Piché M E, Lemieux S, Pérusse L, Weisnagel S J
Department of Food Science and Nutrition, Laval University, Québec City, QC, Canada.
Diabetologia. 2005 Apr;48(4):732-40. doi: 10.1007/s00125-005-1701-y. Epub 2005 Mar 12.
AIMS/HYPOTHESIS: The aim of this study was to evaluate differences in insulin sensitivity, insulin secretion and risk factors for cardiovascular disease between subjects with a 2-h plasma glucose (2hPG) level within the normal range (NPG) and subjects with IGT, following a 75-g OGTT. We also aimed to determine the respective contributions made by 2hPG and fasting plasma glucose to the metabolic risk profile.
We compared cardiovascular risk factors and insulin sensitivity and insulin secretion by using several indices calculated using measurements obtained during an OGTT. Subjects (n=643, age 18-71 years) were participants in the Quebec Family Study and were categorised according to 2hPG as having low NPG (2hPG <5.6 mmol/l, the group median for normal values), high NPG (2hPG 5.6-7.7 mmol/l) or IGT (2hPG 7.8-11.0 mmol/l). Subjects with type 2 diabetes were excluded from all analyses.
Beta cell function and insulin sensitivity progressively decreased with increasing 2hPG. Compared with subjects with low NPG, subjects with high NPG were more insulin-resistant (p<0.05) and had reduced insulin secretion (adjusted for insulin resistance) (p<0.001). They also had higher plasma triglyceride concentrations (p<0.01) and cholesterol:HDL cholesterol ratios (p<0.05). These differences remained even after adjustment for age, sex, BMI and waist circumference. Multivariate analyses showed that 2hPG was closely associated with risk factors for diabetes and with cardiovascular variables, including triglycerides (p<0.0001) and apolipoprotein B (p<0.01).
CONCLUSIONS/INTERPRETATION: These results show that deteriorations in glucose-insulin metabolism, which may predispose individuals to type 2 diabetes and cardiovascular disease, are already present in subjects with 2hPG concentrations within the high normal range. Independently of obesity, 2hPG was found to explain, in part, the variance observed in cardiovascular and diabetes risk factors. In addition, elevated 2hPG was associated with metabolic alterations that appear to be the most detrimental to metabolic health. Thus, 2hPG values within the high normal range may be an important marker for the identification of people at risk of complications related to type 2 diabetes.
目的/假设：本研究旨在评估口服75克葡萄糖耐量试验（OGTT）后，2小时血浆葡萄糖（2hPG）水平在正常范围内（NPG）的受试者与糖耐量受损（IGT）受试者之间胰岛素敏感性、胰岛素分泌及心血管疾病风险因素的差异。我们还旨在确定2hPG和空腹血糖对代谢风险谱的各自贡献。
我们通过使用根据OGTT期间获得的测量值计算的几个指标，比较心血管风险因素、胰岛素敏感性和胰岛素分泌。受试者（n = 643，年龄18 - 71岁）为魁北克家庭研究的参与者，根据2hPG分为低NPG（2hPG < 5.6 mmol/L，正常值组中位数）、高NPG（2hPG 5.6 - 7.7 mmol/L）或IGT（2hPG 7.8 - 11.0 mmol/L）。所有分析均排除2型糖尿病患者。
随着2hPG升高，β细胞功能和胰岛素敏感性逐渐降低。与低NPG受试者相比，高NPG受试者胰岛素抵抗更强（p < 0.05），胰岛素分泌减少（校正胰岛素抵抗后）（p < 0.001）。他们的血浆甘油三酯浓度也更高（p < 0.01），胆固醇与高密度脂蛋白胆固醇比值更高（p < 0.05）。即使在调整年龄、性别、体重指数和腰围后，这些差异仍然存在。多变量分析表明，2hPG与糖尿病风险因素以及心血管变量密切相关，包括甘油三酯（p < 0.0001）和载脂蛋白B（p < 0.01）。
结论/解读：这些结果表明，在2hPG浓度处于高正常范围的受试者中，已经存在葡萄糖 - 胰岛素代谢的恶化，这可能使个体易患2型糖尿病和心血管疾病。独立于肥胖因素，发现2hPG部分解释了在心血管和糖尿病风险因素中观察到的差异。此外，升高的2hPG与似乎对代谢健康最有害的代谢改变相关。因此，高正常范围内的2hPG值可能是识别有2型糖尿病相关并发症风险人群的重要标志物。
