Table 3.
Associations of cumulative average dietary and lifestyle indices with risk of colorectal cancer diagnosed before and after age 50 in the Nurses’ Health Study II, 1991–20151
| Age at colorectal cancer diagnosis | Phet2 | ||
|---|---|---|---|
| <50 years | ≥50 years | ||
| Number of events | 111 | 221 | |
| Prime Dietary Quality Score | |||
| Age-adjusted HR (95% CI)3 | 0.90 (0.55, 1.48) | 0.84 (0.59, 1.20) | 0.82 |
| Multivariable-adjusted HR (95% CI)4 | 0.90 (0.55, 1.50) | 0.91 (0.62, 1.31) | >0.99 |
| Overall Plant-based Diet Index | |||
| Age-adjusted HR (95% CI)3 | 1.13 (0.68, 1.88) | 1.03 (0.70, 1.50) | 0.75 |
| Multivariable-adjusted HR (95% CI)4 | 1.24 (0.74, 2.08) | 1.10 (0.75, 1.62) | 0.70 |
| Empirical Dietary Index for Hyperinsulinemia | |||
| Age-adjusted HR (95% CI)3 | 1.34 (0.80, 2.27) | 1.50 (1.02, 2.19) | 0.72 |
| Multivariable-adjusted HR (95% CI)4 | 1.24 (0.72, 2.16) | 1.51 (1.00, 2.29) | 0.54 |
| Empirical Lifestyle Index for Hyperinsulinemia | |||
| Age-adjusted HR (95% CI)3 | 1.71 (1.04, 2.81) | 1.17 (0.82, 1.66) | 0.21 |
| Multivariable-adjusted HR (95% CI)5 | 1.86 (1.12, 3.07) | 1.20 (0.83, 1.73) | 0.16 |
Abbreviations: CI, confidence interval; het, heterogeneity; HR, hazard ratio.
Continuous analyses used rank-order indices for a 75 percentile increment in rank (e.g., median of first to fourth quartile)
P for heterogeneity between CRC diagnosed before age 50 years and at age 50 years or older by contrast test.
Adjusted for total energy intake (continuous). Age (months) and follow-up cycle (2-year intervals) were included as stratification variables.
Additionally adjusted for alcohol consumption (continuous), height (continuous), race (white or nonwhite), body mass index (continuous), family history of colorectal cancer (yes/no), history of diabetes (yes/no), smoking pack-years (continuous), physical activity (continuous), regular use of aspirin (yes/no), regular use of nonsteroidal anti-inflammatory drugs (yes/no), multivitamin use (yes/no), menopausal status and menopausal hormone therapy (premenopausal, postmenopausal/never hormone use, and postmenopausal/ever hormone use), and history of lower endoscopy (yes/no).
Additionally adjusted for factors listed in4, except for body mass index and physical activity.