Table 7.

Pooled Analysis Odds Ratios for Colorectal Cancer Risk Among Persons With the Methylenetetrahydrofolate Reductase (MTHFR) 677TT Genotype, by Body Mass Index^a Category^b

BMI Category	No. of Subjects	CC		CT		TT		CT vs. CC		TT vs. CC
		No.	%	No.	%	No.	%	ORc	95% CI	ORc	95% CI
<18.5	299
Controls		73	43.71	67	40.12	27	16.17
Cases		61	46.21	55	41.67	16	12.12	1.08	0.62, 1.89	0.64	0.28, 1.46
18.5–24.9	4,365
Controls		1,123	41.39	1,180	43.49	410	15.11
Cases		719	43.52	730	44.19	203	12.29	0.97	0.85, 1.12	0.79	0.64, 0.96
25.0–29.9	3,355
Controls		1,004	47.43	863	40.77	250	11.81
Cases		588	47.50	509	41.11	141	11.39	0.97	0.82, 1.13	0.91	0.71, 1.17
≥30.0	1,566
Controls		547	55.42	342	34.65	98	9.93
Cases		313	54.06	221	38.17	45	7.77	1.02	0.81, 1.30	0.76	0.51, 1.14

Abbreviations: BMI, body mass index; CI, confidence interval; OR, odds ratio.

^aWeight (kg)/height (m)².

^bUnadjusted P value for interaction between BMI category and MTHFR genotype: P = 0.47. Wald χ² test (2 df) P value, by BMI category: BMI <18.5—P = 0.46; BMI 18.5–24.9—P = 0.0664; BMI 25.0–29.9—P = 0.73; BMI ≥30.0—P = 0.36.

^cAdjusted for age, sex, study, and ethnic group.