MRC Lifelong Health & Ageing at UCL, 33 Bedford Place, London WC1 B5JU, United Kingdom; MRC Elsie Widdowson Laboratory, Cambridge CB1 9NL, United Kingdom; NNEdPro Global Centre for Nutrition and Health (Affiliated with: Cambridge University Health Partners, Wolfson College Cambridge and the British Dietetic Association), St John's Innovation Centre, Cowley Road, Cambridge CB4 0WS, United Kingdom.
MRC Elsie Widdowson Laboratory, Cambridge CB1 9NL, United Kingdom; School of Population and Global Health, The University of Western Australia, 35 Stirling Highway, Crawley 6009, Perth, Western Australia, Australia.
Clin Nutr. 2019 Jun;38(3):1464-1473. doi: 10.1016/j.clnu.2018.06.969. Epub 2018 Jun 28.
Diet may influence vascular function through elevated homocysteine (Hcy) concentrations. However the relationship between dietary patterns (DP), characterised by Hcy and its associated nutrients is unknown.
To identify a DP characterised by plasma Hcy, dietary folate and dietary vitamin B12, and examine its associations with two markers of vascular function: carotid intima-media thickness (cIMT) and pulse wave velocity (PWV).
1562 participants of the MRC National Survey of Health and Development (NSHD), a British birth cohort, with dietary data measured at least once between 36 and 60-64 years, and cIMT or PWV measured at 60-64 years were included. DPs were derived using reduced rank regression with three intermediate variables: 1) plasma Hcy (μmol/L) 2) folate intake (μg/1000 kcal) 3) vitamin B12 intake (μg/1000 kcal). Multiple regression models assessed associations between the derived DP z-scores and vascular function adjusting for dietary misreporting, socioeconomic position, BMI, smoking, physical activity and diabetes.
A DP explaining the highest amount of shared variation (4.5%) in plasma Hcy, dietary folate and dietary vitamin B12 highly correlated with folate (r = 0.96), moderately correlated with vitamin B12 (r = 0.27), and weakly correlated with Hcy (r = 0.10). This "high B-vitamin" DP (including folate) was characterised by high intakes of vegetables, fruit and low fibre breakfast cereal, and low intakes of processed meat, white bread, sugar and preserves. No associations were observed between DP z-scores and vascular function at any time point following adjustment for covariates.
This study explored a specific hypothesised pathway linking diet to vascular function. Although we found no consistent evidence for an association between a high B-vitamin DP and vascular function, we did observe an association with CRP and triglycerides in secondary analyses. Further analyses using strongly correlated and biologically relevant intermediate variables are required to refine investigations into diet and CVD in longitudinal cohort data.
饮食可能通过升高同型半胱氨酸（Hcy）浓度来影响血管功能。然而，饮食模式（DP）与 Hcy 及其相关营养素之间的关系尚不清楚。
确定一种以血浆 Hcy、膳食叶酸和维生素 B12 为特征的 DP，并研究其与血管功能的两个标志物（颈动脉内膜中层厚度（cIMT）和脉搏波速度（PWV））之间的关系。
纳入了英国出生队列 MRC 国家健康与发展调查（NSHD）中的 1562 名参与者，这些参与者在 36 至 60-64 岁之间至少进行了一次饮食数据测量，在 60-64 岁时进行了 cIMT 或 PWV 测量。使用降秩回归方法，以三个中间变量（1）血浆 Hcy（μmol/L）、2）叶酸摄入量（μg/1000 千卡）和 3）维生素 B12 摄入量（μg/1000 千卡）为基础，推导出 DP。使用多元回归模型调整了饮食报告错误、社会经济地位、BMI、吸烟、体力活动和糖尿病等因素后，评估了衍生 DP z 分数与血管功能之间的关系。
一种能够解释血浆 Hcy、膳食叶酸和维生素 B12 最大共享变异量（4.5%）的 DP 与叶酸高度相关（r=0.96），与维生素 B12 中度相关（r=0.27），与 Hcy 低度相关（r=0.10）。这种“高维生素 B”DP（包括叶酸）的特点是蔬菜、水果和低纤维早餐谷物摄入量高，加工肉、白面包、糖和蜜饯摄入量低。在调整了协变量后，在任何时间点，DP z 分数与血管功能之间均无关联。
本研究探索了一种将饮食与血管功能联系起来的特定假设途径。尽管我们没有发现高维生素 B DP 与血管功能之间存在一致的关联证据，但在二次分析中，我们确实观察到了与 CRP 和甘油三酯之间的关联。在对纵向队列数据进行进一步分析时，需要使用强相关且具有生物学相关性的中间变量来改进饮食与 CVD 之间的研究。
