title: Dyspnea in ambulatory patients with SLE: prevalence, severity, and correlation with incremental exercise testing.
abstract: OBJECTIVE
  We sought to determine the prevalence and severity of dyspnea, and to correlate dyspnea with clinical features and exercise limitation in ambulatory patients with systemic lupus erythematosus (SLE).
  
  
  METHODS
  Twenty-five consecutive patients were evaluated with a validated pulmonary questionnaire, chest radiograph, 2-dimensional echocardiography, resting pulmonary function tests, and incremental exercise testing.
  
  
  RESULTS
  Dyspnea was reported by 60% (95% CI 39-79) of patients; 20% (95% CI 7-40) had severe dyspnea (inability to dress without dyspnea) and 12% (95% CI 3-31) had moderate dyspnea (dyspnea after walking 100 yards). Compared to patients without dyspnea, patients with dyspnea were more likely to have had a history of clinical lupus involving the lung (80 vs 40%, p = 0.05), a lower total lung capacity (77.5 vs 94.8%, p = 0.002), and a reduced maximum oxygen consumption (VO2max of 53.4 vs 67.7%, p = 0.01). Patients with severe dyspnea and patients without dyspnea did not differ in duration of prednisone use, activity of disease, weight, or in frequency of Raynaud's phenomenon (p > 0.05). Only 4% of all patients had abnormal left ventricular motion on 2-dimensional echo; patients with moderate or severe dyspnea had normal left ventricular motion. Of the 5 patients with severe dyspnea, 4 (80%) had restrictive lung disease and 1 (20%) had an isolated diffusion defect. All patients with dyspnea had an abnormal exercise test, but so did 9/10 without dyspnea (p > 0.05). Severity of dyspnea correlated highly with maximum exercise tolerance measured by VO2max (R2 = 0.51, p = 0.0001).
  
  
  CONCLUSIONS
  In ambulatory patients with SLE, dyspnea is common, frequently disabling, associated with a history of lupus involvement of the lung, and correlates highly with objective measures of exercise limitation.
authors.affiliation: Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Hellman
authors.forename: C M
authors.initials: CM
authors.lastname: Kirsch
authors.forename: Q
authors.initials: Q
authors.lastname: Whiting-O'Keefe
authors.forename: J
authors.initials: J
authors.lastname: Simonson
authors.forename: N B
authors.initials: NB
authors.lastname: Schiller
authors.forename: M
authors.initials: M
authors.lastname: Petri
authors.forename: G
authors.initials: G
authors.lastname: Gamsu
authors.forename: W
authors.initials: W
authors.lastname: Gold
mesh_terms: D000328:Adult; D004417:Dyspnea / Q000150:complications* / Q000453:epidemiology* / Q000503:physiopathology; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000503:physiopathology; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008180:Lupus Erythematosus, Systemic / Q000150:complications*; D010045:Outpatients; D015995:Prevalence