by hummingbirds
背景：纤维蛋白原、激活的因子XII （FXIIa）增多和因子VII凝血活性（FVIIc）的升高与致死性缺血性心脏疾病有关。这项研究证实了这个假设，即降低饮食的n-6与n-3多不饱和脂肪酸的比率（n-6:n-3）能够改变老年人的这些危险因子。目的：这项研究的目的是，改变饮食n-6与n-3多不饱和脂肪酸的比率6个月后，测量空腹的止血危险因子及餐后激活的因子XII浓度的改变。设计：年龄在45-70岁之间的258个受试者进行随机平行实验设计，我们以 n-6与n-3多不饱和脂肪酸比率为10:1作为对照饮食，比较了4种以多不饱和脂肪酸提供6％能量的饮食，其n-6与n-3多不饱和脂肪酸比率在5:1到3:1之间。饮食富含α-亚麻酸和/或二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）。结果： n-6与n-3多不饱和脂肪酸比率接近3:1饮食，其空腹和3小时血浆三酰基甘油浓度降低11.1％和7.2％，即富含EPA和DHA的饮食与其它饮食相比。空腹的纤维蛋白原、激活的因子XII、因子VII凝血活性，激活的因子VII和因子VII抗原、餐后激活的因子VII不受饮食影响。测量前一天避免高脂饮食可以降低因子VII凝血活性和激活的因子VII分别为8%和19.2％。一个试验餐包含50克脂肪，6小时后平均增加激活的因子VII 47％（95%可信区间：42％-52%），但是对n-6与n-3多不饱和脂肪酸比率的反应并没有差别。结论：通过增加EPA和DHA摄取，减少n-6与n-3多不饱和脂肪酸比率至接近3:1，可以降低老年人空腹和餐后血浆三酰基甘油浓度，但不影响止血危险因子。
出处：Am J Clin Nutr. 2006 Sep;84(3):513-22.
Effect of varying the ratio of n-6 to n-3 fatty acids by increasing the dietary intake of alpha-linolenic acid, eicosapentaenoic and docosahexaenoic acid, or both on fibrinogen and clotting factors VII and XII in persons aged 45-70 y: the OPTILIP study.
BACKGROUND: Elevated fibrinogen, activated factor XII (FXIIa), and factor VII coagulant activity (FVIIc) are associated with higher risk of fatal ischemic heart disease. This study tested the hypothesis that lowering the dietary ratio of n-6 to n-3 polyunsaturated fatty acids (n-6:n-3) would modify these risk factors in older men and women. OBJECTIVE: The objective of the study was to measure fasting hemostatic risk factors and postprandial changes in activated FVII (FVIIa) concentrations after a 6-mo alteration in dietary n-6:n-3. DESIGN: In a randomized, parallel design in 258 subjects aged 45-70 y, we compared 4 diets providing 6% of energy as polyunsaturated fatty acids at an n-6:n-3 between 5:1 and 3:1 with a control diet that had an n-6:n-3 of 10:1. The diets were enriched in alpha-linolenic acid, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid, or both. RESULTS: Fasting and 3-h plasma triacylglycerol concentrations were 11.1% and 7.2% lower with the diet that had an n-6:n-3 of approximately 3:1 and that was enriched with EPA and DHA than with the other diets. Fasting fibrinogen, FXIIa, FVIIc, FVIIa, and FVII antigen and postprandial FVIIa were not influenced by the diets. Avoiding foods high in fat the day before measurement decreased FVIIc and FVIIa by 8% and 19.2%, respectively. A test meal containing 50 g fat resulted in a mean 47% (95% CI: 42%, 52%) increase in FVIIa 6 h later, but the response did not differ by n-6:n-3. CONCLUSION: Decreasing the n-6:n-3 to approximately 3:1 by increasing the intake of EPA and DHA lowers fasting and postprandial plasma triacylglycerol concentrations in older persons but does not influence hemostatic risk factors.
PMID: 16960164
描述标准化急性饮食制度对尿，血浆和唾液的蜕变中间产物对健康人类的影响
By zhangxinsheng31
背景：人体营养研究要面对蜕变中间产物的挑战——是由于饮食改变的代谢形式可能很难区分于正常的生理改变。目的：评估正常人们代谢形式内在的和个体差异的程度，调查标准饮食对减少变化的影响。设计：分别在4个早晨收集30名健康自愿者（23名女性，7名男性）的尿，血浆，和唾液。拜访前2天，在收集生物液体之前提供免费的精选的食品。在拜访的3天前就达到了预期的结果，并且在拜访的4天前所有的食物达到标准化。样品用氕核磁共振分光检定法遵循多变量数据分析。结果：各自生物体液对于内在的和个体间差异是相当重要的。在食用标准膳食后，主成份分析视觉检验的分曲线表明在尿液中个体间差异是减少，但是在血浆和唾液中没有减少。部分最小二乘法表明在尿和唾液中是按照时间依从性改变的，主要由于尿中的肌酸酐和唾液中的醋酸盐。按照每个模型的预测力来分类这些样品无论是白天还是黑夜，尿液是85％，唾液是75％。结论：尿代表一个敏感的指标反映了急性摄入饮食，而血浆和唾液并没有。将来蜕变中间产物的研究应该考虑到近期饮食的摄入和样品收集的时间，将它作为一种减少正常生理改变得方式。
出处：Am J Clin Nutr. 2006 Sep;84(3):531-9.
Effect of acute dietary standardization on the urinary, plasma, and salivary metabolomic profiles of healthy humans.
BACKGROUND: Metabolomics in human nutrition research is faced with the challenge that changes in metabolic profiles resulting from diet may be difficult to differentiate from normal physiologic variation. OBJECTIVE: We assessed the extent of intra- and interindividual variation in normal human metabolic profiles and investigated the effect of standardizing diet on reducing variation. DESIGN: Urine, plasma, and saliva were collected from 30 healthy volunteers (23 females, 7 males) on 4 separate mornings. For visits 1 and 2, free food choice was permitted on the day before biofluid collection. Food choice on the day before visit 3 was intended to mimic that for visit 2, and all foods were standardized on the day before visit 4. Samples were analyzed by using 1H nuclear magnetic resonance spectroscopy followed by multivariate data analysis. RESULTS: Intra- and interindividual variations were considerable for each biofluid. Visual inspection of the principal components analysis scores plots indicated a reduction in interindividual variation in urine, but not in plasma or saliva, after the standard diet. Partial least-squares discriminant analysis indicated time-dependent changes in urinary and salivary samples, mainly resulting from creatinine in urine and acetate in saliva. The predictive power of each model to classify the samples as either night or morning was 85% for urine and 75% for saliva. CONCLUSIONS: Urine represented a sensitive metabolic profile that reflected acute dietary intake, whereas plasma and saliva did not. Future metabolomics studies should consider recent dietary intake and time of sample collection as a means of reducing normal physiologic variation.
PMID: 16960166
编辑：bluelove
