Huang Zhiliang, Wang Baowu, Pace Ralphenia D, Yoon Seokjoo
Department of Food and Nutritional Sciences, Tuskegee University, Tuskegee, AL 36088, USA.
Nutr Res. 2009 Mar;29(3):206-12. doi: 10.1016/j.nutres.2009.01.008.
Epidemiologic studies have demonstrated that trans fat intake increases the risk of some chronic diseases. We hypothesize that trans fat intake would increase the risk of cardiovascular disease and type 2 diabetes mellitus by changing the lipid profile in plasma, the secretion of adipokines in adipose tissue, and the insulin sensitivity. Accordingly, the major objective of present study was to investigate the effect of dietary intake of trans fat on lipid profile, insulin sensitivity, and adipokine levels in plasma. Two groups of Wistar rats were fed a diet containing 4.5% trans fat or a control diet containing no trans fat for 16 weeks. Fasting glucose level was monitored every 2 weeks. At the end of feeding experiment, blood, heart, kidney, liver, omental adipose tissue, and semitendinosus muscle were collected. The trans fat content in organs, lipid profile, adipokine, insulin, and glucose levels in plasma were analyzed. The trans fat content in adipose tissue, heart, kidney, liver, and muscle of rats fed trans fat were 169.9, 0.6, 1.2, 1.7, and 2.5 mg/g samples, respectively. The trans fat content in these organs contributed to 15.9%, 1.2%, 2.3%, 4.3%, and 6.1% of the total fat, respectively. The plasma glucose level, insulin level, and insulin sensitivity index were not significantly different between the trans fat and control groups. The results indicated that trans fat intake might not be related to insulin resistance. However, lipid profile and plasma adipokine levels were significantly changed after trans fat feeding. The trans fat fed group showed significantly lower total cholesterol and high-density lipoprotein cholesterol levels than the control group. The decreased high-density lipoprotein cholesterol level may indicate the detrimental effect of trans fat intake on lipid profile. Adiponectin and resistin levels were significantly higher in the trans fat group than the control group. Leptin levels were significantly lower in the trans fat group than the control group. The results indicated that dietary intake of trans fat can significantly change the adipokine levels, but the possible links between adipokine level change caused by trans fat intake and metabolic effects of this change need further investigations.
流行病学研究表明，反式脂肪的摄入会增加某些慢性疾病的风险。我们推测，反式脂肪的摄入会通过改变血浆中的脂质谱、脂肪组织中脂肪因子的分泌以及胰岛素敏感性，从而增加心血管疾病和2型糖尿病的风险。因此，本研究的主要目的是调查饮食中反式脂肪的摄入对血浆脂质谱、胰岛素敏感性和脂肪因子水平的影响。将两组Wistar大鼠分别喂食含4.5%反式脂肪的饮食或不含反式脂肪的对照饮食，持续16周。每2周监测一次空腹血糖水平。在喂养实验结束时，收集血液、心脏、肾脏、肝脏、网膜脂肪组织和半腱肌。分析器官中的反式脂肪含量、脂质谱、脂肪因子、胰岛素和血浆中的葡萄糖水平。喂食反式脂肪的大鼠的脂肪组织、心脏、肾脏、肝脏和肌肉中的反式脂肪含量分别为169.9、0.6、1.2、1.7和2.5毫克/克样本。这些器官中的反式脂肪含量分别占总脂肪的15.9%、1.2%、2.3%、4.3%和6.1%。反式脂肪组和对照组之间的血浆葡萄糖水平、胰岛素水平和胰岛素敏感性指数没有显著差异。结果表明，反式脂肪的摄入可能与胰岛素抵抗无关。然而，喂食反式脂肪后，脂质谱和血浆脂肪因子水平发生了显著变化。反式脂肪喂养组的总胆固醇和高密度脂蛋白胆固醇水平显著低于对照组。高密度脂蛋白胆固醇水平的降低可能表明反式脂肪摄入对脂质谱有不利影响。反式脂肪组中的脂联素和抵抗素水平显著高于对照组。反式脂肪组中的瘦素水平显著低于对照组。结果表明，饮食中反式脂肪的摄入可显著改变脂肪因子水平，但反式脂肪摄入引起的脂肪因子水平变化与这种变化的代谢效应之间的可能联系需要进一步研究。
