Table 1 Baseline demographics and pulmonary functions (mean ± SD) of 45 asthmatic patients

Number of subjects (n)

30

15

45

Male/female

10/20

9/6

19/26

Age (mean ± SD)

38 ± 14

40 ± 13

38 ± 13

Smoking (pack-years)

0

11 ± 10

-

Race (black/white/asian)

20/9/1

10/5/0

30/14/1

PC₂₀ (provocative concentration causing a 20 % drop in FEV₁, in mg/ml)

2.4 ± 4.2

2.6 ± 2.1

2.4 ± 3.6

FEV₁ (forced expiratory volume in 1-second, in L)

2.7 ± 0.7

2.8 ± 0.8

2.7 ± 0.7

FEV₁ % predicted (forced expiratory volume in 1-second)

87 ± 10 %

91 ± 13 %

88 ± 11 %

FVC % predicted (forced vital capacity)

90 ± 12 %

97 ± 15 %

92 ± 13 %

FEV₁/FVC

0.80 ± 0.08

0.78 ± 0.01

0.79 ± 0.08

TLC (total lung capacity, in L)

5.0 ± 1.4

5.1 ± 1.2

5.0 ± 1.4

SVC (slow vital capacity, in L)

3.3 ± 1

3.5 ± 0.9

3.4 ± 1.0

FRC (functional residual capacity, in L)

3.0 ± 0.9

3.3 ± 1.5

3.1 ± 1.1

RV (residual volume, in L)

1.7 ± 0.7

1.7 ± 0.8

1.7 ± 0.7

RV/TLC

0.34 ± 0.09

0.33 ± 0.08

0.34 ± 0.09

Diffusing capacity of carbon monoxide (mL/min/mm Hg)

22.5 ± 5.9

22.9 ± 5.4

22.7 ± 5.6

Specific airway resistance, (in kiloPascals · s)

6.1 ± 3.4

6.0 ± 3.4

6.04 ± 3.3

Exhaled nitric oxide (ppb)

10.4 ± 11

6.15

9.1 ± 10