高糖、高饱和脂肪酸及高不饱和脂肪酸饮食对老年大鼠胰岛素抵抗的影响

目的 探讨不同类型高脂肪酸及高糖饮食对老年大鼠胰岛素抵抗（IR）的影响。方法 用高不饱和脂肪酸（HUFA），高饱和脂肪酸（HSFA），高糖（HS）饲料饲养大鼠24w，观察体重（BW）、总胆固醇（TC）、甘油三酯（TG）、空腹血糖（FBG）、空腹胰岛素（FINS）、游离脂肪酸（FFA）的变化，并以正常血糖高胰岛素钳夹技术的葡萄糖输注率（GIR）对大鼠IR进行评价。结果 12w和24w GIR在不同实验组间出现显著差异（均P〈0.01），HSFA组GIR最低，24w时HUFA组、HSFA组、HS组及对照组（NC组）GIR与0w相比分别下降51.6％、52.1％、34.2％、26.4％。各实验组BW、TG、TC、FFA、FBG、FINS与NC组相比有不同程度升高，经多元回归分析，GIR与FFA、TG呈显著负相关（均P〈0.01）。结论 HUFA、HSFA和HS饮食长期摄入均可诱导大鼠IR；TG及FFA的升高与IR的形成有明显相关；随月龄增长大鼠的GIR有显著下降趋势，但饮食结构的影响更重要。

Effects of high sucrose, high saturated fatty acid and high unsaturated fatty acid diets on insulin resistance in aging rats

Objective To study the effect of high different type of fatty acid and high sucrose diet on insulin resistance(IR) in aging rats.Methods The rats fed by high saturated fatty acid,high unsaturated fatty acid and high sucrose for 24 weeks to observe the change of body weight(BW),total cholesterol(TC),triglyceride(TG),fasting blood glucose(FBG),fasting blood insulin(FINS),free fatty acid(FFA) and evaluate IR of aging rats by glucose infusion rate (GIR) of hyperinsulinemic euglycemic clamp technique.Results 1.There were significant difference in GIR among experimental groups at 12 and 24 weeks(P<0.01) with the lowest GIR in high saturated fatty acid(HSFA) group.2.The GIR decreased by 51.6%,52.1%,34.2%,26.4% at 24 weeks in high unsaturated fatty acid(HUFA) group,HSFA group,high sucrose(HS) group and normal control(NC) group respectively than that at 0 week.3.BW,TC,TG,FBG,FINS,and FFA were increased obviously in experimental groups than those in NC group.Multiple stepwise regressions showed that TG and FFA were negatively related to GIR(P<0.01).Conclusions 1. Long-term intake of HUFA,HSFA and HS diet could induce IR of aging rats.2.Increased TG and FFA could be related to the development of IR.3.GIR of aging rats might have significant descending trend with aging,especially diet composition.