Prostate Cancer Risk in the Swedish AMORIS Study The Interplay Among Triglycerides, Total Cholesterol, and Glucose

BACKGROUND: In a cohort including 5112 prostate cancer (pCa) patients, the authors investigated associations among triglycerides (TG), total cholesterol (TC), and pCa while taking into account glucose. METHODS: A cohort (n = 200,660) based on 4 groups of men, according to age at cohort entry, with TG, TC, and glucose measurements was selected from the Apolipoprotein MOrtality RISk (AMORIS) database. Of these, 5112 men developed pCa. Multivariate Cox proportional hazard models were used to analyze associations among TG, TC, and pCa. Competing risks were assessed graphically. RESULTS: Age-stratified analyses for quartiles of TG, TC, and glucose showed a negative association between glucose and pCa risk (HR, 0.93; 95% CI, 0.86-1.01), 0.93 (0.86-1.01), 0.87 (0.81-0.94) for the second, third, and fourth quartiles compared with the first (P-trend = .001). Stratified analysis by glucose levels (< 6.11 or >= 6.11 mmol/L) showed a positive association between hypertriglyceridemia (TG >= 1.71 mmol/L) and pCa risk, when there were high glucose levels (HR, 1.23; 95% CI, 1.01-1.48). No association was found for hypercholesterolemia (TC >= 6.50 mmol/L). Competing risk analysis showed that protective effects of glucose were overestimated in conventional Cox proportional hazard models and strengthened positive findings between TG and pCa risk. CONCLUSIONS: The authors' findings supported the hypothesis that factors of the glucose and lipid metabolism influence pCa risk. Competing risk assessment showed that it is important to take into account the long natural history and age distribution of pCa when interpreting results. The authors' findings indicate another reason to fight the increasing prevalence of obesity and dyslipidemia. Cancer 2011; 117: 2086-95. (C) 2010 American Cancer Society.