Metabolic and inflammatory indices in colorectal adenoma: A real-world colonoscopy cohort study

Table 1 Baseline characteristics and colonoscopy findings of the study population, median (interquartile range)/n (%)

Variable	Study population (n = 1570)
Age (years)	61 (51-70)
Sex
Male	773 (49.2)
Female	797 (50.8)
Colonoscopy findings
Normal colonoscopy	995 (63.4)
Adenoma present	395 (25.2)
Diverticulosis	52 (3.3)
Benign ulceration	33 (2.1)
Polyp histology
Tubular adenoma	306 (19.5)
Tubulovillous adenoma	47 (3.0)
Villous adenoma	7 (0.4)
Adenoma, subtype not specified	35 (2.2)
Hyperplastic polyp	78 (5.0)
Inflammatory polyp	29 (1.8)
Polyp localization
Rectum	90 (5.6)
Sigmoid colon	106 (6.6)
Descending colon	52 (3.2)
Splenic flexure	7 (0.4)
Transverse colon	63 (3.9)
Ascending colon	35 (2.2)
Cecum	18 (1.1)
Hepatic flexure	4 (0.2)

Percentages were calculated based on the final analytic cohort. Patients with colorectal malignancy, inflammatory bowel disease, prior colorectal surgery, undefined colonoscopy findings, and invalid demographic records were excluded before final analyses. Due to the retrospective cohort design, some patients had multiple non-neoplastic colonoscopic findings. Polyp localization frequencies may exceed the number of adenoma patients because some individuals had multiple lesions involving different colonic segments.

Table 2 Comparison of metabolic and lipid parameters according to adenoma status

Variable	Non-adenoma group (n)	Adenoma group (n)	Mean rank (non-adenoma)	Mean rank (adenoma)	Z value	Effect size (r)	P value
Glucose (mg/dL)	1239	351	728.60	1031.66	-10.920	0.274	< 0.001
Triglycerides (mg/dL)	1208	337	715.33	979.73	-9.620	0.245	< 0.001
HDL cholesterol (mg/dL)	1207	337	801.50	668.63	-4.839	0.123	< 0.001
LDL cholesterol (mg/dL)	1206	337	739.07	889.86	-5.493	0.140	< 0.001
TyG index	1208	337	701.16	1030.52	-11.984	0.305	< 0.001
AIP	1207	337	717.28	970.26	-9.209	0.234	< 0.001

Continuous variables were compared using the Mann-Whitney U test. Higher mean rank values indicate higher levels of the corresponding variable. Effect size r was calculated as |Z|/√n. Analyses were performed using complete-case data for each parameter because laboratory availability varied across patients in this retrospective cohort. TyG: Triglyceride-glucose; AIP: Atherogenic index of plasma; LDL: Low-density lipoprotein; HDL: High-density lipoprotein.

Table 3 Comparison of hematological and inflammatory parameters according to adenoma status

Variable	Non-adenoma group (n)	Adenoma group (n)	Mean rank (non-adenoma)	Mean rank (adenoma)	Z value	Effect size (r)	P value
Neutrophils (103/μL)	1244	352	778.18	870.32	-3.312	0.083	0.001
Lymphocytes (103/μL)	1244	352	789.29	831.04	-1.501	0.038	0.133
Platelets (103/μL)	1244	351	803.07	780.04	-0.827	0.021	0.408
NLR	1244	352	789.85	829.06	-1.409	0.035	0.159
PLR	1244	352	809.36	760.10	-1.770	0.044	0.077
SII	1244	352	794.11	814.01	-0.715	0.018	0.475
NHR	1207	337	740.85	885.86	-5.279	0.134	< 0.001

Continuous variables were compared using the Mann-Whitney U test. Higher mean rank values indicate higher levels of the corresponding variable. Effect size r was calculated as |Z|/√n. Analyses were performed using complete-case data for each parameter because laboratory availability varied across patients in this retrospective cohort. NLR: Neutrophil-to-lymphocyte ratio; PLR: Platelet-to-lymphocyte ratio; SII: Systemic immune-inflammation index; NHR: Neutrophil-to-high-density lipoprotein ratio.

Table 4 Receiver operating characteristic analysis of metabolic and inflammatory markers for adenoma detection

Variable	AUC	95%CI	P value	Optimal cut-off (Youden)	Sensitivity (%)	Specificity (%)
TyG index	0.714	0.684-0.744	< 0.001	8.648	81.0	55.0
Glucose (mg/dL)	0.696	0.666-0.726	< 0.001	97.5	65.5	68.0
Triglycerides (mg/dL)	0.671	0.640-0.702	< 0.001	142.5	63.0	64.2
AIP	0.664	0.633-0.695	< 0.001	0.496	60.7	69.0
HDL cholesterol (mg/dL)	0.414	0.384-0.445	< 0.001	44.5	62.0	41.8
Neutrophils (103/μL)	0.560	0.529-0.591	0.001	4.65	58.0	54.0
NHR	0.593	0.562-0.624	< 0.001	0.087	61.5	56.0
NLR	0.517	0.486-0.548	0.266	-	-	-
PLR	0.522	0.491-0.553	0.177	-	-	-
SII	0.508	0.477-0.539	0.594	-	-	-

Receiver operating characteristic analyses were performed to evaluate the ability of each marker to discriminate adenoma presence. Optimal cut-off values were determined using the Youden index. Analyses were performed using complete-case data for each parameter because laboratory availability varied across patients in this retrospective cohort. Cut-off values were not calculated for parameters without statistically significant receiver operating characteristic discrimination. Because high-density lipoprotein cholesterol was inversely associated with colorectal adenoma, an area under the curve below 0.50 reflects the direction of this association rather than poor discriminatory performance. AUC: Area under the curve; TyG: Triglyceride-glucose; AIP: Atherogenic index of plasma; HDL: High-density lipoprotein; NHR: Neutrophil-to-high-density lipoprotein ratio; NLR: Neutrophil-to-lymphocyte ratio; PLR: Platelet-to-lymphocyte ratio; SII: Systemic immune-inflammation index.

Table 5 Age-adjusted and sex-adjusted logistic regression analyses for adenoma presence

Variable	Adjusted OR	95%CI	P value
TyG index	1.32	1.10-1.58	0.003
AIP	1.24	1.05-1.47	0.011
NLR	1.05	0.94-1.18	0.340
PLR	0.96	0.86-1.08	0.470
SII	1.04	0.93-1.16	0.480
NHR	1.12	0.99-1.27	0.071

Logistic regression models were adjusted for age and sex. Odds ratios with 95%CIs are presented per 1 standard deviation increase of each variable. TyG: Triglyceride-glucose; AIP: Atherogenic index of plasma; NLR: Neutrophil-to-lymphocyte ratio; PLR: Platelet-to-lymphocyte ratio; SII: Systemic immune-inflammation index; NHR: Neutrophil-to-high-density lipoprotein ratio; OR: Odds ratio.