Interactions between diet and peroxisome proliferator-activated receptor-gamma gene Pro12Ala and C161T polymorphisms on prostate cancer risk in Japanese men

背景资料。前列腺癌的发生可能是高脂肪摄入与影响脂代谢的基因多态性相互作用的结果，如PPAR-γ基因。我们研究了饮食、PPAR-γ基因多态(Pro12Ala和C161T)以及基因-饮食交互作用与日本人前列腺癌风险的关系。方法：研究方法。样本来自新诊断的110例前列腺癌患者和214例活检阴性对照。比较病例组和对照组的每日能量和常量营养素的消耗量。采用Logistic回归分析，根据各基因多态性估计前列腺癌风险的优势比(OR)和95%可信区间(CI)。低/高营养素摄入量与PPAR-γ基因多态对前列腺癌风险的交互作用已得到证实。结果。每日能量和常量营养素的摄入量在病例组和对照组之间没有差异。Pro12Ala基因多态性与前列腺癌风险无关。相比之下，C161T替代与前列腺癌风险降低相关。C161T T等位基因携带者对前列腺癌有保护作用(多因素调整OR：0.53，95%CI：0.31~0.93)。在低脂肪或碳水化合物摄入量组中，C161T T等位基因携带者降低前列腺癌风险(多因素调整OR(95%CI)分别为0.33(0.13~0.83)和0.42(0.18~0.97))。然而，营养物质的摄入与PPAR-γ基因多态对前列腺癌风险的影响不存在交互作用。在日本，PPAR-γ基因C161T替换与前列腺癌风险降低相关；然而，没有观察到Pro12Ala多态与前列腺癌风险显著相关。低脂肪或碳水化合物摄入量可能会加强C161T替代导致的风险降低。

Background. Prostate cancer could be arisen from interactions between high fat consumption and gene polymorphisms influencing lipid metabolism, such as peroxisome proliferator-activated receptor gamma (PPAR-γ) gene. We examined associations of diet, PPAR-γ gene polymorphisms (Pro12Ala and C161T) and the gene-diet interactions on prostate cancer risk in Japanese. Methods. Samples were obtained from newly diagnosed 110 prostate cancer cases and 214 biopsy-negative controls. Daily consumption of energy and macronutrients were compared between cases and controls. We used logistic regression analysis to estimate the odds ratio (OR) and 95% confidence interval (CI) for prostate cancer risk according to genotype of each polymorphism. Interactions between low/high nutrient intakes and PPAR-γ gene polymorphisms on prostate cancer risk were proved. Results. Daily intake of energy and macronutrients were not different between cases and controls. Pro12Ala polymorphism was not associated with prostate cancer risk. In contrast, C161T substitution was associated with reduced prostate cancer risk. The T allele carriers of C161T showed a protective effect (multiple-adjusted OR: 0.53, 95% CI: 0.31-0.93) on prostate cancer. Among low fat or carbohydrate intake groups, the T allele carriers of C161T reduced prostate cancer risk (multiple-adjusted OR (95% CI): 0.33 (0.13-0.83) and 0.42 (0.18-0.97), respectively). However, there were no interactions between consumption of nutrients and PPAR-γ gene polymorphisms for prostate cancer risk.Conclusions. PPAR-γ gene C161T substitution was associated with decreased prostate cancer risk in Japanese; however, no significant link was observed for Pro12Ala polymorphism. Low intake of fat or carbohydrate may strength the risk reduction by C161T substitution.