title: Dysnatremia, vasopressin, atrial natriuretic peptide and mortality in patients with community-acquired pneumonia: results from the german competence network CAPNETZ.
abstract: BACKGROUND
  Dysnatremia is a frequent finding in patients with community acquired pneumonia (CAP) and a predictor of mortality. We studied the relation between dysnatremia, comorbidities and CT-pro-AVP and MR-proANP.
  
  
  METHODS
  We enrolled 2138 patients (60 ± 18 years, 55% male) with CAP from the CAPNETZ database. Pro-atrial natriuretic peptide (proANP), pro-vasopressin (proAVP), serum sodium and CRB-65 score were determined on admission. Patients were followed up for 28 days. Sodium concentration on admission was examined as a function of mortality at 28 days. Hyponatremia (HypoN) was defined as admission serum sodium <136 mmol/L, hypernatremia (HyperN) as admission serum sodium >145 mmol/L.
  
  
  RESULTS
  HypoN was diagnosed in 680 (31.8%) patients, HyperN in 29 (1.4%) patients. Comorbidities were associated with sodium levels, and CT-pro-AVP and MR-proANP were inversely related to sodium levels. Patients with HypoN were older, had a higher CRB-65 score and higher values of CT-proAVP and MR-proANP (all p < 0.05). When examined as a function of sodium values, a U-shaped association was found between sodium levels and 28 day mortality. In multivariate Cox proportional hazards analysis, HypoN and HyperN were independent predictors of 28 day mortality. Sodium levels added to the predictive potential of proAVP and proANP.
  
  
  CONCLUSIONS
  HypoN is common at admission among CAP patients and is independently associated with mortality. HyperN is rare at admission among CAP patients but is also independently associated with mortality. The combination of sodium and CT-pro-AVP and MR-proANP levels achieved the highest prediction of mortality.
authors.affiliation: Medical Clinic I, Medical Faculty, RWTH University Aachen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Krüger
authors.affiliation: Thoraxzentrum Ruhrgebiet, Kliniken für Pneumologie und Infektiologie, Ev. Krankenhaus Herne und Augusta Kranken-Anstalt Bochum, Germany.
authors.forename: Santiago
authors.initials: S
authors.lastname: Ewig
authors.affiliation: Research Department, BRAHMS AG, Hennigsdorf, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Giersdorf
authors.affiliation: Research Department, BRAHMS AG, Hennigsdorf, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Hartmann
authors.affiliation: Medical Clinic I, Medical Faculty, RWTH University Aachen, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Frechen
authors.affiliation: Department of Pneumology, Maastricht Medical Centrum, University Hospital Maastricht, The Netherlands.
authors.forename: Gernot
authors.initials: G
authors.lastname: Rohde
authors.affiliation: Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charite University Medicine, Berlin, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Suttorp
authors.affiliation: Department of Pneumology, Hannover Medical School, University Clinic, Hannover, Germany. Electronic address: welte.tobias@mh-hannover.de.
authors.forename: Tobias
authors.initials: T
authors.lastname: Welte
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D009320:Atrial Natriuretic Factor / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D017714:Community-Acquired Infections / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000401:mortality; D015897:Comorbidity; D016208:Databases, Factual; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D006955:Hypernatremia / Q000097:blood / Q000382:microbiology / Q000401:mortality; D007010:Hyponatremia / Q000097:blood / Q000382:microbiology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000097:blood / Q000150:complications* / Q000175:diagnosis / Q000401:mortality; D011237:Predictive Value of Tests; D011379:Prognosis; D012964:Sodium / Q000097:blood; D014667:Vasopressins / Q000097:blood*
chemical_list: D015415:Biomarkers; D014667:Vasopressins; D009320:Atrial Natriuretic Factor; D012964:Sodium
keywords: Community acquired pneumonia; Hyponatremia; Prognosis; Vasopressin