Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, United Kingdom.
International Agency for Research on Cancer, Lyon, France.
Am J Clin Nutr. 2021 Jul 1;114(1):338-347. doi: 10.1093/ajcn/nqab045.
Vitamin B6 insufficiency has been linked to increased risk of cancer and other chronic diseases. The circulating concentration of pyridoxal 5'-phosphate (PLP) is a commonly used measure of vitamin B6 status. Ratios of substrates indicating PLP coenzymatic function and metabolism may be useful complementary measures to further explore the role of vitamin B6 in health.
We explored the sensitivity of 5 outcomes, namely PLP concentration, homocysteine:cysteine (Hcy:Cys), cystathionine:cysteine (Cysta:Cys), the 3´-hydroxykynurenine ratio (HKr), and the 4-pyridoxic acid ratio (PAr) to vitamin B6 intake as well as personal and lifestyle characteristics.
Dietary intake and biomarker data were collected from participants from 3 nested case-control studies within the European Prospective Investigation into Cancer and Nutrition (EPIC). Bayesian regression models assessed the associations of the 5 biomarker outcomes with vitamin B6 intake and personal and lifestyle covariates. Analogous models examined the relations of Hcy:Cys, Cysta:Cys, and HKr with PLP.
In total, 4608 participants were included in the analyses. Vitamin B6 intake was most strongly associated with PLP, moderately associated with Hcy:Cys, Cysta:Cys, and HKr, and not associated with PAr (fold change in marker given a doubling of vitamin B6 intake: PLP 1.60 [95% credible interval (CrI): 1.50, 1.71]; Hcy:Cys 0.87 [95% CrI: 0.84, 0.90]; Cysta:Cys 0.89 [95% CrI: 0.84, 0.94]; HKr 0.88 [95% CrI: 0.85, 0.91]; PAr 1.00 [95% CrI: 0.95, 1.05]). PAr was most sensitive to age, and HKr was least sensitive to BMI and alcohol intake. Sex and menopause status were strongly associated with all 5 markers.
We found that 5 different markers, capturing different aspects of vitamin B6-related biological processes, varied in their associations with vitamin B6 intake and personal and lifestyle predictors.
维生素 B6 不足与癌症和其他慢性疾病风险增加有关。吡哆醛 5'-磷酸（PLP）的循环浓度是衡量维生素 B6 状况的常用指标。指示 PLP 辅酶功能和代谢的底物比值可能是进一步探索维生素 B6 在健康中作用的有用补充措施。
我们探讨了 5 种结果（即 PLP 浓度、同型半胱氨酸：半胱氨酸（Hcy：Cys）、胱硫醚：半胱氨酸（Cysta：Cys）、3´-羟基犬尿氨酸比（HKr）和 4-吡啶氧乙酸比（PAr））对维生素 B6 摄入以及个人和生活方式特征的敏感性。
从欧洲癌症与营养前瞻性调查（EPIC）中的 3 项嵌套病例对照研究的参与者中收集饮食摄入和生物标志物数据。贝叶斯回归模型评估了 5 种生物标志物结果与维生素 B6 摄入以及个人和生活方式协变量的关联。类似的模型检查了 Hcy：Cys、Cysta：Cys 和 HKr 与 PLP 的关系。
共纳入 4608 名参与者进行分析。维生素 B6 摄入与 PLP 相关性最强，与 Hcy：Cys、Cysta：Cys 和 HKr 中度相关，与 PAr 不相关（维生素 B6 摄入翻倍时标志物的变化倍数：PLP 1.60[95%可信区间（CrI）：1.50，1.71]；Hcy：Cys 0.87[95% CrI：0.84，0.90]；Cysta：Cys 0.89[95% CrI：0.84，0.94]；HKr 0.88[95% CrI：0.85，0.91]；PAr 1.00[95% CrI：0.95，1.05]）。PAr 对年龄最敏感，而 HKr 对 BMI 和酒精摄入量最不敏感。性别和绝经状态与所有 5 种标志物均密切相关。
我们发现，5 种不同的标志物，分别反映了维生素 B6 相关生物过程的不同方面，其与维生素 B6 摄入以及个人和生活方式预测因子的相关性存在差异。
