Mustad V, Derr J, Reddy C C, Pearson T A, Kris-Etherton P M
Graduate Program in Nutrition, Pennsylvania State University, University Park 16802, USA.
Atherosclerosis. 1996 Sep 27;126(1):117-29. doi: 10.1016/0021-9150(96)05900-x.
Seasonal variation in the plasma lipids and lipoproteins is reported in the literature. Whether this variation is the result of changes in diet or other factors has not been adequately addressed. We investigated the effects of a controlled diet on the seasonal variation in the levels of plasma lipids and apolipoproteins and also on the excretion of urine metabolites of TXA2 and PGI2 in healthy males. Two well-controlled diet studies were conducted to evaluate effects of dietary fatty acids on plasma lipids (Studies 1 and 2; n = 33) and eicosanoid excretion (Study 2 only; n = 15). Participants consumed whole-food test diets in a randomized, four-period crossover design during each 26-day experimental period. A non-intervention control group also participated in each study (Study 1, n = 12; Study 2, n = 11). Blood was collected monthly and analyzed for plasma lipids and apolipoproteins A-1 (Apo A-1) and B100 (Apo B). Twenty-four hour urine samples were collected monthly only in Study 2 and analyzed for TXB2 and 6-keto-PGF1 alpha by RIA. Seasonal fluctuations were observed in all subjects in plasma Apo A-1 (zenith = July, with 95% CI June-July; P < 0.05) and Apo B (zenith = October, 95% CI September-November, P < 0.05). Although there was no significant variation in plasma cholesterol levels, the increase in Apo B is consistent with an increase in LDL particle number during the fall/winter. Additionally, excretion of both eicosanoid metabolites and the ratio of 6-keto-PGF1 alpha/TXB2 was markedly elevated in July (95% CI June-July, P < 0.001). Three seasonal fluctuations were observed both in participants who consumed a highly-controlled experimental diet and in the non-intervention controls. Thus, these results suggest a diet-independent seasonal variation in parameters thought to be involved in coronary heart disease risk status. An understanding of these variations is important not oly for clinical evaluation and metabolic study design issues, but more importantly, to clarify their clinical significance with the seasonal incidence of CHD events.
文献报道了血浆脂质和脂蛋白的季节性变化。这种变化是饮食变化还是其他因素导致的，尚未得到充分探讨。我们研究了控制饮食对健康男性血浆脂质和载脂蛋白水平季节性变化的影响，以及对血栓素A2（TXA2）和前列环素（PGI2）尿液代谢产物排泄的影响。进行了两项严格控制的饮食研究，以评估膳食脂肪酸对血浆脂质的影响（研究1和2；n = 33）以及类花生酸排泄（仅研究2；n = 15）。在每个为期26天的实验期内，参与者采用随机、四期交叉设计食用全食物测试饮食。一个非干预对照组也参与了每项研究（研究1，n = 12；研究2，n = 11）。每月采集血液，分析血浆脂质以及载脂蛋白A-1（Apo A-1）和B100（Apo B）。仅在研究2中每月采集24小时尿液样本，并通过放射免疫分析法（RIA）分析血栓素B2（TXB2）和6-酮-前列腺素F1α。在所有受试者中均观察到血浆Apo A-1（峰值在7月，95%置信区间为6月至7月；P < 0.05）和Apo B（峰值在10月，95%置信区间为9月至11月，P < 0.05）的季节性波动。尽管血浆胆固醇水平没有显著变化，但Apo B的增加与秋冬期间低密度脂蛋白颗粒数量的增加一致。此外，7月类花生酸代谢产物的排泄以及6-酮-前列腺素F1α/TXB2的比值均显著升高（95%置信区间为6月至7月，P < 0.001）。在食用高度控制的实验饮食的参与者和非干预对照组中均观察到三种季节性波动。因此，这些结果表明，在被认为与冠心病风险状况相关的参数中存在与饮食无关的季节性变化。了解这些变化不仅对于临床评估和代谢研究设计问题很重要，更重要的是，要阐明它们与冠心病事件季节性发病率的临床意义。
