Detection rate and risk factors of colorectal adenoma in high-altitude population: A cross-sectional study

Table 1 Univariate analysis of clinical features in colorectal adenoma patients, n (%)

	Colorectal adenoma group (n = 89)	Healthy group (n = 1065)	Statistic (t/χ²/z)	P value
Age (years)	52.70 ± 13.03	45.97 ± 14.17	-4.294	< 0.001
Age distribution (year)			19.924	< 0.001
< 40	14 (15.7)	387 (36.3)
40-49	21 (23.6)	248 (23.3)
50-59	26 (29.2)	229 (21.5)
≥ 60-69	28 (31.5)	201 (18.9)
Sex			13.383	< 0.001
Male	61 (68.5)	515 (48.4)
Female	28 (31.5)	550 (51.6)
BMI (kg/m2)	24.91 ± 3.54	24.30 ± 4.22	-2.038	0.042
BMI > 24.9 kg/m2			2.521	0.112
No	46 (51.7)	642 (60.3)
Yes	43 (48.3)	423 (39.7)
Residence			2.745	0.840
Lhasa	35 (39.3)	341 (32.0)
Shannan	8 (9.0)	87 (8.2)
Nyingchi	3 (3.4)	39 (3.7)
Shigatse	17 (19.1)	210 (19.7)
Chamdo	8 (9.0)	112 (10.5)
Nagqu	16 (18.0)	251 (23.6)
Ngari	2 (2.2)	25 (2.3)
Altitude of residence (m)			4.236	0.237
2000-3000	1 (1.1)	56 (5.3)
3000-4000	38 (42.7)	388 (36.4)
4000-5000	48 (54.0)	606 (56.9)
> 5000	2 (2.2)	15 (1.4)
Smoking history			3.361	0.067
No	70 (78.7)	914 (85.5)
Yes	19 (21.3)	151 (14.2)
Hypertension			0.010	0.920
No	82 (92.1)	978 (91.8)
Yes	7 (7.9)	87 (8.2)
Diabetes mellitus			0.290	0.590
No	86 (96.6)	1039 (97.6)
Yes	3 (3.4)	26 (2.4)
History of abdominal surgery			0.038	0.846
No	80 (90.0)	964 (90.5)
Yes	8 (9.0)	101 (9.5)
Family history of CRC			0.017	0.896
No	82 (92.1)	977 (91.7)
Yes	7 (7.9)	88 (8.3)
China risk score for sporadic CRC			18.026	< 0.001
Low risk	68 (76.4)	966 (90.7)
High risk	21 (23.6)	99 (9.3)
Asia-Pacific risk score for CRC			15.980	< 0.001
Average risk	27 (30.3)	504 (47.3)
Moderate risk	44 (49.4)	464 (43.6)
High risk	18 (20.2)	97 (9.1)

CRC: Colorectal cancer; BMI: Body mass index.

Table 2 Multivariate logistic regression analysis of variables in colorectal adenoma patients

Predictor variables	B	SE	Wald	df	P value	OR	95%CI
							Lower	Upper
Age	0.034	0.008	17.782	1	< 0.001	1.035	1.019	1.052
Body mass index	0.036	0.027	1.809	1	0.179	1.037	0.984	1.092
Sex (male)	0.770	0.245	9.904	1	0.002	2.161	1.337	3.492
Altitude (m)			3.942	3	0.268
3000-4000	1.703	1.030	2.733	1	0.098	5.491	0.729	41.348
4000-5000	1.511	1.029	2.155	1	0.142	4.530	0.603	34.035
> 5000	2.279	1.275	3.196	1	0.074	9.768	0.803	118.826
Smoking history (yes)	0.455	0.291	2.440	1	0.118	1.576	0.890	2.790
Diabetes mellitus (yes)	-0.189	0.639	0.087	1	0.767	0.828	0.237	2.895
Family history of colorectal cancer (yes)	0.010	0.422	0.001	1	0.981	1.010	0.422	2.308

B: Regression coefficient; SE: Standard error; Wald: Wald χ² test; df: Degrees of freedom.

Table 3 Comparison of colorectal adenoma detection rates between the Beijing and Xizang Autonomous Region populations, n (%)

	Study population (n = 3462)	Beijing population (n = 2308)	Xizang Autonomous Region population (n = 1154)	Statistic (χ2)	P value
Groups				120.64	< 0.001
Healthy group	2847 (82.2)	1782 (77.2)	1065 (92.3)
Colorectal adenoma group	615 (17.8)	526 (22.8)	89 (7.7)