<p>Supplementary Table 1. Odd Ratio for Rectal Neuroendocrine Tumors by Demographic Characteristics (Subgroup analysis) Variable Cases, n(%) OR (95%CI) p-value Men Age (years) 0.999 (0.975-1.023) 0.913 Diabetes 0.491 No 71 (97.3) Reference Yes 2 (2.7) 0.491 (0.120-2.005) HbA1c (%) 0.450 (0.050-4.026) 0.475 Glucose (mg/dL) 1.133 (0.305-4.206) 0.852 Insulin (uIU/mL) 0.968 (0.600-1.561) 0.894 C-peptide (ng/mL) 1.027 (0.739-1.428) 0.872 Hypertension 0.846 No 61 (83.6) Reference Yes 12 (16.4) 1.063 (0.572-1.976) Hyperlipidemia 0.746 No 72 (98.6) Reference Yes 1 (1.4) 0.381 (0.053-2.742) Cholesterol (mg/dL) 1.008 (1.002-1.015) 0.008 HDL-cholesterol (mg/dL) 0.987 (0.968-1.007) 0.199 LDL-cholesterol (mg/dL) 1.007 (1.000-1.014) 0.067 Triglyceride (mg/dL) 1.402 (0.907-2.165) 0.128 Metabolic syndrome 0.202 No 71 (97.3) Reference Yes 2 (2.7) 1.436 (0.824-2.503) Ferritin (ng/mL) 1.237 (0.841-1.821) 0.280 CRP (mg/dL) 1.288 (1.026-1.617) 0.029 Total protein (g/dL) 0.853 (0.497-1.464) 0.564 Albumin (g/dL) 1.249 (0.554-2.815) 0.592 Family (1st degree) history of colorectal cancer 0.127 No 65 (89.0) Reference Yes 8 (11.0) 1.924 (0.831-4.455) Family (1st degree) history of any cancer 0.093 No 67 (91.8) Reference Yes 6 (8.2) 1.587 (0.925-2.723) Women Age (years) 1.006 (0.966-1.047) 0.783 Diabetes 0.155 No 27 (93.1) Reference Yes 2 (6.9) 2.837 (0.673-11.955) HbA1c (%) 14.765 (1.09-199.47) 0.043 Glucose (mg/dL) 2.594 (0.260-25.850) 0.417 Insulin (uIU/mL) 1.008 (0.488-2.081) 0.983 C-peptide (ng/mL) 1.131 (0.603-2.123) 0.701 Hypertension 0.085 No 23 (79.3) Reference Yes 6 (20.7) 2.206 (0.897-5.423) Hyperlipidemia 0.341 No 27 (93.1) Reference Yes 2 (6.9) 2.011 (0.478-8.469) Cholesterol (mg/dL) 1.007 (0.997-1.017) 0.154 HDL-cholesterol (mg/dL) 0.993 (0.968-1.018) 0.577 LDL-cholesterol (mg/dL) 1.007 (0.996-1.018) 0.203 Triglyceride (mg/dL) 1.549 (0.738-3.250) 0.247 Metabolic syndrome 0.003 No 29 (100.0) Reference Yes 0 (0.0) 3.437 (1.521-7.769) Ferritin (ng/mL) 1.692 (0.738-3.250) 0.033 CRP (mg/dL) 1.182 (0.787-1.775) 0.421 Total protein (g/dL) 1.063 (0.458-2.466) 0.887 Albumin (g/dL) 1.034 (0.262-4.079) 0.962 Family (1st degree) history of colorectal cancer 0.634 No 26 (92.9) Reference Yes 2 (7.1) 1.418 (0.336-5.982) Family (1st degree) history of any cancer 0.192 No 20 (71.4) Reference Yes 8 (28.6) 1.727 (0.760-3.923) OR, odd ratio; CI, confidence interval; SD, standard deviation; CRP, C-reactive protein; Supplementary Table 2. Odd Ratio for Rectal Neuroendocrine Tumors by Modifiable Characteristics (Subgroup analysis) Variable Cases (n) OR (95%CI) p-value Men Smoking status Never 13 (20.6) Reference Former (Quit ≥ 1yr ago) 13 (20.6) 1.173 (0.543-2.533) 0.684 Current 37 (58.7) 1.304 (0.692-2.454) 0.412 Smoking duration (years) 1.014 (0.995-1.033) 0.142 Alcohol consumption status 0.998 Never 27 (40.9) Reference Ever 39 (59.1) 1.001 (0.612-1636) Alcohol consumption duration (years) 1.014 (0.986-1.042) 0.331 BMI (kg/m2) 0.836 Non-obese (<25) 39 (57.4) Reference Obese (≥25) 29 (42.6) 0.950 (0.587-1.538) Waist circumference (cm) 0.342 Men <90cm or Women <80cm 36 (57.1) Reference Men ≥90cm or Women ≥80cm 27 (42.9) 1.274 (0.773-2.100) Physical activity degree, n(%) Never/rarely 5 (12.2) Reference Mild 9 (22.0) 0.619 (0.207-1.850) 0.391 Moderate 23 (36.5) 0.812 (0.308-2.137) 0.673 Vigorous 4 (9.8) 0.932 (0.250-3.479) 0.917 Physical activity frequency Never/rarely 3 (7.3) Reference 1-2 days/week 17 (41.5) 0.937 (0.274-3.203) 0.917 3-4 days/week 10 (24.4) 0.624 (0.171-2.271) 0.474 11 (26.8) 1.261 (0.351-4.528) 0.722 ≥ 5 days/week Physical activity time (min) ≤ 20 min/day 3 (7.7) Reference 21-40 min/day 5 (12.8) 0.551 (0.131-2.312) 0.415 41-60 min/day 9 (23.1) 0.529 (0.143-1.959) 0.341 22 (56.4) 0.676 (0.202-2.264) 0.526 ≥ 60 min/day Women Smoking status Never 24 (96.0) Reference Former (Quit ≥ 1yr ago) 0 (0.0) <0.001 (<0.001-999.999) 0.983 Current 1 (4.0) 1.545 (0.365-6.530) 0.555 Smoking duration (years) 0.949 (0.813-1.108) 0.507 Alcohol consumption status 0.199 Never 15 (60.0) Reference Ever 10 (40.0) 0.599 (0.274-1.309) Alcohol consumption duration (years) 1.036 (0.949-1.131) 0.427 BMI (kg/m2) 0.396 Non-obese (<25) 19 (65.5) Reference Obese (≥25) 10 (34.5) 1.446 (0.617-3.387) Waist circumference (cm) 0.236 Men <90cm or Women <80cm 14 (50.0) Reference Men ≥90cm or Women ≥80cm 14 (50.0) 1.566 (0.746-3.287) Physical activity degree Never/rarely 1 (4.8) Reference Mild 3 (14.3) 0.866 (0.090-8.338) 0.901 Moderate 14 (66.7) 1.054 (0.138-8.024) 0.960 Vigorous 3 (14.3) 1.872 (0.194-18.024) 0.588 Physical activity frequency, n(%) Never/rarely 2 (10.0) Reference 1-2 days/week 2 (10.0) 0.220 (0.031-1.561) 0.130 3-4 days/week 8 (40.0) 0.557 (0.118-2.629) 0.460 8 (40.0) 0.734 (0.156-3.464) 0.696 ≥ 5 days/week Physical activity time (min) ≤ 20 min/day 2 (10.0) Reference 21-40 min/day 1 (5.0) 0.199 (0.018-2.201) 0.188 41-60 min/day 6 (30.0) 0.488 (0.098-2.422) 0.380 11 (55.0) 0.335 (0.074-1.515) 0.155 ≥ 60 min/day OR, odd ratio; CI, confidence interval; Supplementary Table 3. Risk Factors of Rectal Carcinoids Estimated from Multivariable Logistic Regression Models (Subgroup analysis) Variable Univariate analysis Multivariate analysis OR (95% CI) p-value OR (95% CI) p-value Men Cholesterol 1.008 (1.002-1.015) 0.008 1.009 (1.002-1.015) 0.011 CRP 1.288 (1.026-1.617) 0.029 1.282 (1.015-1.619) 0.037 Women HbA1c 14.765 (1.09-199.47) 0.043 Metabolic syndrome 3.437 (1.521-7.769) 0.003 2.881 (1.165-7.127) 0.022 Ferritin 1.692 (0.738-3.250) 0.033 1.529 (0.949-2.461) 0.081 OR, odd ratio; CI, confidence interval; HDL, high density lipoprotein; LDL, low density lipoprotein; CRP, C-reactive protein;</p>