Health Diagnostic Laboratory, Inc, 737 N 5th Street, Suite 103, Richmond, VA 23219, USA; OmegaQuant Analytics, LLC, Sioux Falls, SD, USA; Department of Internal Medicine, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, USA.
J Clin Lipidol. 2013 Sep-Oct;7(5):433-40. doi: 10.1016/j.jacl.2013.05.001. Epub 2013 May 7.
Omega-3 fatty acid (n-3 FA) biostatus can be estimated with red blood cell (RBC) membranes or plasma. The matrix that exhibits the lower within-person variability and is less affected by an acute dose of n-3 FA is preferred in clinical practice.
We compared the acute effects of a large dose of n-3 FA on RBC and plasma levels of eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA).
Healthy volunteers (n = 20) were given 4 capsules containing 3.6 g of n-3 FA with a standardized breakfast. Blood samples were drawn at 0, 2, 4, 6, 8, and 24 hours. The EPA + DHA content of RBC membranes and plasma (the latter expressed as a percentage of total FA and as a concentration) were determined. General linear mixed models were used to analyze the mean response profiles in FA changes over time for plasma and RBCs.
At 6 hours after load, the plasma concentration of EPA + DHA had increased by 47% (95% confidence interval [CI], 24% to 73%) and the plasma EPA + DHA percentage of total FA by 19% (95% CI, 4.7% to 36%). The RBC EPA + DHA percentage of composition was unchanged [-0.6% (95% CI, -2.6% to 1.5%)]. At 24 hours, the change in both of the plasma EPA + DHA markers was 10-fold greater than that in RBCs.
An acute dose of n-3 FA (eg, a meal of oily fish or fish oil supplements) taken within a day before a doctor's visit can elevate levels of EPA + DHA in plasma, whether expressed as a percentage or a concentration, but not in RBC membranes. Similar to hemoglobin A1c, which is not affected by an acute glycemic deviation, RBCs provide a more reliable estimate of a patient's chronic EPA + DHA status than does plasma.
可以通过红细胞（RBC）膜或血浆来估计ω-3 脂肪酸（n-3 FA）的生物状态。在临床实践中，更倾向于选择个体内变异性较低且受 n-3 FA 急性剂量影响较小的基质。
我们比较了大剂量 n-3 FA 对红细胞和血浆中二十碳五烯酸（EPA）加二十二碳六烯酸（DHA）水平的急性影响。
健康志愿者（n=20）在标准早餐时服用 4 粒含 3.6 g n-3 FA 的胶囊。在 0、2、4、6、8 和 24 小时抽取血样。测定 RBC 膜和血浆（后者表示为总脂肪酸的百分比和浓度）中 EPA+DHA 的含量。采用广义线性混合模型分析 FA 变化在血浆和 RBC 中随时间的平均反应曲线。
负荷后 6 小时，血浆 EPA+DHA 浓度增加了 47%（95%置信区间 [CI]，24%至 73%），血浆 EPA+DHA 占总 FA 的百分比增加了 19%（95% CI，4.7%至 36%）。红细胞 EPA+DHA 的组成百分比无变化[-0.6%（95% CI，-2.6%至 1.5%）]。24 小时时，两种血浆 EPA+DHA 标志物的变化均比 RBC 高 10 倍。
在就诊前一天内服用 n-3 FA（例如，一顿油性鱼或鱼油补充剂）的急性剂量可以提高血浆中 EPA+DHA 的水平，无论是以百分比还是浓度表示，但不会提高 RBC 膜中的水平。类似于不受急性血糖偏差影响的糖化血红蛋白，红细胞为患者的慢性 EPA+DHA 状态提供了比血浆更可靠的估计。
