Risk of inflammatory bowel disease in patients with chronic obstructive pulmonary disease: A nationwide, population-based study

Table 1 Baseline characteristics of study population, n (%)

	Non-COPD controls (n = 6515105)	COPD group (n = 1303021)	P value
Sex (Male %)	2867470 (44.0)	573494 (44.0)	1
Age (yr)	57.1 ± 10.72	57.1 ± 10.72	1
40-64	5025580 (77.1)	1005116 (77.1)
65-	1489525 (22.9)	297905 (22.9)
COPD severity
Mild		1191562 (91.4)
Severe		111459 (8.6)
Income Low1	1597508 (24.5)	357627 (27.5)	< 0.001
Urban residents	2965581 (45.8)	567359 (44.1)
Comorbidity
Diabetes mellitus	640544 (9.8)	164860 (12.7)	< 0.001
Hypertension	1703988 (26.2)	418880 (32.2)	< 0.001
Dyslipidemia	1002279 (15.4)	272449 (20.9)	< 0.001
Follow up duration (yr)	3.9 ± 1.4	3.9 ± 1.4	0.8803

¹Denotes subjects with annual income lower than 20% among total population. COPD: Chronic obstructive pulmonary disease.

Table 2 Incidence rate and risk of inflammatory bowel disease in patients with chronic obstructive pulmonary disease

		Event	DURATION (Person-years)	Incidence rateof IBD	Model 11 HR (95%CI)	Model 22 HR (95%CI)	P value
		IBD
COPD	No	1846	25697723.08	7.18	1 (Ref.)	1 (Ref.)	< 0.001
	Yes	513	5139283.39	9.98	1.39 (1.26-1.53)	1.379 (1.25-1.52)
		UC
COPD	No	1540	25697723.08	5.99	1 (Ref.)	1 (Ref.)	< 0.001
	Yes	406	5139283.39	7.9	1.32 (1.18-1.47)	1.315 (1.18-1.47)
		CD
COPD	No	306	25697723.08	1.19	1 (Ref.)	1 (Ref.)	< 0.001
	Yes	107	5139283.39	2.08	1.75 (1.40-2.171)	1.691 (1.35-2.10)

¹Model 1: adjustment for age and sex;

²Model 2: adjustment for model 1+ place of resident, income, diabetes mellitus, hypertension, dyslipidemia. CD: Crohn’s disease; CI: Confidence interval; COPD: Chronic obstructive pulmonary disease; HR: Hazard ratio; IBD: Inflammatory bowel disease; UC: Ulcerative colitis.

Table 3 Incidence and risk of inflammatory bowel disease in patients with chronic obstructive pulmonary disease according to disease severity

		Event	DURATION (Person-years)	Incidence rateof IBD	Model 11 HR (95%CI)	Model 22 HR (95%CI)	P value
		IBD
COPD Severity	Non	1846	25697723.08	7.18	1 (Ref.)	1 (Ref.)	< 0.001
	Mild	461	4719752.21	9.77	1.36 (1.23-1.50)	1.35 (1.22-1.49)
	Sev-ere	52	419531.18	12.39	1.717 (1.29-2.24)	1.70 (1.27-2.21)
		UC
COPD Severity	Non	1540	25697723.08	5.99	1 (Ref.)	1 (Ref.)	< 0.001
	Mild	371	4719752.21	7.86	1.31 (1.17-1.47)	1.31 (1.17-1.47)
	Sev-ere	35	419531.18	8.34	1.39 (0.97-1.91)	1.38 (0.96-1.89)
		CD
COPD Severity	Non	306	25697723.08	1.19	1 (Ref.)	1 (Ref.)	< 0.001
	Mild	90	4719752.21	1.91	1.60 (1.26-2.02)	1.548 (1.22-1.95)
	Sev-ere	17	419531.18	4.05	3.38 (2.00-5.33)	3.29 (1.94-5.20)

¹Model 1: adjustment for age and sex;

²Model 2: adjustment for model 1+ place of resident, income, diabetes mellitus, hypertension, dyslipidemia. CD: Crohn’s disease; CI: Confidence interval; COPD: Chronic obstructive pulmonary disease; HR: Hazard ratio; IBD: Inflammatory bowel disease; UC: Ulcerative colitis.

Table 4 Risk of inflammatory bowel disease in patients with chronic obstructive pulmonary disease according to sex and age

	COPD	IBD	UC	CD
Male	No	1 (Ref.)	1 (Ref.)	1 (Ref.)
	Yes	1.47 (1.23-1.60)	1.35 (1.16-1.55)	1.75 (1.26-2.39)
Female	No	1 (Ref.)	1 (Ref.)	1 (Ref.)
	Yes	1.35 (1.16-1.55)	1.27 (1.07-1.5)	1.64 (1.20-2.21)
Age (40-64)	No	1 (Ref.)	1 (Ref.)	1 (Ref.)
	Yes	1.36 (1.21-1.52)	1.31 (1.15-1.48)	1.62 (1.25-2.08)
Age (65-)	No	1 (Ref.)	1 (Ref.)	1 (Ref.)
	Yes	1.46 (1.19-1.79)	1.36 (1.07-1.71)	1.93 (1.23-2.96)

CD: Crohn’s disease; COPD: Chronic obstructive pulmonary disease; IBD: Inflammatory bowel disease; UC: Ulcerative colitis.