The association of renin–angiotensin system blockades and pneumonia requiring admission in patients with COPD

Figures & data

Table 1 Clinical characteristics of study population

Characteristics	COPD patients with pneumonia (n=130)	COPD patients without pneumonia (n=245)a	P-valueb
Age, years (%)
40–49	11 (8.5)	15 (6.1)	0.74
50–59	21 (16.2)	45 (18.4)
60–69	58 (44.6)	116 (47.4)
≥70	40 (30.7)	69 (28.1)
Sex
Male/female (ratio)	110/20 (5.5)	210/35 (6.0)	0.77
FEV1, % predicted (%)
<30	8 (6.1)	7 (2.9)	0.28
30–50	50 (38.5)	85 (34.7)
50–80	66 (50.8)	144 (58.8)
>80	6 (4.6)	9 (3.7)
Smoking habits (%)
Never	7/90 (7.8)	14/144 (9.7)	0.11
Ex-smoker	62/90 (68.9)	86/144 (59.7)
Current smoker	21/90 (23.3)	44/144 (30.6)
Comorbidities (%)
Pulmonary tuberculosis	53 (40.8)	68 (27.8)	0.03
Diabetes mellitus	27 (20.8)	39 (15.9)	0.35
Hypertension	45 (34.6)	72 (29.4)	0.42
Ischemic heart disease	12 (9.2)	17 (6.9)	0.50
Congestive heart failure	11 (8.5)	11 (4.5)	0.20
Other heart diseases	17 (13.1)	21 (8.6)	0.27
Cerebrovascular disease	10 (7.7)	20 (8.2)	0.63
Liver disease	5 (3.9)	14 (5.7)	0.37
Renal disease	12 (9.2)	11 (4.5)	0.13
Malignant disease	9 (6.9)	30 (12.2)	0.17

Notes:

a Controls matched with age, sex, and category of post-FEV₁ spirometry results within proper index date of matched patients; two matched controls for 115 cases and one matched control for 15 cases.

b Chi-square test for categorical variables and Student’s t-test for continuous variables.

Abbreviation: FEV₁, forced expiratory volume for 1 second.

Table 2 Distribution of therapeutic medication in study population

Therapeutic medication	COPD patients with pneumonia (n=130)	COPD patients without pneumonia (n=245)	P-valuea
ACEi/ARBs
Ever use (%)	28 (21.5)	66 (26.9)	0.25
Months, mean (SD)	9.8 (3.5)	9.6 (3.6)	0.83
Inhaled corticosteroids
Ever use (%)	77 (59.2)	144 (58.8)	0.32
Types (%)
Fluticasone	56 (72.7)	102 (70.8)	0.77b
Budesonide	20 (26.0)	38 (26.4)
Beclomethasone	1 (1.3)	4 (2.8)
Daily dose, μg/day (%)
Low (<250)	32 (42.6)	49 (34.0)	0.33
Medium (≥250, <500)	14 (18.2)	38 (26.4)
High (≥ 500)	31 (40.2)	57 (39.6)
Equivalent dose, median (IQR)	333.3 (125.0–625.0)	354.2 (200.0–500.0)	0.93c
Systemic steroids
Ever use (%)	30 (23.1)	27 (11.0)	0.005
Cumulative dose, median (IQR)	359.5 (176.0–811.0)	172.0 (128.0–336.0)	0.03d
Statins
Ever use (%)	9 (6.9)	37 (15.1)	0.52

Notes:

a Chi-square test for categorical variables and Student’s t-test for continuous variables.

b Fisher’s exact test.

c Wilcoxon rank sum test.

d Equivalent dose of fluticasone.

Abbreviations: ACEi, angiotensin-converting enzyme inhibitors; ARB, angiotensin II receptor blocker; IQR, interquartile range; SD, standard deviation.

Table 3 Risk of pneumonia (cOR) according to each variable in univariate analysis

Variable	cOR	95% CI	P-valuea
Comorbidities
Pulmonary tuberculosis	1.85	1.12–3.06	0.02
Congestive heart failure	1.84	0.79–4.31	0.16
Renal disease	2.18	0.96–4.95	0.06
Malignant disease	0.56	0.26–1.20	0.15
ACEi/ARB
No use	1.00		0.21
Ever use	0.70	0.41–1.23
Inhaled corticosteroids
No use	1.00		0.74
Ever use	0.92	0.58–1.47
Inhaled corticosteroids, equivalent dose (μg/day)
No use	1.00		0.34b
Low (<250)	1.09	0.61–1.94
Medium (≥250, <500)	0.63	0.31–1.30
High (≥500)	0.96	0.54–1.69
Systemic steroids
No use	1.00		0.005
Ever use	2.33	1.28–4.23
Statins
No use	1.00		0.48
Ever use	0.72	0.28–1.83

Notes:

a Conditional logistic regression analysis for the incidence of pneumonia by each variable.

b P-value for trend.

Abbreviations: ACEi, angiotensin-converting enzyme inhibitors; ARB, angiotensin II receptor blocker; CI, confidence interval; cOR, crude odds ratio.

Table 4 Risk of pneumonia (aOR) in multivariate analysis

Variable	aORa	95% CI	P-value	aORb	95% CI	P-value
Comorbidities
Pulmonary tuberculosis	2.16	1.27–3.69	0.005	2.18	1.27–3.74	0.005
Congestive heart failure	2.10	0.83–5.35	0.12	2.14	0.83–5.49	0.11
Renal disease	2.94	1.18–7.31	0.02	2.75	1.10–6.87	0.03
Malignant disease	0.58	0.26–1.32	0.19	0.60	0.26–1.37	0.22
ACEi/ARB
No use	1.00		0.04	1.00		0.04
Ever use	0.51	0.27–0.98		0.51	0.26–0.98
ICS				NA	NA
No use	1.00		0.39	NA	NA
Ever use	0.80	0.48–1.34		NA	NA
ICS, equivalent dose (μg/day)	NA	NA
No use	NA	NA		1.00		0.69
Low (<250)	NA	NA		0.97	0.52–1.80
Middle (≤250, <500)	NA	NA		0.58	0.26–1.31
High (≥500)	NA	NA		0.75	0.40–1.42
Systemic steroids
No use	1.00		0.002	1.00		0.002
Ever use	2.83	1.47–5.46		2.87	1.48–5.56

Notes:

a Conditional logistic regression for the incidence of pneumonia adjusting for the past history of pulmonary tuberculosis, chronic renal disease, the use of systemic steroids, and the use of inhaled corticosteroids.

b Conditional logistic regression for the incidence of pneumonia adjusting for the past history of pulmonary tuberculosis, chronic renal disease, the use of systemic steroids, and the daily dose of inhaled corticosteroids.

Abbreviations: ACEi, angiotensin-converting enzyme inhibitors; aOR, adjusted odds ratio; ARB, angiotensin II receptor blocker; CI, confidence interval; ICS, inhaled corticosteroid; NA, not assessed.