. Author manuscript; available in PMC: 2015 Jul 1.

Published in final edited form as: Am J Respir Crit Care Med. 2015 Jan 1;191(1):54–62. doi: 10.1164/rccm.201402-0314OC

Table 1.

Subject characteristics

	Healthy Controls	Non-severe Asthma	Severe Asthma
Number	10	9	9
Age, years	39.0 ±11.3	31.8 ± 16	41.4 ± 12
Gender, F/M	5/5	4/5	5/4
Duration of asthma, years	N/A	18.2 ± 3.8	25.7 ± 9.7 ^*
Inhaled corticosteroid dose, μg BDP equivalent	N/A	622 ± 290	2160±466 ^*
Atopy (n)^$	3	6	5
Receiving oral prednisolone (n)	N/A	N/A	6
FEV₁, L	3.15 ± 1.860	2.96 ± 0.46	2.0 ± 0.47 **
FEV₁,% predicted	91.0 ±15.6	81.5 ± 8.3	61.59 ± 4.9 ^***
FEV₁/FVC, %	77.2 ± 3.9	75.0 ± 3.1	69.0 ± 5.9 ^*
β-agonist reversibility^#, %	N/A	24.0 ± 3.5	31.0 ± 4.11^*
PC₂₀, mg/mL	> 16	2.7 ± 0.104	0.331 ± 0.13 (4/9)

BDP, beclomethasone dipropionate; FEV₁, forced expiratory volume in 1s; FVC, forced vital capacity; PC₂₀, provocative concentration of metacholine causing a 20% fall in FEV₁; N/A: not applicable.

Defined as positive skin prick tests to one or more common aeroallergens.

Measured as percent increase in FEV₁ after 400 μg salbutamol.

p<0.05

^***

p<0.001 vs non-severe asthma.