Effects of indacaterol versus tiotropium on respiratory mechanics assessed by the forced oscillation technique in patients with chronic obstructive pulmonary disease

Figures & data

Table 1 Characteristics of patients with COPD

	Indacaterol treatment group (n=41)	Tiotropium treatment group (n=41)
Age, years	72.2 (8.4)	72.8 (9.0)
Sex
Male	39 (95.1)	41 (100)
Female	2 (4.9)	0 (0)
Smoking status
Former smoker	33 (80.5)	37 (90.2)
Current smoker	8 (19.5)	4 (9.8)
Pack-years	61.8 (53.1)	58.7 (31.1)
GOLD criteria
I/II/III/IV	9/19/13/0	11/15/15/0
Body mass index (kg/m^2)	22.2 (3.9)	22.7 (3.1)
Pulmonary function tests
FVC (L)	2.90 (0.64)	3.00 (0.83)
FEV1 (L)	1.59 (0.52)	1.62 (0.66)
FEV1, % predicted	62.0 (19.5)	61.1 (18.7)
FEV1/FVC (%)	54.5 (13.1)	54.1 (14.1)
Inspiratory capacity (L)	1.97 (0.47)	2.00 (0.59)
MMF (L/s)	0.73 (0.63)	0.75 (0.47)
V50 (L/s)	1.07 (0.84)	1.09 (0.62)
V25 (L/s)	0.31 (0.27)	0.31 (0.16)
CAT	11.2 (6.6)	11.0 (7.4)

Note: Data are expressed as number (%) or mean (SD).

Abbreviations: COPD, chronic obstructive pulmonary disease; GOLD, Global initiative for chronic Obstructive Lung Disease; FVC, forced vital capacity; FEV₁, forced expiratory volume in 1 second; MMF, maximum midexpiratory flow rate; V₅₀, maximum expiratory flow rate at 50% FVC; V₂₅, maximum expiratory flow rate at 25% FVC; CAT, COPD assessment test; SD, standard deviation.

Table 2 Pulmonary function and COPD assessment scores before and after indacaterol and tiotropium treatment for 8 weeks

	Indacaterol treatment			Tiotropium treatment			Comparison between treatment†
	Baseline	After	Change	Baseline	After	Change
FVC (L)	2.90 (0.64)	3.06 (0.61)*	0.13 (0.26)	3.00 (0.83)	3.07 (0.78)	0.07 (0.31)	0.363
FEV1 (L)	1.59 (0.52)	1.76 (0.53)*	0.16 (0.19)	1.62 (0.66)	1.70 (0.67)*	0.08 (0.18)	0.041**
FEV1, % predicted	62.0 (19.5)	68.6 (18.3)*	7.05 (8.00)	61.1 (18.7)	63.6 (19.2)*	2.56 (7.64)	0.013**
FEV1/FVC (%)	54.5 (13.1)	57.9 (13.3)*	3.43 (4.55)	54.1 (14.1)	55.7 (14.1)	1.54 (7.36)	0.156
Inspiratory capacity (L)	1.97 (0.47)	2.07 (0.48)	0.06 (0.24)	2.00 (0.59)	1.96 (0.58)	−0.04 (0.38)	0.154
MMF (L/s)	0.73 (0.63)	0.89 (0.72)*	0.15 (0.27)	0.75 (0.47)	0.88 (0.63)	0.13 (0.45)	0.732
V50 (L/s)	1.07 (0.84)	1.30 (0.91)*	0.23 (0.33)	1.09 (0.62)	1.20 (0.78)	0.11 (0.34)	0.144
V25 (L/s)	0.31 (0.27)	0.36 (0.32)*	0.05 (0.13)	0.31 (0.16)	0.33 (0.18)	0.02 (0.10)	0.309
CAT	11.2 (6.6)	7.5 (5.6)*	−3.54 (4.67)	11.0 (7.4)	10.0 (7.3)	−0.90 (3.63)	0.008**

Notes: Values are expressed as mean (SD).

† Comparison of changes in indacaterol treatment and tiotropium treatment.

* P<0.05 compared with baseline.

** P<0.05, significant difference between changes with indacaterol treatment and tiotropium treatment.

Abbreviations: COPD, chronic obstructive pulmonary disease; FVC, forced vital capacity; FEV₁, forced expiratory volume in 1 second; MMF, maximum midexpiratory flow rate; V₅₀, maximum expiratory flow rate at 50% FVC; V₂₅, maximum expiratory flow rate at 25% FVC; CAT, COPD assessment test; SD, standard deviation.

Table 3 Respiratory resistance and respiratory reactance at whole-breath, inspiratory, and expiratory phases, and differences between inspiratory and expiratory phases

	Indacaterol			Tiotropium			Comparison between treatment**
	Baseline	After	Change	Baseline	After	Change
Whole-breath
R5	3.38 (1.20)	3.14 (1.05)*	−0.21 (1.01)	3.44 (1.31)	2.97 (1.18)*	−0.46 (1.08)	0.280
R20	2.67 (0.79)	2.56 (0.77)	−0.07 (0.66)	2.66 (0.85)	2.34 (0.82)*	−0.32 (0.79)	0.131
R5–R20	0.70 (0.54)	0.59 (0.45)	−0.12 (0.58)	0.76 (0.55)	0.64 (0.50)	−0.13 (0.46)	0.957
X5	−1.24 (1.14)	−0.74 (0.59)*	0.43 (0.72)	−1.49 (1.50)	−0.99 (1.11)*	0.50 (1.00)	0.711
Fres	13.78 (5.99)	10.84 (4.39)*	−2.86 (4.89)	14.80 (6.75)	12.22 (5.68)*	−2.58 (4.13)	0.782
ALX	9.15 (10.27)	4.44 (5.22)*	−4.30 (7.50)	12.34 (16.21)	7.13 (9.72)*	−5.22 (11.23)	0.673
Expiratory phase
R5	3.68 (1.35)	3.53 (1.25)	−0.13 (1.20)	3.77 (1.41)	2.30 (1.38)*	−0.48 (1.29)	0.220
R20	2.81 (0.86)	2.75 (0.87)	−0.02 (0.71)	2.82 (0.91)	2.48 (0.87)*	−0.34 (0.85)	0.077
R5–R20	0.87 (0.65)	0.78 (0.58)	−0.11 (0.73)	0.94 (0.62)	0.81 (0.70)	−0.13 (0.68)	0.878
X5	−1.51 (1.56)	−0.85 (0.82)*	0.60 (1.06)	−1.98 (2.33)	−1.24 (1.46)*	0.74 (1.88)	0.682
Fres	14.91 (7.02)	11.33 (5.40)*	−3.52 (5.80)	16.35 (8.10)	13.18 (7.03)*	−3.17 (5.20)	0.772
ALX	12.13 (14.69)	5.67 (7.78)*	−6.06 (11.05)	17.19 (25.14)	10.68 (14.96)*	−6.51 (17.99)	0.893
Inspiratory phase
R5	3.09 (0.76)	2.76 (0.95)*	−0.28 (0.88)	3.09 (1.28)	2.65 (1.10)*	−0.45 (1.01)	0.451
R20	2.56 (0.76)	2.37 (0.73)	−0.15 (0.59)	2.48 (0.85)	2.19 (0.81)*	−0.29 (0.79)	0.380
R5–R20	0.53 (0.47)	0.38 (0.36)*	−0.15 (0.47)	0.61 (0.52)	0.46 (0.45)*	−0.15 (0.40)	0.986
X5	−0.94 (0.78)	−0.64 (0.42)*	0.23 (0.46)	−1.00 (0.76)	−0.56 (1.12)*	0.44 (1.05)	0.262
Fres	12.64 (5.23)	10.04 (3.22)*	−2.50 (4.26)	13.35 (5.85)	11.27 (4.62)*	−2.08 (3.63)	0.634
ALX	6.08 (6.46)	3.19 (3.06)*	−2.46 (4.32)	6.97 (7.81)	3.47 (7.57)*	−3.49 (8.08)	0.486
Differences between inspiratory and expiratory phases
R5	0.59 (0.64)	0.76 (0.72)	0.15 (0.60)	0.68 (0.66)	0.64 (0.78)*	−0.03 (0.86)	0.279
R20	0.24 (0.42)	0.38 (0.46)*	0.13 (0.36)	0.33 (0.40)	0.30 (0.36)*	−0.03 (0.40)	0.062
R5–R20	0.34 (0.33)	0.39 (0.36)	0.02 (0.37)	0.34 (0.41)	0.37 (0.57)	0.03 (0.61)	0.942
X5	−0.55 (0.97)	−0.20 (0.56)*	0.36 (0.78)	−0.97 (1.75)	−0.77 (1.66)*	0.19 (1.72)	0.597
Fres	2.27 (3.11)	1.29 (3.44)*	−1.02 (2.97)	2.90 (3.73)	1.91 (3.49)*	−1.00 (3.33)	0.968
ALX	5.96 (9.82)	2.50 (5.56)*	−3.48 (7.70)	10.48 (19.61)	7.32 (14.05)*	−3.17 (16.17)	0.913

Notes:

* P<0.05 compared with baseline.

** Comparison of changes in indacaterol treatment and tiotropium treatment. Values are expressed as mean (SD).

Abbreviations: R5, resistance at 5 Hz; R20, resistance at 20 Hz; X5, reactance index, reactance at 5 Hz; Fres, resonant frequency; ALX, low-frequency reactance area; SD, standard deviation.