Table 3.

Dietary insulin load, dietary insulin index, and risk of colorectal cancer stratified by BMI and physical activitya

Dietary insulin load (tertiles) P trend
123
BMI <27.5 kg/m21.01.00 (0.86–1.17)0.92 (0.81–1.04)0.13
BMI ≥27.5 kg/m21.01.14 (0.83–1.56)0.90 (0.71–1.14)0.39
High physical activityb1.01.09 (0.95–1.25)0.95 (0.82–1.11)0.13
Low physical activityb1.00.99 (0.85–1.17)0.90 (0.76–1.07)0.39
BMI <27.5 and high physical activity1.01.05 (0.85–1.30)0.95 (0.80–1.13)0.14
Intermediate group1.01.02 (0.86–1.20)0.86 (0.72–1.03)0.26
BMI ≥27.5 and low physical activity1.00.94 (0.65–1.36)0.90 (0.63–1.28)0.44
Dietary insulin index (tertiles) P trend
1 2 3
BMI <27.5 kg/m21.00.96 (0.85–1.08)0.91 (0.80–1.03)0.23
BMI ≥27.5 kg/m21.01.06 (0.80–1.40)0.96 (0.76–1.21)0.50
High physical activityb1.00.95 (0.82–1.10)0.93 (0.78–1.12)0.31
Low physical activityb1.01.00 (0.85–1.18)0.89 (0.75–1.06)0.37
BMI <27.5 and high physical activity1.00.93 (0.79–1.10)0.93 (0.78–1.10)0.30
Intermediate group1.00.98 (0.83–1.16)0.87 (0.72–1.04)0.23
BMI ≥27.5 and low physical activity1.00.98 (0.71–1.35)0.97 (0.68–1.38)0.54

NOTE: NHS and HPFS were pooled using random-effects models.Dietary insulin load and dietary insulin index were measured at baseline, 1980 for NHS and 1986 for HPFS.

  • aAdjusted for age, body mass index (kg/m2 in quintiles), physical activity (quintiles), family history of colorectal cancer (yes/no), lower endoscopy (yes/no), ulcerative colitis (yes/no), history of polyps (yes/no), aspirin use (never, 1–3, 4–7, ≥ 8 tablets/wk), multivitamin use (yes/no), pack-years of smoking (never smoker, 1–9, 10–24, 25–44, and ≥45 pack-years), alcohol intake (NHS: never, 0.1–4.9, 5–14.9, ≥15 g/d; HPFS: never, 0.1–9.9, 10–19.9, ≥20 g/d), and energy intake (quintiles).

  • bAbove or below median (NHS: 3.0 h/wk; HPFS: 11.5 MET-h/wk).