grade I hypertension (OR 2.168).

CONCLUSION

Esaxerenone is effective in patients with a broad range of backgrounds, though some factors may predict increased benefit. Regarding elevated serum potassium, careful therapeutic management is recommended for patients with higher baseline serum potassium and reduced renal function.

CLINICAL TRIAL REGISTRATION

UMIN000047026.

Serum protein and electrolyte imbalances are associated with chemotherapy induced neutropenia

Introduction

Cancer and its treatment using various chemotherapeutic agents can have many adverse side effects. These side effects often result in significant changes in haematological and biochemical composition of blood. As a result, the regular monitoring of serum biochemical and haematological changes plays an important role in management of disease. The present study aimed to determine the relationship between haematological and biochemical changes in neutropenic cancer patients following chemotherapy. Specifically we evaluated the association between neutrophil count and serum proteins and electrolytes.

Methods

For this purpose we analysed retrospectively collected laboratory results from two independent patient cohorts. Each cohort was divided into a control group consisting of patients with normal haematological parameters and a study group which included patients with reduced neutrophil counts. Neutropenic patients (study group) were cancer patients on chemotherapy.

Results and conclusion

Blood samples of cancer patients in study group showed reduction in haemoglobin, neutrophils and platelets. Neutropenic group showed a significant reduction in serum albumin, total protein, calcium, and potassium. Our results show that patients with severe neutropenia had pronounced changes in serum protein and electrolytes and increased incidence of abnormal serum protein and electrolyte level. The changes in the neutrophil counts showed a positive correlation with the changes in serum protein and electrolyte levels. A similar trend was seen in both the patient cohorts: the discovery set (176 patients) and the validation set (200 patients). Taken together our results suggest that chemotherapy-induced neutropenia is associated with dysregulation in haemoglobin, platelets, serum proteins and electrolytes.

Potassium and fiber: a controversial couple in the nutritional management of children with chronic kidney disease

BACKGROUND

Fruit and vegetable intake is commonly discouraged in children with chronic kidney disease (CKD) to avoid hyperkalemia. However, direct evidence in support of this widespread practice is lacking. Furthermore, the resultant restricted fiber exposure may deprive CKD patients from potential health benefits associated with the latter. Therefore, we investigated associations between dietary potassium intake, fiber intake, and serum potassium levels in pediatric CKD.

METHODS

This study is a longitudinal analysis of a 2-year, prospective, multi-institutional study, following children with CKD at 3-month intervals. At each visit, dietary potassium and fiber intake were assessed, using 24-h recalls and 3-day food records. On the same occasion, serum potassium concentrations were determined. Associations between dietary potassium intake, dietary fiber intake, and serum potassium concentrations were determined using linear mixed models.

RESULTS

Fifty-two CKD patients (7 transplant recipients, none on dialysis) aged 9 [4;14] years with an estimated glomerular filtration rate (eGFR) of 49 [25;68] mL/min/1.73 m² were included. For every g/day decrease in dietary potassium intake, the estimated mean daily fiber intake was 5.1 g lower (95% confidence interval (CI), 4.3-5.9 g/day; p < 0.001). Neither dietary potassium intake (p = 0.40) nor dietary fiber intake (p = 0.43) was associated with circulating potassium in a model adjusted for time point, eGFR, treatment with a renin-angiotensin-aldosterone system blocker, serum bicarbonate concentration, and body surface area.

CONCLUSIONS

Dietary potassium and fiber intake are closely related but were not associated with circulating potassium levels in pediatric CKD. A higher-resolution version of the graphical abstract is available as Supplementary information.

Clinical and electrocardiogram presentations of patients with high serum potassium concentrations within emergency settings: a prospective study

BACKGROUND

Elevated potassium level is a common and reversible peri-arrest condition. Diagnosis and management of hyperkalemia in a short time is critical, where electrocardiogram (ECG) alterations might be helpful. We aimed to investigate the role of clinical features and ECGs in early diagnosing and treating hyperkalemia.

METHODS

Prospectively, adult patients who presented to the emergency department (ED) from July 2019 to March 2020 with hyperkalemia (serum potassium ≥5.5mmol/L) were included. History was obtained, and laboratory investigations and ECGs were performed at the presentation and before initiating hyperkalemia therapy. Hyperkalemia severity was divided into mild (5.5-5.9mmol/L), moderate (6.0-6.4mmol/L), and severe (≥6.5mmol/L). A cardiologist and emergency physician blinded to laboratory values, study design, and patients' diagnoses interpreted ECGs and presenting symptoms independently to predict hyperkalemia.

RESULTS

Sixty-seven hyperkalemic patients with a mean (±SD) serum potassium level of 6.5±0.7mmol/L were included in this study. The mean age was 63.9±15.1, and 58.2% were females. Hyperkalemia was mild in 10.4%, moderate in 40.3%, and severe in 49.3%. Almost two thirds of patients (71.6%) had hypertension, 67.2% diabetes, and 64.2% chronic kidney disease. About one-quarter of patients (22.4%) were asymptomatic, while fatigue (46.3%), dyspnea (28.4%), and nausea/vomiting (20.9%) were the most common presenting symptoms. Normal ECGs were observed in 25.4% of patients, while alterations in 74.6%. Atrial fibrillation (13.4%), peaked T wave (11.9%), widened QRS (11.9%), prolonged PR interval (10.5%), and flattening P wave (10.5%) were the most common. Peaked T wave was significantly more common in severe hyperkalemia (87.5%) than in mild and moderate hyperkalemia (12.5%, 0.0%, respectively) (p=0.041). The physicians' sensitivities for predicting hyperkalemia were 35.8% and 28.4%, improved to 51.5% and 42.4%, respectively, when limiting the analyses to severe hyperkalemia. The mean (±SD) time to initial hyperkalemia treatment was 63.8±31.5 min. Potassium levels were positively correlated with PR interval (r=0.283, p=0.038), QRS duration (r=0.361, p=0.003), peaked T wave (r=0.242, p=0.041), and serum levels of creatinine (r=0.347, p=0.004), BUN (r=0.312, p=0.008), and CK (r=0.373, p=0.039).

CONCLUSIONS

The physicians' abilities to predict hyperkalemia based on ECG and symptoms were poor. ECG could not be solely relied on, and serum potassium tests should be conducted for accurate diagnosis.

Prognostic significance of serum potassium in patients hospitalized for acute heart failure

Aim

We investigated the prognostic significance of serum potassium abnormalities at discharge in patients hospitalized for acute heart failure (AHF).

Methods and results

In a retrospective analysis, we included 926 patients hospitalized for AHF, stratified by serum potassium levels at discharge as hypokalaemia (<3.5 mEq/L), normokalaemia (3.5–5.0 mEq/L), and hyperkalaemia (>5.0 mEq/L). The primary endpoint was all‐cause death at 1 year since hospital discharge. At discharge, 40 patients had hypokalaemia (4.3%), 840 normokalaemia (90.7%), and 46 hyperkalaemia (5.0%). Patients with hyperkalaemia at discharge were more frequently men, had more signs of congestion, and lower LVEF while patients with hypokalaemia were more likely to be women with HFpEF. Treatment with ACEi/ARBs and MRAs ≥50% of target dose at discharge was similar across groups. One year all‐cause death occurred in 10% of the patients with hypokalaemia, 13.9% of those with normokalaemia, and 30.4% of those with hyperkalaemia (P = 0.006). After adjustment for covariates, including renal function, background treatment, and baseline potassium level, hyperkalaemia resulted an independent predictor of the primary endpoint (HR 1.96, 95% IC [1.01–3.82]; P = 0.048).

Conclusions

In patients with AHF, the presence of hyperkalaemia at discharge is an independent predictor of 1 year all‐cause death.

Plasma aldosterone concentration is associated with white matter lesions in patients with primary aldosteronism

PURPOSE

Primary aldosteronism (PA) is the most frequent form of secondary hypertension. Hypertension is a risk factor for cognitive decline and dementia. White matter lesions (WMLs) are linked to vascular risk factors, which increase the risk of dementia. We aimed to analyze the association of PA-related parameters and WMLs in patients with PA.

METHODS

We conducted a retrospective analysis of all patients with PA in the Hypertension Center of the People's Hospital of Xinjiang Uygur Autonomous Region from January 1, 2011 to April 1, 2021. We analyzed the relationship between plasma aldosterone concentration (PAC), plasma renin activity (PRA), aldosterone-renin ratio (ARR), serum potassium, and WMLs.

RESULTS

We enrolled 138 patients with WMLs and matched these to controls without WMLs at a 1:4 ratio. Among the analytic sample (N = 711) with ages ranging from 30 to 64 years, 69% were male. In the logistic regression analysis, PAC, PRA and serum potassium were treated as continuous variables. The results showed that PAC (OR 1.04, 95% CI 1.01, 1.06, P = 0.008) was positively associated with the risk of WMLs, and serum potassium (OR 0.26, 95% CI 0.16, 0.44, P < 0.001) was inversely associated with the risk of WMLs. PRA (OR 0.86, 95% CI 0.68, 1.08, P = 0.384) was not associated with the risk of WMLs after adjusting for confounders. The results of restricted cubic splines showed the dose-response association between increasing PAC, ARR, decreasing serum potassium, and the risk of WMLs. We also divided PAC, ARR and serum potassium into two groups according to the result of restricted cubic splines. After adjusting for confounders, patients who were in Q2 (≥23.12 ng/dl) of PAC (OR 2.07, 95% CI 1.36, 3.15), Q2 (≥56.81 (ng/dl per ng/ml*h) of ARR (OR 1.82, 95% CI 1.22, 2.72) and Q2 (≤3.58 mmol/l) of serum potassium (OR 2.99, 95% CI 1.95, 4.50) had a significantly higher risk of WMLs than their counterparts. In stratified analyses, there was no evidence of subgroup heterogeneity regarding the change in the risk of WMLs (P > 0.05 for interaction for all).

CONCLUSION

Our results suggested that the PAC and serum potassium were related to the risk of WMLs in patients with PA. In particular, PAC ≥23.12 ng/dl significantly increased the risk of WMLs in patients with PA.

Association of serum potassium level with early and late mortality in very elderly patients with acute kidney injury

Background

The kidneys play a central role in serum potassium (K ⁺) homeostasis, and their dysfunction leads to electrolyte disorders. We aimed to examine the relationship between different levels of K ⁺ and mortality among very elderly patients with acute kidney injury (AKI).

Methods

We retrospectively enrolled very elderly patients (≥75 years) with AKI from the hospital information system of the Chinese PLA General Hospital from January 1, 2007 to December 31, 2018. All-cause mortality was examined according to six predefined K ⁺ levels: <3.50 mmol/L, 3.50-3.79 mmol/L, 3.80-4.09 mmol/L, 4.10-4.79 mmol/L, 4.80-5.49 mmol/L, and ≥5.50 mmol/L. We estimated the risk of all-cause mortality using the multivariable adjusted Cox proportional hazard model with the normal K ⁺ level at 3.50-3.79 mmol/L as a reference.

Results

In total, 747 patients were deemed suitable for the final evaluation. The median age of the 747 participants was 88 (84-91) years. After 90 days, the mortality rates in the six strata were 28.3%, 21.9%, 30.1%, 35.4%, 45.2%, and 58.3%, respectively. In the multivariable adjusted analysis, patients with K ⁺ levels of 4.10-4.79 mmol/L (hazard ratio [HR]: 1.638; 95% confidence interval [CI]: 1.016-2.642), 4.80-5.49 mmol/L (HR: 2.585; 95% CI: 1.524-4.384), and ≥5.50 mmol/L (HR: 2.587; 95% CI: 1.495-4.479) had an increased risk of all-cause mortality. After 1 year, the mortality rates in the six strata were 44.8%, 41.1%, 45.1%, 51.8%, 63.1%, and 76.3%, respectively. In the multivariable adjusted analysis, patients with K ⁺ levels of 4.10-4.79 mmol/L (HR: 1.452; 95% CI: 1.014-2.079), 4.80-5.49 mmol/L (HR: 2.151; 95% CI: 1.427-3.241), and ≥5.50 mmol/L (HR: 2.341; 95% CI: 1.514-3.620) had an increased risk of all-cause mortality.

Conclusion

Increased serum K ⁺ levels, including levels of 4.10-5.49 mmol/L and ≥5.50 mmol/L, were associated with a significantly increased short- and long-term risk of death. Serum K ⁺ has the potential to be a marker of disease severity among very elderly patients with AKI.

Serum potassium concentration and its association with hypertension among Ghanaian migrants and non-migrants: The RODAM study

BACKGROUND AND AIMS

Low serum potassium concentration is associated with hypertension, but whether the same association can be found in African origin populations, is unknown. We assessed serum potassium concentration, and its association with hypertension among Ghanaians living in different geographical locations.

METHODS

Baseline data of 962 rural, 1420 urban, and 2947 migrant Ghanaians from the Research on Obesity and Diabetes among African Migrants study were analysed. Mean serum potassium concentration was compared between the groups, and the association between serum potassium and hypertension was assessed using multivariate regression analyses.

RESULTS

Mean serum potassium concentration was higher in rural Ghana (4.28, 95% confidence interval 4.25-4.32 mmol/L) than in Ghanaians living in Amsterdam (3.90, 3.88-3.92 mmol/L) and London (4.11, 4.07-4.14 mmol/L), but lower than in Ghanaians living in urban Ghana (4.38, 4.34-4.42 mmol/L) and Berlin (4.57, 4.51-4.62 mmol/L) in both sexes. In the age-adjusted analyses, serum potassium was associated with hypertension in urban- (odds ratio 0.44, 0.23-0.82), London- (0.34, 0.17-0.64) and Amsterdam-Ghanaian males (0.41, 0.20-0.86), and in rural- (0.49, 0.28-0.84), London- (0.29, 0.17-0.49) and Amsterdam-Ghanaian females (0.33, 0.17-0.64). However, after adjustment for demographic, lifestyle, and health factors, serum potassium was associated with hypertension in Amsterdam-Ghanaian males only (0.12, 0.02-0.59).

CONCLUSIONS

This study shows differences in mean serum potassium among Ghanaian populations living in different locations in Europe and Ghana, and different associations with hypertension between sites. Further research should focus on elucidating the mechanism underlying potassium handling and blood pressure regulation in African populations, in order to mitigate the burden of hypertension among these populations.

Pharmacokinetics of caffeine self-administered in overdose in a Japanese patient admitted to hospital

Background

Caffeine (0.1 g) is used as a central nervous system stimulant and as a nontoxic phenotyping probe for cytochrome P450 1A2. However, an increasing number of suicide attempts by caffeine overdose have been recently reported.

Case presentation

A 25-year-old woman (body weight, 43 kg) who intentionally took an overdose of 5.9 g caffeine as a suicide attempt was emergently admitted to Kyoto Medical Center. The plasma concentrations of caffeine and its primary metabolite, N-demethylated paraxanthine, in the current case were 100 and 7.3 μg/mL, 81 and 9.9 μg/mL, 63 and 12 μg/mL, and 21 and 14 μg/mL, at 12, 20, 30, and 56 h after oral overdose, respectively. The observed apparent terminal elimination half-life of caffeine during days 1 and 2 of hospitalization was 27 h, which is several times longer than the reported normal value. This finding implied nonlinearity of caffeine pharmacokinetics over such a wide dose range, which could affect the accuracy of values simulated by a simplified physiologically based pharmacokinetic model founded on a normal dose of 100 mg. Low serum potassium levels (2.9 and 3.5 mM) on days 1 and 2 may have been caused by the caffeine overdose in the current case.

Conclusions

The patient underwent infusion with bicarbonate Ringer’s solution and potassium chloride and was discharged on the third day of hospitalization despite taking a potentially lethal dose of caffeine. The virtual plasma exposures of caffeine estimated using the current simplified PBPK model were higher than the measured values. The present results based on drug monitoring data and additional pharmacokinetic predictions could serve as a useful guide in cases of caffeine overdose.

How SARS-CoV-2 might affect potassium balance via impairing epithelial sodium channels?

Severe acute respiratory syndrome coronaviruses 2 (SARS-CoV-2) is the causative agent of current coronavirus disease 2019 (COVID-19) pandemic. Electrolyte disorders particularly potassium abnormalities have been repeatedly reported as common clinical manifestations of COVID-19. Here, we discuss how SARS-CoV-2 may affect potassium balance by impairing the activity of epithelial sodium channels (ENaC). The first hypothesis could justify the incidence of hypokalemia. SARS-CoV-2 cell entry through angiotensin-converting enzyme 2 (ACE2) may enhance the activity of renin–angiotensin–aldosterone system (RAAS) classical axis and further leading to over production of aldosterone. Aldosterone is capable of enhancing the activity of ENaC and resulting in potassium loss from epithelial cells. However, type II transmembrane serine protease (TMPRSS2) is able to inhibit the ENaC, but it is utilized in the case of SARS-CoV-2 cell entry, therefore the ENaC remains activated. The second hypothesis describe the incidence of hyperkalemia based on the key role of furin. Furin is necessary for cleaving both SARS-CoV-2 spike protein and ENaC subunits. While the furin is hijacked by the virus, the decreased activity of ENaC would be expected, which causes retention of potassium ions and hyperkalemia. Given that the occurrence of hypokalemia is higher than hyperkalemia in COVID-19 patients, the first hypothesis may have greater impact on potassium levels. Further investigations are warranted to determine the exact role of ENaC in SARS-CoV-2 pathogenesis.

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.

Co-trimoxazole induced hyperkalemia and potassium monitoring in hospitalized patients

Background Co-trimoxazole is an antibiotic combination used for the treatment of Pneumocystis jirovecii pneumonia, amongst others. Co-trimoxazole is known to increase serum potassium. For this reason, Dutch guidelines advise serum potassium monitoring in high-risk patients. Objective This study aimed to determine average serum potassium rise after administration of intravenous co-trimoxazole in hospitalized patients, compared to intravenous ceftriaxone. This study also aimed to determine adherence to Dutch guidelines by measuring the incidence of serum potassium monitoring in these patients. Setting Data was collected retrospectively from patients in five departments of the Canisius Wilhelmina Hospital, a teaching hospital in Nijmegen, the Netherlands. Method Data was collected and compared from patients that received intravenous co-trimoxazole (n = 66) and intravenous ceftriaxone (n = 132) in the period of November 2008-November 2017. For each patient using co-trimoxazole, two patients using ceftriaxone were included in a paired fashion. Baseline and follow-up potassium were collected, if available. Additionally, it was tested if serum potassium was measured around the initiation of antibiotic therapy. Main outcome measure Changes in serum potassium where obtainable in 30 patients using cotrimoxazole and 40 patients using ceftriaxone. When compared to ceftriaxone, administration of intravenous co-trimoxazole was associated with a significant mean increase in serum potassium (+0.55 mmol/l, 95% CI 0.29-0.80, p < 0.001). After correction for confounders (baseline potassium, estimated glomerular filtration rate 30 ≤ 60, the presence of haematological malignancies and the usage of corticosteroids), this effect shrunk noticeably, but remained significant (+0.28 mmol/l, 95% CI 0.03-0.53, p = 0.031). Results The incidence of hyperkalemia at follow-up was 20% in the cotrimoxazole group, compared to 5% in the ceftriaxone group. Despite this, serum potassium was often not measured in patients using intravenous cotrimoxazole, being 76% at baseline and 55% in the period of 48-120 h after antibiotic therapy initiation, compared to 87% and 34% in the ceftriaxone group respectively. Conclusion Adherence to Dutch guidelines was poor as serum potassium monitoring was often not performed. As intravenous co-trimoxazole usage is associated with a significant increase in mean serum potassium, monitoring is strongly recommended.

Rising Trend of Hypokalemia Prevalence in the US Population and Possible Food Causes

Background: Potassium intake deficiency is a chronic issue in the US and many other countries. Possible causes of the deficiency are understudied.Objective: This study examined potassium deficiency in the US population and possible causes for the new trend.Methods: Serum potassium data of 28,379 men and 29,617 women between ages 12 and 80 years old who participated in the US National Health and Nutrition Examination Survey (NHANES) between 1999 and 2016 were examined. Blood samples were collected by NHANES and blood biochemistry data were measured in designed laboratories. The data were released bi-annually. Possible causes of low potassium intakes were explored.Results: There was an apparent decline of serum potassium in the US population between ages 12 and 80 years from 1999 to 2016. Annual average serum potassium concentrations changed from 4.14 ± 0.01 to 3.97 ± 0.01 mmol/l during this period. Hypokalemia prevalence in the US rose from 3.78%±0.68% to 11.06%±1.08% during this period with a higher hypokalemia prevalence in non-Hispanic black than in non-Hispanic white persons. It is possible that declining potassium concentration in food sources in the US contributed to lower potassium intake and increasing potassium deficiency.Conclusion: The rising trend of hypokalemia prevalence in the US population between 1999 and 2016 is alarming. Renewed efforts to reduce potassium intake deficiency in the US at population level are needed. The impact of possible decreasing crop available potassium levels and increasing consumption of processed food on the potassium deficit trend in the US are possible explanations for the rise in hypokalemia prevalence and require further study.

Co-trimoxazole induced hyperkalemia and potassium monitoring in hospitalized patients

Background Co-trimoxazole is an antibiotic combination used for the treatment of Pneumocystis jirovecii pneumonia, amongst others. Co-trimoxazole is known to increase serum potassium. For this reason, Dutch guidelines advise serum potassium monitoring in high-risk patients. Objective This study aimed to determine average serum potassium rise after administration of intravenous co-trimoxazole in hospitalized patients, compared to intravenous ceftriaxone. This study also aimed to determine adherence to Dutch guidelines by measuring the incidence of serum potassium monitoring in these patients. Setting Five departments of the Canisius Wilhelmina Hospital, a teaching hospital in Nijmegen, the Netherlands. Method Data was collected and compared from patients that received intravenous co-trimoxazole (n = 66) and intravenous ceftriaxone (n = 132) in the period of November 2008–November 2017. For each patient using co-trimoxazole, two patients using ceftriaxone were included in a paired fashion. Baseline and follow-up potassium were collected, if available. Additionally, it was tested if serum potassium was measured around the initiation of antibiotic therapy. Main outcome measure Changes in serum potassium where obtainable in 30 patients using cotrimoxazole and 40 patients using ceftriaxone. When compared to ceftriaxone, administration of intravenous co-trimoxazole was associated with a significant mean increase in serum potassium (+ 0.55 mmol/l, 95% CI 0.29–0.80, p < 0.001). After correction for confounders (baseline potassium, estimated glomerular filtration rate 30 to < 60, the presence of haematological malignancies and the usage of corticosteroids), this effect shrunk noticeably, but remained significant (+ 0.28 mmol/l, 95% CI 0.03–0.53, p = 0.031). Results The incidence of hyperkalemia at follow-up was 20% in the cotrimoxazole group, compared to 5% in the ceftriaxone group. Despite this, serum potassium was often not measured in patients using intravenous cotrimoxazole, being 76% at baseline and 55% in the period of 48–120 h after antibiotic therapy initiation, compared to 87% and 34% in the ceftriaxone group respectively. Conclusion Adherence to Dutch guidelines was poor as serum potassium monitoring was often not performed. As intravenous co-trimoxazole usage is associated with a significant increase in mean serum potassium, monitoring is strongly recommended.

Evaluating the risk of hyperkalaemia and acute kidney injury with cotrimoxazole: a retrospective observational study

OBJECTIVES

Increasing antimicrobial resistance has renewed interest in older, less used antimicrobials. Cotrimoxazole shows promise; however, hyperkalaemia and acute kidney injury (AKI) are potential complications. Identifying risk factors for and quantification of these events is required for safe use. This study aimed to evaluate predictors of cotrimoxazole-associated AKI and hyperkalaemia in a clinical setting.

METHODS

Patients prescribed cotrimoxazole were identified using electronic healthcare records over 3 years (1 April 2016 to 31 March 2019). Individual risk factors were recognized. Serum creatinine and potassium trends were analysed over the subsequent 21 days. AKI and patients with hyperkalaemia were classified using Kidney Disease Improving Global Outcomes (KDIGO) and laboratory criteria. Univariate and multiple logistic regression analyses were performed.

RESULTS

Among 214 patients prescribed cotrimoxazole, 42 (19.6%, 95% confidence interval (CI) 14.6-25.7) met AKI criteria and 33 (15.4%, 95% CI 11.0-21.1) developed hyperkalaemia. Low baseline estimated glomerular filtration rate (<60 mL/min/1.73 m², odds ratio (OR) 7.78, 95% CI 3.57-16.13, p < 0.0001) and cardiac disorders (OR 2.40, 95% CI 1.17-4.82, p 0.011) predicted AKI, while low baseline estimated glomerular filtration rate (<60 mL/min/1.73 m², OR 6.80, 95% CI 3.09-15.06, p < 0.0001) and higher baseline serum potassium (p 0.001) predicted hyperkalaemia. Low-dose cotrimoxazole (<1920 mg/d) was associated with lower AKI and hyperkalaemia risk (p 0.007 and 0.019 respectively). Early (within the first 2-4 days of therapy) serum creatinine changes predicted AKI (OR 3.65, 95% CI 1.73-7.41, p 0.001), and early serum potassium changes predicted hyperkalaemia (>0.6 mmol/L, OR 2.47, 95% CI 1.14-5.27, p 0.0236).

CONCLUSIONS

Cotrimoxazole-associated AKI and hyperkalaemia is frequent and dose dependent. Renal function, serum potassium and preexisting cardiac disorders should be evaluated before prescribing cotrimoxazole. Serum creatinine and potassium monitoring within first 2 to 4 days of treatment to identify susceptible patients is recommended, and the lowest effective dose ought to be prescribed.

Clinical characterization of patients with primary aldosteronism plus subclinical Cushing's syndrome

BACKGROUND

Primary aldosteronism (PA) plus subclinical Cushing's syndrome (SCS), PASCS, has occasionally been reported. We aimed to clinically characterize patients with PASCS who are poorly profiled.

METHODS

A population-based, retrospective, single-center, observational study was conducted in 71 patients (age, 58.2 ± 11.2 years; 24 males and 47 females) who developed PA (n = 45), SCS (n = 12), or PASCS (n = 14). The main outcome measures were the proportion of patients with diabetes mellitus (DM), serum potassium concentration, and maximum tumor diameter (MTD) on the computed tomography (CT) scans.

RESULTS

The proportion of DM patients was significantly greater in the PASCS group than in the PA group (50.0% vs. 13.9%, p <  0.05), without a significant difference between the PASCS and SCS groups. Serum potassium concentration was significantly lower in the PASCS group than in the SCS group (3.2 ± 0.8 mEq/L vs. 4.0 ± 0.5 mEq/L; p <  0.01), without a significant difference between the PASCS and PA groups. Among the 3 study groups of patients who had a unilateral adrenal tumor, MTD was significantly greater in the PASCS group than in the PA group (2.7 ± 0.1 cm vs. 1.4 ± 0.1 cm; p <  0.001), without a significant difference between the PASCS and SCS groups.

CONCLUSIONS

Any reference criteria were not obtained that surely distinguish patients with PASCS from those with PA or SCS. However, clinicians should suspect the presence of concurrent SCS in patients with PA when detecting a relatively large adrenal tumor on the CT scans.

Renal safety outcomes of spironolactone in patients with resistant hypertension

INTRODUCTION

Resistant hypertension (RH) is a significant health problem with complex management. The aim of this study was to evaluate the risks and benefits of adding spironolactone to treat RH.

MATERIAL AND METHODS

In total, 216 patients with RH in whom spironolactone (12.5-25mg daily) was added as an antihypertensive were evaluated. One-hundred and twenty-five (125) were analysed retrospectively and 91 prospectively. Blood pressure (BP) and laboratory parameters (serum creatinine [sCrea], estimated glomerular filtration rate [eGFR] and serum potassium [sK]) were analysed at baseline and at 3-6-12 months after introducing spironolactone.

RESULTS

A change of systolic/diastolic BP (mean±standard deviation) of -10.9±2.7/-4.3±1.6mmHg at 3 months and -13.6±2.8/-6.0±1.6mmHg at 12 months; p<0.001 was observed. These values were confirmed with ambulatory-BP monitoring at 12 months. At 3 months, an increase in sCrea of 0.10±0.04mg/dl, a decrease in eGFR of -5.4±1.9ml/min/1.73m² and an increase in sK of 0.3±0.1mmol/l; p<0.001 was observed for all cases. These changes were maintained after 12 months. There were no significant differences in changes of BP, sCrea, eGFR and sK between 3 and 12 months. Results of the retrospective and prospective cohorts separately were superimposable. In the prospective cohort, spironolactone was withdrawn in 9 patients (9.9%) because of adverse effects.

CONCLUSIONS

After 3 months with spironolactone, a decrease in BP associated with a decrease in the eGFR and an increase in sCrea and sK was observed. These changes were maintained at 12 months. Spironolactone is an effective and safe treatment for RH in patients with baseline eGFR ≥30ml/min/1.73m².

Data and methods to calculate cut-off values for serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest

The data and estimation methods presented in this article are associated with the research article, “Cut-off values of serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest: a retrospective multi-centre study” [1]. In this article we estimate recommended cut-off values for in-hospital triage with respect to extracorporeal rewarming. With only 6 survivors of 103 patients collected over a period of 20 years the ability to estimate reliable threshold values is limited. In addition, because the number of avalanche victims is also limited, a significantly larger dataset is unlikely to be obtained. We have therefore adapted two non-parametric estimation methods (bootstrapping and exact binomial distribution) to our specific needs and performed a simulations to confirm validity and reliability.

Racial and Ethnic Differences in Mortality Associated with Serum Potassium in Incident Peritoneal Dialysis Patients

BACKGROUND

Abnormalities in serum potassium are risk factors for sudden cardiac death and arrhythmias among dialysis patients. Although a previous study in hemodialysis patients has shown that race/ethnicity may impact the relationship between serum potassium and mortality, the relationship remains unclear among peritoneal dialysis (PD) patients where the dynamics of serum potassium is more stable.

METHODS

Among 17,664 patients who started PD between January 1, 2007 and December 31, 2011 in a large US dialysis organization, we evaluated the association of serum potassium levels with all-cause and arrhythmia-related deaths across race/ethnicity using time-dependent Cox models with adjustments for demographics. We also used restricted cubic spline functions for serum potassium levels to explore non-linear associations.

RESULTS

Baseline serum potassium levels were the highest among Hispanics (4.2 ± 0.7 mEq/L) and lowest among non-Hispanic blacks (4.0 ± 0.7 mEq/L). Among 2,949 deaths during the follow-up of median 2.2 (interquartile ranges 1.3-3.2) years, 683 (23%) were arrhythmia-related deaths. Overall, both hyperkalemia and hypokalemia (i.e., serum potassium levels >5.0 and <3.5 mEq/L, respectively) were associated with higher all-cause and arrhythmia-related mortality. In a stratified analysis according to race/ethnicity, the association of hypokalemia with all-cause and arrhythmia-related mortality was consistent with an attenuation for arrhythmia-related mortality in non-Hispanic blacks. Hyperkalemia was associated with all-cause and arrhythmia-related mortality in non-Hispanic whites and non-Hispanic blacks, but no association was observed in Hispanics.

CONCLUSION

Among incident PD patients, hypokalemia was consistently associated with all-cause and arrhythmia-related deaths irrespective of race/ethnicity. However, while hyperkalemia was associated with both death outcomes in non-Hispanic blacks and whites, it was not associated with either death outcome in Hispanic patients. Further studies are needed to demonstrate whether different strategies should be followed for the management of serum potassium levels according to race/ethnicity.

Admission serum sodium and potassium levels predict survival among critically ill patients with acute kidney injury: a cohort study

BACKGROUND

Patients suffering from acute kidney injury (AKI) were associated with impaired sodium and potassium homeostasis. We aimed to investigate how admission serum sodium and potassium independently and jointly modified adverse clinical outcomes among AKI patients.

METHODS

Patient data were extracted from the Multiparameter Intelligent Monitoring in Intensive Care Database III. Participants were categorized into three groups according to admission serum sodium and potassium, and the cut-off values were determined using smooth curve fitting. The primary outcome was 90-day mortality in the intensive care unit (ICU). Cox proportional hazards models were used to evaluate the prognostic effects of admission serum sodium and potassium levels.

RESULTS

We included 13,621 ICU patients with AKI (mean age: 65.3 years; males: 55.4%). The middle category of admission serum sodium and potassium levels were 136.0-144.9 mmol/L and 3.7-4.7 mmol/L through fitting smooth curve. In multivariable Cox models, compared with the middle category, patients with hyponatremia or hypernatremia were associated with excess mortality and the HRs and its 95%CIs were 1.38 (1.27, 1.50) and 1.56 (1.36, 1.79), and patients with either hypokalemia or hyperkalemia were associated with excess mortality and the hazard ratios (HRs) and its 95% confidential intervals (95% CIs) were 1.12 (1.02, 1.24) and 1.25 (1.14, 1.36), respectively. Significant interactions were observed between admission serum sodium and potassium levels (P interaction = 0.001), with a higher serum potassium level associated with increased risk of 90-day mortality among patients with hyponatremia, whereas the effects of higher sodium level on prognostic effects of potassium were subtle.

CONCLUSIONS

Admission serum sodium and potassium were associated with survival in a U-shaped pattern among patients with AKI, and hyperkalemia predict a worse clinical outcome among patients with hyponatremia.

Cut-off values of serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest: A retrospective multi-centre study

AIM

Evidence of existing guidelines for the on-site triage of avalanche victims is limited and adherence suboptimal. This study attempted to find reliable cut-off values for the identification of hypothermic avalanche victims with reversible out-of-hospital cardiac arrest (OHCA) at hospital admission. This may enable hospitals to allocate extracorporeal life support (ECLS) resources more appropriately while increasing the proportion of survivors among rewarmed victims.

METHODS

All avalanche victims with OHCA admitted to seven centres in Europe capable of ECLS from 1995 to 2016 were included. Optimal cut-off values, for parameters identified by logistic regression, were determined by means of bootstrapping and exact binomial distribution and served to calculate sensitivity, rate of overtriage, positive and negative predictive values, and receiver operating curves.

RESULTS

In total, 103 avalanche victims with OHCA were included. Of the 103 patients 61 (58%) were rewarmed by ECLS. Six (10%) of the rewarmed patients survived whilst 55 (90%) died. We obtained optimal cut-off values of 7 mmol/L for serum potassium and 30 °C for core temperature.

CONCLUSION

For in-hospital triage of avalanche victims admitted with OHCA, serum potassium accurately predicts survival. The combination of the cut-offs 7 mmol/L for serum potassium and 30 °C for core temperature achieved the lowest overtriage rate (47%) and the highest positive predictive value (19%), with a sensitivity of 100% for survivors. The presence of vital signs at extrication is strongly associated with survival. For further optimisation of in-hospital triage, larger datasets are needed to include additional parameters.

Potassium homoeostasis and pathophysiology of hyperkalaemia

Determination of potassium level is one of the most frequent laboratory tests in clinical medicine. Hyperkalaemia is defined as a potassium level >5.0 mmol/L and is one of the most clinically important electrolyte abnormalities, because it may cause dangerous cardiac arrhythmia and sudden cardiac death. Here, we review methodological challenges in the determination of potassium levels, important clinical aspects of the potassium homoeostasis as well as of the pathophysiology of hyperkalaemia.

Association of Abnormal Serum Potassium Levels with Arrhythmias and Cardiovascular Mortality: a Systematic Review and Meta-Analysis of Observational Studies

PURPOSE

To provide the first systematic review and meta-analysis of observational studies on the association of abnormal serum potassium and cardiovascular outcomes.

METHODS

Medline and ISI Web of Knowledge were systematically searched from inception until November 24, 2017. Data synthesis of relevant studies was performed using random effects model meta-analyses.

RESULTS

Meta-analyses included 310,825 participants from 24 studies. In the older general population, low serum potassium was associated with a 1.6-fold increased risk of supraventricular arrhythmias (risk ratio [95% confidence interval] 1.62 [1.02-2.55]). Contrarily, high serum potassium was associated with increased cardiovascular mortality (CVM) (1.38 [1.14-1.66]). In patients with acute myocardial infarction, the risk of ventricular arrhythmias was increased for high serum potassium (2.33 [1.60-3.38]). A U-shaped association was observed with a composite cardiovascular outcome in hypertensive patients (2.6-fold increased risk with hypokalemia and 1.7-fold increased risk with hyperkalemia), with CVM in dialysis patients (1.1-fold increased risk with hypokalemia and 1.4-fold increased risk with hyperkalemia) and with CVM in heart failure patients (albeit not statistically significant). Further, only hyperkalemia was associated with an increased risk of a composite cardiovascular outcome in both dialysis (1.12 [1.03-1.23]) and chronic kidney disease (1.34 [1.06-1.71]) patients.

CONCLUSIONS

Controlled clinical trials are needed to determine which populations may profit from more frequent potassium-monitoring and subsequent interventions, e.g., change or withdrawal of potassium-influencing drugs, in order to restore normal values and prevent cardiovascular outcomes.

REGISTRATION DETAILS

Registration in PROSPERO (Centre for Reviews and Dissemination University of York, York, UK): CRD42016048897 ( https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=48897 ).

Serum potassium and clinical outcomes in heart failure patients: results of risk calculations in 21 334 patients in the UK

Aims

At present, the clinical burden of hypokalaemia and hyperkalaemia among European heart failure patients, and relationships between serum potassium and adverse clinical outcomes in this population, is not well characterized. The aim of this study was to investigate associations between mortality, major adverse cardiac events, and renin–angiotensin–aldosterone system inhibitor (RAASi) discontinuation across serum potassium levels, in a UK cohort of incident heart failure patients.

Methods and results

This was a retrospective observational cohort study of newly diagnosed heart failure patients listed in the Clinical Practice Research Datalink, with a first record of heart failure (index date) between 2006 and 2015. Hypokalaemia and hyperkalaemia episodes were defined as the number of serum potassium measurements exceeding each threshold (<3.5, ≥5.0, ≥5.5, and ≥6.0 mmol/L), without such a measurement in the preceding 7 days. Risk equations developed using Poisson generalized estimating equations were utilized to estimate adjusted incident rate ratios (IRRs) relating serum potassium and clinical outcomes (death, major adverse cardiac event, and RAASi discontinuation). Among 21,334 eligible heart failure patients, 1969 (9.2%), 7648 (35.9%), 2725 (12.8%), and 763 (3.6%) experienced episodes of serum potassium <3.5, ≥5.0, ≥5.5, and ≥6.0 mmol/L, respectively. The adjusted IRRs for mortality exhibited a U‐shaped association pattern with serum potassium. Relative to the reference category (4.5 to <5.0 mmol/L), adjusted IRRs for mortality were estimated as 1.98 (95% confidence interval: 1.69–2.33), 1.23 (1.12–1.36), 1.35 (1.14–1.60), and 3.02 (2.28–4.02), for patients with serum potassium <3.5, ≥5.0 to <5.5, ≥5.5 to <6.0, and ≥6.0 mmol/L, respectively. The adjusted IRRs for major adverse cardiac events demonstrated a non‐statistically significant relationship with serum potassium. Discontinuation of RAASi therapy exhibited a J‐shaped trend in association with serum potassium. Compared with the reference category (4.5 to <5.0 mmol/L), adjusted IRRs were estimated as 1.07 (0.89–1.28) in patients with serum potassium <3.5 mmol/L, increasing to 1.32 (1.14–1.53) and 2.19 (1.63–2.95) among those with serum potassium ≥5.5 to <6.0 and ≥6.0 mmol/L, respectively.

Conclusions

In UK patients with new onset heart failure, both hypokalaemia and hyperkalaemia were associated with increased mortality risk, and hyperkalaemia was associated with increased likelihood of RAASi discontinuation. Our results demonstrate the potential importance of serum potassium monitoring for heart failure outcomes and management.

Serum sodium concentration and the progression of established chronic kidney disease

Background

Higher serum sodium concentration has been reported to be a risk factor for the development of incident chronic kidney disease (CKD), but its relationship with the progression of established CKD has not been investigated. We hypothesised that increased serum sodium concentration is a risk factor for estimated glomerular filtration rate (eGFR) decline in CKD.

Methods

This was a retrospective cohort study using data collected over a 6-year period, with baseline data obtained during the first 2 years. We included patients known to our renal service who had had a minimum of three blood tests every 2 years and an eGFR of < 60 mL/min/1.73 m² at baseline. Exclusion criteria were renal replacement therapy, diabetes mellitus, heart failure and decompensated liver disease. A multiple linear regression model investigated the relationship between baseline serum sodium and eGFR decline after adjustment for confounding factors.

Results

7418 blood results from 326 patients were included. There was no relationship between serum sodium concentration and estimated glomerular filtration rate at baseline. After multivariable adjustment, a 1 mmol/L increase in baseline serum sodium was associated with a 1.5 mL/min/1.73 m² decline in eGFR during the study period (95% CI 0.9, 2.0). A reduction in eGFR was not associated with significant changes in serum sodium concentration over 6 years.

Conclusion

Higher serum sodium concentration is associated with the progression of CKD, independently of other established risk factors. Conversely, significant alterations in serum sodium concentration do not occur with declining kidney function.

Abnormal serum potassium levels and 6-month all-cause mortality in patients co-treated with antipsychotic and diuretic drugs - A Danish register-based cohort study

Psychiatric patients have excess mortality compared to the general population, and several potential mechanisms may explain this increased risk. This study examined the relationship between serum potassium levels and risk of all-cause mortality in patients co-treated with antipsychotic and diuretic drugs. Using a register-based cohort design, we identified patients between 1995 and 2012 who received a combination of an antipsychotic and a diuretic drug and who further had a serum potassium measurement within 90 days. During the study period, we included the most frequently redeemed antipsychotic drugs with regard to the propensity of corrected QT (QTc) prolongation: zuclopenthixol (unknown/mild), flupentixol (mild), levomepromazine (moderate), and quetiapine (moderate/severe). Patients co-treated with antidepressant drugs, lithium, and other antipsychotic drugs were excluded. Outcome was 6-month all-cause mortality, estimated with multivariable Cox regression. Patients were divided into seven serum potassium levels using restricted cubic splines (reference: 4.2-4.4 mmol/L) and stratified according to the included antipsychotic drugs. Of 6729 patients (median age: 74.0 years; women: 65.3%), 10.8% had hypokalemia and 4.9% had hyperkalemia. Hyperkalemia (>5.0 mmol/L, HR 2.82 [95% CI 2.25-3.54]), hypokalemia (<3.5 mmol/L, HR 1.59 [95% CI 1.29-1.95]), and high normal potassium levels (4.5-4.7 mmol/L, HR 1.44 [95% CI 1.19-1.75]; 4.8-5.0 mmol/L, HR 1.60 [95% CI 1.26-2.04]) were associated with an increased risk of 6-month all-cause mortality. This risk was independent of antipsychotic drugs (interaction: P = 0.06). Our findings imply that excess mortality in patients co-treated with antipsychotic and diuretic drugs is related to serum potassium levels and independent of antipsychotic drugs.

Effect of serum electrolytes within normal ranges on QTc prolongation: a cross-sectional study in a Chinese rural general population

Background

Many previous clinical studies have reported that prolongation of the QT interval corrected for heart rate (QTc) is associated with an increased risk of sudden cardiac death and all-cause mortality. This study aimed to explore associations between serum electrolytes and QTc prolongation in the north-eastern Chinese rural general population.

Methods

We performed a cross-sectional study including 10,334 (4820 men and 5514 women) from the general population aged ≥35 years in the Liaoning Province from 2012 to 2013. Anthropometric measurements, laboratory examinations and self-reported lifestyle factor information, echocardiography and electrocardiogram were collected by trained personnel. The associations between serum electrolytes and QTc prolongation were tested using multiple linear regression and logistic regression analyses.

Results

The mean QTc interval were 415.6 ± 18.8 and 470.1 ± 23.1 ms in normal group and QTc prolongation group respectively. The prevalence of QTc prolongation increased significantly with a decrease in serum potassium and an increase in magnesium. Stepwise multiple linear regression showed that age, hypertension, waist circumference were prominently positive associated with QTc interval both in male and female population. But serum potassium was significantly inversely associated with QTc interval. Serum magnesium and calcium also showed a positive relationship with QTc interval. Furthermore, multiple logistic regression found that lower quartile of serum potassium had higher risk for QTc prolongation, especially in female population (Q2 vs. Q4: OR: 1.54, 95%CI: 1.01–2.35; Q1 vs. Q4: OR: 2.02, 95%CI: 1.36–3.01). In addition, the higher serum magnesium increased the risk of QTc prolongation, which was significantly only in male population.

Conclusions

In present Chinese rural general population, even with normal range, a decrease in serum potassium and an increase in serum magnesium are important risk factors for QTc prolongation.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0906-1) contains supplementary material, which is available to authorized users.

Dialysate Potassium and Mortality in a Prospective Hemodialysis Cohort

BACKGROUND

Studies examining the association of dialysate potassium concentration and mortality in hemodialysis patients show conflicting findings. We hypothesized that low dialysate potassium concentrations are associated with higher mortality, particularly in patients with high pre-dialysis serum potassium concentrations.

METHODS

We evaluated 624 hemodialysis patients from the prospective Malnutrition, Diet, and Racial Disparities in Kidney Disease study recruited from 16 outpatient dialysis facilities over 2011-2015 who underwent protocolized collection of dialysis treatment characteristics every 6 months. We examined the association of dialysate potassium concentration, categorized as 1, 2, and 3 mEq/L, with all-cause mortality risk in the -overall cohort, and stratified by pre-dialysis serum potassium (< 5 vs. ≥5 mEq/L) using case-mix adjusted Cox models.

RESULTS

In baseline analyses, dialysate potassium concentrations of 1 mEq/L were associated with higher mortality, whereas concentrations of 3 mEq/L were associated with similar mortality in the overall cohort (reference: 2 mEq/L): adjusted hazard ratios (aHRs; 95% CI) 1.70 (1.01-2.88) and 0.95 (0.64-1.39), respectively. In analyses stratified by serum potassium, baseline dialysate potassium concentrations of 1 mEq/L were associated with higher mortality in patients with serum potassium ≥5 mEq/L but not in those with serum potassium < 5 mEq/L: aHRs (95% CI) 2.87 (1.51-5.46) and 0.74 (0.27-2.07), respectively (p interaction = 0.04). These findings were robust with incremental adjustment for serum potassium, potassium-binding resins, and potassium-modifying medications.

CONCLUSION

Low (1 mEq/L) dialysate potassium -concentrations were associated with higher mortality, particularly in hemodialysis patients with high pre-dialysis serum potassium. Further studies are needed to identify therapeutic strategies that mitigate inter-dialytic serum potassium accumulation and subsequent high dialysate serum potassium gradients in this population.

Clinical predictor of postoperative hyperkalemia after parathyroidectomy in patients with hemodialysis

OBJECTIVE

Hyperkalaemia is one of the most common reasons for patients requiring emergency treatment. This study is to investigate the risk factors of postoperative hyperkalemia in renal failure patients undergoing parathyroidectomy with autotransplantation (PTXa).

METHODS

One hundred and eight patients [ 54 men and 54 women; age, 45.1 ± 11.1 years (mean ± SD)] with secondary hyperparathyroidism undergoing parathyroidectomy with autotransplantation were involved in this study. Laboratory chemistries (hemoglobin, fasting blood glucose, serum calcium level, alkaline phosphatase, phosphorus, parathyroid hormone) were measured before surgery. Serum potassium level was obtained before surgery and at 0 h after surgery.

RESULTS

Serum potassium level increased in 108 patients after surgery (P < 0.05). Sixteen patients (14.8%) potassium levels rose more than 6.0 mmol/L after parathyroidectomy with autotransplantation. Age and preoperative serum potassium level were significantly negative correlated with postoperative serum potassium level. Correlation analysis and receiver operating characteristic curve method confirmed that use of the preoperative serum potassium level was the primary predictor of postoperative hyperkalemia. The cutoff point for preoperative serum potassium level was 4.40 mmol/L, according to the Youden index of the receiver operating characteristic curve.

CONCLUSIONS

Preoperative serum potassium increased after parathyroidectomy with autotransplantation in patients with secondary hyperparathyroidism. The preoperative serum potassium level could help the surgeon to predict postoperative hyperkalemia in case of emergency dialysis following surgery.

[Serum potassium levels and long-term mortality in the elderly with hypertension]

There is increasing evidence that small variations within the normal range (3.5-5mEq/L) of potassium are associated with mortality.

OBJECTIVE

To determine whether there is an association between serum potassium level (sK) and mortality in a cohort of elderly hypertensive patients.

PATIENTS AND METHODS

A retrospective, observational study was conducted on patients who had sK levels available in a period of clinical stability during their recruitment between January and April 2006 and followed-up for 10 years. The study obtained a total of 62 stable patients, with a mean age of 82.19±6 years (range 69-97), with 74.2% women, 33.9% diabetics, 20.3% with a history of heart failure, Ischaemic heart disease was observed in 19.4% and 44.3% received Angiotensin Converting Enzyme (ACE) inhibitors. An analysis was performed on the mortality rate during the 10 year period. The statistics were performed using the SPSS15.0 package.

RESULTS

There were 49 deaths. The sK had a normal distribution. Baseline mean sK levels and median were 4.45±0.5mEq/L (range 3.1-5.5 mEq/L). Baseline sK levels were significantly higher in diabetic patients and patients on ACE inhibitors. The patients that died had higher sK levels (4.53±0.49mEq/L versus 4.14±0.40mEq/L, P=.011). Survival estimated using Kaplan Meier showed that patients with sK levels higher than the median and P75 had higher mortality.

CONCLUSIONS

In our study, sK levels greater than 4.45mEq/L were associated with mortality. When selecting antihypertensive treatment in hypertensive elderly patients,, the use of ACE inhibitors should be assessed individually, with close monitoring at sK levels and try to keep them in the lower limit of the normal range (<4.45 mEq/L).

Serum potassium concentrations: Importance of normokalaemia

Abnormalities in potassium concentrations are associated with morbidity and mortality. In recent years it has been considered that small variations in serum potassium concentrations within normal intervals may also be associated with mortality. Strategies for achieving normokalaemia include dietary measures, limiting the use of potassium retaining drugs, and use of conventional cation exchange resins (calcium/sodium polystyrene sulfonate) and/or the new non-absorbed cation exchange polymer (patiromer).

Updates in hyperkalemia: Outcomes and therapeutic strategies

Hyperkalemia is a frequent clinical abnormality in patients with chronic kidney disease, and it is associated with higher risk of mortality and malignant arrhythmias. Severe hyperkalemia is a medical emergency, which requires immediate therapies, followed by interventions aimed at preventing its recurrence. Current treatment paradigms for chronic hyperkalemia management are focused on eliminating predisposing factors, such as high potassium intake in diets or supplements, and the use of medications known to raise potassium level. Among the latter, inhibitors of the renin-angiotensin aldosterone system are some of the most commonly involved medications, and their discontinuation is often the first step taken by clinicians to prevent the recurrence of hyperkalemia. While this strategy is usually successful, it also deprives patients of the recognized benefits of this class, such as their renoprotective effects. The development of novel potassium binders has ushered in a new era of hyperkalemia management, with a focus on chronic therapy while maintaining the use of beneficial, but hyperkalemia-inducing medications such as renin-angiotensin aldosterone system inhibitors. This review article examines the incidence and clinical consequences of hyperkalemia, and its various treatment options, with special emphasis on novel therapeutic agents and the potential benefits of their application.

A Comparative Effectiveness Study of Renal Parameters Between Imidapril and Amlodipine in Patients with Hypertension: A Retrospective Cohort Study

Introduction

Imidapril is an angiotensin converting enzyme inhibitor (ACEI) that is frequently used as an antihypertensive drug in Japan. Although ACEIs are known to have adverse effects of decreasing glomerular filtration rate (GFR) and causing hyperkalemia, there are very few clinical data on the long-term effect of imidapril on glomerular function. We conducted a retrospective cohort study using a clinical database to evaluate and compare the long-term effects of imidapril and amlodipine on renal parameters in Japanese hypertensive patients in routine clinical practice.

Methods

We identified cohorts of new users of imidapril (n = 57) and a propensity score-matched group with an equal number of new users of amlodipine (n = 57). We used a multivariable regression model to evaluate and compare the effects of the drugs on laboratory parameters including serum levels of creatinine, potassium, sodium, blood urea nitrogen, and estimated GFR (eGFR) between imidapril users and amlodipine users up to 12 months after the initiation of study drug administration. The mean exposure of imidapril and amlodipine was 226.2 and 235.2 days, respectively.

Results

We found a significant increase of serum creatinine and potassium levels and a decrease of eGFR in imidapril users from the baseline period to the exposure period. The reduction of eGFR and the increase of serum creatinine and potassium levels in imidapril users were significantly greater than those in amlodipine users.

Conclusions

Our study showed that imidapril decreased eGFR and increases the serum levels of creatinine and potassium compared with amlodipine, at least during 1 year of administration.

New clinical decision rule to exclude subarachnoid haemorrhage for acute headache: a prospective multicentre observational study

OBJECTIVE

To ensure good outcomes in the management of subarachnoid haemorrhage (SAH), accurate prediction is crucial for initial assessment of patients presenting with acute headache. We conducted this study to develop a new clinical decision rule using only objectively measurable predictors to exclude SAH, offering higher specificity than the previous Ottawa SAH Rule while maintaining comparable sensitivity.

DESIGN

Multicentre prospective cohort study.

SETTING

Tertiary-care emergency departments of five general hospitals in Japan from April 2011 to March 2014.

PARTICIPANTS

Eligible patients comprised 1781 patients aged >15 years with acute headache, excluding trauma or toxic causes and patients who presented in an unconscious state.

MAIN OUTCOME MEASURES

Definitive diagnosis of SAH was based on confirmation of SAH on head CT or lumbar puncture findings of non-traumatic red blood cells or xanthochromia.

RESULTS

A total of 1561 patients were enrolled in this study, of whom 277 showed SAH. Using these enrolled patients, we reached a rule with mainly categorical predictors used in previous reports, called the 'Ottawa-like rule', offering 100% sensitivity when using any of age ≥40 years, neck pain or stiffness, altered level of consciousness or onset during exertion. Using the 1317 patients from whom blood samples were obtained, a new rule using any of systolic blood pressure >150 mm Hg, diastolic blood pressure >90 mm Hg, blood sugar >115 mg/dL or serum potassium <3.9 mEq/L offered 100% sensitivity (95% CI 98.6% to 100%) and 14.5% specificity (12.5% to 16.9%), while the Ottawa-like rule showed the same sensitivity with a lower specificity of 8.8% (7.2% to 10.7%).

CONCLUSIONS

While maintaining equal sensitivity, our new rule seemed to offer higher specificity than the previous rules proposed by the Ottawa group. Despite the need for blood sampling, this method can reduce unnecessary head CT in patients with acute headache.

TRIAL REGISTRATION NUMBER

UMIN 00004871.

Role of Dietary Components in Modulating Hypertension

Hypertension is a major health issue, particularly in medically underserved populations that may suffer from poor health literacy, poverty, and limited access to healthcare resources. Management of the disease reduces the risk of adverse outcomes, such as cardiovascular or cerebrovascular events, vision impairment due to retinal damage, and renal failure. In addition to pharmacological therapy, lifestyle modifications such as diet and exercise are effective in managing hypertension. Current diet guidelines include the DASH diet, a low-fat and low-sodium diet that encourages high consumption of fruits and vegetables. While the diet is effective in controlling hypertension, adherence to the diet is poor and there are few applicable dietary alternatives, which is an issue that can arise from poor health literacy in at-risk populations. The purpose of this review is to outline the effect of specific dietary components, both positive and negative, when formulating a dietary approach to hypertension management that ultimately aims to improve patient adherence to the treatment, and achieve better control of hypertension.

Management of Hyperkalemia: An Update for the Internist

Hyperkalemia is a clinically important electrolyte abnormality that occurs most commonly in patients with chronic kidney disease. Due to its propensity to induce electrophysiological disturbances, severe hyperkalemia is considered a medical emergency. The management of acute and chronic hyperkalemia can be achieved through the implementation of various interventions, one of which is the elimination of medications that can raise serum potassium levels. Because many such medications (especially inhibitors of the renin-angiotensin aldosterone system) have shown beneficial effects in patients with cardiovascular and renal disease, their discontinuation for reasons of hyperkalemia represent an undesirable clinical compromise. The emergence of 2 new potassium-binding medications for acute and chronic therapy of hyperkalemia may soon allow the continued use of medications such as renin-angiotensin-aldosterone system inhibitors even in patients who are prone to hyperkalemia. This review article provides an overview of the physiology and the pathophysiology of potassium metabolism and hyperkalemia, the epidemiology of hyperkalemia, and its acute and chronic management. We discuss in detail emerging data about new potassium-lowering therapies, and their potential future role in clinical practice.

Short-term mortality risk of serum potassium levels in acute heart failure following myocardial infarction

AIMS

Diuretic treatment is often needed in acute heart failure following myocardial infarction (MI) and carries a risk of abnormal potassium levels. We examined the relation between different levels of potassium and mortality.

METHODS AND RESULTS

From Danish national registries we identified 2596 patients treated with loop diuretics after their first MI episode where potassium measurement was available within 3 months. All-cause mortality was examined according to seven predefined potassium levels: hypokalaemia <3.5 mmol/L, low normal potassium 3.5-3.8 mmol/L, normal potassium 3.9-4.2 mmol/L, normal potassium 4.3-4.5 mmol/L, high normal potassium 4.6-5.0 mmol/L, mild hyperkalaemia 5.1-5.5 mmol/L, and severe hyperkalaemia: >5.5 mmol/L. Follow-up was 90 days and using normal potassium 3.9-4.2 mmol/L as a reference, we estimated the risk of death with a multivariable-adjusted Cox proportional hazard model. After 90 days, the mortality rates in the seven potassium intervals were 15.7, 13.6, 7.3, 8.1, 10.6, 15.5, and 38.3%, respectively. Multivariable-adjusted risk for death was statistically significant for patients with hypokalaemia [hazard ratio (HR): 1.91, confidence interval (95%CI): 1.14-3.19], and mild and severe hyperkalaemia (HR: 2, CI: 1.25-3.18 and HR: 5.6, CI: 3.38-9.29, respectively). Low and high normal potassium were also associated with increased mortality (HR: 1.84, CI: 1.23-2.76 and HR: 1.55, CI: 1.09-2.22, respectively).

CONCLUSION

Potassium levels outside the interval 3.9-4.5 mmol/L were associated with a substantial risk of death in patients requiring diuretic treatment after an MI.

Evaluation of laboratory critical serum potassium values and their association with clinical symptoms in Chinese Han patients

OBJECTIVES

A retrospective, observational study to evaluate the association between critical potassium values and clinical symptoms, and to define critical potassium limits in hospital inpatients of Chinese Han ethnicity.

METHODS

Adult patients (aged ≥ 18 years) of Chinese Han ethnicity admitted to the Beilun People's Hospital of Ningbo, Zhejiang University, China, were sequentially enrolled. Inpatient data recorded on admission (or at first time during hospital stay for serum potassium values) between 1 January 2011 and 31 December 2012 were used to calculate the percentage of patients with relevant clinical symptoms, the percentage of critical patients (presence of neurological symptoms and deterioration of at least two physiological systems), and the hospital prevalence of clinical symptoms. Correlations between critical serum potassium values and clinical symptoms were determined.

RESULTS

Out of 3 665 included patients, 1 514 patients with a critical serum potassium value (as determined in the present study) were mainly treated in the intensive care unit or the haematology department (low serum potassium, ≤ 2.9 mmol/l), and Renal and Hepatitis departments (high serum potassium, ≥ 6.0 mmol/l). High critical serum potassium values (≥ 6.0 mmol/l) were significantly correlated with clinical symptoms (such as neurological symptoms, loss of appetite, oliguria and hypotension). Low critical serum potassium values (≤ 2.9 mmol/l) were significantly correlated with clinical symptoms (such as neurological symptoms, loss of appetite and dyspnoea).

CONCLUSIONS

Based on the present findings, the lower and upper critical potassium limits were defined as 2.9 mmol/l and 6.0 mmol/l, respectively.

Myofibrillar protein overdegradation in overweight patients with chronic heart failure: the relationship to serum potassium levels

OBJECTIVES

Muscle release of the amino acid 3-methyl-histidine (3MH) is a sensitive index of myofibrillar protein overdegradation (MPO). We hypothesized that patients with chronic heart failure (CHF) could have increased muscle release of 3MH, which in turn reflects MPO, and that serum electrolyte sodium (Na(+)) and potassium (K(+)) levels may be associated with this 3MH muscle release.

METHODS

Thirty-one overweight outpatients (body mass index, 27 ± 4.4 kg/m(2); 22 men and 9 women; age, 56 ± 8.7 y) with clinically stable CHF were studied. After a 24-hour meat-free diet and overnight fasting, patients underwent blood sampling from a cannulated arm vein (V) and concomitantly from the arterial artery (A) to determine plasma 3MH levels and to calculate the A-V difference. Serum levels of Na(+) and K(+) in the venous blood were determined, and the Na(+)/K(+) ratio was calculated. Ten healthy subjects who were matched for gender, age, and body mass index served as controls and underwent the same protocol as the patients with CHF.

RESULTS

The patient group had higher arterial (P = 0.02) and venous (P = 0.005) 3MH levels but a similar A-V 3MH difference (P = 0.28) as compared with the controls. Within the CHF group, 67.7% of patients released 3MH, which resulted in a negative A-V value (P < 0.02 as compared with controls). In patients with CHF, the A-V 3MH difference correlated positively with the serum K(+) level (r = 0.62; P = 0.0002) and negatively with Na(+)/K(+) ratio (r = -0.55; P = 0.002). No association was found between the A-V 3MH difference and the Na(+) level.

CONCLUSIONS

The study demonstrated the existence of MPO in resting overweight patients with CHF, thereby suggesting that low serum levels of K(+) may contribute to MPO.

Serum potassium levels and the risk of atrial fibrillation: the Rotterdam Study

BACKGROUND

Atrial fibrillation is the most common sustained arrhythmia in the elderly. Serum potassium is associated with ventricular arrhythmias and cardiac arrest. Little is known about the association of serum potassium with atrial fibrillation. The objective of this study was to investigate the association of serum potassium and the risk of atrial fibrillation in a population based setting.

METHODS

The study was performed within the prospective population-based Rotterdam Study. The study population consisted of 4059 participants without atrial fibrillation at baseline for whom baseline levels of serum potassium were measured. Atrial fibrillation was ascertained from centre visit ECG assessments as well as medical records.

RESULTS

During a mean follow up of 11.8 years (SD=5.2 yr), 474 participants developed atrial fibrillation. Participants with hypokalemia (<3.5 mmol/l) had a higher risk of atrial fibrillation (HR: 1.63, 95%CI: 1.03-2.56) than those with normokalemia (3.5-5.0 mmol/l). This association was independent of age, sex, serum magnesium, and other potential confounders. Especially in participants with a history of myocardial infarction, those with hypokalemia had a higher risk of atrial fibrillation than those with normokalemia (HR: 3.81, 95%-CI: 1.51-9.61).

CONCLUSIONS

In this study low serum levels of potassium were associated with a higher risk of atrial fibrillation.

Serum potassium level is associated with metabolic syndrome: a population-based study

BACKGROUND & AIMS

Evidence has suggested that low serum potassium concentration or low dietary potassium intake can result in many metabolic disorders. Our objective was to evaluate the association between serum potassium level and risk of prevalent metabolic syndrome.

METHODS

We conducted a cross-sectional study in 10,341 participants aged 40 years or older. Metabolic syndrome was defined according to guidelines from the National Cholesterol Education Program with modification.

RESULTS

The prevalence rate of metabolic syndrome was 51.7% in participants with hypokalemia and 37.7% in those with normokalemia. With the reduction of serum potassium quartiles, participants were tended to have higher level of triglycerides and uric acid, lower level of high-density lipoprotein cholesterol (HDL-C), larger waist circumference and more severe insulin resistance. Serum potassium level significantly decreased with the increasing number of metabolic syndrome components. Compared with subjects in the highest quartile of serum potassium level, multivariate adjusted odds ratios for prevalent metabolic syndrome in the lowest quartile was 1.48 (95% confidence interval, 1.16-1.87). Moreover, compared with subjects without central obesity, hypertriglyceridemia, low HDL-C and elevated fasting plasma glucose, those with each of these metabolic syndrome components have lower level of serum potassium after adjusted for age and sex.

CONCLUSIONS

Low serum potassium level significantly associated with prevalence of metabolic syndrome in middle-aged and elderly Chinese.

pre-operative serum potassium levels and peri-operative outcomes in patients undergoing cardiac surgery

Although potassium is critical for normal electro physiology, the associations between pre-operative serum potassium level and peri-operative adverse events such as arrhythmias in cardiac surgery have not been examined in detail.The objective of this study was to determine the prevalence of abnormal pre-operative serum potassium levels and whether such levels were associated with adverse peri-operative events in 50 patients undergoing coronary artery bypass grafting. Intra-operative and post-operative arrhythmias, the need for cardio-pulmonary resuscitation, cardiac death and death due to any cause prior to discharge from the post-operative intensive care unit were studied. The incidence for adverse outcome was 0.5% for death, 0.5% for cardiac death and 2% for cardio pulmonary resuscitation in patients with hypokalemia (serum potassium level <3.5 meq. L(-1)). Hypokalemia was found to be a predictor of serious peri-operative (OR:2.2; 95% Cl: 1.2-4.1) and post-operative arrhythmias (OR: 1.7;95%Cl: 1.0-2.7).Pre-operative potassium repletion is low cost and low risk treatment measure and the data from this study suggests that screening and repletion be considered in patients scheduled for cardiac surgery.