Effects of n-6 PUFAs compared with SFAs on liver fat, lipoproteins, and inflammation in abdominal obesity: a randomized controlled trial
Effects of n-6 PUFAs compared with SFAs on liver fat, lipoproteins, and inflammation in abdominal obesity: a randomized controlled trial
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DOI：
10.3945/ajcn.111.030114
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发表时间：
2012-05-01
影响因子：
7.1
通讯作者：
Riserus, Ulf
中科院分区：
文献类型：
--
作者：
Bjermo, Helena;Iggman, David;Riserus, Ulf
背景：用植物PUFAs代替SFAs对心脏代谢有益，但对肝脏脂肪的影响尚不清楚。然而，饮食中增加n-6 PUFAs也被认为会促进炎症——这是一个尚未得到证实的理论。目的：研究PUFAs对肝脏脂肪、全身性炎症和代谢紊乱的影响。设计：我们随机分配67名腹部肥胖受试者（15%患有2型糖尿病），在不改变常量营养素摄入量的情况下，采用10周等量热量饮食（含蔬菜n-6 PUFA饮食）或主要来自黄油的SFA饮食（SFA饮食）。采用核磁共振（MRI）和质子磁共振（1H）谱（MRS）对肝脏脂肪进行评估。检测蛋白转化酶枯草素/酮素9型（PCSK9，一种肝脏ldl受体调节剂）、炎症和脂肪组织中炎症和脂质生成基因的表达。结果：共61名受试者完成研究。体重适度增加，但各组之间没有差异。PUFA饮食组的肝脏脂肪低于SFA饮食组[与基线相比，组间相对变化差异；16% (mri; p < 0.001), 34% (mrs; p = 0.02)]。PUFA饲粮中PCSK9 （P = 0.001）、TNF受体-2 （P < 0.01）和IL-1受体拮抗剂（P = 0.02）浓度较低，而SFA饲粮中胰岛素（P = 0.06）趋于较高。在依从性受试者（定义为血清亚油酸的变化）中，PUFA饮食组的胰岛素、总/高密度脂蛋白胆固醇比率、LDL胆固醇和甘油三酯低于SFA饮食组（P < 0.05）。脂肪组织基因表达不变。结论：与SFA摄入相比，n-6 PUFAs可以减少肝脏脂肪，适度改善代谢状态，但不会减轻体重。高n-6 PUFA摄入量不会引起任何炎症或氧化应激的迹象。PCSK9的下调可能是PUFAs降胆固醇作用的新机制。该试验在clinicaltrials.gov注册为NCT01038102。[J]中华临床医学杂志，2012;25(5):391 - 391。
Background: Replacing SFAs with vegetable PUFAs has cardiometabolic benefits, but the effects on liver fat are unknown. Increased dietary n-6 PUFAs have, however, also been proposed to promote inflammation-a yet unproven theory.Objective: We investigated the effects of PUFAs on liver fat, systemic inflammation, and metabolic disorders.Design: We randomly assigned 67 abdominally obese subjects (15% had type 2 diabetes) to a 10-wk isocaloric diet high in vegetable n-6 PUFA (PUFA diet) or SFA mainly from butter (SFA diet), without altering the macronutrient intake. Liver fat was assessed by MRI and magnetic resonance proton (1H) spectroscopy (MRS). Proprotein convertase subtilisin/kexin type-9 (PCSK9, a hepatic LDL-receptor regulator), inflammation, and adipose tissue expression of inflammatory and lipoeenic genes were determined.Results: A total of 61 subjects completed the study. Body weight modestly increased but was not different between groups. Liver fat was lower during the PUFA diet than during the SFA diet [between-group difference in relative change from baseline; 16% (MRI; P < 0.001), 34% (MRS; P = 0.02)]. PCSK9 (P = 0.001), TNF receptor-2 (P < 0.01), and IL-1 receptor antagonist (P = 0.02) concentrations were lower during the PUFA diet, whereas insulin (P = 0.06) tended to be higher during the SFA diet. In compliant subjects (defined as change in serum linoleic acid), insulin, total/HDL-cholesterol ratio, LDL cholesterol, and triglycerides were lower during the PUFA diet than during the SFA diet (P < 0.05). Adipose tissue gene expression was unchanged.Conclusions: Compared with SFA intake, n-6 PUFAs reduce liver fat and modestly improve metabolic status, without weight loss. A high n-6 PUFA intake does not cause any signs of inflammation or oxidative stress. Downregulation of PCSK9 could be a novel mechanism behind the cholesterol-lowering effects of PUFAs. This trial was registered at clinicaltrials.gov as NCT01038102. Am J Clin Nutr 2012;95:1003-12.