Different Relationships between F_ENO and COPD Characteristics in Smokers and Ex-Smokers

Figures & data

Figure 1. The F_ENO₅₀ values in ex-smokers and smokers according to sex. Females had lower F_ENO₅₀ values than men did.

Table 1. Characteristics of the ex-smoking subjects divided into tertiles with regard to F_ENO₅₀.

	Low FENO50 <11.5 ppb (n = 126)	Intermediate FENO50 ≥11.5– ≤19 ppb (n = 129)	High FENO50 >19 ppb (n = 128)	p-value
Females, n (%)	76 (60)	72 (56)	64 (50)	0.253
Age (years)	70 ± 7	69 ± 8	70 ± 6	0.682
BMI	26 ± 5	28 ± 5	27 ± 5	0.131
Lung function
FEV1 % predicted	53 ± 17^a	57 ± 17	60 ± 19	0.005
FVC % predicted	67 ± 16^a	70 ± 16	73 ± 20	0.024
FEV1/FVC	0.49 ± 0.12	0.52 ± 0.11	0.51 ± 0.12	0.109
Asthma and IgE sensitisation
Asthma	47 (37%)	43 (33%)	41 (32)	0.606
IgE sensitised	5 (8%)	16 (21%)	19 (21%)	0.068
Inflammatory markers
B-Neu 10^9/L	4.9 (4.6, 5.2)^b	4.4 (4.1, 4.6)	4.2 (4.0, 4.5)	0.006
B-Eos 10^9/L	0.15 (0.13, 0.17)	0.16 (0.14, 0.18)	0.20 (0.18, 0.23)^c	0.003
Symptom burden
CAT $\ge$ 10	78 (62%)	82 (64%)	77 (60%)	0.854
mMRC $\ge$ 2	64 (51%)	68 (53%)	52 (41%)	0.115
Exacerbations
Frequent exacerbations	36 (29%)	31 (24%)	33 (26%)	0.708
Hospital admissions	12 (10%)	8 (6%)	6 (5%)	0.293
Treatments
ICS alone or in combination	87 (69%)	78 (61%)	73 (57%)	0.127
GOLD 2017
A/B/C/D	29/43/9/19%	33/43/3/21%	34/42/6/18%	0.623

Data given as n (%), mean ± SD, geometrical mean (CI_95%). IgE sensitisation performed in 227 subjects. p-values derived by Kruskal-Wallis test.

a Post hoc test Tukey HSD: low F_ENO₅₀ vs. high F_ENO₅₀.

b Post hoc test Tukey HSD: low F_ENO₅₀ vs. both intermediate and high F_ENO₅₀.

c Post hoc test Tukey HSD: high F_ENO₅₀ vs. both low p = 0.002 and intermediate F_ENO₅₀.

BMI, body mass index; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; B-Eos, eosinophil blood count; B-Neu, neutrophil blood count; CAT, COPD assessment test; mMRC, modified British Medical Research Council; ICS, inhaled corticosteroids.

Table 2. Characteristics of the smoking subjects divided into tertiles with regard to F_ENO₅₀.

	Low FENO50 <7 ppb (n = 48)	Intermediate FENO50 ≥$7$–11 ppb (n = 51)	High FENO50 >11 ppb (n = 51)	p-value
Females, n (%)	38 (77)^a	34 (67)	26 (51)	0.023
Age (years)	65 ± 10	64 ± 8	66 ± 6	0.210
BMI	24 ± 4	25 ± 5	26 ± 4	0.053
Lung function
FEV1 % predicted	53 ± 15^a	62 ± 17	61 ± 17	0.020
FVC % predicted	67 ± 18	72 ± 15	75 ± 16	0.028
FEV1/FVC	0.48 ± 0.11^b	0.54 ± 0.12	0.52 ± 0.11	0.020
Asthma and IgE sensitisation
Asthma	17 (35%)	13 (26%)	20 (39%)	0.317
IgE sensitised	5 (10%)	6 (12%)	6 (12%)	0.731
Inflammatory markers
B-Neu 10^9/L	4.7 (4.3, 5.1)	4.9 (4.5, 5.4)	4.9 (4.5, 5.3)	0.924
B-Eos 10^9/L	0.14 (0.11, 0.17)	0.19 (0.16, 0.23)	0.19 (0.16, 0.24)	0.066
Symptom burden
CAT $\ge$ 10	32 (67%)	30 (59%)	27 (53%)	0.379
mMRC $\ge$ 2	21 (44%)	11 (22%)	17 (33%)	0.062
Exacerbations
Frequent exacerbations	15 (31%)	9 (18%)	13 (26%)	0.288
Hospital admissions	5 (10%)	3 (6%)	3 (6%)	0.610
Treatments
ICS alone or in combination	28 (52%)	21 (46%)	24 (48%)	0.164
GOLD 2017
A/B/C/D	22/44/8/26%	41/42/4/13%	46/32/2/20%	0.226

Data given as n (%), mean ± SD, geometrical mean (CI_95%). IgE sensitisation preformed in 82 subjects. p-values derived by Kruskal-Wallis test.

a Post hoc test Tukey HSD: low F_ENO₅₀ vs. high F_ENO₅₀ group.

b Post hoc test Tukey HSD: low F_ENO₅₀ vs. intermediate F_ENO₅₀ group.

BMI, body mass index; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; B-Eos, eosinophil blood count; B-Neu, neutrophil blood count; CAT, COPD assessment test; mMRC, modified British Medical Research Council; ICS, inhaled corticosteroids.

Figure 2. The F_ENO₅₀ values in ex-smokers and smokers according to positive or negative IgE sensitisation (defined as ≥0.35 kUA/L). No significant difference was found.

Figure 3. The F_ENO₅₀ values in ex-smokers and smokers according to usage of ICS. Ex-smokers had a significantly lower F_ENO₅₀ value statistically when treated with ICS, while no difference was found in smokers.