Table 2. Relationship between reduced diffusing capacity of the lung for carbon monoxide (DLCO) and patient/disease characteristics
Trip [41]Chandra [44]
DLCO <45%DLCO ≥45%p-valueDLCO <43%DLCO 43–64%DLCO >64%p-value
Subjects n48118135135138
Age years67#46#<0.001554745<0.0001
Former smoker58300.07
Current smoker19180.77
6MWD m275+390+0.03
Metabolic equivalents2.63.74.2<0.0001
NYHA WHO FC I/II21350.05§92526<0.0001ƒ
NYHA WHO FC III/IV7965917574
Anti-nuclear antibodies38200.06795532<0.0001
RAP mmHg7.3+8.1+ns1111110.83
mPAP mmHg47+52+ns4954540.02
CI mL·min−1·m−22.3+2.5+ns2220.78
PVR Wood Unitsns1113130.03
TPVR dyn·s·cm−51000+1004+
HR (95% CI)3.8 (2.2–6.6)##<0.0012.7 (1.9–3.9)##<0.001
2.4 (1.1–5.0)¶¶0.025
  • Data are presented as %, unless otherwise stated. 6MWD: 6-min walking distance; NYHA: New York Heart Association; WHO: World Health Organization; FC: functional class; RAP: right atrial pressure; mPAP: mean pulmonary artery pressure; CI: cardiac index; PVR: pulmonary vascular resistance; TPVR: total PVR; HR: hazard ratio; ns: nonsignificant. #: median age at diagnosis; : mean age at study entry; +: approximate value based on data from [42]; §: FC I/II versus III/IV; ƒ: across all groups; ##: univariate analysis; ¶¶: multivariate analysis.