Determinants of circulating asymmetric and symmetric dimethylarginines in patients evaluated for acute dyspnea.

BACKGROUND: The relationship between asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) plasma concentrations and acute heart failure is unknown. We evaluated ADMA and SDMA in patients with acute dyspnea. METHODS: We studied 57 dyspneic subjects (50-95 years), with estimated glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73 m², presenting to the emergency department. Troponin I, N terminal-proBNP (NT-proBNP), ADMA, and SDMA were measured. Electrocardiogram, chest X-ray and lung ultrasound were performed. Patients were classified into cardiogenic dyspnea and non-cardiogenic dyspnea, and were also classified on the basis of renal function according to their eGFR. RESULTS: Two-way analysis of variance demonstrated that ADMA and SDMA did not differ for type of dyspnea, but increased in renal dysfunction. NT-proBNP significantly increased both in cardiogenic dyspnea and renal dysfunction. Multiple regression analysis demonstrated that after adjustment for troponin and dyspnea, the only variables which significantly correlated with SDMA plasma concentrations were renal function (ß = -0.47, p < 0.001) and NT-proBNP (ß = 0.28, p = 0.02). CONCLUSIONS: Neither type of dimethylarginine showed cardiogenic dyspnea to be a determinant for plasma concentrations. Renal dysfunction was a confounder for both ADMA and SDMA.