Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University Medical Center, Nashville, TN, USA.
Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA.
Am J Clin Nutr. 2022 Jul 6;116(1):189-196. doi: 10.1093/ajcn/nqac047.
High glycemic index (GI) diets have been linked to elevated risk of cardiometabolic diseases. One possible underlying mechanism comes from high GI diet's potential to promote lipid peroxidation.
We aim to evaluate whether and to what extent dietary carbohydrate quality and quantity are associated with systemic levels of lipid peroxidation in females.
In this cross-sectional analysis of 2163 middle-aged women, a subset of the Shanghai Women's Health Study, we measured lipid peroxidation biomarkers F2-isoprostanes (F2-IsoPs) and its metabolite, 2,3-dinor-5,6-dihydro-15-F2t-IsoP (F2-IsoP-M), in urine. The quality of carbohydrate was defined by dietary GI, assessed using a validated FFQ via in-person interviews. A multivariable linear regression model with restricted cubic spline functions was used to evaluate the association of measured biomarkers with carbohydrate intake and dietary GI.
After adjustment for potential confounding factors such as cigarette smoking, BMI, and comorbidities, among others, we found that F2-IsoP-M concentrations were positively associated with both carbohydrate intake and dietary GI. Carbohydrate intake and dietary GI were weakly correlated (r = 0.12). When further mutually adjusted for the 2 factors, the positive association with F2-IsoP-M remained statistically significant for GI (P = 0.004) but not for carbohydrate intake (P = 0.50). Compared with those in the 10th percentile of dietary GI, fold increases (95% CI) in F2-IsoP-M concentrations for those in the 30th, 50th, 70th, and 90th percentiles were 1.03 (1.00, 1.07), 1.06 (1.01, 1.10), 1.09 (1.03, 1.14), and 1.13 (1.05, 1.21), respectively. Moreover, there appeared a threshold regarding the association between dietary GI and F2-IsoP-M concentrations, with the dose-effect slope of GI being 2.3 times greater when GI was ≥75 relative to GI <75.
This study provides evidence that the quality of dietary carbohydrate may be more important than the quantity of the intake with regard to systemic lipid peroxidation.
高血糖指数（GI）饮食与心血管代谢疾病风险增加有关。其潜在的作用机制之一可能是高 GI 饮食促进脂质过氧化。
我们旨在评估女性膳食碳水化合物的质量和数量与全身脂质过氧化水平之间是否存在关联，以及关联程度如何。
在这项对 2163 名中年女性（上海女性健康研究的一部分）的横断面分析中，我们测量了尿液中的脂质过氧化生物标志物 F2-异前列腺素（F2-IsoPs）及其代谢产物 2,3-二去氢-5,6-二氢-15-F2t-异前列腺素（F2-IsoP-M）。通过面对面访谈使用经过验证的 FFQ 评估饮食 GI，以此来定义碳水化合物质量。使用受限立方样条函数的多变量线性回归模型来评估生物标志物与碳水化合物摄入量和饮食 GI 之间的关联。
在调整了其他潜在混杂因素（如吸烟、BMI 和合并症等）后，我们发现 F2-IsoP-M 浓度与碳水化合物摄入量和饮食 GI 均呈正相关。碳水化合物摄入量和饮食 GI 之间呈弱相关（r=0.12）。当进一步相互调整这 2 个因素时，GI 与 F2-IsoP-M 之间的正相关仍具有统计学意义（P=0.004），而碳水化合物摄入量则没有统计学意义（P=0.50）。与饮食 GI 处于第 10 百分位数的女性相比，饮食 GI 处于第 30、50、70 和 90 百分位数的女性 F2-IsoP-M 浓度的 fold increase（95% CI）分别为 1.03（1.00，1.07）、1.06（1.01，1.10）、1.09（1.03，1.14）和 1.13（1.05，1.21）。此外，饮食 GI 与 F2-IsoP-M 浓度之间的关联似乎存在一个阈值，当 GI≥75 时，GI 的剂量-效应斜率比 GI<75 时高 2.3 倍。
本研究提供的证据表明，饮食碳水化合物的质量可能比摄入量更为重要，与全身脂质过氧化有关。
