Comparison of diets high in monounsaturated versus polyunsaturated fatty acid on postprandial lipoproteins in diabetes

Background  

Postprandial hypertriglyceridaemia is common in diabetes. Fatty acids are regulators of gene expression and may play an important role in regulating the postprandial lipoprotein cascade.     

Omega-3多不饱和脂肪酸对脂肪代谢调节作用研究进展

肥胖是2型糖尿病、心血管病和多种癌症的危险因素，其防治形势十分严峻。Omega-3多不饱和脂肪酸（n-3 PUFA）是一种从深海鱼类中提取出来的多不饱和脂肪酸，具有显著的抗炎和降低三酰甘油的作用，但其抗肥胖作用仍有争议。在动物模型中发现，n-3 PUFA可以有效降低脂肪含量；然而人体研究却表明n-3 PUFA可能无助于减肥，但可能会减少体质量进一步增加。n-3 PUFA可通过调节肠道菌群、调节脂质代谢、抑制食欲、缓解脂肪组织炎症和表观遗传改变等机制改善与肥胖相关的代谢变化，从而在肥胖与其相关代谢性疾病的防治中发挥重要作用。     

Effects of avocado as a source of monounsaturated fatty acids on plasma lipid levels.

To examine the effects of avocado on plasma lipid concentrations, a three-diet trial involving 16 healthy volunteers was carried out. A diet rich in monounsaturated fatty acids using avocado as their major source (30% of the total energy was consumed as fat: 75% of the total fat from the avocado), with restriction of saturated fats and less than 300 mg of cholesterol per day was evaluated. Subjects also were in a free-diet period with the addition of the same amount of avocado. Finally, volunteers received a low-saturated fat diet without avocado. The first and third diets were designed to simulate a usual diet and volunteers carried on their normal activities during the trial, only the three daily meals were eaten in our clinical unit. Diets lasted 2 weeks and they were assigned in a randomized order. In both rich-monounsaturated fat (RMF) and low-saturated fat (LSF) diets, there were similar reductions in the plasma total cholesterol and low-density lipoprotein cholesterol levels. The levels of high-density lipoprotein cholesterol significantly decreased (p < 0.05) after 2 weeks of the LSF and free monounsaturated-enriched (FME) diets. The plasma triacyglycerol levels lessened after RMF and FME diets, while LSF diet increased them. In total cholesterol and in low-lipoprotein cholesterol levels, there were statistically significant differences between the FME and the LSF diet periods. Avocado is an excellent source of monounsaturated fatty acid in diets designed to avoid hyperlipidemia without the undesirable effects of low-saturated fat diets on HDL-cholesterol and triacylglycerol concentrations.     

The relationships between plasma cholesteryl polyunsaturated fatty acids, age and atherosclerosis

The ages, plasma cholesteryl dienoic acid, 2-hr blood sugar and plasma cholesterol concentrations of 146 patients with aorto-iliac and femoro-popliteal atherosclerosis, were compared with their arterial lesions classified into occlusions, irregularities and stenoses by pulses and arteriograms.     

脂蛋白对人血管内皮细胞间隙连接通讯功能的影响

The effects of HDL, LDL and ascorbic acid on cultured human vascular endothelial gap junctional intercellular communication (GJIC) were observed using fluorescence recovery after photobleaching assay under confocal laser scanning microscopy in this study. The results showed that in culture, human vascular endothelial cells could produce functional gap junctions. The fluorescence recovery rates of the LDL group were 6.691 +/- 2.634, 4.153 +/- 2.125 and 2.441 +/- 0.720 respectively; when these rates were compared with the control and with each other, significant differences were found(P < 0.05). When the fluorescence recovery rates of the HDL group and Vitamin C group were compared with the control, no significant differences were found(P > 0.05). The fluorescence recovery rates of the LDL + HDL group were 3.500 +/- 0.890, 4.339 +/- 1.126 and 5.243 +/- 1.278(n = 15) respectively, when these rates were compared with the control and with each other, significant differences were found (P < 0.05). These suggested that LDL should be able to inhibit GJIC in human vascular endothelial cells, and the inhibition could be diminished by HDL or ascorbic acid. Inhibition of vascular endothelial GJIC may be one of the atherosclerogenic mechanisms of LDL, whereas HDL and ascorbic acid may be conducive to the improvement of endothelial GJIC. But it may also be only a compensatory behavior of endothelial cells to injuries.     

The changes of plasma lipoproteins in rat with diabetes induced by streptozotocin

Summary Diabetes was induced in Wistar male rats by streptozotocin given peritoneally. The control rats received the rame volume of buffer. Twelve days after injection of streptozotocin, the levels of plasma triglyceride, total cholesterol and free fatty acid increased significantly as compared with those of the control rats. The plasma very low density lipoprotejn-choleslerol (VLDL-C) of the diabetic rats was twice as much as that of the control rats. No difference in low density lipoprotein-cholesterol (LDL-C) and high density lipoproteincholesterol (HDL-C) was found between the two groups. However, the HDL₃ in diabetic rats increased significantly. These results indicated that the degradation of VLDL was reduced in diabetic rats and concurrently the conversion of HDL3 to HDL₂ was impaired. Therefore, we are led to assume that the accumulation of VLDL remnants and the impairment of reverse transport of tissue cholesterol may facilitate the development of atherosclerosis in diabetes mellitus.     

精神分裂症患者治疗前后血浆多不饱和脂肪酸水平变化的研究

目的 研究精神分裂症患者血浆中的4种多不饱和脂肪酸(亚油酸,LA;花生四烯酸,AA;二十碳五烯酸,EPA;二十二碳六烯酸,DHA)治疗前后的变化,探讨脂肪酸代谢在精神分裂症病理生理机制中的作用.方法 以30例精神分裂症为研究对象,27名正常人群作为对照.用气相色谱仪(GC)测定其血浆中LA、AA 、EPA和DHA等4种多不饱和脂肪酸的浓度.治疗6周后重测1次.结果 抗精神病药物治疗前后,精神分裂症患者血浆中ω-6族脂肪酸LA浓度[分别是(735.86±40.48)mg/L,(783.75±29.05)mg/L]均低于正常对照组[(995.83±14.23)mg/L,(991.39±14.20)mg/L,P<0.01],而AA浓度与对照差异无显著性.ω-3族脂肪酸EPA和DHA浓度在治疗前高于对照组(P<0.05),治疗后恢复正常.结论 精神分裂症血浆中ω-3族脂肪酸EPA和DHA增多,治疗后恢复正常,支持精神分裂症的脂质过氧化假说.     

"五禽戏"对老年人血脂及血液流变学指标的影响

目的 探讨"五禽戏"对老年人健康的意义.方法 80名老年人随机分为"五禽戏"组(n=40)和对照组(n=40),对两组受试者血脂和血液流变学指标进行2年的观察比较研究.结果 "五禽戏"组血脂及血液流变学指标和对照组比较有统计学显著性差异(P<0.05、P<0.01).结论 老年人坚持"五禽戏"运动有调节脂类代谢,降低血液流变学指标的作用.     

髌下脂肪垫对全膝关节置换术后髌骨高度的影响

目的:研究保留或切除髌下脂肪垫对全膝关节置换术(total knee arthroplasty,TKA)术后髌骨高度的影响。方法:将86例骨性关节炎患者(116膝)分为A、B两组。A组为保留髌下脂肪垫组(59膝),B组为切除髌下脂肪垫组(57膝)。应用屈膝30°的侧位X线片,测量术前及术后随访时的Insall-Salvati比值以反映髌骨高度。结果:A组术前及术后随访时的Insall-Salvati比值差异无统计学意义(P>0.05),B组术前及术后随访时的Insall-Salvati比值差异有统计学意义(P<0.05)。结论:在TKA术中切除髌下脂肪垫会造成TKA术后髌骨高度下降,导致低位髌骨及髌腱短缩。     

硒对多不饱和脂肪酸负荷大鼠机体保护作用的研究

目的 :观察硒对饲添加多不饱和脂肪酸饲料大鼠全血谷胱甘肽过氧化物酶 ( GSH- Px)和脂质过氧化物 ( LPO)水平的影响。方法 :GSH- Px采用 DTNB法 ,LPO采用碘量法测定。结果 :添加多不饱和脂肪酸 ( PUFAs,50 g/kg)饲料喂养大鼠 30 d,血中 GSH- Px活性明显降低 ,同时伴有LPO含量升高。补硒后上述变化均有明显纠正。结论 :PUFAs长期负荷能够降低动物体内抗氧化能力 ,硒具有明显保护作用     

高脂饮食对兔肺动脉结构及增殖细胞核抗原表达的影响

目的 探讨高脂饮食对兔肺动脉组织形态学、平滑肌增殖和肺小动脉肌化的影响.方法 建立高脂兔模型,对肺动脉及肺组织石蜡切片进行α-smooth muscle-actin、增殖细胞核抗原(PCNA)免疫组化检查及HE染色结合形态计量分析观察肺血管重构.结果 高脂饮食组肺动脉粥样硬化面积占血管内膜面积的比值、中膜厚度、小动脉肌化比例、中膜平滑肌细胞增殖指数均明显高于对照组.结论 高脂饮食时除了肺动脉出现粥样硬化外,肺动脉平滑肌细胞增殖增加、肺血管出现重构.     

高脂饮食对兔肺动脉结构及增殖细胞核抗原表达的影响

目的 探讨高脂饮食对兔肺动脉组织形态学、平滑肌增殖和肺小动脉肌化的影响.方法 建立高脂兔模型,对肺动脉及肺组织石蜡切片进行α-smooth muscle-actin、增殖细胞核抗原(PCNA)免疫组化检查及HE染色结合形态计量分析观察肺血管重构.结果 高脂饮食组肺动脉粥样硬化面积占血管内膜面积的比值、中膜厚度、小动脉肌化比例、中膜平滑肌细胞增殖指数均明显高于对照组.结论 高脂饮食时除了肺动脉出现粥样硬化外,肺动脉平滑肌细胞增殖增加、肺血管出现重构.     

Effects of protein, monounsaturated fat, and carbohydrate intake on blood pressure and serum lipids: results of the OmniHeart randomized trial

Context  Reduced intake of saturated fat is widely recommended for prevention of cardiovascular disease. The type of macronutrient that should replace saturated fat remains uncertain. Objective  To compare the effects of 3 healthful diets, each with reduced saturated fat intake, on blood pressure and serum lipids. Design, Setting, and Participants  Randomized, 3-period, crossover feeding study (April 2003 to June 2005) conducted in Baltimore, Md, and Boston, Mass. Participants were 164 adults with prehypertension or stage 1 hypertension. Each feeding period lasted 6 weeks and body weight was kept constant. Interventions  A diet rich in carbohydrates; a diet rich in protein, about half from plant sources; and a diet rich in unsaturated fat, predominantly monounsaturated fat. Main Outcome Measures  Systolic blood pressure and low-density lipoprotein cholesterol. Results  Blood pressure, low-density lipoprotein cholesterol, and estimated coronary heart disease risk were lower on each diet compared with baseline. Compared with the carbohydrate diet, the protein diet further decreased mean systolic blood pressure by 1.4 mm Hg (P = .002) and by 3.5 mm Hg (P = .006) among those with hypertension and decreased low-density lipoprotein cholesterol by 3.3 mg/dL (0.09 mmol/L; P = .01), high-density lipoprotein cholesterol by 1.3 mg/dL (0.03 mmol/L; P = .02), and triglycerides by 15.7 mg/dL (0.18 mmol/L; P<.001). Compared with the carbohydrate diet, the unsaturated fat diet decreased systolic blood pressure by 1.3 mm Hg (P = .005) and by 2.9 mm Hg among those with hypertension (P = .02), had no significant effect on low-density lipoprotein cholesterol, increased high-density lipoprotein cholesterol by 1.1 mg/dL (0.03 mmol/L; P = .03), and lowered triglycerides by 9.6 mg/dL (0.11 mmol/L; P = .02). Compared with the carbohydrate diet, estimated 10-year coronary heart disease risk was lower and similar on the protein and unsaturated fat diets. Conclusion  In the setting of a healthful diet, partial substitution of carbohydrate with either protein or monounsaturated fat can further lower blood pressure, improve lipid levels, and reduce estimated cardiovascular risk. Clinical Trials Registration  ClinicalTrials.gov Identifier: NCT00051350.      

大豆胚轴提取物对糖尿病大鼠血浆脂蛋白脂质过氧化的影响

[目的 ]研究大豆胚轴提取物对糖尿病大鼠血浆脂蛋白脂质过氧化的影响 .[方法 ]给GK/JclⅡ型糖尿病大鼠饲喂添加 10 0g/kg大豆胚轴提取物的饲料 2 0周 ,检测其血浆脂蛋白过氧化脂质含量 .血浆极低密度脂蛋白、低密度脂蛋白和高密度脂蛋白的分离采用序列超速离心分离法 .[结果 ]长期食用大豆胚轴提取物的GK/Jcl糖尿病大鼠血浆总过氧化脂质和高密度脂蛋白过氧化脂质明显减少 ,低密度脂蛋白过氧化脂质表观水平有所下降 .[结论 ]大豆胚轴提取物显著降低糖尿病大鼠血浆总过氧化脂质和高密度脂蛋白过氧化脂质 ,对糖尿病及其并发症的发生和发展起有效的防治作用 .     

不同换药方法对肥胖患者腹部切口脂肪液化的影响

目的观察不同换药方法对肥胖患者腹部切口脂肪液化发生的影响。方法选择到我院就诊行腹部手术的肥胖患者122例,随机分为脂肪层深部探查组(A组)和常规换药组(B组)。A组在术后2～3 d进行切口脂肪层探查,发现油滴或渗液后放置纱布引流条。B组常规换药治疗。结果 A组未发生脂肪液化,B组脂肪液化发生率为25%,两组差异有统计学意义。结论脂肪层深部探查换药,发现油滴或渗液后提前放置纱布引流条能够减少肥胖患者手术切口脂肪液化的发生。     

六味地黄丸对糖尿病大鼠血糖和血脂的影响

[目的]研究六味地黄丸对糖尿病大鼠血糖和血脂的影响。[方法]Wistar大鼠尾静脉注射四氧嘧啶复制糖尿病动物模型。将成模的糖尿病大鼠按血糖和体质量随机分为糖尿病组、六味地黄丸组,同时设立正常对照组,并分别给予蒸馏水和六味地黄丸灌胃6周,每3周测量体质量1次,6周后测定空腹血糖,总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白-胆固醇(HDL-C)和低密度脂蛋白-胆固醇(LDL-C)。[结果]糖尿病组大鼠体质量下降,血糖显著升高,TC、TG、LDL-C含量显著增加,补充六味地黄丸后,体质量逐渐增加,血糖显著下降,TC、TG、LDL-C含量显著降低。[结论]六味地黄丸能增加糖尿病大鼠体质量,对其糖、脂代谢有一定的改善作用。