An Unsuspected Cause of Hyponatremia: Beer Potomania

Serum sodium and risk of hypertension: a cohort study

This study aimed to investigate the cross-sectional association between serum sodium and blood pressure at baseline and, more importantly, investigate the prospective association between serum sodium and the risk of incident hypertension. We used data from 1 638 workers aged 18 to 71 years who participated in 2015-2016 survey of the Furukawa Nutrition and Health Study. During a maximum follow-up of 3 years, 229 participants developed hypertension. Multivariable linear regression models were used to evaluate the cross-sectional association. The Cox proportional hazards model was used to calculate the hazard ratio and 95% confidence interval of incident hypertension across quartiles of serum sodium (137-140, 141-142, 143, and 144-147 mmol/L). In the cross-sectional analysis, we did not observe a significant association between serum sodium and blood pressure at baseline. In the prospective analysis, the multivariable-adjusted hazard ratios (95% confidence intervals) for incident hypertension were 1.03 (0.71-1.51), 1.35 (0.87-2.08), and 1.46 (0.97-2.20) for the upper three quartiles of the serum sodium levels compared with the lowest quartile (P for trend=0.02). When serum sodium was treated as a continuous variable, the multivariable-adjusted hazard ratio for hypertension was 1.10 (1.03-1.18). The association was slightly attenuated after additionally adjusting for baseline blood pressure, with a hazard ratio of 1.08 (1.00-1.16) for a 1 mmol/L increase in serum sodium. In conclusion, an elevated serum sodium level was associated with an increased risk of developing hypertension, suggesting that serum sodium could be a potential risk factor for hypertension.

Beer Potomania: A View on the Dynamic Process of Developing Hyponatremia

Poor solute intake has been ascribed to hyponatremia seen in patients with beer potomania, an uncommon etiology of hyponatremia. Our current understanding of how hyponatremia develops in these patients is derived only from individual cases described in the literature. In these case reports, the pathophysiology of beer potomania is explained exclusively by the concept of solute-free water clearance in the kidney. Specifically, low solute intake reduces urinary excretion of osmoles, thereby capping a ceiling on the renal capacity of free water excretion. A positive water balance follows an excess of water intake, causing dilutional hyponatremia. We propose that further inquiry is needed to explain how water is retained by the kidney. From reviewing the clinical data of these case reports, it is evident that there is a broad range of urine osmolality, ranging from levels below to above plasma osmolality. This finding is consistent with a dynamic course of vasopressin secretion during the development of hyponatremia. Vasopressin raises epithelial permeability to water in the collecting duct; the amount of luminal osmoles then determines the osmotic gradient for water transport. At a certain degree of hyponatremia, vasopressin secretion may cease and profound water diuresis ensues. Unfortunately, the status of vasopressin release is rarely investigated. We propose that in patients with beer potomania detailed fluid balance studies, sequential observations of changes in urine and plasma osmolality corresponding to dynamics of vasopressin release would advance our understanding of its pathophysiology.

Severe Hyponatremia due to Levofloxacin Treatment for Pseudomonas aeruginosa Community-Acquired Pneumonia in a Patient with Oropharyngeal Cancer

Hyponatremia (serum Na levels of <135 mEq/L) is the most common electrolyte imbalance encountered in clinical practice, affecting up to 15–28% of hospitalized patients. This case report refers to a middle-aged man with severe hyponatremia due to Syndrome of Inappropriate Antidiuretic Hormone Secretion related to four possible etiological factors: glossopharyngeal squamous cell carcinoma, cisplatin treatment, right basal pneumonia with Pseudomonas aeruginosa, and the treatment with Levofloxacin. This case report discusses a rare complication of common conditions and of a common treatment. To our knowledge this is the first case of hyponatremia related to Levofloxacin and the second related to fluoroquinolones.

Current Challenges in the Evaluation and Management of Hyponatremia

BACKGROUND

Hyponatremia is a common electrolyte imbalance that clinicians face on a regular basis.

SUMMARY

This review aims to discuss four current challenges that can arise when diagnosing and treating hyponatremia: low solute intake, heart failure, exercise-associated hyponatremia, and mild chronic hyponatremia. Low solute intake in a person who already has a urinary concentrating defect will lead to increased retention of free water. The free water retention will cause or worsen hyponatremia that is already present. Low solute intake is overlooked in patients with other disease processes that can cause hyponatremia, such as liver disease or heart failure. Heart failure and hyponatremia present their own set of challenges specifically with treatment as there are limited options. The newer class of aquaretics allows for the short-term treatment of hyponatremia. Exercise-associated hyponatremia is a phenomenon that has been described in ultra-endurance athletes. This happens when a person drinks a significant amount of water while exercising in the setting of antidiuretic hormone production from prolonged exercise. This acute drop in sodium must be treated with hypertonic saline. The term asymptomatic mild chronic hyponatremia is no longer valid. Mild chronic hyponatremia carries an increased risk of falls and fractures, specifically in the elderly populations.

KEY MESSAGE

In summary, hyponatremia is a multifaceted disease and presents many challenges for physicians treating it.

Ten common pitfalls in the evaluation of patients with hyponatremia

Hyponatremia is the most common electrolyte disorder in hospitalized patients associated with increased morbidity and mortality. On the other hand, inappropriate treatment of hyponatremia (under- or mainly overtreatment) may also lead to devastating consequences. The appropriate diagnosis of the causative factor is of paramount importance for the proper management and avoidance of treatment pitfalls. Herein, we describe the most common pitfalls in the evaluation of the hyponatremic patient, such as failure to exclude pseudohyponatremia or hypertonic hyponatremia (related to glucose, mannitol or glycine), to properly assess urine sodium concentration and other laboratory findings, to diagnose other causes of hyponatremia (cerebral salt wasting, reset osmostat, nephrogenic syndrome of inappropriate antidiuresis, prolonged strenuous exercise, drugs) as well as inability to measure urine osmolality or delineate the diagnosis and cause of the syndrome of inappropriate antidiuretic hormone secretion. Clinicians should be aware of these common clinical practice pitfalls, which could endanger patients with hyponatremia.