Table 5.

Adjusted Associations^a of dietary (DIS) and lifestyle (LIS) inflammation scores with incident colorectal cancer according to colorectal cancer site; the Iowa Women’s Health Study (n = 34,254), 1986 – 2012.

	Dietary inflammation scoreb		Lifestyle inflammation scorec
Colorectal site	Adjusted HR	95% CI	Adjusted HR	95% CI
Proximal colond (n = 890)
Continuous	1.00	0.97, 1.03	1.16	1.06, 1.26
Quintiles
1	1.00	Referent	1.00	Referent
2	0.85	0.69, 1.06	1.10	0.89, 1.36
3	1.09	0.89, 1.33	1.16	0.92, 1.46
4	0.97	0.78, 1.19	1.21	0.98, 1.50
5	0.95	0.77, 1.18	1.43	1.16, 1.77
Ptrend	0.96		<0.01
Pheterogeneity	0.01		0.21
Distal colone (n = 422)
Continuous	1.04	1.00, 1.09	1.24	1.09, 1.41
Quintiles
1	1.00	Referent	1.00	Referent
2	0.90	0.64, 1.25	1.39	1.00, 1.94
3	1.40	1.03, 1.90	1.68	1.20, 2.35
4	1.10	0.80, 1.52	1.49	1.07, 2.06
5	1.34	0.98, 1.84	1.78	1.29, 2.47
Ptrend	0.03		<0.01
Pheterogeneity	0.27		0.05
Rectum (n = 236)
Continuous	1.00	0.95, 1.06	1.01	0.85, 1.19
Quintiles
1	1.00	Referent	1.00	Referent
2	1.16	0.77, 1.75	1.16	0.78, 1.73
3	0.95	0.61, 1.47	1.11	0.72, 1.70
4	1.33	0.89, 2.00	1.06	0.70, 1.59
5	1.18	0.77, 1.80	1.10	0.72, 1.67
Ptrend	0.31		0.83
Pheterogeneity	ref		ref

Abbreviations: CI, confidence interval; HR, hazards ratio; ref, referent.

^aHRs and 95% CIs from Cox proportional hazards models.

^bFor score construction, see text and Table 1; a higher score indicates a more proinflammatory diet; model covariates included age (years; continuous), education (< high school, high school, > high school and < college, ≥ college), family history of colorectal cancer in a first-degree relative (yes/no), smoking status (current, past, never smoker), alcohol use (servings/week; continuous), comorbidity score (sum of yes/no for diabetes, heart disease, and cirrhosis), hormone replacement therapy use (current, past, never), physical activity (low, medium, high), body mass index (weight [kg]/height [m]²; continuous), former smoker (yes/no), and total energy intake (kcal/day; continuous).

^cIncludes current smoking (yes/no), physical activity, alcohol use, and body mass index; for score construction, see text; a higher score indicates a more proinflammatory lifestyle; model covariates included age (years; continuous), education (< high school, high school, > high school and < college, ≥ college), family history of colorectal cancer in a first-degree relative (yes/no), comorbidity score (includes sum of yes/no for diabetes, heart disease, and chronic colitis), hormone replacement therapy use (current, past, never use), former smoker (yes/no), total energy intake (kcal/day; continuous), and unweighted dietary inflammation score (DIS).

^dIncludes cecum, ascending colon, hepatic flexure, and transverse colon.

^eIncludes splenic flexure, descending colon, and sigmoid colon.