Hyponatremia in Acute Stroke Patients: Pathophysiology, Clinical Significance, and Management Options.

BACKGROUND: Hyponatremia is frequent in acute stroke patients, and it is associated with worse outcomes and increased mortality. SUMMARY: Nonstroke-related causes of hyponatremia include patients' comorbidities and concomitant medications, such as diabetes mellitus, chronic kidney disease, heart failure, and thiazides. During hospitalization, "inappropriate" administration of hypotonic solutions, poor solute intake, infections, and other drugs, such as mannitol, could also lower sodium levels in patients with acute stroke. On the other hand, secondary adrenal insufficiency due to pituitary ischemia or hemorrhage, syndrome of inappropriate antidiuretic hormone secretion, and cerebral salt wasting are additional stroke-related causes of hyponatremia. Although it is yet unclear whether the appropriate restoration of sodium level improves outcomes in patients with acute stroke, the restoration of the volume depletion remains the cornerstone of treatment in hypovolemic hyponatremia. In case of hyper- and euvolemic hyponatremia, apart from the correction of the underlying cause (e.g., withdrawal of an offending drug), fluid restriction, administration of hypertonic solution, loop diuretics, and vasopressin-receptor antagonists (vaptans) are among the therapeutic options. Key Messages: Hyponatremia is frequent in patients with acute stroke. The plethora of underlying etiologies warrants a careful differential diagnosis which should take into consideration comorbidities, concurrent medication, findings from the clinical examination, and laboratory measurements, which in turn will guide management decisions. However, it is yet unclear whether the appropriate restoration of sodium level improves outcomes in patients with acute stroke.

Uric acid and cardiovascular risk: What genes can say.

BACKGROUND: Although the relationship of elevated serum uric acid levels and cardiovascular disease has been established in a great number of studies, the causal relevance of this finding remains ambiguous. An approach to evaluate the causal relevance of biomarkers is to exploit the natural randomised allocation of allelic variation in genes affecting their level, also known as Mendelian randomisation. AIM: The aim of this paper is to review the current literature regarding serum uric acid levels and cardiovascular and renal disease risk in Mendelian randomisation studies. METHODS: PubMed and Scopus databases were searched to retrieve Mendelian studies regarding uric acid, hyperuricaemia and cardiovascular risk. CONCLUSIONS: Genetic evidence based on conventional and novel Mendelian randomisation approaches suggest a modest, if any, causal effect of serum uric acid concentration on the development of cardiovascular disease, suggesting that further study of uric acid genes is needed in order to elucidate the relationship of serum uric acid levels and cardiovascular disease.

Significant Weight Loss in a Patient Taking Olmesartan: An Unusual Case Report.

OBJECTIVE: Olmesartan-induced enteropathy consists a syndrome that mimics celiac disease both clinically and histologically. Cases of this entity have sporadically been reported since 2012 and are usually characterized by severe diarrhea and malabsorption, followed by significant weight loss. CASE REPORT: Herein, we report an uncommon case of this syndrome, where weight loss preceded several months the onset of gastrointestinal symptoms. DISCUSSION AND CONCLUSION: Physicians should be aware of unexplained weight loss in patients taking olmesartan, as prompt discontinuation of the drug may prevent the deleterious consequences of malabsorption.

Hyponatremia in the elderly: challenges and solutions.

Decreased serum sodium concentration is a rather frequent electrolyte disorder in the elderly population because of the presence of factors contributing to increased antidiuretic hormone, the frequent prescription of drugs associated with hyponatremia and also because of other mechanisms such as the "tea and toast" syndrome. The aim of this review is to present certain challenges in the evaluation and treatment of hyponatremia in the elderly population and provide practical solutions. Hyponatremia in elderly subjects is mainly caused by drugs (more frequently thiazides and antidepressants), the syndrome of inappropriate antidiuretic hormone secretion (SIAD) or endocrinopathies; however, hyponatremia is multifactorial in a significant proportion of patients. Special attention is needed in the elderly population to exclude endocrinopathies as a cause of hyponatremia before establishing the diagnosis of SIAD, which then requires a stepped diagnostic approach to reveal its underlying cause. The treatment of hyponatremia depends on the type of hyponatremia. Special attention is also needed to correct serum sodium levels at the appropriate rate, especially in chronic hyponatremia, in order to avoid the osmotic demyelination syndrome. In conclusion, both the evaluation and the treatment of hyponatremia pose many challenges in the elderly population.