title: Gender and respiratory factors associated with dyspnea in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  We had shown that COPD women expressed more dyspnea than men for the same degree of airway obstruction.
  
  
  OBJECTIVE
  Evaluate gender differences in respiratory factors associated with dyspnea in COPD patients.
  
  
  METHODS
  In a FEV1 % matched population of 100 men and women with COPD we measured: age, MMRC, FEV1, FVC, TLC, IC/TLC, PaO2, PaCO2, DLCO, Pimax, P0.1, Ti/Ttot, BMI, ffmi, 6MWD and VAS scale before and after the test, the Charlson score and the SGRQ. We estimated the association between these parameters and MMRC scores. Multivariate analysis determined the independent strength of those associations.
  
  
  RESULTS
  MMRC correlated with: BMI (men:-0.29, p = 0.04; women:-0.28, p = 0.05), ffmi (men:-0.39, p = 0.01), FEV1 % (men:-0.64, p < 0.001; women:-0.29, p = 0.04), FVC % (men:-0.45, p = 0.001; women:-0.33, p = 0.02), IC/TLC (men:-0.52, p < 0.001; women: -0.27, p = 0.05), PaO2 (men:-0.59, p < 0.001), PaCO2 (men:0.27, p = 0.05), DLCO (men:-0.54, p < 0.001), P0.1/Pimax (men:0.46, p = 0.002; women:0.47, p = 0.005), dyspnea measured with the Visual Analog Scale before (men:0.37, p = 0.04; women:0.52, p = 0.004) and after 6MWD (men:0.52, p = 0.002; women:0.48, p = 0.004) and SGRQ total (men:0.50, p < 0.001; women:0.59, p < 0.001). Regression analysis showed that P0.1/Pimax in women (r2 = 0.30) and BMI, DLCO, PaO2 and P0.1/Pimax in men (r2 = 0.81) were the strongest predictors of MMRC scores.
  
  
  CONCLUSIONS
  In mild to severe COPD patients attending a pulmonary clinic, P0.1/Pimax was the unique predictor of MMRC scores only in women. Respiratory factors explain most of the variations of MMRC scores in men but not in women. Factors other than the respiratory ones should be included in the evaluation of dyspnea in women with COPD.
authors.affiliation: Respiratory Research Unit, Hospital Nuestra Sra de Candelaria, Tenerife, Spain. jupa65@hotmail.com
authors.forename: Juan P
authors.initials: JP
authors.lastname: de Torres
authors.forename: Ciro
authors.initials: C
authors.lastname: Casanova
authors.forename: Angela
authors.initials: A
authors.lastname: Montejo de Garcini
authors.forename: Armando
authors.initials: A
authors.lastname: Aguirre-Jaime
authors.forename: Bartolome R
authors.initials: BR
authors.lastname: Celli
mesh_terms: D015897:Comorbidity; D004417:Dyspnea / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology*; D012129:Respiratory Function Tests / Q000706:statistics & numerical data*; D015656:Respiratory Mechanics; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012737:Sex Factors; D013030:Spain / Q000453:epidemiology