Adverse outcomes and mortality in individuals with eating disorder-related electrolyte abnormalities in Ontario, Canada: a population-based cohort study.

BACKGROUND: Individuals with eating disorders are at a higher risk of electrolyte abnormalities than the general population. We conducted the first representative cohort study assessing whether electrolyte abnormalities in people with eating disorders were associated with mortality and physical health outcomes. METHODS: This was a retrospective population-based cohort study in Ontario including people aged 13 years or older with an eating disorder and an outpatient electrolyte measure within 1 year (between Jan 1, 2008 and June 30, 2019). An electrolyte abnormality was any of hypokalaemia, hyperkalaemia, hyponatraemia, hypernatraemia, hypomagnesaemia, hypophosphataemia, metabolic acidosis, or metabolic alkalosis. The primary outcome was all-cause mortality. Secondary outcomes were hospitalisation, a cardiac event, infection, acute or chronic kidney disease, fracture, and bowel obstruction. In additional analyses, we examined a younger cohort (<25 years old) and individuals with no previously diagnosed secondary outcome. We involved people with related lived or family experience in the study. FINDINGS: 6163 patients with an eating disorder and an electrolyte measure within 1 year since diagnosis (mean age 26·8 years [SD 17·5]; 5456 [88·5%] female, 707 [11·5%] male; median follow-up 6·4 years [IQR 4-9]) were included. Ethnicity data were not available. The most common electrolyte abnormalities were hypokalaemia (994/1987 [50·0%]), hyponatraemia (752/1987 [37·8%]), and hypernatraemia (420/1987 [21·1%]). Overall, mortality occurred in 311/1987 (15·7%) of those with an electrolyte abnormality versus 234/4176 (5·6%) in those without (absolute risk difference 10·1%; adjusted hazard ratio 1·23 [95% CI 1·03-1·48]). Hospitalisation (1202/1987 [60·5%] vs 1979/4176 [47·4%]; 1·35 [1·25-1·46]), acute kidney injury (206/1987 [10·4%] vs 124/4176 [3%]; 1·91 [1·50-2·43]), chronic kidney disease (245/1987 [12·3%] vs 181/4176 [4·3%]; 1·44 [1·17-1·77]), bone fracture (140/1987 [7·0%] vs 167/4176 [4·0%]; 1·40 [1·10-1·78]), and bowel obstruction (72/1987 [3·6%] vs 57/4176 [1·4%]; 1·62 [1·12-2·35]) were associated with an electrolyte abnormality, but not infection or a cardiovascular event. Findings were consistent in young individuals (<25 years old) and those without secondary outcomes at baseline, by eating disorder type, and by sex. INTERPRETATION: Electrolyte abnormalities are associated with death and poor physical health outcomes, supporting the importance of monitoring and possible interventions to prevent adverse outcomes. Findings also call for a refinement of the definition of severity of eating disorder and replication of these findings in other jurisdictions. FUNDING: None.

Hyponatremia Is Associated with Mortality in Acute Pancreatitis Patients.

BACKGROUND: Disorders of serum sodium are common among general patients and are associated with poor outcomes. The prognostic value of serum sodium disorders in patients with acute pancreatitis (AP) has not been studied. We conducted this retrospective study to explore the association between serum sodium levels and the outcomes of patients with AP. MATERIALS AND METHODS: Patients with AP from the Medical Information Mart for Intensive Care III (MIMIC-III) were screened for this study. The laboratory variables, including serum sodium levels, were obtained by analyzing the first blood sample on the first day after admission. Univariate logistic regression was performed to discover potential factors for mortality of AP. The unadjusted and adjusted association between serum sodium level and mortality of AP was shown by the restricted cubic spline (RCS). The categorical cutoff for the detrimental effect of serum sodium level on the prognosis of AP was also confirmed by stepwise logistic regression after adjusting for con-founding effects of significant factors in the univariate logistic regression. RESULTS: A total of 869 patients with AP in the MIMIC-III were included with a mortality of 13.1%. Unadjusted logistic regression showed that age (p < 0.001), simplified acute physiological score (SAPS) (p < 0.001), systolic blood pressure (p < 0.001), diastolic blood pressure (p < 0.001), hemoglobin (p = 0.040), serum creatinine (p = 0.046), and serum phosphorus (p < 0.001) were significantly associated with the mortality of AP. The RCS showed that the serum sodium level was negatively and linearly associated with mortality of AP after adjusting for confounding effects of significant factors in the univariate logistic regression. Serum sodium < 133 mmol/L, which indicated hyponatremia, was significantly correlated with a higher mortality risk than serum sodium ≥ 133 mmol/L (p = 0.013). CONCLUSIONS: Hyponatremia is widely developed among patients with AP and correlates with a higher mortality risk of AP. Physicians should pay more attention to managing patients with AP with hyponatremia.

Association Between Preoperative Hyponatremia and Survival After Liver Transplant: A Systematic Review and Meta-Analysis.

OBJECTIVES: Numerous studies have been conducted to investigate the effects of preoperative hyponatremia on survival after liver transplantation. The variable findings underscore the necessity for performing a systematic review to elucidate the potential effects of preoperative hyponatremia. MATERIALS AND METHODS: We searched PubMed, Scopus, Web of Science, Science Direct, Cochrane Library, and reference lists of articles for observational cohort studies that reported association between preopera-tive hyponatremia and survival after liver transplant in adults regardless of publication year. We used the random-effect model to pool the extracted data for meta-analysis. RESULTS: Meta-analyses of mean difference in serum sodium levels showed that nonsurviving recipients had 2.58 mEq/L lower preoperative serum sodium levels than surviving recipients (0.02; 95% CI, .33-4.83). Two observational methods were used to assess survival after liver transplant of patients with preoperative hyponatremia. According to meta-analyses, no dif-ference in survival was shown between recipients with and without preoperative hyponatremia (sodium> 130 mEq/L) (≤1 month : 0.69 [95% CI, 0.9-1.07], 3-month survival: 0.54 [95% CI, 0.95-1.02]). Second, when we compared posttransplant survival of recipients with preoperative hypo-natremia versus those with normal serum sodium levels (sodium = 130-145 mEq/L), we found that recipients with preoperative hyponatremia had lower survival after liver transplant than those with normal preoperative serum sodium levels. CONCLUSIONS: Liver transplant recipients with preop-erative hyponatremia probably have shorter survival posttransplant than those with normal preoperative serum sodium level.

Association of serum sodium levels with fractures and mortality in patients undergoing maintenance hemodialysis.

BACKGROUND: Hyponatremia is implicated in pathological bone resorption and has been identified as a risk factor for bone fracture in the general population. However, there are limited data on the association between serum sodium levels and fracture risk in patients undergoing hemodialysis (HD). METHODS: We analyzed a historical cohort of 2220 maintenance HD patients to examine the association between serum sodium levels and the risk of fracture and mortality. We also examined the association between serum sodium levels and osteoporosis, based on metacarpal bone mineral density, in a subcohort of 455 patients with available data. In addition, we examined the association between serum sodium levels and bone turnover markers in a separate cross-sectional cohort of 654 maintenance HD patients. RESULTS: During a median follow-up of 5.4 years, 712 patients died, 113 experienced clinical fractures, and 64 experienced asymptomatic vertebral fractures. Lower serum sodium levels were associated with an increased risk of mortality (HR 1.06 per 1 mEq/L decrease; 95% CI 1.03-1.09) but not with the risk of clinical fracture (HR 1.04 per 1 mEq/L decrease; 95% CI 0.97-1.11). A similar lack of association was observed for asymptomatic vertebral fracture and any fracture. Serum sodium levels were also not associated with osteoporosis in a subcohort with available data (n = 455) or with bone alkaline phosphatase or tartrate-resistant acid phosphatase-5b in a separate cross-sectional cohort. CONCLUSION: Serum sodium levels were associated with mortality but not with fracture risk, osteoporosis, or bone turnover markers in maintenance HD patients.

Mortality predictors of patients diagnosed with severe hyponatremia in the emergency department.

PURPOSE: To determine the factors affecting mortality as a result of the analysis of the demographic and clinical characteristics and laboratory parameters of patients whose serum Na value was determined to be 125 mEq/L or below at the time of admission to the emergency department (ED). METHOD: Patients over 18 years of age who admitted to the ED of a tertiary hospital between September 2021 and September 2022 and whose serum sodium level was determined to be 125 mEq/L and below were included in the study. Demographic and clinical characteristics, admission complaints, medications used, Charles comorbidity index (CCI), laboratory parameters, and outcomes of the patients included in the study were recorded in the data form. RESULTS: Three hundred ninety-nine patients were included in the study. When the 30-day mortality of the patients is examined, the mortality rate was found to be 21.6%. In the analyses performed for the predictive power of laboratory parameters for mortality, it was determined that the highest predictive power among the predictive values determined by the area under the curve (AUC) was the albumin level (AUC 0.801, 95% CI 0.753-0.849, p < 0.001). In the binary logistic regression analysis, urea and albumin were independent predictors of 30-day mortality. CONCLUSION: According to study data, albumin and urea levels are independent predictors of 30-day mortality in patients diagnosed with severe hyponatremia in the emergency department.

Retrospective analysis of patients diagnosed with severe hyponatraemia in the emergency department.

Background . We investigated the demographic, aetiological and clinical characteristics of patients who presented to the emergency department and had severe hyponatraemia. Methods . We retrospectively evaluated 1171 patients who presented to the emergency department and were diagnosed with severe hyponatraemia. Results . Over half the patients studied were women (53.5%). The mean age of women was higher (p<0.0001). The most common complaint was dyspnoea (16.8%) and 42.5% of the patients had an oral intake disorder. In addition, 22.3% of the patients were on loop diuretics. About 76.3% of patients were conscious, and the mean sodium level of these patients was higher than the mean sodium level of those who responded to verbal and painful stimuli (p<0.001). Severe isolated hyponatraemia was observed in 61.8% of the patients. The mortality rate was 12.8%. There was no difference between the mean sodium levels of the deceased and discharged patients (p=1.0). The mortality rate was higher in patients who had a history of cirrhosis and cancer, but was lower in patients with a history of coronary artery disease (p=0.0002, p<0.0001 and p=0.04, respectively). Conclusion . Severe hyponatraemia was more prevalent in women, serum sodium levels were higher in conscious patients, and the mortality rate was higher in patients who had a history of cirrhosis and cancer. We found that the mean serum sodium levels did not help in distinguishing between the deceased and discharged patients.

Dysnatremia is a Predictor for Morbidity and Mortality in Hospitalized Patients with COVID-19.

CONTEXT: Dysnatremia is an independent predictor of mortality in patients with bacterial pneumonia. There is paucity of data about the incidence and prognostic impact of abnormal sodium concentration in patients with coronavirus disease 2019 (COVID-19). OBJECTIVE: This work aimed to examine the association of serum sodium during hospitalization with key clinical outcomes, including mortality, need for advanced respiratory support and acute kidney injury (AKI), and to explore the role of serum sodium as a marker of inflammatory response in COVID-19. METHODS: This retrospective longitudinal cohort study, including all adult patients who presented with COVID-19 to 2 hospitals in London over an 8-week period, evaluated the association of dysnatremia (serum sodium < 135 or > 145 mmol/L, hyponatremia, and hypernatremia, respectively) at several time points with inpatient mortality, need for advanced ventilatory support, and AKI. RESULTS: The study included 488 patients (median age, 68 years). At presentation, 24.6% of patients were hyponatremic, mainly due to hypovolemia, and 5.3% hypernatremic. Hypernatremia 2 days after admission and exposure to hypernatremia at any time point during hospitalization were associated with a 2.34-fold (95% CI, 1.08-5.05; P = .0014) and 3.05-fold (95% CI, 1.69-5.49; P < .0001) increased risk of death, respectively, compared to normonatremia. Hyponatremia at admission was linked with a 2.18-fold increase in the likelihood of needing ventilatory support (95% CI, 1.34-3.45, P = .0011). Hyponatremia was not a risk factor for in-hospital mortality, except for the subgroup of patients with hypovolemic hyponatremia. Sodium values were not associated with the risk for AKI and length of hospital stay. CONCLUSION: Abnormal sodium levels during hospitalization are risk factors for poor prognosis, with hypernatremia and hyponatremia being associated with a greater risk of death and respiratory failure, respectively. Serum sodium values could be used for risk stratification in patients with COVID-19.

Active management of severe hyponatraemia is associated with improved mortality.

OBJECTIVE: Severe hyponatraemia (plasma sodium concentration, pNa <120 mmol/L) is reported to be associated with mortality rates as high as 50%. Although there are several international guidelines for the management of severe hyponatraemia, there are few data on the impact of treatment. DESIGN AND METHODS: We have longitudinally reviewed rates of specialist input, active management of hyponatraemia, treatment outcomes and mortality rates in patients with severe hyponatraemia (pNa <120 mmol/L) in 2005, 2010 and 2015, and compared the recent mortality rate with that of patients with pNa 120-125 mmol/L. RESULTS: Between 2005 and 2010 there was a doubling in the rate of specialist referral (32 to 68%, P = 0.003) and an increase in the use of active management of hyponatraemia in patients with pNa <120 mmol/L (63 to 88%, P = 0.02), associated with a reduction in mortality from 51 to 15% (P < 0.001). The improved rates of intervention were maintained between 2010 and 2015, but there was no further reduction in mortality. When data from all three reviews were pooled, specialist consultation in patients with pNa <120 mmol/L was associated with a 91% reduction in mortality risk, RR 0.09 (95% CI: 0.03-0.26), P < 0.001. Log-rank testing on in-hospital survival in 2015 found no significant difference between patients with pNa <120 mmol/L and pNa 120-125 mmol/L (P = 0.56). CONCLUSION: Dedicated specialist input and active management of severe hyponatraemia are associated with a reduction in mortality, to rates comparable with moderate hyponatraemia.

Prognostic Significance of Hyponatremia in Acute Stroke: A Systematic Review and Meta-Analysis.

OBJECTIVE: Hyponatremia is a common electrolyte disorder in patients with stroke, which leads to various fatal complications. We performed a systematic review and meta-analysis to investigate the outcomes of acute stroke patients with hyponatremia. METHODS: We searched MEDLINE, EMBASE, and the Cochrane Library databases for relevant literature in English published up to March 2020. Two review authors independently screened and selected the studies by assessing the eligibility and validity based on the inclusion criteria. Mortality at 90 days was set as the primary end point, and in-hospital mortality and length of hospital stay were set as the secondary end points. We conducted the data synthesis and analyzed the outcomes by calculating the odds ratio (OR) and mean difference. RESULTS: Of 835 studies, 15 studies met the inclusion criteria (n = 10,745). The prevalence rate of stroke patients with hyponatremia was 7.0-59.2%. They had significantly higher 90-day mortality (OR, 1.73; 95% confidence interval (CI), 1.24-2.42) and longer length of hospital stay (mean difference, 10.68 days; 95% CI, 7.14-14.22) than patients without hyponatremia. Patients with hyponatremia had a higher tendency of in-hospital mortality than those without hyponatremia (OR, 1.61; 95% CI, 0.97-2.69). CONCLUSIONS: The development of hyponatremia in the clinical course of stroke is associated with higher short-term mortality and a longer hospital stay. Although the causal relationship is unclear, hyponatremia could be a significant predictor of poor outcomes after stroke.

Risks of severe hyponatremia in children receiving hypotonic fluids.

Intravenous fluids are frequently used in hospitalized children. Hypotonic fluids have been the standard of care in pediatrics for many years. This might be explained by the empiricism of early recommendations favoring fluids with dextrose, but an insufficient amount of sodium. The risk of hyponatremia (<135mmol/L) might be increased by the occurrence of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in the course of common acute diseases (e.g., bronchiolitis, acute gastroenteritis, encephalitis, meningitis) in children. Severe hyponatremia (<130mmol/L) is often associated with neurologic complications leading to sequelae or even death. Over the last few years, hyponatremia induced by hypotonic fluids has been increasingly reported, and significant progress has been made in the understanding of cerebral edema and osmotic demyelination. Several randomized clinical trials have shown weak but significant evidence that isotonic fluids were superior to hypotonic solutions in preventing hyponatremia. However, clinical practices have not changed much in France, as suggested by the analysis of intravenous fluids ordered from the Assistance Publique-Hôpitaux de Paris (AP-HP) central pharmacy (PCH) in 2017. Therefore, it would be advisable that national guidelines be released under the French Health Authorities regarding the safe infusion of infants and children.

Risk of Adverse Clinical Outcomes in Hyponatremic Adult Patients Hospitalized for Acute Medical Conditions: A Population-Based Cohort Study.

CONTEXT: Hyponatremia has been associated with excess long-term morbidity and mortality. However, effects during hospitalization are poorly studied. OBJECTIVE: The objective of this work is to examine the association of hyponatremia with the risk of in-hospital mortality, 30-day readmission, and other short-term adverse events among medical inpatients. DESIGN AND SETTING: A population-based cohort study was conducted using a Swiss claims database of medical inpatients from January 2012 to December 2017. PATIENTS: Hyponatremic patients were 1:1 propensity-score matched with normonatremic medical inpatients. MAIN OUTCOME MEASURE: The primary outcome was a composite of all-cause in-hospital mortality and 30-day hospital readmission. Secondary outcomes were intensive care unit (ICU) admission, intubation rate, length-of-hospital stay (LOS), and patient disposition after discharge. RESULTS: After matching, 94 352 patients were included in the cohort. Among 47 176 patients with hyponatremia, 8383 (17.8%) reached the primary outcome compared with 7994 (17.0%) in the matched control group (odds ratio [OR] 1.06 [95% CI, 1.02-1.10], P = .001). Hyponatremic patients were more likely to be admitted to the ICU (OR 1.43 [95% CI, 1.37-1.50], P < .001), faced a 56% increase in prolonged LOS (95% CI, 1.52-1.60, P < .001), and were admitted more often to a postacute care facility (OR 1.38 [95% CI 1.34-1.42, P < .001). Of note, patients with the syndrome of inappropriate antidiuresis (SIAD) had lower in-hospital mortality (OR 0.67 [95% CI, 0.56-0.80], P < .001) as compared with matched normonatremic controls. CONCLUSION: In this study, hyponatremia was associated with increased risk of short-term adverse events, primarily driven by higher readmission rates, which was consistent among all outcomes except for decreased in-hospital mortality in SIAD patients.

The association between hyponatraemia and long-term functional outcome in patients with aneurysmal subarachnoid haemorrhage: A single centre prospective cohort study.

To assess the association between hyponatraemia and long-term functional outcome and other relevant outcomes in patients with aneurysmal subarachnoid haemorrhage (aSAH) we conducted a prospective cohort study in a Neurosciences Intensive Care Unit (ICU) in Sydney, Australia. The primary exposure variable was hyponatraemia (Na+ <135 mmol/L). The primary outcome was favourable outcome, a score of 5-8 on the extended Glasgow Outcome Score (GOSe) at 12 months. We also measured mortality, the incidence of delayed cerebral ischaemia (DCI) and cerebral arterial vasospasm and duration of ICU and hospital admission. There were 200 participants, 111 (56%) developed hyponatraemia. Hyponatraemia was not associated with favourable outcome at 12 months (unadjusted odds ratio [OR] OR 1.31, 95% confidence interval [CI] 0.65-2.65, p = 0.56). The result was similar after adjustment for baseline covariates (adjusted OR 0.60, 95% CI 0.16-1.99, p = 0.43). There was no association between hyponatraemia and the incidence of DCI (OR 0.95, 95% CI 0.46 to 2.0, p > 0.99) nor cerebral arterial vasospasm (OR 1.4, 95% CI 0.8 to 2.5, p = 0.27). Those who developed hyponatraemia had a longer median duration of ICU admission (17 days, interquartile range [IQR] 12 to 20, compared to 13 days, IQR 8-21, p = 0.02) and longer median duration of hospital admission (24 days, IQR 21-30, compared to 22 days IQR 14-31, p = 0.05). While hyponatraemia is common following aSAH, it is not associated with worse long-term functional outcome, increased rate of DCI, nor cerebral arterial vasospasm. Hyponatraemia in patients with aSAH was associated with longer duration of ICU and hospital admission.

Sex Differences in Clinical Characteristics and 1- and 10-Year Mortality Among Patients Hospitalized With Acute Heart Failure.

BACKGROUND: The impact of sex on mortality in patients with acute heart failure (AHF) is unresolved. We aimed to investigate the impact of sex on both short- and long-term mortality outcomes after hospitalization for AHF. METHODS: We analyzed data of 2,328 patients with AHF who were enrolled in the multicenter national survey in Israel between March and April 2003 and followed up until December 2014. RESULTS: Women comprised 45% of the study population. In comparison with men, women were older, had higher rates of heart failure with preserved ejection fraction as well as hypertensive heart disease and had a lower rate of coronary artery disease (all P < 0.001). Survival analysis showed that at 1 year the rate of all-cause mortality was 31% among women compared to 28% among men (P = 0.19). At 10-year follow-up mortality rates were significantly higher among women compared to men (87% vs. 83%, P = 0.048). However, this sex association disappeared once multivariable analysis was carried out, (hazard ratio [HR] = 0.93; CI = 0.79-1.09, P = 0.36). Renal dysfunction, older age and severe heart failure were consistent independent predictors of mortality among men and women. Hyponatremia was a prognostic predictor only among men, whereas digoxin use predicted mortality only among women. CONCLUSIONS: There are important differences in the clinical characteristics between women and men hospitalized with AHF. There were no significant differences in both short- and long-term mortality following multivariable analysis. Although, most independent predictors of mortality were consistent among both sexes, few sex-based differences in prognostic predictors were identified.

The prognostic importance of serum sodium levels at hospital discharge and one-year mortality among hospitalized patients.

BACKGROUND: The optimal range of serum sodium at hospital discharge is unclear. Our objective was to assess the one-year mortality based on discharge serum sodium in hospitalized patients. METHODS: We analyzed a cohort of hospitalized adult patients between 2011 and 2013 who survived hospital admission at a tertiary referral hospital. We categorized discharge serum sodium into five groups; ≤132, 133-137, 138-142, 143-147, and ≥148 mEq/L. We assessed one-year mortality risk after hospital discharge based on discharge serum sodium, using discharge sodium of 138-142 mEq/L as the reference group. RESULTS: Of 55 901 eligible patients, 4.9%, 29.8%, 56.1%, 8.9%, 0.3% had serum sodium of ≤132, 133-137, 138-142, 143-147, and ≥148 mEq/L, respectively. We observed a U-shaped association between discharge serum sodium and one-year mortality, with nadir mortality in discharge serum sodium of 138-142 mEq/L. When adjusting for potential confounders, including admission serum sodium, one-year mortality was significantly higher in both discharge serum sodium ≤137 and ≥143 mEq/L, compared with discharge serum sodium of 138-142 mEq/L. The mortality risk was the most prominent in elevated discharge serum sodium of ≥148 mEq/L (HR 3.86; 95% CI 3.05-4.88), exceeding the risk associated with low discharge serum sodium of ≤132 mEq/L (HR 1.43; 95% CI 1.30-1.57). CONCLUSION: The optimal range of serum sodium at discharge was 138-142 mEq/L. Both hypernatremia and hyponatremia at discharge were associated with higher one-year mortality. The impact on higher one-year mortality was more prominent in hypernatremia than hyponatremia.

Trajectories of Serum Sodium on In-Hospital and 1-Year Survival among Hospitalized Patients.

BACKGROUND AND OBJECTIVES: This study aimed to investigate the association between in-hospital trajectories of serum sodium and risk of in-hospital and 1-year mortality in patients in hospital. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This is a single-center cohort study. All adult patients who were hospitalized from years 2011 through 2013 who had available admission serum sodium and at least three serum sodium measurements during hospitalization were included. The trend of serum sodium during hospitalization was analyzed using group-based trajectory modeling; the five main trajectories were grouped as follows: (1) stable normonatremia, (2) uncorrected hyponatremia, (3) borderline high serum sodium, (4) corrected hyponatremia, and (5) fluctuating serum sodium. The outcome of interest was in-hospital mortality and 1-year mortality. Stable normonatremia was used as the reference group for outcome comparison. RESULTS: A total of 43,539 patients were analyzed. Of these, 47% had stable normonatremia, 15% had uncorrected hyponatremia, 31% had borderline high serum sodium, 3% had corrected hyponatremia, and 5% had fluctuating serum sodium trajectory. In adjusted analysis, there was a higher in-hospital mortality among those with uncorrected hyponatremia (odds ratio [OR], 1.33; 95% CI, 1.06 to 1.67), borderline high serum sodium (OR, 1.66; 95% CI, 1.38 to 2.00), corrected hyponatremia (OR, 1.50; 95% CI, 1.02 to 2.20), and fluctuating serum sodium (OR, 4.61; 95% CI, 3.61 to 5.88), compared with those with the normonatremia trajectory. One-year mortality was higher among those with uncorrected hyponatremia (hazard ratio [HR], 1.28; 95% CI, 1.19 to 1.38), borderline high serum sodium (HR, 1.18; 95% CI, 1.11 to 1.26), corrected hyponatremia (HR, 1.24; 95% CI, 1.08 to 1.42), and fluctuating serum sodium (HR, 2.10; 95% CI, 1.89 to 2.33) compared with those with the normonatremia trajectory. CONCLUSIONS: More than half of patients who had been hospitalized had an abnormal serum sodium trajectory during hospitalization. This study demonstrated that not only the absolute serum sodium levels but also their in-hospital trajectories were significantly associated with in-hospital and 1-year mortality. The highest in-hospital and 1-year mortality risk was associated with the fluctuating serum sodium trajectory. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_03_25_CJN.12281019.mp3.

Age Difference in the Association between Hyponatremia and Infection-Related Mortality in Peritoneal Dialysis Patients.

OBJECTIVES: This study aimed to examine the association of serum sodium with infection-related mortality and its age difference among continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: A total of 1,656 CAPD patients from January 2006 to December 2013 were included in this study. All patients were followed up until December 2018. Hyponatremia was defined as serum sodium <135 mmol/L. Cox proportional hazards regression model was used to investigate the relationship between baseline serum sodium levels and infection-related mortality. RESULTS: Participants were aged 47.5 ± 15.3 years, 666 (40.2%) patients were female. Glomerulonephritis was the main cause of end-stage renal disease (61.1%). After a median of 46 months of follow-up, 507 patients died. Among the deaths, 252 (49.7%) died from cardiovascular diseases, 105 (20.7%) from infections, and 150 (29.6%) from other causes. The overall infection-related mortality was 14.8 events per 1,000 patients-year, which was higher in patients aged ≥50 years than those younger than 50 years (28.3 vs. 5.3 events per 1,000 patients-year). In the entire cohort, hyponatremia at was not associated with infection-related (hazards ratios [HR] 1.66, 95% CI 0.91-3.02) and all-cause mortality (HR 1.14, 95% CI 0.83-1.57) after adjusting for potential confounders. There was a significant interaction by age of association of serum sodium with infection-related (p = 0.002) and all-cause (p = 0.0002) death. Age-stratified analysis showed that compared with control group, hyponatremia was independently related to increased risks of infection-related death, but not all-cause mortality in patients aged ≥50 years, with HR of 2.32 (95% CI 1.25-4.32) and 1.33 (95% CI 0.95-1.87), respectively. CONCLUSIONS: Hyponatremia was associated with increased risk of infection-related mortality in CAPD patients aged ≥50 years.

Abnormal Serum Sodium is Associated With Increased Mortality Among Unselected Cardiac Intensive Care Unit Patients.

Background Abnormal serum sodium levels have been associated with higher mortality among patients with acute coronary syndromes and heart failure. We sought to describe the association between sodium levels and mortality among unselected cardiac intensive care unit (CICU) patients. Methods and Results We retrospectively reviewed consecutive adult patients admitted to our cardiac intensive care unit from 2007 to 2015. Hyponatremia and hypernatremia were defined as admission serum sodium <135 and >145 mEq/L, respectively. In-hospital mortality was assessed by multivariable regression, and postdischarge mortality was evaluated by Cox proportional-hazards analysis. We included 9676 patients with a mean age of 68±15 years (37.5% females). Hyponatremia occurred in 1706 (17.6%) patients, and hypernatremia occurred in 322 (3.3%) patients; these groups had higher illness severity and a greater number of comorbidities. Risk of hospital mortality was higher with hyponatremia (15.5% versus 7.5%; unadjusted odds ratio, 2.41; 95% CI, 2.06-2.82; P<0.001) or hypernatremia (17.7% versus 8.6%; unadjusted odds ratio, 2.82; 95% CI, 2.09-3.80; P<0.001), with a J-shaped relationship between admission sodium and mortality. After multivariate adjustment, only hyponatremia was significantly associated with in-hospital mortality (adjusted odds ratio, 1.42; 95% CI, 1.14-1.76; P=0.002). Among hospital survivors, risk of postdischarge mortality was higher in patients with hyponatremia (adjusted hazard ratio, 1.28; 95% CI, 1.17-1.41; P<0.001) or hypernatremia (adjusted hazard ratio, 1.36; 95% CI, 1.12-1.64; P=0.002). Conclusions Hyponatremia and hypernatremia on admission to the cardiac intensive care unit are associated with increased unadjusted short- and long-term mortality. Further studies are needed to determine whether correcting abnormal sodium levels can improve outcomes in cardiac intensive care unit patients.

Analysis of Factors Influencing the Prognostic Significance of Hyponatremia in Peritoneal Dialysis Patients.

BACKGROUND: The evidence linking low serum sodium levels with the risk of mortality in peritoneal dialysis (PD) patients is controversial. Considering the different mechanisms contributing to hyponatremia in these patients, it is conceivable that the prognostic significance of this factor may vary, according to the clinical setting. METHODS: Following a retrospective, observational design, we analyzed the association between hyponatremia and mortality in 748 patients incident on PD. We applied multivariate strategies of analysis, with the main objective of identifying subgroups of patients in whom hyponatremia could sustain different degrees of association with mortality (main outcome variable). For this purpose, we performed preliminary analyses to: (1) disclose predictors of serum sodium levels before and after (mean of first 3 months) initiation of PD (main study variable) and (2) investigate the overall prognostic significance of hyponatremia, in our patients. RESULTS: Comorbidity, hypoalbuminemia, and lower glomerular filtration rate (GFR) were main predictors of hyponatremia. Use of icodextrin was another inverse correlate of serum sodium, and the only consistent predictor of a decline of natremia, once PD was started. Multivariate analysis confirmed early hyponatremia as an independent marker of survival. However, stratified analyses showed that this association was most apparent in specific subsets, namely, hypoalbuminemic, more anemic patients with higher baseline levels of GFR and C-reactive protein and faster peritoneal solute transport rates. Other factors potentially reinforcing the prognostic significance of hyponatremia included lower lean body mass levels, nonprescription of renin-angiotensin-aldosterone system antagonists, and use of icodextrin-based PD solution. On the contrary, baseline overhydration or categorization by classic predictors of mortality (age, comorbidity, diabetes) did not appear to influence the risk pattern associated with lower serum sodium levels. CONCLUSIONS: Our results suggest that hyponatremia performs as a consistent correlate of the risk of mortality mainly in PD patients manifesting direct or indirect signs of inflammation and wasting, while this association is not apparently linked to the presence of overhydration or nominal, preexisting comorbid conditions.

[The prevalence and causes of hyponatremia in hospitalized patients].

Objective: The study was aimed to investigate the prevalence and causes of hyponatremia in hospitalized patients, and to analyze the relationship between hyponatremia and mortality. Methods: A retrospective analysis was carried out in 525 patients with hyponatremia, who were older than 14 years old and hospitalized in the Zhoushan Hospital from Jan. 2014 to Apr. 2014. Based on the severity of the hyponatremia the patients were divided into three groups: the mild, moderate and severe hyponatremia groups. The underlying causes of hyponatremia were analyzed, and the association between hyponatremia and mortality was explored using logistic regression analyses. Results: (1) The prevalence of hyponatremia was 5.26% in whole hospitalized patients (n=9 989) during the study period. It was 6.1% in the elderly population (≥60 years old). (2) Malignant tumors and infectious diseases were the main primary diseases of hyponatremia in all three groups. Among them, lung cancer was the most common malignant tumor, and pneumonia was the most common infectious disease associated with hyponatremia. Cerebral hemorrhage was common in patients with moderate and severe hyponatremia, in which subarachnoid hemorrhage was the major primary disease associated with moderate to severe hyponatremia. In the subgroup of elderly patients, malignant tumor and infectious diseases were the major basic diseases. (3) Among the 525 cases, 13.7% and 3.8% of them were diagnosed with syndrome of inappropriate antidiuretic hormone secretion (SIADH) and cerebral salt-wasting syndrome (CSWS), respectively. The proportions of SIADH and CSWS increased to 17.4% and 4.2%, respectively, in the elderly hyponatremic patients (n=264). (4) More patients were prescribed with sodium-excretion drugs in the moderate and severe hyponatremia groups than those in the mild one(42.2% vs.21.4%, 43.2% vs.21.4%, all P<0.05). (5) Patients with moderate or severe hyponatremia had a higher mortality compared to those with mild hyponatremia (moderate vs. mild group: OR 6.92, 95%CI 2.53-18.92, P<0.001; severe vs. mild group: OR 4.54, 95%CI 1.05-19.58, P=0.043). Conclusions: Hyponatremia was common in hospitalized patients. The major primary diseases were malignant tumor (lung cancer), infectious diseases (pneumonia) and cerebral hemorrhage complicated with SIADH and CSWS. Use of sodium-excretion drugs increased the risk of moderate to severe hyponatremia. Patients with moderate to severe hyponatremia had a higher risk of death in hospitals.