间歇低氧暴露对高脂膳食大鼠胰岛素敏感性的影响

目的:探讨间歇低氧暴露对高脂膳食肥胖大鼠胰岛素抵抗的影响。方法:40只雄性SD大鼠随机分为普通膳食常氧组、普通膳食间歇低氧组、高脂膳食常氧组、高脂膳食间歇低氧组。普通膳食采用普通饲料,高脂膳食采用高脂饲料,间歇低氧暴露采用常压低氧方法,氧浓度控制在15.4%,每天10小时。干预6周后取材测试大鼠内脏脂肪总量、空腹血糖和胰岛素,并计算胰岛素敏感指数。结果:与普通膳食常氧组相比,高脂膳食常氧组大鼠Lee指数、内脏脂肪总量和血清胰岛素水平极显著增加而胰岛素敏感指数极显著下降(P<0.01),但普通膳食间歇低氧组大鼠Lee指数、内脏脂肪总量显著减少(P<0.05,P<0.01),胰岛素敏感指数显著升高(P<0.05);与高脂膳食常氧组比较,高脂膳食间歇低氧组大鼠Lee指数、内脏脂肪总量和胰岛素水平极显著下降(P<0.01),胰岛素敏感指数极显著提高(P<0.01)。相关性分析显示,内脏脂肪总量与胰岛素水平存在一定正相关,且胰岛素水平和胰岛素敏感指数存在高度负相关(P<0.01)。结论:体内脂肪总量增加可使血清胰岛素水平升高,胰岛素敏感性下降,而间歇低氧暴露可以减少高脂膳食大鼠体内脂肪含量,提高胰岛素敏感性,改善胰岛素抵抗。

Effect of Intermittent Hypoxic Exposure on Insulin Sensitivity of Obese Rats

Objective To explore the effect of intermittent hypoxic exposure on the insulin sensitivity of obese rats induced by high-fat diet.Methods Forty male SD rats were randomly divided into normal diet(fed with standard chow)+ normoxic group,normal diet + intermittent hypoxic exposure group,high-fat diet(fed with high-fat diet)+ normoxic group and high-fat diet + intermittent hypoxic expose group.Rats in intermittent hypoxic groups were exposed in hypoxic atmospheric(15.4% oxygen),10hrs/day.After 6 weeks intervention,visceral fat volume and serum FBG and FINS were tested,and insulin sensitivity index was calculated.Results As compared with normal diet + normoxic group,visceral fat amount,serum insulin level in high-fat diet + normoxic group decreased significantly(P < 0.01),Lee index and visceral fat volume decreased significantly(P < 0.05,P < 0.01),and insulin sensitivity index increased significantly(P < 0.05)in normal diet + intermittent hypoxic exposure group.As compared with high-fat diet + normoxic group,Lee index,visceral fat volume and serum insulin level decreased significantly(P < 0.01),insulin sensitivity index increased significantly(P < 0.01)in high-fat diet + intermittent hypoxic exposure group.Analysis showed that there were positive correlation between visceral fat volume and insulin level,and negative correlation between insulin level and insulin sensitivity index(P < 0.01).Conclusion Increase in visceral fat induces elevation of serum insulin level,and reduces insulin sensitivity,while intermittent hypoxia exposure reduces visceral fat content and increases insulin sensitivity