Table 2.

Association between regular glucosamine use and risk of cancers.

	Regular glucosamine use						Adjusted hazard ratio (95% confidence interval)
	No (N = 338,015)			Yes (N = 80,045)			Model 1a	Model 2b	Model 3c	Model 4d
Site of cancer	Number of events (%)	Person-years	Incidence (per 1000 person-years)	Number of events (%)	Person years	Incidence (per 1000 person-years)
Overall cancer	49,596 (14.7)	3,925,149	12.635	13,834 (17.3)	918,147	15.067	1.03 (1.01–1.05)**	1.03 (1.01–1.05)**	1.04 (1.02–1.06)***	1.04 (1.01–1.06) ***
Prostate (male)	7,264 (4.6)	1,843,831	3.940	1847 (6.2)	343,544	5.376	1.11 (1.05–1.17)***	1.09 (1.03–1.15)**	1.08 (1.03–1.14)**	1.07 (1.01–1.13)*
Other male specific	401 (0.3)	1,960,805	0.205	74 (0.2)	368,863	0.201	0.90 (0.70–1.15)	0.82 (0.63–1.06)	0.93 (0.72–1.19)	0.84 (0.64–1.09)
Cervical (female)	373(0.2)	2,242,193	0.166	74 (0.1)	630,931	0.117	1.08 (0.84–1.39)	1.18 (0.90–1.54)	1.08 (0.84–1.40)	1.18 (0.90–1.54)
Breast (female)	6,937 (3.9)	2,068,394	3.354	2131 (4.2)	580,142	3.673	1.04 (0.99–1.09)	1.04 (0.98–1.09)	1.03 (0.98–1.08)	1.03 (0.98–1.09)
Ovarian (female)	648 (0.4)	2,045,160	0.317	195 (0.4)	574,998	0.339	0.94 (0.80–1.10)	0.91 (0.77–1.09)	0.94 (0.80–1.11)	0.91 (0.77–1.09)
Endometrium (female)	962 (0.5)	2,244,076	0.429	332 (0.7)	630,466	0.527	1.07 (0.95–1.22)	1.01 (0.89–1.16)	1.10 (0.97–1.25)	1.03 (0.90–1.18)
Other female specific	233 (0.1)	2,244,369	0.104	89 (0.2)	630,996	0.141	1.18 (0.92–1.52)	1.18 (0.91–1.54)	1.17 (0.91–1.50)	1.17 (0.90–1.53)
Lung	2,615 (0.8)	4,202,895	0.622	521 (0.7)	999,567	0.521	0.74 (0.67–0.81) ***	0.85 (0.77–0.94) **	0.77 (0.70–0.85) ***	0.88 (0.79–0.97)*
Esophagus	700 (0.2)	3,779,066	0.185	146 (0.2)	898,356	0.163	0.81 (0.67–0.96)*	0.85 (0.70–1.02)	0.84 (0.70–1.00)	0.87 (0.72–1.05)
Stomach	471 (0.1)	3,841,060	0.123	102 (0.1)	913,081	0.112	0.85 (0.69–1.06)	0.96 (0.76–1.21)	0.89 (0.71–1.10)	0.99 (0.78–1.25)
Colorectal	4,072 (1.2)	3,959,252	1.028	1041 (1.3)	941,037	1.106	0.94 (0.87–1.00)	0.95 (0.88–1.02)	0.95 (0.89–1.02)	0.96 (0.89–1.03)
Hepatobiliary	600 (0.2)	3,753,322	0.160	146 (0.2)	892,010	0.164	0.90 (0.75–1.08)	0.96 (0.79–1.17)	0.95 (0.79–1.14)	1.01 (0.83–1.23)
Pancreas	790 (0.2)	3,853,922	0.205	248 (0.3)	915,380	0.271	1.11 (0.96–1.28)	1.13 (0.97–1.32)	1.11 (0.96–1.28)	1.14 (0.97–1.33)
Malignant melanoma	2,674 (0.8)	4,024,980	0.664	793 (1.0)	952,917	0.832	1.11 (1.03–1.21)**	1.08 (0.99–1.17)	1.10 (1.01–1.19)*	1.07 (0.98–1.17)
Skin	15,650 (4.6)	4,112,501	3.805	5018 (6.3)	969,892	5.174	1.13 (1.10–1.17)***	1.11 (1.07–1.15)***	1.14 (1.10–1.17)***	1.11 (1.07–1.15)***
Kidney	1,026 (0.3)	3,801,720	0.270	230 (0.3)	903,729	0.255	0.84 (0.73–0.97)*	0.89 (0.76–1.03)	0.87 (0.75–1.01)	0.91 (0.78–1.07)
Thyroid	297 (0.1)	3,756,325	0.079	62 (0.1)	889,399	0.070	0.73 (0.55–0.96)*	0.78 (0.58–1.05)	0.75 (0.57–0.99)*	0.80 (0.60–1.08)
Brain	537 (0.2)	3,714,623	0.145	128 (0.2)	882,834	0.145	0.93 (0.76–1.13)	0.92 (0.75–1.13)	0.92 (0.76–1.13)	0.91 (0.74–1.12)
All other cancers	6,734 (2.0)	3,925,149	1.716	1705 (2.1)	918,147	1.857	0.99 (0.93–1.03)	0.99 (0.94–1.05)	1.00 (0.94–1.05)	1.01 (0.95–1.07)

^aAdjusted for sociodemographic variables (including gender, ethnicity, education and Townsend Deprivation Index).

^bAdjusted for sociodemographic variables mentioned above and lifestyle factors (including smoking, alcohol consumption, vegetable consumption, processed meat intake, fresh fruit intake, vitamin supplements, mineral supplements, body mass index, and physical activities).

^cAdjusted for sociodemographic variables mentioned above as well as medical conditions and services (including diagnosis of osteoarthritis/ rheumatoid arthritis/ joint pain/ multiple sclerosis, history of screening for bowel cancer/ breast cancer/ prostate-specific antigen test, use of aspirin/NSAIDs/Hormone-replacement therapy, family history of cancer, and overall health rating).

^dAdjusted for all covariates mentioned above, including sociodemographic variables, lifestyle factors, and medical conditions and services.

*P ≤ 0.05.

**P ≤ 0.01.

***P ≤ 0.001.