Physical Activity, Dietary Inflammatory And Insulinemic Potential And Survival In Men With Prostate Cancer

PURPOSE: Inflammation and insulin resistance are hypothesized to play an important role in prognosis of prostate cancer. However, it is unclear whether physical activity and proinflammatory/hyperinsulinemic diets are independently and jointly associated with survival in prostate cancer patients. METHODS: We analyzed 4,592 men with nonmetastatic prostate cancer from the Health Professionals Follow-up Study. Postdiagnosis physical activity and diet were assessed using validated self-reported questionnaires. We used the validated dietary scores to empirically assess the inflammatory (EDIP) and insulinemic (EDIH) potential of dietary patterns based upon specific combinations of food groups. Cox regression model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: During a median of 13 years of follow-up, we identified 2,543 deaths (445 from prostate cancer death). Comparing men with ≥48 vs. <3 MET-hours/week of post-diagnosis physical activity, multivariable-adjusted HR (95% CI) were 0.70 (0.40 to 0.88) for lethal prostate cancer and 0.77 (0.67 to 0.89) for all-cause mortality. We observed a linear dose-response association of post-diagnosis physical activity with lethal prostate cancer and all-cause mortality. However, post-diagnosis EDIP and EDIH were not associated with lethal prostate cancer but marginally positively associated with all-cause mortality (HR per 1-SD increase: 1.04 (1.00-1.08) for EDIP; 1.05 (1.01-1.10) for EDIH). In joint analyses, men with both high physical activity and low EDIP (or EDIH) score showed approximately a 15% lower risk of all-cause mortality, compared to those with low physical activity and high diet scores. CONCLUSION: Postdiagnosis physical activity was inversely associated with mortality in men with non-metastatic prostate cancer while proinflammatory and hyperinsulinemic diets were marginally positively associated. Moreover, men with high physical activity and low proinflammatory and hyperinsulinemic diets after diagnosis may have additional mortality risk reduction. This work was supported by the National Institutes of Health research grants (U01 CA167552, R03CA249027).