Table 2

Randomised controlled clinical trials on the effects of inhaled corticosteroids in patients with corticosteroid naive asthma

StudyMajor outcome measuresMean baseline BHR (range of doses applied)Mean baseline FEV1Effects on BHR (inhaled corticosteroid vs. control)*Effects on lung function (inhaled corticosteroid vs. control)Effects on symptoms, β2 agonists and bronchial epithelium/eosinophils (inhaled corticosteroids vs. control)
Ryan55 PC20 histamine0.5 mg/ml histamine (0.0125–16)3.18 l+0.44 DD
(p = 0.14)
FEV1 =No data
Baets56 PD20 histamine/HDM50 μg histamine (10–1280)90%pred+1.55 DD (p<0.001)FEV1+ (97%), morning PEF+ (20 l/min)Symptoms =, β2 agonists −
Kerrebijn57 PD20 methacholine38 μg methacholine (10–1280)95%pred+2.33 DD (p<0.001)FEV1 =Symptoms =
Bel58 PC20 methacholine, max airway narrowing methacholine3.6 mg/ml methacholine (0.25–256)94%pred+0.65 DD
(p = 0.23)
FEV1=No data
Fuller59 PD35histamine/bradykinin0.28 μmol histamine (0.06–16)89%pred+1.00 DD
(p = 0.21)
(35–50 l/min)
Symptoms =
Laitinen60 PC15 histamine, FEV1, PEF, symptoms, biopsy: bronchial epithelium, inflammatory cells mucosa2.9 mg/ml histamine (1.0–32)89%pred+0.70 DD
(p = 0.25)
FEV1 =, PEF+
(50 l/min)
Symptoms =, β2 agonists =, structure airway epithelium +, lymphocytes −, eosinophils −
Haahtela61 PC15 histamine, FEV1, PEF, symptoms, β agonists7.0 mg/ml histamine (1.0–32)86%pred+1.10 DD (p<0.001)FEV1 =, PEF+
(30 l/min)
Symptoms −, β2 agonists −
O’Connor62 PC20methacholine/MBS/AMP1.4 mg/ml methacholine (0.125–32)96%pred+1.17 DD
(p = 0.009)
FEV1=No data
Evans63 Peripheral blood eosinophils, PC20 methacholine0.13–2.23 mg/ml methacholine (0.125–32)96%pred+0.88 DD (p<0.001)No dataNo data about symptoms/β2 agonists, eosinophils −
Vathenen64 PD20 histamine, FEV1, PEF, symptoms, β agonists0.37 μmol histamine (0.03–32)95%pred+2.40 DD
(p = 0.003)
FEV1+ (98%), PEF+
(40 l/min)
Symptoms −, β2 agonists −
Wiebicke65 PC100 sRaw histamine/methacholine, PV75 sRaw hypervent/So 2 0.2 mg/ml histamine (0.01–8.0)90%pred+0.64 DD (histamine or methacholine)
(p = 0.28)
No dataNo data
  • BHR = bronchial hyperresponsiveness; DD = doubling dose; FEV1 = forced expiratory volume in one second; PEF = peak expiratory flow; sRaw = specific airways resistance; So 2 = oxygen saturation; PC20, PD20 = concentration or dose of provocative agent required to produce a fall in FEV1 of 20% or more.; HDM = house dust mite. According to effects of inhaled corticosteroids versus control group on lung function and symptoms, ‘+’ or ‘−’ means statistically significant increase or decrease (p<0.05), ‘=’ means no statistically significant difference. * See fig 1.