title: Six-minute walk test reflects neurohormonal activation and right ventricular function in systemic sclerosis patients.
abstract: OBJECTIVE
  Heart and pulmonary involvement is a leading cause of systemic sclerosis (SSc)-related deaths. The six-minute walk test (6MWT) is a simple and reproducible test commonly used to evaluate exercise capacity. We tried to assess a potential relationship between exercise capacity assessed by 6MWT, echocardiographic parameters of right ventricular function and serum levels of endothelin-1 and NTproBNP.
  
  
  METHODS
  We prospectively studied 111 consecutive patients (101F, 10M, age 54.2±13.8 years) with diagnosed SSc (mean disease duration 9±12.4 years) and a group of 21 age-matched subjects (18F, 3M, age 49.3±10.5 years). In addition to routine evaluation, 6MWT and transthoracic echocardiography (Phillips iE 33) were performed. We also measured serum endothelin-1 (Human Endothelin-1 immunoassay R & D Systems) and NT-proBNP levels (Elecsys pro-BNP immunoassay; Roche Diagnostics).
  
  
  RESULTS
  The mean 6MWT distance was significantly shorter in the SSc group than in the controls (562.8±60.3 vs. 514.7±102.5 m, p=0.03). In the SSc group 6MWT distance correlated with ET-1 (r=-0.5, p<0.0001), NTproBNP (r=-0.4, p=0.0008) levels, and echocardiographic indices AcT (r=0.4, p=0.0002) and TRPG (r=-0.4, p=0.0011). Moreover, in patients with 6MWT distance <450 m NTproBNP and endotothelin-1 levels were significantly higher than in patients with distance >450 m (311.2, 31.1-17237 vs. 105.3, 5-17670 pg/ml, p=0.0138 and 2.9±2.2 vs. 1.4±0.7 pg/ml, p=0.0032).
  
  
  CONCLUSIONS
  Decreased exercise capacity significantly correlates with biochemical and echocardiographic parameters of right ventricular dysfunction and neurohormonal activation providing a potential link for neuroendocrine derangement in patients with SSc.
authors: Medical University of Warsaw, Department of Internal Medicine and Cardiology, Warsaw, Poland. kirzyk35575@gmail.com
authors: Katarzyna
authors: K
authors: Irzyk
authors: Piotr
authors: P
authors: Bienias
authors: Maciej
authors: M
authors: Kostrubiec
authors: Zuzanna
authors: Z
authors: Rymarczyk
authors: Zbigniew
authors: Z
authors: Bartoszewicz
authors: Maria
authors: M
authors: Siwicka
authors: Anna
authors: A
authors: Stelmaszczyk-Emmel
authors: Elzbieta
authors: E
authors: Górska
authors: Urszula
authors: U
authors: Demkow
authors: Piotr
authors: P
authors: Pruszczyk
authors: Michal
authors: M
authors: Ciurzyński
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D004452:Echocardiography; D019332:Endothelin-1 / Q000097:blood; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D009490:Neurosecretory Systems / Q000378:metabolism* / Q000502:physiology*; D010446:Peptide Fragments / Q000097:blood; D012595:Scleroderma, Systemic / Q000378:metabolism* / Q000503:physiopathology*; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology*; D016278:Ventricular Function, Right / Q000502:physiology*; D016138:Walking / Q000502:physiology
chemical_list: D015415:Biomarkers; D019332:Endothelin-1; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain