Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.
Acta Diabetol. 2012 Oct;49(5):341-8. doi: 10.1007/s00592-011-0298-5. Epub 2011 May 27.
The aim of this study is to determine safe fasting plasma glucose (FPG) levels. We included data on 5,960 individuals aged ≥20 years at baseline with at least one follow-up examination. Diabetes was ascertained in accordance with American Diabetes Association criteria, using standard 2-h post-challenge plasma glucose test. Multivariate restricted cubic splines Weibull regression was implemented for interval-censored survival data on incident diabetes. We used Harrell's C statistic for discrimination, Nam-D'Agostino χ(2) for calibration, and Royston's R(2) for variations in the outcome explained by models. During a 6-year median follow-up, 369 incident cases of diabetes were ascertained. Family history of diabetes, systolic blood pressure, waist-to-height ratio, and triglyceride-to-high-density lipoprotein cholesterol ratio, independent of FPG and each other remained associated with incident diabetes. The cubic splines model achieved good calibration (χ(2) = 12.1) and discrimination (C = 0.828) and explained 75% of variation in the time until incident diabetes. A J-shaped FPG-diabetes relationship was observed. Descending arm of the dose-response relationship curve corresponded to increasing FPG levels up to 4.0 mmol l(-1), where it started increasing. The risk of incident diabetes decreased with decreasing levels of FPG down to 4.0 mmol l(-1), where the risk stopped decreasing. Multivariate-adjusted risk of incident diabetes was zero at FPG = 5.05 mmol l(-1). Although currently there is no firm evidence to show that early intervention among individuals with the elevated FPG levels could prevent or delay onset of diabetes, individuals with FPG levels below 5.05 mmol l(-1) could be safely reassured about their near-term risk of developing incident diabetes and screened on a less frequent basis.
本研究旨在确定安全的空腹血糖（FPG）水平。我们纳入了基线时年龄≥20 岁且至少有一次随访检查的 5960 名个体的数据。糖尿病的确定符合美国糖尿病协会的标准，使用标准的 2 小时餐后血浆葡萄糖试验。对于糖尿病发病的间隔 censored 生存数据，采用多变量限制立方样条 Weibull 回归。我们使用 Harrell 的 C 统计量进行区分，Nam-D'Agostino χ(2)进行校准，以及 Royston 的 R(2)来解释模型对结果的变异。在 6 年的中位随访期间，确定了 369 例新发糖尿病病例。糖尿病家族史、收缩压、腰高比和三酰甘油与高密度脂蛋白胆固醇比值，独立于 FPG 且彼此之间仍然与新发糖尿病相关。立方样条模型具有良好的校准（χ(2) = 12.1）和区分（C = 0.828），并解释了新发糖尿病时间的 75%的变异。观察到 FPG-糖尿病关系呈 J 形。剂量反应关系曲线的下降臂对应于 FPG 水平升高至 4.0mmol/L，在此处开始升高。随着 FPG 水平降低到 4.0mmol/L，新发糖尿病的风险降低，在此处风险停止降低。在 FPG = 5.05mmol/L 时，多变量调整后的新发糖尿病风险为零。虽然目前没有确凿的证据表明早期干预 FPG 水平升高的个体可以预防或延迟糖尿病的发病，但 FPG 水平低于 5.05mmol/L 的个体可以放心，他们在近期内发生新发糖尿病的风险较低，并且可以更不频繁地进行筛查。
