Dietary insulin load, dietary insulin index, and risk of colorectal cancer (Cont'd)
Dietary insulin load (quintiles) | Ptrend | |||||
---|---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | ||
Rectum | ||||||
No. of cases | 71 | 66 | 54 | 59 | 73 | |
Age-adjusted | 1.0 | 0.93 (0.67–1.31) | 0.77 (0.54–1.09) | 0.82 (0.58–1.16) | 0.99 (0.72–1.38) | 0.78 |
Multivariatea | 1.0 | 1.01 (0.71–1.43) | 0.85 (0.58–1.24) | 0.92 (0.63–1.35) | 1.14 (0.79–1.66) | 0.50 |
HPFS | ||||||
Quintile median | 34 | 38 | 41 | 43 | 47 | |
Person-years | 159,133 | 163,853 | 164,305 | 166,404 | 165,344 | |
Colorectal | ||||||
No. of cases | 252 | 223 | 213 | 196 | 177 | |
Age-adjusted | 1.0 | 0.90 (0.75–1.08) | 0.89 (0.74–1.07) | 0.80 (0.67–0.97) | 0.74 (0.61–0.90) | 0.001 |
Multivariatea | 1.0 | 0.99 (0.82–1.20) | 1.03 (0.84–1.26) | 0.97 (0.78–1.19) | 0.92 (0.74–1.15) | 0.41 |
Colon | ||||||
No. of cases | 165 | 140 | 138 | 136 | 115 | |
Age-adjusted | 1.0 | 0.87 (0.69–1.09) | 0.88 (0.70–1.11) | 0.85 (0.68–1.07) | 0.73 (0.57–0.93) | 0.01 |
Multivariatea | 1.0 | 0.94 (0.74–1.19) | 0.98 (0.77–1.26) | 0.99 (0.77–1.28) | 0.88 (0.67–1.16) | 0.44 |
Rectum | ||||||
No. of cases | 51 | 51 | 43 | 36 | 41 | |
Age-adjusted | 1.0 | 1.04 (0.70–1.53) | 0.91 (0.60–1.37) | 0.74 (0.48–1.14) | 0.87 (0.58–1.32) | 0.26 |
Multivariatea | 1.0 | 1.12 (0.74–1.69) | 1.05 (0.67–1.64) | 0.87 (0.54–1.41) | 1.05 (0.65–1.69) | 0.95 |
NHS and HPFS, multivariate a,b | ||||||
Colorectal | 1.0 | 0.97 (0.86–1.10) | 1.00 (0.88–1.14) | 0.94 (0.82–1.07) | 0.93 (0.81–1.08) | 0.14 |
Colon | 1.0 | 0.96 (0.83–1.12) | 1.03 (0.88–1.20) | 0.95 (0.81–1.12) | 0.91 (0.77–1.07) | 0.09 |
Rectum | 1.0 | 1.05 (0.80–1.37) | 0.92 (0.69–1.23) | 0.89 (0.66–1.20) | 1.09 (0.81–1.47) | 0.66 |
NOTE: 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).
↵bNHS and HPFS were pooled using random-effects models.