EFFECTS OF DIET DIFFERING IN GLYCEMIC INDEX

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 越来越多的证据表明，胰岛素抵抗、慢性亚临床炎症和血栓形成/纤溶受损在冠心病(CHD)和2型糖尿病的发生发展中起着重要作用。这些过程在以下方面尤其加速 超重/肥胖的个人。尽管非裔美国人(AA)的胰岛素抵抗、高胰岛素血症以及炎症和血栓形成/纤溶受损的某些标记物比高加索人(C)更高，但这些因素与AA更高的疾病患病率有关的可能性尚不清楚。旨在减少这些过程的早期干预可能对降低疾病风险至关重要。血糖指数(GI)和血糖负荷(GL)不同的饮食，指的是食物引起的血糖反应和伴随的胰岛素分泌，在这方面可能是有益的，因为它们可能会影响胰岛素循环和/或改善胰岛素敏感性(Si)。目前还缺乏随机对照试验来评估不同GI和GL饮食干预措施对胰岛素抵抗的影响。炎症和血栓形成/纤溶。 因此，我们建议对25名超重或肥胖的AA和C男性进行一项随机、交叉对照喂养研究，研究低GI/GL饮食和高GI/GL饮食(各4周)对这些影响的影响。本研究的目的是：1)比较只有GI和GL不同的配对日粮对 超重/肥胖男性对胰岛素敏感性(SI)、炎症标志物、血栓形成和纤溶标志物的影响；2)评估低和高GVGL饮食干预的反应是否可以通过基线胰岛素浓度和/或SI来预测；3)评估低和高GI/GL饮食干预对饱腹感的影响。 研究设计包括：1)对25名超重/肥胖的AA和C男性进行随机、交叉对照喂养研究，分别采用低GI/GL饮食和高GI/GL饮食(各4周)；2)测量基线和干预后的空腹血清胰岛素和血糖浓度。并比较低GI/GL饮食和高GI/GL饮食中的这些指标；3)测量基线和干预后的SI和急性胰岛素对葡萄糖的反应(AirG)，并比较低GI/GL饮食和高GI/GL饮食中的这些指标；4)测量基线和干预后的满足感评分，并比较低GI/GL饮食和高GI/GL饮食中的这些指标。 我们假设1)与高GI/GL饮食相比，低GI/GL饮食将导致较低的空腹胰岛素和AIR-G以及较高的Si；2)相对于高GI/GL饮食，低GI/GL饮食将导致较低的血浆炎症标志物浓度；3)相对于高GI/GL饮食，低GI/GL饮食将导致较低的血浆PAI-1和纤维蛋白原浓度；4)较高基线胰岛素浓度和/或较低SI的受试者，主要是AA，低GI/GL饮食的受试者将更多；5)低GI/GL日粮比高GI/GL日粮具有更好的营养价值。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. There is increasing evidence that insulin resistance, chronic subclinical inflammation, and Thrombosis/impaired fibrinolysis play a role in the development and progression of coronary heart disease (CHD) and type 2 diabetes mellitus. These processes are particularly accelerated in overweight/obese individuals. Although insulin resistance, hyperinsulinemia, and some markers of inflammation and thrombosis/impaired fibrinolysis are greater among African Americans (AA) compared to Caucasians (C), the possibility that these factors are related to greater disease prevalence in AA is unknown. Early intervention aimed at the reduction of these processes may be crucial for disease risk reduction. Diets differing in glycemic index (GI) and glycemic load (GL), referring to the glycemic responses induced by foods and the accompanying insulin secretion, could be beneficial in this context, because they may have an effect on circulating insulin and/or improve insulin sensitivity (Si). There is a lack of randomized, controlled trial evaluating the effects of dietary interventions differing in GI and GL on insulin resistance. inflammation, and thrombosis/fibrinolysis. Therefore, we propose to conduct a randomized, cross-over controlled feeding study of low- and high-GI/GL diets (4 weeks each) in 25 overweight or obese AA and C men to investigate these effects. The objectives of this study are 1) to compare the effects of matched diets differing only in GI and GL in overweight/obese men on insulin sensitivity (Si), markers of inflammation, and markers of thrombosis and fibrinolysis; 2) to assess whether the responses to low- and high- GVGL dietary interventions are predicted by baseline insulin concentration and/or Si; 3) to assess the effects of the low-and high-GI/GL dietary interventions on satiety. The study design includes 1) conducting a randomized, cross-over controlled feeding study of low- and high-GI/GL diets (4 weeks each) in 25 overweight/ obese AA and C men; 2) measuring baseline and post-intervention fasting serum concentrations of insulin and glucose. and comparing these in low- and high-GI/GL diets; 3) measuring baseline and post-intervention Si and the acute insulin response to glucose (AIRg), and comparing these in low- and high-GI/GL diets; 4) and measuring baseline and postintervention satiety scores, and comparing these in the low- and high-GI/GL diets. We hypothesize that 1) a low-GI/GL diet will result in lower fasting insulin and AIRg and higher Si relative to the high-GI/GL diet; 2) a low-GI/GL diet will result in lower plasma concentrations of markers of inflammation relative to the high-GI/GL diet; 3) a low GI/GL diet will result in lower plasma concentrations of PAI-1 and fibrinogen relative to the high-GI/GL diet; 4) the low-GI/GL diet will be greater in subjects with higher baseline insulin concentrations and/or lower Si, primarily AA; 5) and the low-GI/GL diet will result in greater satietv than the high-GI/GL diet.