动态血糖监测的准确性评估及相关因素分析

Assessment of the Accuracy of Continuous Glucose Monitoring and Its Correlated Factors

目的评价2型糖尿病(type 2diabetes mellitus,T2DM)患者动态血糖监测(continuous glucosemonitoring,CGM)的准确性及其相关因素。方法 2009年1月～2010年1月共纳入患者530例,其中口服降糖药治疗者和胰岛素强化治疗者各265例。应用动态血糖监测系统(美国Medtronic MiniMed公司)连续监测3d,同时每天输入4次指尖血糖值(self-monitoring of blood glucose,SMBG)进行校正。用直线回归分析CGM值与SMBG的相关性,用Clarke误差表格分析一致性,用平均绝对差(mean absolute relative difference,MAD)评价准确性,并分析MAD的相关因素。结果①共收集到6 350对CGM值[(9.66±3.54)mmol/L]与SMBG值[(9.64±3.38)mmol/L],两者差异无统计学意义(P>0.05)。Pearson相关性分析显示,两者呈正相关(r=0.959,P<0.001)。②Clarke误差表格分析显示:99.89%的点位于A区和B区,其中92.37%血糖值位于A区,7.72%位于B区,其余7对(0.11%)位于D区。③总体MAD值为7.2%(5.5%～9.5%),通过分析每天的MAD值见到,随着监测时间的延长,CGM结果的MAD值逐渐降低,而准确性逐渐升高。④胰岛素强化治疗组患者MAD值高于口服药治疗组患者(P<0.05),多元逐步回归分析显示,MAD值与糖化血清白蛋白水平呈独立负相关(β=-0.134,P<0.01),与胰岛素强化治疗呈独立正相关(β=0.117,P<0.05)。结论①动态血糖与毛细血管血糖具有良好的相关性、一致性及准确性。②CGM结果的准确性除了受监测时间的影响外,还可能与患者的降糖治疗方案有关。

Objective To assess the accuracy of continuous glucose monitoring（CGM） for patients with type 2 diabetes mellitus（T2DM）,and its correlated factors.Methods From January 2009 to January 2010,530 patients with T2DM were enrolled in this study,including 265 subjects taking oral hypoglycemic agents and the other 265 subjects taking intensive insulin treatment.All the subjects underwent CGM（American Medtronic MiniMed） for three days.Meanwhile,capillary glucose values through self-monitoring of blood glucose（SMBG） were inputted four times a day for adjustment.The correlation of CGM value and capillary glucose value was analyzed by linear regression method.The consistency was analyzed by Clarke error grid.Mean absolute relative difference（MAD） was used to assess accuracy and correlated factors of MAD were also analyzed.Results ① A total of 6 350 pairs of CGM and SMBG values were collected [（9.66±3.54） mmol/L vs.（9.64±3.38） mmol/L,P0.05].Pearson correlation analysis showed that CGM value was positively correlated with SMBG value（r=0.959,P0.001）.② Clarke error grid demonstrated that 99.89% of paired SMBG-CGM values were located in zone A and zone B and the remaining seven pairs（0.11%） of glucose values were located in zone D.③ The overall MAD value was 7.2%（5.5%-9.5%）.According to the analysis of daily MAD value,MAD value decreased,while accuracy elevated gradually with monitoring time.④ MAD value of intensive insulin treatment group was higher than that of the oral hypoglycemic agent treatment group（P0.05）.And stepwise multiple regression analysis indicated that MAD value had negative correlation with glycated albumin level（β=-0.134,P0.01） and positive correlation with intensive insulin treatment（β= 0.117,P0.05）.Conclusions ① The results of CGM are accurate,and have good correlation and consistency with capillary glucose.② Besides monitoring time,the accuracy of continuous glucose monitoring may be also associated with hypoglycemic treatment strategy.