Characteristics of and risk factors for colorectal neoplasms in young adults in a screening population

Table 1 Baseline characteristics of the subjects according to age n (%)

Variable	Age group				P value
	< 40 (n = 694)	40-44 (n = 591)	45-49 (n = 491)	≥50 (n = 1043)
Males	465 (67.0)	443 (75.0)	363 (73.9)	717 (68.7)	0.790
Body mass index (kg/m2)	23.1 ± 3.3	23.8 ± 3.3	24.0 ± 3.0	24.0 ± 3.0	< 0.001
Waist circumference (cm)	81.5 ± 10.3	82.9 ± 9.5	83.7 ± 8.8	84.1 ± 8.7	< 0.001
Diabetes mellitus	17 (2.4)	21 (3.6)	33 (6.7)	130 (12.5)	< 0.001
Hypertension	89 (12.8)	146 (24.7)	155 (31.6)	462 (44.3)	< 0.001
Metabolic syndrome	48 (6.9)	67 (11.3)	77 (15.7)	226 (21.7)	< 0.001
High hsCRP	54 (7.8)	55 (9.3)	41 (8.4)	131 (12.6)	0.001
Triglyceride (mg/dL)	116.0 ± 91.2	125.4 ± 85.3	130.2 ± 90.2	123.8 ± 83.6	0.039
HDL cholesterol (mg/dL)	58.7 ± 15.1	57.5 ± 14.7	56.3 ± 14.6	56.7 ± 15.1	0.018
LDL cholesterol (mg/dL)	132.0 ± 50.3	136.6 ± 34.1	139.5 ± 36.8	137.4 ± 35.1	0.006
Total cholesterol (mg/dL)	202.1 ± 37.5	208.0 ± 36.0	210.8 ± 41.6	208.2 ± 39.4	0.001
Alcohol consumption	272 (39.2)	263 (44.5)	235 (47.9)	348 (33.4)	0.005
Smoking status
Never	312 (45.0)	212 (35.9)	181 (36.9)	449 (43.0)	< 0.001
Former	134 (19.3)	136 (23.0)	131 (26.7)	366 (35.1)
Current	248 (35.7)	243 (41.1)	179 (36.5)	228 (21.9)
Colorectal adenoma	61 (8.8)	87 (14.7)	105 (21.4)	302 (29.0)	< 0.001
Advanced neoplasm	6 (0.9)	4 (0.7)	6 (1.2)	26 (2.5)	0.004
≥ 1 cm	5 (0.7)	3 (0.5)	5 (1.0)	24 (2.3)	0.001
Villous	1 (0.1)	1 (0.2)	1 (0.2)	7 (0.7)	0.055
High grade	0 (0.0)	1 (0.2)	1 (0.2)	4 (0.4)	0.091
Multiplicity	8 (1.2)	18 (3.0)	33 (6.7)	121 (11.6)	< 0.001

hsCRP: High-sensitivity C-reactive protein; HDL: High-density lipoprotein cholesterol; LDL: Low-density lipoprotein cholesterol.

Table 2 Risk factors of colorectal adenoma in this study population n (%)

Variable	Number of persons		Univariate analysis		Multivariate analysis1
	Non-adenoma	Adenoma	OR (95%CI)	P value	OR (95%CI)	P value
	(n = 2264)	(n = 555)
Males	1530 (67.6)	458 (82.5)	2.27 (1.79-2.87)	< 0.001	1.88 (1.35-2.61)	< 0.001
Age (yr)
≥ 50	741 (32.7)	302 (54.4)	1	< 0.001	1
45-49	386 (17.0)	105 (18.9)	0.67 (0.52-0.86)		0.64 (0.49-0.84)	0.001
40-44	504 (22.3)	87 (15.7)	0.42 (0.33-0.55)		0.40 (0.30-0.53)	< 0.001
< 40	633 (28.0)	61 (11.0)	0.24 (0.18-0.32)		0.25 (0.18-0.34)	< 0.001
Body mass index (kg/m2)
mean ± SD	23.6 ± 3.2	24.4 ± 3.0
< 25	1468 (64.8)	321 (57.8)	1	< 0.001	1
25.0-29.9	624 (27.6)	203 (36.6)	1.52 (1.25-1.86)		0.94 (0.72-1.23)	0.644
≥ 30	76 (3.4)	18 (3.2)	1.11 (0.65-1.88)		0.68 (0.37-1.24)	0.204
Waist circumference (cm)
mean ± SD	82.6 ± 9.4	85.5 ± 8.7
Male < 90, female < 80	1658 (73.2)	353 (63.6)	1	< 0.001	1
Male ≥ 90, female ≥ 80	606 (6.8)	202 (36.4)	1.57 (1.28-1.91)		1.50 (1.14-1.97)	0.004
Diabetes mellitus	144 (6.4)	57 (10.3)	1.69 (1.22-2.33)	0.001	1.12 (0.79-1.57)	0.533
Hypertension	623 (27.5)	229 (41.3)	1.85 (1.53-2.24)	< 0.001	1.27 (0.96-1.67)	0.095
Metabolic syndrome	308 (13.6)	110 (19.8)	1.57 (1.23-2.00)	< 0.001	0.86 (0.59-1.26)	0.445
hsCRP
< 0.10			1	0.020	1
≥ 0.10			1.25 (1.04-1.51)		1.05 (0.82-1.34)	0.725
Triglyceride (mg/dL)
mean ± SD	119.7 ± 85.8	138.1 ± 91.0
< 150	1742 (76.9)	376 (67.7)	1	< 0.001	1
≥ 150	522 (23.1)	179 (32.3)	1.59 (1.30-1.95)		1.15 (0.92-1.45)	0.227
HDL cholesterol (mg/dL)
mean ± SD	57.9 ± 15.0	54.9 ± 14.6
Male < 40, female < 50	277 (12.2)	77 (13.9)	1	0.296
Male ≥ 40, female ≥ 50	1987 (87.8)	478 (86.1)	0.87 (0.66-1.14)
LDL cholesterol (mg/dL)
mean ± SD	135.7 ± 40.3	138.5 ± 36.1
≤ 100	354 (15.6)	76 (13.7)	1	0.070
101-129	699 (30.9)	152 (27.4)	1.01 (0.75-1.37)
≥ 130	1211 (53.5)	327 (58.9)	1.26 (0.95-1.66)
Total cholesterol (mg/dL)
mean ± SD	206.7 ± 38.5	209.0 ± 40.0
< 200	1033 (45.6)	226 (40.7)	1	0.037	1
≥ 200	1231 (54.4)	329 (59.3)	1.22 (1.01-1.48)		1.09 (0.89-1.34)	0.390
Current alcohol	871 (38.5)	247 (44.5)	1.28 (1.06-1.55)	0.009	0.93 (0.75-1.16)	0.513
Smoking status
Never	994 (43.9)	160 (28.8)	1	< 0.001	1
Former	584 (25.8)	18 (33.0)	1.90 (1.54-2.46)		1.21 (0.90-1.63)	0.215
Current	68 (30.3)	21(38.2)	1.90 (1.53-2.41)		1.56 (1.16-2.10)	0.003

¹Adjusted for sex, age, body mass index, waist circumference, diabetes mellitus, hypertension, metabolic syndrome, hsCRP, triglyceride, alcohol, and smoking. hsCRP: High-sensitivity C-reactive protein; HDL: High-density lipoprotein cholesterol; LDL: Low-density lipoprotein cholesterol.

Table 3 Risk factors of colorectal advanced adenoma in this study population n (%)

Variable	Number of persons		Univariate analysis		Multivariate analysis1
	Non-advanced adenoma	Advanced adenoma	OR (95%CI)	P value	OR (95%CI)	P value
	(n = 2778)	(n = 41)
Males	1955 (70.4)	33 (80.5)	1.74 (0.80-3.78)	0.159	0.80 (0.27-2.43)	0.697
Age (yr)
≥ 50	1018 (36.6)	25 (61.0)	1	0.003	1
45-49	485 (17.5)	6 (14.6)	0.50 (0.21-1.24)		0.43 (0.17-1.07)	0.070
40-44	587 (21.1)	4 (9.8)	0.28 (0.10-0.80)		0.24 (0.08-0.71)	0.010
< 40	688 (24.8)	6 (14.6)	0.36 (0.15-0.87)		0.34 (0.13-0.85)	0.022
Body mass index (kg/m2)
mean ± SD	23.7 ± 3.1	24.5 ± 3.0
< 25	1764 (63.5)	25 (61.0)	1	0.518
25.0-29.9	814 (29.3)	13 (31.7)	1.15 (0.59-2.25)
≥ 30	92 (3.3)	2 (4.9)	1.57 (0.37-6.70)
Waist circumference (cm)
mean ± SD	83.1 ± 9.4	85.9 ± 7.1
Male < 90, female < 80	1985 (71.5)	26 (63.4)	1	0.258
Male ≥ 90, female ≥ 80	793 (28.5)	15 (36.6)	1.44 (0.76-2.74)
Diabetes mellitus	196 (7.1)	5 (12.2)	1.83 (0.71-4.72)	0.204
Hypertension	835 (30.1)	17 (41.5)	1.65 (0.88-3.08)	0.114	1.03 (0.45-2.38)	0.947
Metabolic syndrome	409 (14.7)	9 (22.0)	1.63 (0.77-3.44)	0.196	1.06 (0.40-2.80)	0.907
hsCRP (mg/dL)
< 0.10	1747 (62.9)	24 (58.5)	1	0.567
≥ 0.10	1031 (37.1)	17 (41.5)	1.20 (0.64-2.25)
Triglyceride (mg/dL)
mean ± SD	123.1 ± 87.3	136.8 ± 75.3
< 150	2091 (75.3)	27 (65.9)	1	0.166	1
≥ 150	687 (24.7)	14 (34.1)	1.58 (0.82-3.03)		1.23 (0.62-2.45)	0.555
HDL cholesterol (mg/dL)
mean ± SD	57.3 ± 15.0	56.2 ± 15.7
Male < 40, female < 50	348 (12.5)	6 (14.6)	1	0.686
Male ≥ 40, female ≥ 50	2430 (87.5)	35 (85.4)	0.84 (0.35-2.00)
LDL cholesterol (mg/dL)
mean ± SD	136.3 ± 39.4	137.2 ± 46.3
≤ 100	423 (15.2)	7 (17.1)	1	0.876
101-129	840 (30.2)	11 (26.8)	0.79 (0.31-2.06)
≥ 130	1515 (54.5)	23 (56.1)	0.92 (0.39-2.15)
Total cholesterol (mg/dL)
mean ± SD	207.1 ± 38.5	208.7 ± 52.1
< 200	1240 (44.6)	19 (46.3)	1	0.827
≥ 200	1538 (55.4)	22 (53.7)	0.93 (0.50-1.73)
Current alcohol	1093 (39.3)	25 (61.0)	2.41 (1.28-4.53)	0.005	2.39 (1.14-4.99)	0.021
Smoking status
Never	1143 (41.1)	11 (26.8)	1	0.106	1
Former	753 (27.1)	14 (34.1)	1.93 (0.87-4.28)		1.40 (0.50-3.92)	0.516
Current	882 (31.7)	16 (39.0)	1.89 (0.87-4.08)		1.61 (0.58-4.45)	0.363

¹Adjusted for sex, age, hypertension, metabolic syndrome, triglyceride, alcohol, and smoking. hsCRP: High-sensitivity C-reactive protein; HDL: High-density lipoprotein cholesterol; LDL: Low-density lipoprotein cholesterol.

Table 4 Risk factors for colorectal adenoma in young subjects n (%)

Variable	Number of persons		Univariate analysis		Multivariate analysis1
	Non-adenoma	Adenoma	OR (95%CI)	P value	OR (95%CI)	P value
	(n = 1523)	(n = 253)
Males	1060 (69.6)	211 (83.4)	2.19 (1.55-3.11)	< 0.001	1.43 (0.89-2.28)	0.136
Age (yr)
45-49	386 (25.3)	105 (41.5)	1	< 0.001	1
40-44	504 (33.1)	87 (34.4)	0.64 (0.46-0.87)		0.64 (0.46-0.88)	0.006
< 40	633 (41.6)	61 (24.1)	0.35 (0.25-0.50)		0.39 (0.28-0.56)	< 0.001
Body mass index (kg/m2)
mean ± SD	23.5 ± 3.2	24.4 ± 3.1
18.5-24.9	993 (65.2)	144 (56.9)	1	0.002	1
25.0-29.9	402 (26.4)	94 (37.2)	1.66 (1.25-2.20)		0.90 (0.61-1.33)	0.599
≥ 30	55 (3.6)	9 (3.6)	1.16 (0.56-2.40)		0.55 (0.24-1.27)	0.161
Waist circumference (cm)
mean ± SD	82.1 ± 9.7	85.2 ± 9.3
Male < 90, female < 80	1161 (76.2)	164 (64.8)		< 0.001	1
Male ≥ 90, female ≥ 80	362 (23.8)	89 (35.2)	1.74 (1.31-2.31)		1.72 (1.15-2.55)	0.008
Diabetes mellitus	55 (3.6)	16 (6.3)	1.80 (1.02-3.20)	0.041	1.29 (0.71-2.35)	0.403
Hypertension	309 (20.3)	81 (32.0)	1.85 (1.38-2.48)	< 0.001	1.36 (0.92-2.02)	0.127
Metabolic syndrome	154 (10.1)	38 (15.0)	1.57 (1.07-2.30)	0.020	0.88 (0.53-1.46)	0.612
hsCRP (mg/dL)	128 (8.4)	22 (8.7)
< 0.10	1004 (65.9)	156 (61.7)	1	0.187
≥ 0.10	519 (34.1)	97 (38.3)	1.20 (0.91-1.58)
Triglyceride (mg/dL)
mean ± SD	119.2 ± 86.4	146.2 ± 101.3
< 150	1168 (76.7)	165 (65.2)	1	< 0.001	1
≥ 150	355 (23.3)	88 (34.8)	1.76 (1.32-2.33)		1.18 (0.85-1.63)	0.330
HDL cholesterol (mg/dL)
mean ± SD	58.0 ± 14.8	55.4 ± 15.4
Male < 40, female < 50	162 (10.6)	30 (11.9)	1	0.563
Male ≥ 40, female ≥ 50	1361 (89.4)	223 (88.1)	0.89 (0.59-1.34)
LDL cholesterol (mg/dL)
mean ± SD	135.1 ± 43.0	138.7 ± 36.8
≤ 100	244 (16.0)	38 (15.0)	1	0.106
101-129	493 (32.4)	67 (26.5)	0.87 (0.57-1.34)
≥ 130	786 (51.6)	148 (58.5)	1.21 (0.82-1.78)
Total cholesterol (mg/dL)
mean ± SD	205.8 ± 38.1	210.9 ± 39.6
< 200	715 (46.9)	100 (39.5)	1	0.028	1
≥ 200	808 (53.1)	153 (60.5)	1.35 (1.03-1.78)		1.08 (0.81-1.44)	0.595
Current alcohol	637 (41.8)	133 (52.6)	1.54 (1.18-2.01)	0.001	1.04 (0.77-1.40)	0.806
Smoking status
Never	639 (42.0)	66 (26.1)	1	< 0001	1
Former	339 (22.3)	62 (24.5)	1.77 (1.22-2.57)		1.23 (0.79 -1.93)	0.359
Current	545 (35.8)	125 (49.4)	2.22 (1.61-3.06)		1.60 (1.07-2.41)	0.023

¹Adjusted for sex, age, body mass index, waist circumference, diabetes mellitus, hypertension, metabolic syndrome, triglyceride, total cholesterol, alcohol, and smoking. hsCRP: High-sensitivity C-reactive protein; HDL: High-density lipoprotein cholesterol; LDL: Low-density lipoprotein cholesterol.

Table 5 Risk factors of colorectal advanced adenoma in young subjects n (%)

Variable	Number of persons		Univariate analysis		Multivariate analysis1
	Non-advanced adenoma	Advanced adenoma	OR (95%CI)	P value	OR (95%CI)	P value
	(n = 1760)	(n = 16)
Males	1258 (71.5)	13 (81.3)	1.73 (0.49-6.09)	0.388
Age (yr)
45-49	485 (27.6)	6 (37.5)	1	0.570
40-44	587 (33.4)	4 (25.0)	0.55 (0.16-1.96)
< 40	688 (39.1)	6 (37.5)	0.71 (0.23-2.20)
Body mass index (kg/m2)
mean ± SD	23.6 ± 3.2	24.8 ± 2.8
< 25	79 (4.5)	0 (0.0)	1	0.862
25.0-29.9	492 (28.0)	4 (25.0)	1.66 (1.25-2.20)
≥ 30	63 (3.6)	1 (6.3)	1.16 (0.56-2.40)
Waist circumference (cm)
mean ± SD	82.5 ± 9.7	86.1 ± 6.6
Male < 90, female < 80	1313 (74.6)	12 (75.0)	1	0.971
Male ≥ 90, female ≥ 80	447 (25.4)	4 (25.0)	0.98 (0.31-3.05)
Diabetes mellitus	70 (4.0)	1 (6.3)	1.61 (0.21-12.36)	0.644
Hypertension	388 (22.0)	2 (12.5)	0.51 (0.11-2.23)	0.359
Metabolic syndrome	191 (10.9)	1 (6.3)	0.55 (0.07-4.17)	0.555
High hsCRP
mean ± SD	148 (8.4)	2 (12.5)
< 0.10	1149 (65.3)	11 (68.8)	1	0.772
≥ 0.10	611 (34.7)	5 (31.3)	0.86 (0.30-2.47)
Triglyceride (mg/dL)
mean ± SD	123.0 ± 89.3	121.1 ± 72.3
< 150	1321 (75.1)	12 (75.0)	1	0.996
≥ 150	439 (24.9)	4 (25.0)	1.00 (0.32-3.13)
HDL cholesterol (mg/dL)
mean ± SD	57.6 ± 14.8	60.1 ± 19.3
Male < 40, female < 50	191 (10.9)	1 (6.3)	1	0.555
Male ≥ 40, female ≥ 50	1569 (89.1)	15 (93.8)	1.83 (0.24-13.90)
LDL cholesterol (mg/dL)
mean ± SD	135.5 ± 41.9	139.1 ± 43.9
≤ 100	278 (15.8)	4 (25.0)	1	0.703
101-129	559 (31.8)	1 (6.3)	0.12 (0.01-1.12)
≥ 130	923 (52.4)	11 (68.8)	0.83 (0.26-2.62)
Total cholesterol (mg/dL)
mean ± SD	206.4 ± 38.3	214.1 ± 41.3
< 200	810 (46.0)	5 (31.3)	1	0.238
≥ 200	950 (54.0)	11 (68.8)	1.88 (0.65-5.42)
Current alcohol	758 (43.1)	12 (75.0)	3.97 (1.27-12.34)	0.010	3.69 (1.08-12.54)	0.037
Smoking status
Never	701 (39.8)	4 (25.0)	1	0.129	1
Former	398 (22.6)	3 (18.8)	1.32 (0.29-5.93)		0.81 (0.17-3.86)	0.789
Current	661 (37.6)	9 (56.3)	2.39 (0.73-7.79)		1.38 (0.39-4.93)	0.620

¹Adjusted for alcohol and smoking. hsCRP: High-sensitivity C-reactive protein; HDL: High-density lipoprotein cholesterol; LDL: Low-density lipoprotein cholesterol.

Table 6 Comparison of neoplasm characteristics between young and old subjects n (%)

Characteristics of adenoma	Age group		P value
	Young age group, < 50 (n = 253)	Old age group,≥50 (n = 302)
Number	1.31 ± 0.66	1.82 ± 1.39	< 0.001
Multiple	59 (23.3)	121 (40.1)	< 0.001
Rt. side location	112 (44.3)	156 (51.7)	0.083
Advanced neoplasm	16 (6.3)	25 (8.3)	0.381
Villous or tubulovillous	3 (1.2)	7 (2.3)	0.318
High grade	2 (0.8)	4 (1.3)	0.545
Size > 1 cm	13 (5.1)	24 (7.9)	0.187

Table 7 Comparison of sessile serrated adenoma/polyp characteristics between young and old subjects n (%)

	Age group		P value
	Young age group, < 50 (n = 1776)	Old age group,≥50 (n = 1043)
SSA/P	37 (2.1)	57 (5.5)	< 0.001
Number of SSA/P	1.32 ± 0.58	1.32 ± 0.69	0.875
Right Side location	24 (64.9)	37 (64.9)	0.996

SSA/P: Sessile serrated adenoma/polyp.