抗性淀粉的代谢及对血糖的调节作用

目的 :　利用天然稳定同位素技术 ,探讨抗性淀粉吸收代谢的特点及对血糖调节的影响。方法 :　 7名健康志愿者分别试食 40 g天然富1 3C的葡萄糖、可消化淀粉 ( DS)和抗性淀粉( RS) ,测定餐后 0～ 2 40 min血糖 ,1 3C-血糖、血胰岛素水平和餐后 3 0 h呼气中1 3CO2 转化率及累积转化率。结果 :　食用 RS后 ,血糖和 1 3C-血糖水平明显低于食用葡萄糖和 DS;以葡萄糖餐后 1 2 0min的血糖生成指数 ( GI)和 1 3C-GI为 1 0 0 % ,RS的 GI值和 1 3C-GI值分别为 2 3 .5 8%和 5 5 .5 6% ;RS餐后呼气中1 3CO2 转化率的峰值明显低于葡萄糖和 DS( P<0 .0 5 ) ,但是 3 0 h累积转化率可达94.0 % ,与葡萄糖 ( 96.9% )和 DS( 1 0 2 .0 % )接近 ( P>0 .0 5 ) ;RS使餐后胰岛素升高幅度、胰岛素 /葡萄糖比值明显低于葡萄糖和 DS( P<0 .0 5 )。结论 :　抗性淀粉吸收缓慢但较完全 ,与葡萄糖和DS相比 ,具有维持餐后血糖稳态 ,提高机体胰岛素敏感性的作用

METABOLISM OF RESISTANT STARCH AND ITS REGULATIVE EFFECT ON PLASMA GLUCOSE

Objective: The metabolic characteristics of resistant starch and its regulative effect on glucose response were studied by native stable isotope technique. Methods: Seven healthy volunteers repeatedly consumed a meal containing 40 g native 13 C riched glucose, digestible starch (DS), or resistant starch (RS). Blood samples from postprandial zero to 240 min were collected for measurement of glucose, 13 C glucose and insulin. Breath samples (0-30 h) were collected to analyze 13 C fractional and accumulative conversion. Results: Both plasma glucose and 13 C glucose were significantly lower after RS consumption than after glucose and DS. Mean glycemic index (GI) and 13 C GI of RS at 120 min were 23.58% and 55.56% respectively. The peak of 13 C fractional conversion in breath was lower after RS than after glucose and DS (P<0.05), whereas the 13 C accumulative conversion at 30 h (94.0%) was similar to DS (102.0%) and glucose (96.9%). Postprandial insulin excretion and the ratio of insulin/glucose after RS were decreased compared with glucose (P<0.05). No significant difference was found between DS and glucose (P>0.05). Conclusion: RS could be characteristically slowly but completely absorbed, that was different from digestible starch and glucose. RS has potential benefit in sustaining blood glucose status, and improving insulin sensitivity.nd1 3C-glucose were sign