Table 5.

Overall Mortality by Tertile of Prediagnosis Plasma C-Peptide and IGFBP-1 Stratified by Body Mass Index and Physical Activity

Characteristic*	No. of Patients at Risk	No. of Deaths	Tertile 1	Tertile 2		Tertile 3		P (interaction)
			HR†	HR†	95% CI	HR†	95% CI
C-peptide
Body mass index, kg/m2								.91
< 25.1	189	53	1.00	1.29	0.62 to 2.67	1.47	0.65 to 3.33
≥ 25.1	161	45	1.00	0.93	0.38 to 2.28	2.19	0.91 to 5.26
Physical activity, MET-h/wk								.55
< 15.2	175	53	1.00	1.37	0.63 to 3.00	1.73	0.79 to 3.80
≥ 15.2	175	45	1.00	0.91	0.41 to 2.02	1.48	0.63 to 3.45
IGFBP-1
Body mass index, kg/m2								.047
< 25.1	189	53	1.00	1.61	0.69 to 3.73	1.00	0.43 to 2.36
≥ 25.1	179	54	1.00	0.32	0.16 to 0.66	0.13	0.05 to 0.33
Physical activity, MET-h/wk								.58
< 15.2	184	61	1.00	0.57	0.30 to 1.07	0.37	0.18 to 0.77
≥ 15.2	184	46	1.00	1.45	0.59 to 3.51	0.81	0.34 to 1.94

Abbreviations: IGFBP-1, insulin-like growth factor binding protein-1; HR, hazard ratio; MET, metabolic equivalent.

^*Cut points were chosen based on median values for body mass index and physical activity.

^†Adjusted for age at diagnosis, cohort (sex), stage of disease, histologic differentiation, tumor location (colon or rectum), time period of diagnosis (1990-1995, 1996-1999, or 2000-2004), time between last meal and plasma collection, receipt of chemotherapy, and patient characteristics from the most recent questionnaire before blood draw, including smoking status (current, past, or never), aspirin use (< or ≥ 2 times a week), alcohol consumption (g/d), total vitamin D intake (U/d), and postmenopausal hormone use.