Carnevale Schianca Gian Piero, Rossi Antonello, Sainaghi Pier Paolo, Maduli Elisabetta, Bartoli Ettore
Dipartimento di Scienze Mediche (Internal Medicine), Università del Piemonte Orientale A. Avogadro, Novara, Italy.
Diabetes Care. 2003 May;26(5):1333-7. doi: 10.2337/diacare.26.5.1333.
The American Diabetes Association recommended substituting 2hBS (glycemia at the second hour of an oral glucose tolerance test [OGTT]) for fasting blood glucose (FBS) in screening for glucose intolerance. It is debated whether these tests measure the same abnormality and relate to defective insulin secretion or resistance. This study examines the diagnostic effectiveness of FBS versus 2hBS and their relationship with insulin secretion and resistance.
Based on history or physical findings suggesting glucose intolerance, we enrolled 398 unselected subjects admitted to a general Internal Medicine ward. After 5 days of a weight-maintaining diet, FBS, 2hBS, and insulin were measured during OGTT. The homeostatic model assessment was used to assess beta-cell function and insulin resistance.
Excluding 19 patients with diabetes (5%), we identified 284 subjects with normal glucose tolerance (NGT), 22 with isolated impaired fasting glucose (IFG), 59 with isolated impaired glucose tolerance (IGT), and 14 with associated IFG/IGT. The sensitivity of FBS in predicting 2hBS was 19%, specificity 93%. Positive and negative predictive values were 39% and 83%, respectively. Insulin resistance was absent in NGT and IFG and markedly elevated in IGT and IFG/IGT, whereas defective insulin release was significant only in isolated IFG.
In unselected patients, elevated FBS depends primarily on defective insulin secretion, and impaired 2hBS on insulin resistance. Because these tests measure different alterations, they are useful in combination.
美国糖尿病协会建议在筛查葡萄糖耐量异常时，用口服葡萄糖耐量试验（OGTT）2小时血糖（2hBS）替代空腹血糖（FBS）。关于这些检测是否测量相同的异常情况以及与胰岛素分泌缺陷或抵抗的关系仍存在争议。本研究探讨了FBS与2hBS的诊断效能及其与胰岛素分泌和抵抗的关系。
基于提示葡萄糖耐量异常的病史或体格检查结果，我们纳入了398名入住普通内科病房的未经过筛选的受试者。在维持体重饮食5天后，在OGTT期间测量FBS、2hBS和胰岛素。采用稳态模型评估来评估β细胞功能和胰岛素抵抗。
排除19例糖尿病患者（5%）后，我们确定了284例葡萄糖耐量正常（NGT）的受试者、22例单纯空腹血糖受损（IFG）的受试者、59例单纯糖耐量受损（IGT）的受试者以及14例合并IFG/IGT的受试者。FBS预测2hBS的敏感性为19%，特异性为93%。阳性预测值和阴性预测值分别为39%和83%。NGT和IFG中不存在胰岛素抵抗，而IGT和IFG/IGT中胰岛素抵抗明显升高，而仅在单纯IFG中胰岛素释放缺陷显著。
在未经过筛选的患者中，FBS升高主要取决于胰岛素分泌缺陷，而2hBS受损则取决于胰岛素抵抗。由于这些检测测量的是不同的改变，因此联合使用它们很有用。
