TABLE 3.
Multivariable-adjusted HR and 95% CI of the associations of overall and healthful plant-based diet indices and prostate cancer risk, stratified by age, in 47,239 men from the Health Professionals Follow-Up Study1
| Q1 | Q 2 | Q 3 | Q 4 | Q 5 | P-trend | P-interaction | |
|---|---|---|---|---|---|---|---|
| Plant-based diet index | |||||||
| Total prostate cancer2 | 0.58 | ||||||
| Age <65 y (n = 1882) | 1 [Reference] | 1.09 (0.95, 1.25) | 0.94 (0.82, 1.09) | 0.94 (0.81, 1.09) | 0.94 (0.81, 1.09) | 0.12 | |
| Age ≥65 y (n = 4773) | 1 [Reference] | 1.08 (0.99, 1.19) | 1.07 (0.98, 1.18) | 1.05 (0.95, 1.15) | 0.99 (0.90, 1.09) | 0.56 | |
| Localized prostate cancer2 | 0.43 | ||||||
| Age <65 y (n = 1332) | 1 [Reference] | 1.15 (0.98, 1.36) | 0.99 (0.84, 1.18) | 1.00 (0.84, 1.19) | 0.90 (0.75, 1.08) | 0.12 | |
| Age ≥65 y (n = 3241) | 1 [Reference] | 1.10 (0.98, 1.23) | 1.06 (0.94, 1.19) | 1.07 (0.96, 1.20) | 0.99 (0.88, 1.11) | 0.62 | |
| Advanced prostate cancer2 | 0.06 | ||||||
| Age <65 y (n = 150) | 1 [Reference] | 0.65 (0.40, 1.03) | 0.65 (0.41, 1.04) | 0.36 (0.20, 0.65) | 0.58 (0.35, 0.94) | 0.005 | |
| Age ≥65 y (n = 365) | 1 [Reference] | 1.16 (0.81, 1.66) | 1.47 (1.05, 2.06) | 1.16 (0.81, 1.65) | 0.94 (0.65, 1.35) | 0.62 | |
| Lethal prostate cancer2 | 0.14 | ||||||
| Age <65 y (n = 208) | 1 [Reference] | 0.56 (0.37, 0.85) | 0.64 (0.42, 0.97) | 0.61 (0.40, 0.94) | 0.62 (0.41, 0.95) | 0.03 | |
| Age ≥65 y (n = 748) | 1 [Reference] | 1.08 (0.85, 1.37) | 1.02 (0.80, 1.31) | 1.00 (0.78, 1.27) | 0.92 (0.72, 1.18) | 0.35 | |
| Fatal prostate cancer2 | 0.14 | ||||||
| Age <65 y (n = 177) | 1 [Reference] | 0.56 (0.36, 0.88) | 0.62 (0.40, 0.98) | 0.52 (0.32, 0.84) | 0.62 (0.40, 0.97) | 0.02 | |
| Age ≥65 y (n = 629) | 1 [Reference] | 1.05 (0.81, 1.36) | 0.98 (0.75, 1.27) | 0.92 (0.71, 1.20) | 0.89 (0.69, 1.16) | 0.24 | |
| Healthful plant-based diet index | |||||||
| Total prostate cancer2 | 0.19 | ||||||
| Age <65 y (n = 1882) | 1 [Reference] | 0.93 (0.81, 1.07) | 1.03 (0.90, 1.18) | 0.93 (0.80, 1.07) | 0.84 (0.73, 0.98) | 0.046 | |
| Age ≥65 y (n = 4773) | 1 [Reference] | 0.98 (0.88, 1.08) | 1.07 (0.97, 1.18) | 0.95 (0.86, 1.04) | 0.99 (0.90, 1.09) | 0.59 | |
| Localized prostate cancer2 | 0.02 | ||||||
| Age <65 y (n = 1332) | 1 [Reference] | 0.91 (0.77, 1.06) | 0.95 (0.80, 1.11) | 0.88 (0.74, 1.04) | 0.74 (0.62, 0.89) | 0.002 | |
| Age ≥65 y (n = 3241) | 1 [Reference] | 0.98 (0.87, 1.11) | 1.10 (0.98, 1.23) | 0.90 (0.80, 1.02) | 1.00 (0.89, 1.12) | 0.50 | |
| Advanced prostate cancer2 | 0.51 | ||||||
| Age <65 y (n = 150) | 1 [Reference] | 0.94 (0.55, 1.59) | 1.27 (0.77, 2.09) | 1.25 (0.75, 2.08) | 0.97 (0.57, 1.65) | 0.78 | |
| Age ≥65 y (n = 365) | 1 [Reference] | 1.13 (0.80, 1.60) | 0.88 (0.62, 1.27) | 1.11 (0.79, 1.55) | 0.91 (0.64, 1.28) | 0.53 | |
| Lethal prostate cancer2 | 0.04 | ||||||
| Age <65 y (n = 208) | 1 [Reference] | 0.93 (0.60, 1.45) | 1.10 (0.71, 1.69) | 0.80 (0.50, 1.28) | 0.56 (0.34, 0.94) | 0.03 | |
| Age ≥65 y (n = 748) | 1 [Reference] | 1.03 (0.79, 1.34) | 1.22 (0.95, 1.57) | 1.01 (0.78, 1.30) | 1.10 (0.85, 1.41) | 0.65 | |
| Fatal prostate cancer2 | 0.06 | ||||||
| Age <65 y 65 (n = 177) | 1 [Reference] | 0.99 (0.66, 1.49) | 1.12 (0.75, 1.68) | 0.86 (0.56, 1.33) | 0.62 (0.38, 0.99) | 0.048 | |
| Age ≥65 y (n = 629) | 1 [Reference] | 0.88 (0.66, 1.17) | 1.14 (0.87, 1.48) | 0.93 (0.71, 1.22) | 1.00 (0.76, 1.30) | 0.93 |
1Values are presented as HRs (95% Cis) unless otherwise indicated. Diet scores were adjusted for total energy intake using the residual method. Multivariable-adjusted Cox proportional hazards models stratified by age and time period, and adjusted for race, height, BMI, BMI at age 21, smoking, family history of prostate cancer, PSA test in previous cycle, PSA testing in >50% of previous cycles, multivitamin use, vitamin E supplement use, alcohol intake, physical activity, aspirin use, anti-cholesterol medication, and diabetes. We calculated P values for linear trend by assigning the median score for each quintile to all participants in the quintile. MET, metabolic equivalent of task; PSA, prostate-specific antigen; Q, quintile.
2Localized prostate cancer: stage T1/T2 and N0, M0 at diagnosis; advanced prostate cancer: stage T3b/T4/N1/M1 at diagnosis; lethal prostate cancer: prostate cancer death or distant metastasis; fatal prostate cancer: prostate cancer death.