Volek Jeff S, Ballard Kevin D, Silvestre Ricardo, Judelson Daniel A, Quann Erin E, Forsythe Cassandra E, Fernandez Maria Luz, Kraemer William J
Department of Kinesiology and the Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269-1110, USA.
Metabolism. 2009 Dec;58(12):1769-77. doi: 10.1016/j.metabol.2009.06.005. Epub 2009 Jul 25.
We previously reported that a carbohydrate-restricted diet (CRD) ameliorated many of the traditional markers associated with metabolic syndrome and cardiovascular risk compared with a low-fat diet (LFD). There remains concern how CRD affects vascular function because acute meals high in fat have been shown to impair endothelial function. Here, we extend our work and address these concerns by measuring fasting and postprandial vascular function in 40 overweight men and women with moderate hypertriacylglycerolemia who were randomly assigned to consume hypocaloric diets (approximately 1500 kcal) restricted in carbohydrate (percentage of carbohydrate-fat-protein = 12:59:28) or LFD (56:24:20). Flow-mediated dilation of the brachial artery was assessed before and after ingestion of a high-fat meal (908 kcal, 84% fat) at baseline and after 12 weeks. Compared with the LFD, the CRD resulted in a greater decrease in postprandial triacylglycerol (-47% vs -15%, P = .007), insulin (-51% vs -6%, P = .009), and lymphocyte (-12% vs -1%, P = .050) responses. Postprandial fatty acids were significantly increased by the CRD compared with the LFD (P = .033). Serum interleukin-6 increased significantly over the postprandial period; and the response was augmented in the CRD (46%) compared with the LFD (-13%) group (P = .038). After 12 weeks, peak flow-mediated dilation at 3 hours increased from 5.1% to 6.5% in the CRD group and decreased from 7.9% to 5.2% in the LFD group (P = .004). These findings show that a 12-week low-carbohydrate diet improves postprandial vascular function more than a LFD in individuals with atherogenic dyslipidemia.
我们之前报道过，与低脂饮食（LFD）相比，碳水化合物限制饮食（CRD）改善了许多与代谢综合征和心血管风险相关的传统指标。由于已证明高脂肪的急性餐食会损害内皮功能，因此CRD如何影响血管功能仍令人担忧。在此，我们扩展了研究工作，并通过测量40名患有中度高甘油三酯血症的超重男性和女性的空腹和餐后血管功能来解决这些问题，这些受试者被随机分配食用碳水化合物受限的低热量饮食（约1500千卡，碳水化合物-脂肪-蛋白质比例=12:59:28）或LFD（56:24:20）。在基线时以及12周后，在摄入高脂肪餐（908千卡，84%脂肪）之前和之后评估肱动脉的血流介导的扩张。与LFD相比，CRD导致餐后甘油三酯（-47%对-15%，P = 0.007）、胰岛素（-51%对-6%，P = 0.009）和淋巴细胞（-12%对-1%，P = 0.050）反应的更大幅度降低。与LFD相比，CRD使餐后脂肪酸显著增加（P = 0.033）。血清白细胞介素-6在餐后期间显著增加；与LFD（-13%）组相比，CRD组的反应增强（46%）（P = 0.038）。12周后，CRD组3小时时的峰值血流介导的扩张从5.1%增加到6.5%，而LFD组从7.9%降低到5.2%（P = 0.004）。这些发现表明，在患有致动脉粥样硬化性血脂异常的个体中，为期12周的低碳水化合物饮食比LFD更能改善餐后血管功能。
