Creighton University School of Medicine, Omaha, NE 68124, USA.
Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
Nutrients. 2022 Feb 19;14(4):887. doi: 10.3390/nu14040887.
The glycemic index (GI) reflects the relative ability of carbohydrates to raise blood glucose. We utilized a controlled feeding study to assess the impact of the dietary GI on β-cell function in adults with prediabetes (17F/18M, mean ± SEM: BMI 32.44 ± 0.94 kg/m, age 54.2 ± 1.57 years). Following a 2 week Control diet (GI = 55-58), participants were randomized to either a 4 week low GI (LGI: GI < 35, n = 17) or high GI (HGI: GI > 70, n = 18) diet (55% of energy from carbohydrate/30% fat/15% protein). The data from 4 h meal tolerance tests (MTTs) underwent mathematical modeling to assess insulin sensitivity, insulin secretion and β-cell function. Glucose concentrations during the MTT decreased on the LGI diet ( < 0.001) and trended to increase on the HGI diet ( = 0.14; LGI vs. HGI < 0.001), with parallel changes in insulin and C-peptide concentrations. Total insulin secretion, adjusted for glucose and insulin sensitivity, increased on the LGI diet ( = 0.002), and trended lower on the HGI diet ( = 0.10; LGI vs. HGI = 0.001). There was no significant diet effect on insulin sensitivity or other measures of β-cell function. Total insulin clearance increased on the LGI diet ( = 0.01; LGI vs. HGI < 0.001). We conclude that short-term consumption of an LGI diet reduced glucose exposure and insulin secretion but had no impact on measures of β-cell function.
血糖生成指数（GI）反映了碳水化合物升高血糖的相对能力。我们采用控制喂养研究来评估饮食 GI 对糖尿病前期成年人（17F/18M，平均值±SEM：BMI 32.44±0.94kg/m，年龄 54.2±1.57 岁）β细胞功能的影响。在为期 2 周的对照饮食（GI=55-58）后，参与者被随机分为低 GI（LGI：GI<35，n=17）或高 GI（HGI：GI>70，n=18）饮食组（55%的能量来自碳水化合物/30%脂肪/15%蛋白质）。4 小时进餐耐量试验（MTT）的数据进行了数学建模，以评估胰岛素敏感性、胰岛素分泌和β细胞功能。MTT 期间的血糖浓度在 LGI 饮食时降低（<0.001），在 HGI 饮食时呈上升趋势（=0.14；LGI 与 HGI 相比<0.001），同时胰岛素和 C 肽浓度也发生了平行变化。校正葡萄糖和胰岛素敏感性后，总胰岛素分泌在 LGI 饮食时增加（=0.002），在 HGI 饮食时呈下降趋势（=0.10；LGI 与 HGI 相比=0.001）。饮食对胰岛素敏感性或其他β细胞功能指标均无显著影响。LGI 饮食使总胰岛素清除率增加（=0.01；LGI 与 HGI 相比<0.001）。我们的结论是，短期摄入低 GI 饮食可降低血糖暴露和胰岛素分泌，但对β细胞功能的测量没有影响。
