Hyponatremia, all-cause mortality, and risk of cancer diagnoses in the primary care setting: A large population study

Hyponatremia Promotes Cancer Growth in a Murine Xenograft Model of Neuroblastoma

In cancer patients, hyponatremia is detected in about 40% of cases at hospital admission and has been associated to a worse outcome. We have previously observed that cancer cells from different tissues show a significantly increased proliferation rate and invasion potential, when cultured in low extracellular [Na+]. We have recently developed an animal model of hyponatremia using Foxn1nu/nu mice. The aim of the present study was to compare tumor growth and invasivity of the neuroblastoma cell line SK-N-AS in hyponatremic vs. normonatremic mice. Animals were subcutaneously implanted with luciferase-expressing SK-N-AS cells. When masses reached about 100 mm3, hyponatremia was induced in a subgroup of animals via desmopressin infusion. Tumor masses were significantly greater in hyponatremic mice, starting from day 14 and until the day of sacrifice (day 28). Immunohistochemical analysis showed a more intense vascularization and higher levels of expression of the proliferating cell nuclear antigen, chromogranin A and heme oxigenase-1 gene in hyponatremic mice. Finally, metalloproteases were also more abundantly expressed in hyponatremic animals compared to control ones. To our knowledge, this is the first demonstration in an experimental animal model that hyponatremia is associated to increased cancer growth by activating molecular mechanisms that promote proliferation, angiogenesis and invasivity.

Long-term low-dose tolvaptan efficacy and safety in SIADH

PURPOSE

Tolvaptan, a selective vasopressin V2-receptor antagonist, is approved for the treatment of SIADH-related hyponatremia, but its use is limited. The starting dose is usually 15 mg/day, but recent clinical experience suggests a lower starting dose (<15 mg/day) to reduce the risk of sodium overcorrection. However, long-term low-dose efficacy and safety has not been explored, so far. Aim of our study is to characterize safety and efficacy of long-term SIADH treatment with low-dose Tolvaptan.

METHODS

We retrospectively evaluated 11 patients receiving low-dose Tolvaptan (<15 mg/day) for chronic SIADH due to neurological, idiopathic and neoplastic causes. Plasma sodium levels were measured before and 1, 3, 5, 15 and 30 days after starting Tolvaptan and then at 3-month intervals. Anamnestic and clinical data were collected.

RESULTS

Mean time spanned 27.3 ± 29.8 months (range 6 months-7 years). Mean plasma sodium levels were within normal range 1, 3 and 6 months after starting Tolvaptan as well as after 1, 2, 3, 5 and 7 years of therapy. Neither osmotic demyelination syndrome nor overcorrection were observed. Plasma sodium levels normalization was associated with beneficial clinical effects. Neurological patients obtained seizures disappearance, improvement in neurological picture and good recovery from rehabilitation. Neoplastic patients were able to start chemotherapy and improved their general condition. Patients did not show hypernatremia during long-term follow-up and reported mild thirst and pollakiuria.

CONCLUSIONS

The present study shows that long-term low-dose Tolvaptan is safe and effective in SIADH treatment. No cases of overcorrection were documented and mild side effects were reported.

Hyponatremia and Cancer: From Bedside to Benchside

Hyponatremia is the most common electrolyte disorder encountered in hospitalized patients. This applies also to cancer patients. Multiple causes can lead to hyponatremia, but most frequently this electrolyte disorder is due to the syndrome of inappropriate antidiuresis. In cancer patients, this syndrome is mostly secondary to ectopic secretion of arginine vasopressin by tumoral cells. In addition, several chemotherapeutic drugs induce the release of arginine vasopressin by the hypothalamus. There is evidence that hyponatremia is associated to a more negative outcome in several pathologies, including cancer. Many studies have demonstrated that in different cancer types, both progression-free survival and overall survival are negatively affected by hyponatremia, whereas the correction of serum [Na⁺] has a positive effect on patient outcome. In vitro studies have shown that cells grown in low [Na⁺] have a greater proliferation rate and motility, due to a dysregulation in intracellular signalling pathways. Noteworthy, vasopressin receptors antagonists, which were approved more than a decade ago for the treatment of euvolemic and hypervolemic hyponatremia, have shown unexpected antiproliferative effects. Because of this property, vaptans were also approved for the treatment of polycystic kidney disease. In vitro evidence indicated that this family of drugs effectively counteracts proliferation and invasivity of cancer cells, thus possibly opening a new scenario among the pharmacological strategies to treat cancer.

Morbidity Associated with Chronic Hyponatremia

This article will discuss the consequences of chronic hyponatremia. In conditions such as cancer, heart failure, liver cirrhosis, or chronic kidney disease, the presence and magnitude of hypotonic hyponatremia are considered to reflect the severity of the underlying disease and are associated with increased morbidity as well as mortality. Hyponatremia can be acute (<48 h) or chronic (>2-3 days). Chronic hyponatremia is associated with attention deficit, dizziness, tiredness, gait disturbance, falls, sarcopenia, bone fractures, osteoporosis, hypercalciuria (in the syndrome of inappropriate antidiuresis-SIADH), and kidney stones. In vitro studies have shown that cells grown in a low concentration of extracellular sodium have a greater proliferation rate and motility. Patients with chronic hyponatremia are more likely to develop cancer. We will not review the clinical consequences of respiratory arrest and osmotic demyelination syndrome (ODS) of the too-late or excessive treatment of hyponatremia.

Clinical characteristics of paraneoplastic syndromes in patients with head and neck cancer

Background

To summarize the clinical manifestations, diagnosis, and prognosis of head and neck cancer (HNC) patients with paraneoplastic syndromes (PNS).

Methods

The clinical data of 1958 patients with HNC admitted to our hospital from January 1996 to December 2020 were retrospectively analyzed. Demographic and cancer‐related characteristics were extracted. Kaplan–Meier survival curves were compared by log‐rank test. Cox regression was performed to evaluate prognostic factors and hazard ratio.

Results

Totally 40 HNC patients with PNS were included in the final analysis, including 36 men and four women with a mean age of 60.4 years (range 40–82). PNS was dermatologic or cutaneous in 23 (57.50%) patients, endocrine in 10 (25.00%), neurologic in five (12.50%), and osteoarticular or rheumatologic in two (5.00%). Twenty‐five (62.50%) patients had Stage III/IV cancer. PNS regressed after antitumor therapy in 28 (70.00%) patients. Recurrence of PNS was observed in nine of 12 (75.00%) patients with cancer recurrence or metastasis. The 5‐year overall survival (OS) and disease‐free survival (DFS) rates of patients with PNS were 51.52% and 44.44%, respectively. The DFS (p = .001) and OS (p = .003) of patients presented with PNS prior to HNC diagnosis were significantly longer than those of patients with synchronous or metachronous PNS. PNS diagnosed before HNC (adjusted hazard ratio [aHR]: 0.31, 95% confidence interval [CI]: 0.11–0.85, p = .02), Stage IV disease (aHR: 3.27, 95% CI: 1.18–9.05, p = .02), and smoking history (aHR: 3.69, 95% CI: 1.04–13.05, p = .04) were significantly associated with OS and DFS.

Conclusions

Early recognition of PNS could provide clues about underlying tumor condition and result in early diagnosis. Prompt detection of cancer‐associated syndromes could lead to a more favorable prognosis for these patients.

Acute and Chronic Hyponatremia

Hyponatremia is the most common electrolyte disorder in clinical practice. Catastrophic complications can occur from severe acute hyponatremia and from inappropriate management of acute and chronic hyponatremia. It is essential to define the hypotonic state associated with hyponatremia in order to plan therapy. Understanding cerebral defense mechanisms to hyponatremia are key factors to its manifestations and classification and subsequently to its management. Hypotonic hyponatremia is differentiated on the basis of urine osmolality, urine electrolytes and volume status and its treatment is decided based on chronicity and the presence or absence of central nervous (CNS) symptoms. Proper knowledge of sodium and water homeostasis is essential in individualizing therapeutic plans and avoid iatrogenic complications while managing this disorder.

Hyponatremia is an independent predictor of emergency department revisits in acute exacerbation of COPD

INTRODUCTION

Hyponatremia is shown to prolong hospitalization and increase mortality. The role of hyponatremia in chronic obstructive pulmonary disease is widely studied with a focus on hospitalized patients.

OBJECTIVES

To investigate whether hyponatremia increases the probability of re-exacerbations in non-hospitalized patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD).

METHODS

Patients with AECOPD who required an emergency department (ED) visit and who were discharged home were included in this single-center, retrospective study. Demographics and laboratory values were compared between patients with hyponatremia (<135 mmol/L) and normonatremia (135-145 mmol/L). The predictors of the patients' ED revisit in the course of one year were analyzed.

RESULTS

Of all the 3274 patients, baseline sodium values were classified as hyponatremia in 720 (22%). Hyponatremia was most frequently present as mild (85%). Patients with hyponatremia had higher Charlson comorbidity scores, higher leucocytes, lower hemoglobin, lower platelet, higher neutrophil to lymphocyte ratios, lower eosinophilia, higher aspartate aminotransferase and C-reactive protein values (P < 0.001, for all), and higher frequency of 1-month revisit (36.7% vs. 31.5%, P = 0.009). Independent predictors of revisits within 1 year after the index visit were detected as long-term oxygen treatment requirement (HR: 0.768 CI: 0.695-0.848, P < 0.0001), higher urea levels (HR: 0.997 CI: 0.995-0.999, P = 0.003), and baseline hyponatremia (HR: 0.786 CI: 0.707-0.873, P < 0.001). Revisit interval was median 78 ± 3.4 days in patients with normonatremia and 51 ± 4.8 days in hyponatremia.

CONCLUSION

In non-hospitalized AECOPD, hyponatremia is relatively frequent and correlates with inflammatory markers. The presence of hyponatremia is an independent predictor of an earlier ED return visit within 1 year. For patients with AECOPD, sodium values may present guidance on discharge versus longer observation decisions.

Hyponatremia is a Prognostic Factor in Patients Receiving Nutrition Support

BACKGROUND

Hyponatremia, the most common electrolyte disorder, has been reported to be related to increased mortality. However, the association between hyponatremia and prognoses remains unclear in patients with nutrition support team (NST) intervention. This study aimed to determine the prevalence of abnormal serum sodium levels, its relation to patient data, and the impact of hyponatremia on prognosis.

METHODS

Patients who received nutrition support at Tokushima University Hospital for the first time and whose serum sodium levels were measured at the start of NST intervention were enrolled. Patients were classified into three groups according to their serum Na levels at the start of NST intervention: hyponatremia group, normonatremia group, and hypernatremia group.

RESULTS

In the hyponatremia group compared to the normonatremia group, body weight and body mass index were significantly lower. C-reactive protein levels and urea nitrogen/creatinine ratios were significantly higher. Meanwhile, there was no significant difference in the estimated glomerular filtration rate among the groups. The prevalence of malnutrition and anemia were the highest in the hyponatremia group. The 3-year survival rate was approximately 45% in the hyponatremia group, which was the lowest of all three groups. The mortality risk ratio of the hyponatremia group to the normonatremia group was 2.29.

CONCLUSIONS

Hyponatremia in NST intervention patients is an independent prognostic predictor. Therefore, adding an assessment of serum sodium at the beginning of NST intervention can identify patients at high risk at an early stage and may improve the quality of NST activity.

Association between lipid-lowering agents and severe hyponatremia: a population-based case-control study

PURPOSE

Drug-induced hyponatremia is common, with medications from many drug-classes implicated. Lipid-lowering agents are among the most prescribed drugs. Limited evidence suggests an inverse association between statins and hyponatremia, while data on other lipid-lowering agents is absent. The objective of this investigation was to study the association between lipid-lowering drugs and hospitalization due to hyponatremia.

METHODS

This was a register-based case-control study of the general Swedish population. Those hospitalized with a main diagnosis of hyponatremia (n = 11,213) were compared with matched controls (n = 44,801). Multivariable logistic regression adjusting for co-medication, diseases, previous hospitalizations, and socioeconomic factors was used to explore the association between severe hyponatremia and the use of lipid-lowering drugs.

RESULTS

Unadjusted ORs (95% CI) for hospitalization due to hyponatremia were 1.28 (1.22-1.35) for statins, 1.09 (0.79-1.47) for ezetimibe, 1.38 (0.88-2.12) for fibrates, and 2.12 (1.31-3.35) for resins. After adjustment for confounding factors the adjusted odds ratios (95% CI) compared with controls were 0.69 (0.64-0.74) for statins, 0.60 (0.41-0.86) for ezetimibe, 0.87 (0.51-1.42) for fibrates, and 1.21 (0.69-2.06) for resins.

CONCLUSIONS

Use of statins and ezetimibe was inversely correlated with severe hyponatremia. Consequently, these drugs are unlikely culprits in patients with hyponatremia, and they appear safe to initiate in hyponatremic patients. A potential protective effect warrants further studies on how statins and other lipid-lowering drugs are linked to dysnatremias.

Frequency and Impact of Hyponatremia on All-Cause Mortality in Patients With Aortic Stenosis

Asymptomatic aortic stenosis (AS) is a frequent condition that may cause hyponatremia due to neurohumoral activation. We examined if hyponatremia heralds poor prognosis in patients with asymptomatic AS, and whether AS in itself is associated with increased risk of hyponatremia. The study question was investigated in 1,677 individuals that had and annual plasma sodium measurements in the SEAS (Simvastatin and Ezetimibe in AS) trial; 1,873 asymptomatic patients with mild-moderate AS (maximal transaortic velocity 2.5 to 4.0 m/s) randomized to simvastatin/ezetimibe combination versus placebo. All-cause mortality was the primary endpoint and incident hyponatremia (P-Na⁺ <137 mmol/L) a secondary outcome. At baseline, 4% (n = 67) had hyponatremia. After a median follow-up of 4.3 (interquartile range 4.1 to 4.6) years, 140 (9%) of those with initial normonatremia had developed hyponatremia, and 174 (10%) had died. In multiple regression Cox models, both baseline hyponatremia (hazard ratio [HR] 2.1, [95% confidence interval 1.1 to 3.8]) and incident hyponatremia (HR 1.9, [95% confidence interval 1.0 to 3.4], both p ≤ .03) was associated with higher all-cause mortality as compared with normonatremia. This association persisted after adjustment for diuretics as a time-varying covariate. Higher N-terminal pro b-type natriuretic peptide levels and lower sodium levels at baseline was associated with higher risk of incident hyponatremia. Conversely, assignment to simvastatin/ezetimibe protected against incident hyponatremia. In conclusion, both prevalent and incident hyponatremia associate with increased mortality in patients with AS. The prevalence of hyponatremia is around 4% and the incidence about 2% per year, which is comparable to that of older adults without AS.

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH): Optimal Management

Hyponatremia, defined as serum sodium concentration <135 mEq/l, is the most common electrolyte balance disorder in clinical practice. Many causes are listed, but syndrome of inappropriate antidiuretic hormone secretion (SIADH) is certainly the most relevant, mainly in oncological and hospitalized patients. In this review, the pathophysiological and clinical aspects are described in detail. Patients’ extensive medical history and structured physical and biochemical tests are considered the milestones marking the way of the SIADH management as to provide early detection and proper correction. We focused our attention on the poor prognostic role and negative effect on patient’s quality of life of SIADH-induced hyponatremia in both malignant and non-malignant settings, stressing how optimal management of this electrolyte imbalance can result in improved outcomes and lower health costs.

Electrolyte disorders in advanced non-small cell lung cancer patients treated with immune check-point inhibitors: A systematic review and meta-analysis

BACKGROUND

Aim of this meta-analysis was to determine the relative risk (RR) of electrolyte disorders (EDs) in advanced non-small cell lung cancer (aNSCLC) patients treated with immune check-point inhibitors (ICIs).

METHODS

We searched for phase II/III randomized controlled trials (RCTs) comparing ICIs (alone or combined with chemotherapy) with standard chemotherapy in aNSCLC. Summary incidence and RR were calculated.

RESULTS

Six RCTs with data on all-grade hyponatremia were identified (n = 3257). The incidence was 8.7 % in the study group and 4.9 % in the control group (RR 1.78, 95 %CI 1.12-2.80). Looking at all-grade hypokalemia, 7 RCTs were included (n = 4119). Incidence was 10.4 % in ICIs-treated patients and 5.9 % in the control arms (RR 1.62, 95 % CI 1.30-2.02).

CONCLUSIONS

Treatment with ICIs in aNSCLC is associated with a significant increased risk of hyponatremia and hypokalemia compared to chemotherapy. Monitoring of electrolyte levels should be emphasized in this setting.

Elevated neutrophil-lymphocyte ratio combined with hyponatremia indicate poor prognosis in renal cell carcinoma

Background: Elevated neutrophil-lymphocyte ratio (NLR) and hyponatremia each predict poor prognosis in renal cell carcinoma (RCC). Since no previous studies have looked at the combined effect of these two prognostic markers, we examined how NLR and hyponatremia combined associates with mortality and hypothesized that elevated NLR and hyponatremia at RCC diagnosis and at RCC recurrence indicate poorer prognosis.Material and methods: Using Danish medical registries 1999-2015, we included 970 patients from two regions with incident RCC and a measurement of NLR and sodium. NLR was categorized as ≤3.0 and >3.0 and sodium as < lower limit of normal (LLN) and ≥ LLN. Outcomes were survival after RCC diagnosis and first recurrence, respectively. We estimated absolute survival and hazard ratios (HR) using multivariate Cox regression.Results: At RCC diagnosis, 559 (57.6%) had NLR >3.0 and 240 (24.7%) had hyponatremia, the 5 year-survival rate was 35.2% in NLR > 3.0 vs. 69.2% in NLR ≤3.0, adjusted HR 1.8 (95% confidence intervals (CI), 1.4; 2.2). In patients with NLR >3.0 and concomitant hyponatremia vs. NLR ≤3.0 and normal sodium the 5-year survival rate was 21.7% vs. 73.2%, adjusted HR 2.8 (95% CI, 2.1; 3.8). At RCC recurrence, patients with NLR >3.0 and hyponatremia similarly had poorest survival, adjusted HR 3.6 (95% CI, 1.0; 12.8).Conclusion: Elevated NLR alone and in combination with hyponatremia at time of initial RCC diagnosis and at time of RCC recurrence are associated with poor prognosis. Combining these two prognostic markers yield a stronger association than NLR considered alone. This may impact prognostic prediction and its related therapeutic strategy.

Copeptin is not useful as a marker of malignant disease in the syndrome of inappropriate antidiuresis

OBJECTIVE

The syndrome of inappropriate antidiuresis (SIAD) is a common condition in hospitalized patients. It is crucial to establish the cause of SIAD, especially in order to exclude underlying malignancy. As malignant SIAD may be due to a paraneoplastic synthesis of arginine vasopressin, we hypothesized that its stable surrogate marker copeptin can be used as a diagnostic tool to differentiate between malignant and non-malignant SIAD.

METHODS

Prospective observational study. We analyzed data from 146 SIAD patients of two different cohorts from Switzerland and Germany. Patients were included while presenting at the emergency department and underwent a standardized diagnostic assessment including the measurement of copeptin levels.

RESULTS

Thirty-nine patients (median age: 63 years, 51% female) were diagnosed with cancer-related SIAD and 107 (median age: 73 years, 68% female) with non-malignant SIAD. Serum sodium levels were higher in cancer-related versus non-malignant SIAD: median (IQR) 124 mmol/l (120; 127) versus 120 mmol/l (117; 123) (P<0.001). Median (IQR) copeptin levels of patients with cancer-related SIAD were 11.1 pmol/l (5.2; 37.1) and 10.5 pmol/l (5.2; 25.2) with non-malignant SIAD (P = 0.38). Among different cancer entities, patients suffering from small-cell lung cancer showed the highest copeptin values, but overall no significant difference in copeptin levels between cancer types was observed (P = 0.46).

CONCLUSIONS

Copeptin levels are similar in cancer-related and non-malignant SIAD. Therefore, Copeptin does not seem to be suitable as a marker of malignant disease in SIAD.

Weighing the prognostic role of hyponatremia in hospitalized patients with metastatic solid tumors: the HYPNOSIS study

Previous works linked low sodium concentration with mortality risk in cancer. We aimed at weighing the prognostic impact of hyponatremia in all consecutive patients with metastatic solid tumors admitted in a two-years period at our medical oncology department. Patients were included in two cohorts based on serum sodium concentration on admission. A total of 1025 patients were included, of whom 279 (27.2%) were found to be hyponatremic. The highest prevalence of hyponatremia was observed in biliary tract (51%), prostate (45%) and small-cell lung cancer (38.9%). With a median follow-up of 26.9 months, median OS was 2 months and 13.2 months for the hyponatremia versus control cohort, respectively (HR, 2.65; P < 0.001). In the multivariable model, hyponatremia was independently associated with poorer OS (HR, 1.66; P < 0.001). According to the multivariable model, a nomogram system was developed and validated in an external set of patients. We weighed over time the influence of hyponatremia on survival of patients with metastatic solid tumors and pointed out the possibility to exploit serum sodium assessment to design integrated prognostic tools. Our study also highlights the need for a deeper characterization of the biological role of extracellular sodium levels in tumor development and progression.

Hyponatremia and metabolic bone disease in patients with epilepsy: A cross-sectional study

AIM

Patients with epilepsy frequently develop hyponatremia due to the treatment with antiepileptic drugs and have an increased risk of developing metabolic bone disease. Hyponatremia is known to be associated with osteoporosis. The aim of the study was to investigate the association between hyponatremia and osteoporosis in patients with epilepsy.

METHOD AND MATERIAL

This cross-sectional study included patients with epilepsy from a tertiary epilepsy out-patient clinic in Denmark, who had a Dual Energy X-ray Absorptiometry scan performed and an accompanying plasma sodium (p-Na) measured prior to or a maximum of 14 days after the scan. Information regarding the patients' health and medical conditions were obtained from their medical reports.

RESULTS

A total of 695 patients (females 53.8%, age 49 (34:63) years (median (quartiles)) were included. 10.4% had hyponatremia (p-Na ≤ 135 mmol/L). The hyponatremic patients had significantly lower T-scores in the lumbar spine, femoral neck and total femur (all p < 0.023) and the odds ratio of osteoporosis (T-score < -2.5) was significantly increased (2.91 (1.61-5.27) (95% confidence interval) (p = 0.001)). When adjusting for potential confounders the patients with moderate and severe hyponatremia (p-Na < 129 mmol/L) had a significantly lower mean T-score in the lumbar spine (p = 0.030).

CONCLUSION

We conclude that hyponatremia is common in patients with epilepsy and that moderate and severe hyponatremia is independently associated with decreased bone mineral density in the lumbar spine. Therefore, hyponatremia in a patient with epilepsy should warrant further examination of the patient for bone loss and osteoporosis.

Hyponatremia associates with poor outcome in metastatic renal cell carcinoma patients treated with everolimus: prognostic impact

BACKGROUND

The prognostication of metastatic renal cell carcinoma (mRCC) is based on Memorial Sloan Kettering Cancer Center (MSKCC) and International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk classifications. Research has shown that hyponatremia is associated with worse prognosis in cancer. We analyzed the association of hyponatremia and outcome in everolimus-treated mRCC patients.

PATIENTS AND METHODS

Baseline and on-treatment (≤12 weeks) sodium in 233 mRCC patients was analyzed using Kaplan-Meier, Cox regression and logistic regression. Baseline sodium was correlated with baseline thrombocyte and neutrophil values.

RESULTS

65 (28%) and 41 (18%) patients had sodium < lower limit of normal (LLN) at baseline and on-treatment, respectively. Baseline sodium < LLN was associated with shorter overall survival (OS) (6.1 vs. 10.3 months; p < .001) and progression-free survival (PFS) (2.8 vs. 3.5 months; p = .04). On-treatment sodium < LLN was associated with shorter OS (5.4 vs. 9.9 months; p < .001) and PFS (2.8 vs. 4.0 months; p < .001). In multivariate analyses adjusted for IMDC factors, baseline and on-treatment sodium < LLN were significantly associated with shorter OS (adjusted HR 1.46 (95% CI 1.04-2.05); p = .02; adjusted HR 1.80 (95% CI 1.23-2.61); p = .002; respectively). On-treatment sodium < LLN was significantly associated with progressive disease (OR 0.23 (95% CI 0.10-0.56); p = .001). A landmark analysis demonstrated that on-treatment hyponatremia was significantly associated with shorter OS and PFS (p = .01 and p = .03, respectively). On-treatment normalization of hyponatremia was associated with improved OS (unadjusted HR 0.61 (95% CI 0.35-0.98); p = .04), as compared to patients with sustained hyponatremia throughout follow-up.

CONCLUSIONS

Hyponatremia associates with poor outcome in mRCC patients treated with everolimus. On-treatment normalization of hyponatremia to normal sodium values associates with favorable outcome.

Hyponatremia and activation of vasopressin secretion are both independently associated with 30-day mortality: results of a multicenter, observational study

BACKGROUND

Hyponatremia is a common feature of acute illness and associated with increased mortality. This may be explained by a stress-mediated activation of the vasopressin system with an increase in free-water reabsorption.

OBJECTIVES

To investigate whether the association between hyponatremia and mortality could be explained by activation of the vasopressin system.

METHODS

We prospectively enrolled adult, medical patients seeking emergency care in three centres in Switzerland, France and the United States. We investigated associations between admission plasma sodium and copeptin, a stable portion of the vasopressin-precursor peptide, with 30-day mortality. We performed uni- and multivariate regression analysis.

RESULTS

Of 6962 included patients, 18% had hyponatremia (sodium ≤135 mmol L^-1 ), which doubled their risk for mortality compared to patients with normonatremia (8.3% vs. 3.8%). This association was confirmed in a multivariate-adjusted logistic regression analysis [adjusted odds ratio (OR) 1.47, 95% CI 1.12-1.93, P = 0.005]. Vasopressin levels, mirrored by copeptin, were also increased in nonsurvivors and strongly associated with mortality (adjusted OR 3.42, 95% CI 2.76-4.25, P < 0.001). The association between hyponatremia and mortality remained unchanged when adding copeptin levels to the regression model (fully adjusted OR 1.53, 95% CI 1.16-2.00, P = 0.002).

CONCLUSION

This prospective study including medical patients upon emergency room admission found hyponatremia as well as an activation of the vasopressin system to be independently associated with mortality. This suggests that stress- and vasopressin-independent mechanisms are responsible for the association of low sodium levels with mortality.

Could sodium imbalances predispose to postoperative venous thromboembolism? An analysis of the NSQIP database

Background

Hyponatremia is common among patients with pulmonary embolism, while hypernatremia increases the risk of venous thromboembolism (VTE). Our objective was to evaluate the association between sodium imbalances and the incidence of VTE and other selected perioperative outcomes.

Methods

We conducted a retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) and identified 1,108,704 patients undergoing major surgery from 2008 to 2012. We evaluated 30-day perioperative outcomes, including mortality and cardiac, respiratory, neurological, urinary, wound, and VTE outcomes. Multivariate logistic regressions were used to estimate the odds of 30-day perioperative outcomes.

Results

Compared with the normal sodium group, in which VTE occurred in 1.0% of patients, 1.8% of patients in the hyponatremia group (unadjusted odds ratio (OR) 1.84) and 2.4% of patients in the hypernatremia group (unadjusted OR 2.49) experienced VTE. Crude mortality was 1.3% in the normal sodium group, 4.9% in the hyponatremia group (unadjusted OR 3.93) and 8.4% in the hypernatremia group (unadjusted OR 7.01). Crude composite morbidity was 7.1% for the normal sodium group, 16.7% for the hyponatremia group (unadjusted OR 2.63) and 20.6% for the hypernatremia group (unadjusted OR 3.43). After adjusting for potential confounders, hyponatremia and hypernatremia remained significantly and independently associated with an increased risk of VTE (adjusted OR 1.43 and 1.56, respectively), mortality (adjusted OR 1.39 and 1.39, respectively) and composite morbidity (adjusted OR 2.15 and 3.34, respectively).

Conclusions

Pre-operative hyponatremia and hypernatremia are potential prognostic markers for perioperative 30-day morbidity, mortality and VTE.

Diagnosis of hyponatremia and increased risk of a subsequent cancer diagnosis: results from a nationwide population-based cohort study

BACKGROUND

Hyponatremia has recently been associated with subsequent cancer risk. This population-based nationwide study assessed whether the diagnosis of hyponatremia can predict a cancer diagnosis within most common cancers.

MATERIAL AND METHODS

Using Danish medical registries, we identified 16,220 patients with a first-time diagnosis of hyponatremia, without a cancer diagnosis, from January 2006 through November 2013. We quantified the relative risk of a subsequent cancer diagnosis by standardized incidence ratios (SIRs), comparing observed cancer incidence among patients diagnosed with hyponatremia to that expected, based on national cancer incidence during that period.

RESULTS

During 40,207 person-years of follow-up, we observed 1546 cancer diagnoses compared to 956 expected (SIR: 1.62; 95% confidence interval (CI), 1.54-1.70). The increase in risk of a cancer diagnosis following a hyponatremia diagnosis was most pronounced within 0-6 months of follow-up (SIR 4.16; 95% CI, 3.85-4.48) and in the younger age group; 0-29 years (SIR 8.71; 95% CI, 2.82-20.28), 30-49 years (SIR 3.16; 95% CI, 2.26-4.31), 50-69 years (SIR 2.29; 95% CI, 2.10-2.48) and 70 + years (SIR 1.35; 95% CI, 1.27-1.44). Within six months after a hyponatremia diagnosis, the SIRs increased 10-fold for cancers of the lung (SIR 17.14; 95% CI, 15.15-19.32), brain (SIR 13.52; 95% CI, 8.90-19.66) and liver (SIR 13.26; 95% CI, 7.57-21.53) and increased 5 to 10-fold for cancers of the pancreas (SIR 8.25; 95% CI, 5.72-11.53), esophagus (SIR 6.59; 95% CI, 3.15-12.12), kidney (SIR 6.36; 95% CI, 3.39-10.88), pharynx (SIR 6.15; 95% CI, 1.27-17.97) and non-Hodgkin lymphoma (SIR 6.10; 95% CI, 4.17-8.61). The rate increased across virtually all types of cancers, except melanoma and basal cell carcinomas.

CONCLUSIONS

A diagnosis of hyponatremia may be a marker of occult neoplasms, especially cancers of the lung, brain, liver, pancreas, esophagus, kidney, pharynx and non-Hodgkin lymphoma. Hyponatremia may aid in early detection of cancer.

Hyponatremia normalization as an independent prognostic factor in patients with advanced non-small cell lung cancer treated with first-line therapy

The aim of the study was to assess, for the first time, the prognostic role of hyponatremia and sodium normalization in patients receiving first-line chemo- or targeted therapy for advanced non-small cell lung cancer.

Four hundred thirty-three patients with advanced non small cell lung cancer were treated with first line chemo- or targeted therapy between 2006 and 2015 at our institutions. Patients were stratified in two groups, with or without hyponatremia (group A and B, respectively). Progression free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier method. A Cox regression model was carried out for univariate and multivariate analyses.

Sixty-nine patients (16%) presented with hyponatremia at the start of first-line therapy. The median OS was 8.78 months in Group A and 15.5 months in Group B (p < 0.001), while the median PFS was 4.1 months and 6.3 months respectively (p = 0.24). In Group A, median OS was significantly higher in patients who normalized their sodium levels (11.6 vs. 4.7 months, p = 0.0435). Similarly, the median PFS was significantly higher in patients who normalized their sodium levels (6.7 vs. 3.3 months, p = 0.011). At multivariate analysis, sodium normalization was an independent prognostic factor for both OS and PFS.

Sodium normalization during first-line therapy is an independent prognostic factor for OS and PFS in patients with advanced lung cancer treated with first-line therapies. Frequent clinical monitoring and prompt treatment of hyponatremia should be emphasized to optimize the outcome of these patients.

Paraneoplastic endocrine syndromes

The majority of neoplasms are responsible for symptoms caused by mass effects to surrounding tissues and/or through the development of metastases. However, occasionally neoplasms, with or without endocrine differentiation, acquire the ability to secrete a variety of bioactive substances or induce immune cross-reactivity with the normal tissues that can lead to the development of characteristic clinical syndromes. These syndromes are named endocrine paraneoplastic syndromes when the specific secretory components (hormones, peptides or cytokines) are unrelated to the anticipated tissue or organ of origin. Endocrine paraneoplastic syndromes can complicate the patient's clinical course, response to treatment, impact prognosis and even be confused as metastatic spread. These syndromes can precede, occur concomitantly or present at a later stage of tumour development, and along with the secreted substances constitute the biological 'fingerprint' of the tumour. Their detection can facilitate early diagnosis of the underlying neoplasia, monitor response to treatment and/or detect early recurrences following successful initial management. Although when associated with tumours of low malignant potential they usually do not affect long-term outcome, in cases of highly malignant tumours, endocrine paraneoplastic syndromes are usually associated with poorer survival outcomes. Recent medical advances have not only improved our understanding of paraneoplastic syndrome pathogenesis in general but also enhanced their diagnosis and treatment. Yet, given the rarity of endocrine paraneoplastic syndromes, there is a paucity of prospective clinical trials to guide management. The development of well-designed prospective multicentre trials remains a priority in the field in order to fully characterise these syndromes and provide evidence-based diagnostic and therapeutic protocols.