Pre-Diagnosis Metabolic Health-Related Dietary Index and Prostate Cancer–Specific Mortality

Background: Metabolic dysfunction has been linked to prostate cancer (PCa) development and progression. This study sought to assess whether metabolic risk factors influence PCa death or simply reflect overall mortality risk among men with PCa. Methods: We analyzed data from 1497 men enrolled in the North Carolina-Louisiana Prostate Cancer Project (PCaP). Pre-diagnosis dietary and metabolic factors were summarized into a standardized metabolic health-related (MHD) index reflecting higher intake of added sugars, glycemic load, saturated fat, and sodium intake, and lower intake of fiber, fruit, vegetable, and whole grain. Adjusting for demographic, clinical and lifestyle factors, we used multinomial logistic regression to examine associations between the metabolic index and outcomes: PCa death, non-PCa death, and alive at follow-up. Results: Among 1497 men, 95 and 311 died from PCa and non-PCa causes, respectively, and 1091 were alive at follow-up. The MHD index differed across mortality-status groups (p < 0.001) and was higher among men with aggressive PCa (p < 0.001) but did not differ significantly by race (p = 0.187). In adjusted multinomial logistic models, higher MHD index, which represents a less favorable metabolic health–related dietary profile, was significantly associated with increased odds of PCa-specific death adjusted odds ratio [aOR] = 1.38 (95% CI, 1.10–1.73; p = 0.006), but not non-PCa death [aOR] = 1.03 (95% CI, 0.89–1.19; p = 0.687). Conclusions: Less favorable pre-diagnosis metabolic health–related dietary profiles were significantly associated with PCa-specific mortality but not non-PCa mortality, suggesting a potentially distinct role of dietary pattern in PCa progression. The association was not observed for non-PCa death and was attenuated after adjustment for anthropometric and tumor characteristics. These findings support further investigation of overall dietary-metabolic profiles as potentially relevant factors in PCa-specific mortality.