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.

The association of admission hyperglycaemia and adverse clinical outcome in medical emergencies: the multinational, prospective, observational TRIAGE study.

AIMS: The clinical relevance of hyperglycaemia in an emergency department population remains incompletely understood. We investigated the association between admission blood glucose levels and adverse clinical outcomes in a large emergency department cohort. METHODS: We prospectively enrolled 7132 adult medical patients seeking emergency department care in three tertiary care hospitals in Switzerland, France and the USA. We used adjusted multivariable logistic regression models to examine the association between admission blood glucose levels and 30-day mortality, as well as adverse clinical course stratified by pre-existing diabetes and principal medical diagnoses. RESULTS: In 6044 people without diabetes (84.7%), severe hyperglycaemia, defined as a glucose level of > 11.1 mmol/l (200 mg/dl), was associated with a doubling in the risk of 30-day mortality [adjusted odds ratio (OR) 1.9; 95% confidence interval (95% CI), 1.1 to 3.3; P = 0.018] and a three-fold increase in the risk of intensive care unit admission (adjusted OR 3.0; 95% CI, 1.9 to 4.9; P < 0.001). These associations were similar among different diagnoses. In the population with diabetes (n = 1088), no association with 30-day mortality was found (adjusted OR 1.0; 95% CI, 0.6 to 1.8; P for interaction = 0.001), whereas the association with intensive care unit admission was weaker (adjusted OR 2.4; 95% CI, 1.5 to 4.1; P for interaction = 0.011). Overall 30-day mortality was higher in those with diabetes than in those without (6.1 vs. 4.4%, P = 0.015). CONCLUSIONS: In this large medical emergency department patient cohort, admission hyperglycaemia was strongly associated with adverse clinical course in people without diabetes. (Clinical Trial Registry No: NCT01768494).