Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, University of Washington, Seattle, WA, USA.
Eur J Clin Nutr. 2012 Oct;66(10):1146-52. doi: 10.1038/ejcn.2012.107. Epub 2012 Aug 15.
BACKGROUND/OBJECTIVES: The effect of a low glycemic load (GL) diet on insulin-like growth factor-1 (IGF-1) concentration is still unknown but may contribute to lower chronic disease risk. We aimed to assess the impact of GL on concentrations of IGF-1 and IGF-binding protein-3 (IGFBP-3).
SUBJECTS/METHODS: We conducted a randomized, controlled crossover feeding trial in 84 overweight obese and normal weight healthy individuals using two 28-day weight-maintaining high- and low-GL diets. Measures were fasting and post-prandial concentrations of insulin, glucose, IGF-1 and IGFBP-3. In all 80 participants completed the study and 20 participants completed post-prandial testing by consuming a test breakfast at the end of each feeding period. We used paired t-tests for diet component and linear mixed models for biomarker analyses.
The 28-day low-GL diet led to 4% lower fasting concentrations of IGF-1 (10.6 ng/ml, P=0.04) and a 4% lower ratio of IGF-1/IGFBP-3 (0.24, P=0.01) compared with the high-GL diet. The low-GL test breakfast led to 43% and 27% lower mean post-prandial glucose and insulin responses, respectively; mean incremental areas under the curve for glucose and insulin, respectively, were 64.3±21.8 (mmol/l/240 min; P<0.01) and 2253±539 (μU/ml/240 min; P<0.01) lower following the low- compared with the high-GL test meal. There was no effect of GL on mean homeostasis model assessment for insulin resistance or on mean integrated post-prandial concentrations of glucose-adjusted insulin, IGF-1 or IGFBP-3. We did not observe modification of the dietary effect by adiposity.
Low-GL diets resulted in 43% and 27% lower post-prandial responses of glucose and insulin, respectively, and modestly lower fasting IGF-1 concentrations. Further intervention studies are needed to weigh the impact of dietary GL on risk for chronic disease.
背景/目的：低血糖负荷（GL）饮食对胰岛素样生长因子-1（IGF-1）浓度的影响尚不清楚，但可能有助于降低慢性疾病的风险。我们旨在评估 GL 对 IGF-1 和 IGF 结合蛋白-3（IGFBP-3）浓度的影响。
受试者/方法：我们在 84 名超重肥胖和正常体重的健康个体中进行了一项随机、对照交叉喂养试验，使用两种 28 天维持体重的高 GL 和低 GL 饮食。测量包括空腹和餐后胰岛素、血糖、IGF-1 和 IGFBP-3 浓度。在所有 80 名参与者中完成了研究，20 名参与者在每个喂养期结束时通过食用测试早餐完成了餐后测试。我们使用配对 t 检验进行饮食成分分析，使用线性混合模型进行生物标志物分析。
与高 GL 饮食相比，28 天的低 GL 饮食导致空腹 IGF-1 浓度降低 4%（10.6ng/ml，P=0.04）和 IGF-1/IGFBP-3 比值降低 4%（0.24，P=0.01）。低 GL 测试早餐导致餐后血糖和胰岛素的平均反应分别降低 43%和 27%；血糖和胰岛素的平均增量 AUC 分别降低 64.3±21.8（mmol/l/240min；P<0.01）和 2253±539（μU/ml/240min；P<0.01），与高 GL 测试餐相比。GL 对平均稳态模型评估的胰岛素抵抗或平均餐后血糖调整后的胰岛素、IGF-1 或 IGFBP-3 浓度没有影响。我们没有观察到肥胖对饮食效果的修饰作用。
低 GL 饮食导致餐后血糖和胰岛素反应分别降低 43%和 27%，空腹 IGF-1 浓度略有降低。需要进一步的干预研究来权衡膳食 GL 对慢性疾病风险的影响。
