Table 1

Characteristics of subjects

Subject no.	Age (years)	Sex	PD₂₀ (μg)	FEV ^* (% pred)	FEV₁ (% pred)
1	45	M	890	113	120
2	23	F	55	95	97
3	47	F	85	92	89
4	45	M	170	110	114
5	29	M	538	97	100
6	33	F	652	99	97
7	24	F	676	112	109
8	18	F	47	89	84
9	23	F	89	107	110
10	40	F	1039	95	98
11	28	M	20	94	94
12	56	F	154	100	100
13	31	F	120	95	93
14	39	M	770	105	109
15	21	M	466	95	96
16	39	M	219	89	88
Mean	33.8			99.2	99.9
SD	11.0			7.9	10.0
Geometric mean			215

FEV₁ ^* = forced expiratory volume in one second performed prior to sputum induction on day without methacholine challenge.
FEV₁ = forced expiratory volume in one second performed prior to methacholine challenge.
PD₂₀ = concentration of methacholine provoking a 20% reduction in FEV₁.