Table 1 Clinical characteristics of phenotypes based on severity of emphysema*
CharacteristicNo/mild(n = 105)Moderate(n = 124)Severe(n = 45)Total(n = 274)
Age (years)70 (64–76)72 (64–75)71 (68–77)71 (64–76)
Sex (male/female)96/9119/543/2258/16
BMI (kg/m2)23.5 (0.3)21.7 (0.3)†21.2 (0.5)†22.3 (0.2)
Smoking (pack-years)58 (3)65 (3)66 (4)63 (2)
Current smoker (%)39/105 (37)26/124 (21)10/45 (22)75/274 (27)
Clinical symptoms (%)
    Chronic cough11/105 (11)18/124 (15)5/45 (11)34/274 (12)
    Chronic sputum19/105 (18)23/124 (19)7/45 (16)49/274 (18)
    Chronic cough and sputum8/105 (8)16/124 (13)5/45 (11)29/274 (11)
Pulmonary function tests
Pre-bronchodilator
    FVC (% predicted)91.4 (2.0)94.7 (2.0)88.3 (3.1)92.4 (1.3)
    FEV1 (% predicted)63.0 (2.0)56.9 (2.1)†46.5 (3.0)†‡57.5 (1.4)
Post-bronchodilator
    FVC (% predicted)98.9 (1.8)102.6 (1.8)98.4 (2.9)100.5 (1.2)
    FEV1 (% predicted)69.5 (1.9)62.7 (2.0)52.0 (3.0)†‡63.5 (1.3)
    FEV1/FVC0.56 (0.01)0.48 (0.01)†0.42 (0.02)†‡0.50 (0.01)
Transfer factor
    Tlco/Va (% predicted)78.1 (2.2)58.4 (1.8)†41.6 (2.5)†‡63.3 (1.5)
Blood analysis
    Eosinophils (log cells/μl)2.26 (0.03)2.16 (0.03)2.19 (0.05)2.20 (0.02)
    Serum total IgE (log IU/ml)1.87 (0.07)1.72 (0.06)1.74 (0.09)1.78 (0.04)
    α1-antitrypsin (mg/dl)128 (2)129 (2)135 (3)129 (1)
Medications, no. of patients/total (%)
    Anticholinergic agents41/105 (39)64/124 (52)32/45 (71)†‡137/274 (50)
    β2 agonists29/105 (28)43/124 (35)18/45 (40)90/274 (33)
    Theophyllines36/105 (34)59/124 (48)†27/45 (60)†122/274 (45)
    ICS12/105 (11)10/124 (8)9/45 (20)31/274 (11)
  • BMI, body mass index; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 s; Tlco, carbon monoxide transfer factor; Va, alveolar volume; ICS, inhaled corticosteroids; no/mild, no or mild emphysema (emphysema score <1); moderate, moderate emphysema (emphysema score ⩾1–<2.5); severe, severe emphysema (emphysema score ⩽2.5).

  • *Data shown as mean (SE) values except for skewed data which are expressed as median (interquartile range). Univariate analysis used χ2 tests for categorical variables and one-way analysis of variance for quantitative variables with Scheffe’s test as a post-hoc test for multiple comparisons.

  • †p<0.05 vs no/mild emphysema; ‡p<0.05 vs moderate emphysema.