Abdul-Ghani Muhammad, DeFronzo Ralph A, Jayyousi Amin
aDivision of Diabetes, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA bDepartment of Medicine, Diabetes and Obesity Clinical Research Center, Hamad General Hospital, Doha, Qatar.
Curr Opin Clin Nutr Metab Care. 2016 Sep;19(5):394-399. doi: 10.1097/MCO.0000000000000307.
The purpose of this review is to summarize the distinct metabolic and pathophysiologic phenotype of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) and the subsequent clinical implications with regard to future type 2 diabetes mellitus (T2DM) and cardiovascular risk.
Both IFG and IGT manifest the two core defects of T2DM, that is, insulin resistance and β-cell dysfunction. However, the site of insulin resistance and shape of β-cell dysfunction differ. These distinct metabolic and pathophysiologic phenotypes explain the greater cardiovascular disease (CVD) risk associated with an increase in the 2-h plasma glucose concentration, that is, IGT compared with an increase in the fasting plasma glucose (FPG) concentration, that is, IFG. Moreover, the increase in future T2DM risk in IFG study participants is, at least in part, explained by the strong correlation between the increase in FPG and the increase in 2-h plasma glucose concentration.
Last, recent studies have reported the presence of diabetic microvascular complications, that is, retinopathy and neuropathy, at the IGT stage.Thus, a glucose load (e.g. oral glucose tolerance test) is required in study participants with elevated FPG concentration to accurately assess their future risk for T2DM, as well as their risk for CVD to identify the subgroup of IFG who are at greater risk and subject them to an intervention program to decrease their future T2DM and CVD risk.
本综述旨在总结空腹血糖受损（IFG）和糖耐量受损（IGT）独特的代谢和病理生理表型，以及其对未来2型糖尿病（T2DM）和心血管疾病风险的临床意义。
IFG和IGT均表现出T2DM的两个核心缺陷，即胰岛素抵抗和β细胞功能障碍。然而，胰岛素抵抗的部位和β细胞功能障碍的形式有所不同。这些独特的代谢和病理生理表型解释了与2小时血浆葡萄糖浓度升高（即IGT）相关的心血管疾病（CVD）风险高于空腹血糖（FPG）浓度升高（即IFG）。此外，IFG研究参与者未来发生T2DM风险的增加，至少部分可由FPG升高与2小时血浆葡萄糖浓度升高之间的强相关性来解释。
最后，最近的研究报告了IGT阶段存在糖尿病微血管并发症，即视网膜病变和神经病变。因此，对于FPG浓度升高的研究参与者，需要进行葡萄糖负荷试验（如口服葡萄糖耐量试验），以准确评估他们未来患T2DM的风险以及心血管疾病风险，从而识别出风险更高的IFG亚组，并让他们接受干预计划，以降低其未来患T2DM和心血管疾病的风险。
