Risk factors and long-term prognosis for colorectal strictures in ulcerative colitis

Table 1 Basic information and clinical characteristics of the study population, mean ± SD/n (%)

	Stricture group			Non-stricture group	1P value	2P value
	All stricture cases	Malignant stricture group	Benign stricture group
Number of patients	116	10	106	822
Male	58 (50.0)	6 (60.0)	52 (49.1)	474 (57.7)	0.119	0.092
Age at diagnosis, year (median, IQR)	38.97 (30.52-49.39)	36.06 (32.19-42.39)	40.69 (29.36-51.95)	34.50 (26.61-47.14)	0.020	0.016
≥ 40	57 (49.1)	3 (30.0)	54 (50.9)	310 (37.7)	0.018	0.009
Disease duration, year (median, IQR)	11.55 (7.13-18.74)	25.39 (19.38-32.39)	10.75 (6.81-15.69)	8.96 (5.67-13.59)	< 0.001	0.005
Follow-up time, year (median, IQR)	9.85 (4.25-17.22)	24.10 (19.17-32.37)	7.95 (3.70-14.42)	8.65 (4.87-12.82)	0.373	0.660
Montreal classification					0.068	0.023
E1 (proctitis)	23 (19.8)	0 (0.0)	23 (21.7)	104 (12.7)
E2 (left-sided colitis)	28 (24.1)	3 (30.0)	25 (23.6)	253 (30.8)
E3 (pancolitis)	65 (56.0)	7 (70.0)	58 (54.7)	465 (56.6)
Smoking status					0.736	0.961
Active smoker	7 (6.0)	0 (0.0)	7 (6.6)	58 (7.1)
Former smoker	19 (16.4)	0 (0.0)	19 (17.9)	154 (18.7)
Nonsmoker	90 (77.6)	10 (100.0)	80 (75.5)	610 (74.2)
Family history of IBD	4 (3.4)	1 (10.0)	3 (2.8)	39 (4.7)	0.532	0.519
Family history of CRC	3 (2.6)	0 (0.0)	3 (2.8)	33 (4.0)	0.623	0.744
History of appendectomy	2 (1.7)	0 (0.0)	2 (1.9)	16 (1.9)	1.000	1.000
Weight loss	81 (69.8)	6 (60.0)	75 (70.8)	544 (66.2)	0.435	0.347
Extraintestinal involvement	27 (23.3)	3 (30.0)	24 (22.6)	112 (13.6)	0.006	0.013
Arthropathy	4 (3.4)	0 (0.0)	4 (3.8)	40 (4.9)	0.499	0.618
Skin lesions	7 (6.0)	0 (0.0)	7 (6.6)	25 (3.0)	0.165	0.108
Oral ulcer	12 (10.3)	1 (10.0)	11 (10.4)	44 (5.4)	0.034	0.039
Ophthalmopathy	1 (0.9)	0 (0.0)	1 (0.9)	4 (0.5)	0.484	0.455
Thrombosis	9 (7.8)	1 (10.0)	8 (7.5)	13 (1.6)	< 0.001	< 0.001
PSC	2 (1.7)	1 (10.0)	1 (1.2)	10 (1.2)	0.989	1.000
Hemoglobin, g/L	103.78 ± 23.59	108.10 ± 20.43	103.38 ± 23.91	111.63 ± 26.28	< 0.001	< 0.001
CRP, mg/L (median, IQR)	11.82 (2.20, 43.65)	4.61 (2.57, 20.35)	12.41 (2.10, 44.23)	9.27 (2.07, 33.00)	0.374	0.268
ESR, mm/hour (median, IQR)	23 (12, 46)	15 (7, 16)	24 (12, 49)	20 (9, 40)	0.171	0.097
Treatment until stricture or the end of follow-up
5-ASA	111 (95.7)	10 (100.0)	101 (95.3)	811 (98.7)	0.053	0.034
Systemic glucocorticoids	98 (84.5)	7 (70.0)	91 (85.8)	611 (74.3)	0.017	0.009
Immunomodulators	32 (27.6)	2 (20.0)	30 (28.3)	202 (24.6)	0.483	0.404
Biologics	25 (21.6)	0 (0.0)	25 (23.6)	314 (38.2)	< 0.001	0.003

¹Statistical comparisons were conducted between stricture and non-stricture groups.

²Statistical comparisons were limited to the benign-stricture and non-stricture groups; the malignant-stricture group (n = 10) was summarized descriptively and omitted from the main analyses owing to its small size.

IQR: Interquartile range; IBD: Inflammatory bowel disease; CRC: Colorectal cancer; PSC: Primary sclerosing cholangitis; CRP: C-reactive protein; ESR: Erythrocyte sedimentation rate; 5-ASA: 5-aminosalicylic.