von Schacky Clemens
Medizinische Klinik I, Department Preventive Cardiology, Ludwig-Maximilians-University, Ziemssenstrasse 1, D-80336 Munich, Germany; Omegametrix, Am Klopferspitz 19, 82152 Martinsried, Germany(1).
Prostaglandins Leukot Essent Fatty Acids. 2015 Jan;92:41-7. doi: 10.1016/j.plefa.2014.05.004. Epub 2014 May 28.
In cardiology, results of recent large intervention trials with eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) supplements were neutral. In contrast, in epidemiologic studies, an inverse relation between clinical events and intake of EPA+DHA was found which was steeper for higher levels of EPA+DHA. A standardized way of determining levels is the Omega-3 Index, which is the percentage of EPA+DHA of a total of 26 fatty acids measured in erythrocytes. According to current criteria, a low Omega-3 Index is a cardiovascular risk factor. What can explain this contradiction? Trial participants were recruited irrespective of their baseline status in EPA+DHA - an important predictor of events. Levels of EPA+DHA have a statistically normal distribution; together with the large inter-individual variability of levels' responding to increased intake, this created a large overlap of EPA+DHA levels between intervention and control groups. Moreover, trial participants were advised to take EPA+DHA supplements with breakfast, frequently a low fat meal, resulting in poor bioavailability. As a result, there is an urgent need for new intervention trials in cardiology, for which participants with a low baseline omega-3 index are recruited, and then treated with individually tailored doses of EPA+DHA to a prespecified target range.
在心脏病学领域，近期关于补充二十碳五烯酸（EPA）加二十二碳六烯酸（DHA）的大型干预试验结果呈中性。相比之下，在流行病学研究中，发现临床事件与EPA+DHA摄入量之间存在负相关关系，且对于较高水平的EPA+DHA，这种关系更为显著。一种标准化的测定水平的方法是Omega-3指数，它是红细胞中测量的26种脂肪酸中EPA+DHA所占的百分比。根据当前标准，低Omega-3指数是一种心血管危险因素。如何解释这种矛盾呢？试验参与者的招募并未考虑他们EPA+DHA的基线状态——这是事件的一个重要预测指标。EPA+DHA水平呈统计学上的正态分布；再加上个体对摄入量增加的反应存在较大差异，这导致干预组和对照组之间的EPA+DHA水平有很大重叠。此外，试验参与者被建议在早餐时服用EPA+DHA补充剂，而早餐通常是低脂餐，这导致生物利用度较差。因此，心脏病学领域迫切需要开展新的干预试验，招募基线omega-3指数较低的参与者，然后用根据个体情况量身定制的剂量将EPA+DHA治疗至预先设定的目标范围。
