Correlation between inflammatory markers and disease severity in ulcerative colitis

Table 1 Baseline demographic and clinical characteristics of ulcerative colitis patients, n (%)

Factor	Mild group (n = 37)	Moderate group (n = 45)	Severe group (n = 35)	χ2/F	P value
Age (year), mean ± SD	45.43 ± 12.62	45.07 ± 11.58	46.00 ± 11.38	0.061	0.941
Gender				0.514	0.773
Male	17 (45.95)	23 (51.11)	19 (54.29)
Female	20 (54.05)	22 (48.89)	16 (45.71)
BMI (kg/m2), mean ± SD	22.73 ± 2.82	22.53 ± 2.90	22.40 ± 1.90	0.147	0.864
Smoking history				0.595	0.743
No	29 (78.38)	35 (77.78)	25 (71.43)
Yes	8 (21.62)	10 (22.22)	10 (28.57)
Alcohol abuse history				0.232	0.890
No	27 (72.97)	32 (71.11)	24 (68.57)
Yes	10 (27.03)	13 (28.89)	11 (31.43)
Lesion location				0.504	0.777
Rectum	12 (32.43)	18 (40.00)	13 (37.14)
Colon	25 (67.57)	27 (60.00)	22 (62.86)

BMI: Body mass index.

Table 2 Univariate analysis of factors associated with disease severity in ulcerative colitis patients, n (%)

Factor	Mild-to-moderate group (n = 82)	Severe group (n = 35)	χ2	P value
Age (years)			0.218	0.640
< 45 (n = 54)	39 (47.56)	15 (42.86)
≥ 45 (n = 63)	43 (52.44)	20 (57.14)
Gender			0.020	0.888
Male (n = 59)	41 (50.00)	18 (51.43)
Female (n = 58)	41 (50.00)	17 (48.57)
BMI (kg/m2)			1.632	0.202
< 23 (n = 54)	41 (50.00)	13 (37.14)
≥ 23 (n = 63)	41 (50.00)	22 (62.86)
Smoking history			4.788	0.029
No (n = 89)	67 (81.71)	22 (62.86)
Yes (n = 28)	15 (18.29)	13 (37.14)
Alcohol abuse history			5.294	0.022
No (n = 83)	64 (78.05)	20 (57.14)
Yes (n = 34)	18 (21.95)	15 (42.86)
Lesion location			0.003	0.954
Rectum (n = 43)	30 (36.59)	13 (37.14)
Colon (n = 74)	52 (63.41)	22 (62.86)
IL-6 (pg/mL)			5.670	0.017
< 13 (n = 46)	38 (46.34)	8 (22.86)
≥ 13 (n = 71)	44 (53.66)	27 (77.14)
TNF-α (pg/mL)			5.606	0.018
< 20 (n = 63)	50 (60.98)	13 (37.14)
≥ 20 (n = 54)	32 (39.02)	22 (62.86)
CRP (mg/L)			5.985	0.014
< 15 (n = 70)	55 (67.07)	15 (42.86)
≥ 15 (n = 47)	27 (32.93)	20 (57.14)

BMI: Body mass index; IL-6: Interleukin-6; TNF-α: Tumor necrosis factor-alpha; CRP: C-reactive protein.

Table 3 Multivariate logistic regression analysis of factors independently associated with ulcerative colitis disease severity

Factor	β	SE	Wald	P value	OR	95%CI
Smoking history	1.431	0.547	6.844	0.009	4.185	1.432-12.229
Alcohol abuse history	1.271	0.513	6.132	0.013	3.565	1.303-9.749
IL-6 (pg/mL)	1.039	0.523	3.942	0.047	2.826	1.013-7.878
TNF-α (pg/mL)	1.223	0.483	6.414	0.011	3.396	1.318-8.747
CRP (mg/L)	1.047	0.481	4.743	0.029	2.849	1.110-7.311

OR: Odds ratio; CI: Confidence interval; IL-6: Interleukin-6; TNF-α: Tumor necrosis factor-alpha; CRP: C-reactive protein.

Table 4 Performance of the multi-factor combined prediction model

Factor	AUC	95%CI	Sensitivity	Specificity	Optimal cutoff
IL-6 (pg/mL)	0.797	0.697-0.897	62.86%	95.12%	18.94
TNF-α (pg/mL)	0.820	0.735-0.905	65.71%	85.37%	24.85
CRP (mg/L)	0.763	0.662-0.863	74.29%	71.95%	14.32
Combined	0.917	0.861-0.972	88.57%	80.49%	0.26

AUC: Area under the curve; CI: Confidence interval; IL-6: Interleukin-6; TNF-α: Tumor necrosis factor-alpha; CRP: C-reactive protein.