. Author manuscript; available in PMC: 2013 Sep 1.

Published in final edited form as: Cancer Epidemiol Biomarkers Prev. 2012 Jul 11;21(9):1574–1581. doi: 10.1158/1055-9965.EPI-12-0138-T

Table 3.

Association between relative mtDNA copy number and colorectal cancer risk

mtDNA level^*		All cases		Incident cases^†		Prevalent cases^†
mtDNA level^*	No. of controls	n	OR^‡ (95%CI)	n	OR^‡ (95%CI)	n	OR^‡ (95%CI)
1^st quartile	219	130	1.81 (1.13–2.89)	61	3.51 (1.60–7.68)	69	1.32 (0.77–2.26)
2^nd quartile	219	59	1.00	22	1.00	37	1.00
3^rd quartile	219	74	1.40 (0.86–2.29)	27	1.58 (0.69–3.62)	47	1.20 (0.68–2.11)
4^th quartile	217	159	3.40 (2.15–5.36)	58	4.66 (2.15–10.11)	101	3.37 (2.02–5.62)
P-value for curvilinearity			<0.0001		<0.0001		<0.0001

Quartile levels are based on gender-specific cutoff values: men ≤ 0.36, 0.37–0.47, 0.48–0.62, >0.62; women ≤ 0.40, 0.41–0.54, 0.55–0.71, >0.71.

^†

Blood samples were collected 28.9 (SD = 26.4) months prior to cancer diagnosis for incident cases and 13.1(SD = 12.5) months after cancer diagnosis for prevalent cancer cases.

^‡

Adjusted for age at sample collection, gender, BMI, smoking status, alcohol drinking, weekly moderate or vigorous physical activity, history of diabetes and batch number for mtDNA copy number assay.