摘要目的 应用频繁静脉取血法在2型糖尿病患者中对回顾性动态血糖监测系统(CGMS)的点准确度及趋势准确度进行评价.方法 2010年8月至10月共纳入11例2型糖尿病患者,应用美敦力公司GOLDTM (GMS)连续监测3d血糖,同时每天输入4次指尖血糖值进行校正.受试者在CGMS监测的3 d内随机选择1d参加连续7h的频繁静脉取血(15 min取1次),并用美国YSI STAT PlusTM葡萄糖乳酸分析仪(YSI值)进行血浆葡萄糖值的测定.应用多种统计方法和统计量来综合进行准确性评估,包括CGMS值和匹配的YSI值相比在20％和30％偏差范围内的一致率、误差栅格分析、绝对差值的相对数(ARD)、Bland-Altman分析以及趋势分析等.两变量相关分析采用Pearson相关分析.结果 11例患者共收集到319对YSI-CGMS配对数据值；与YSI值相比,88.4％ (95％ CI:0.84～0.92)的CGMS值在20％偏差范围内,96.9％的CGMS值在30％偏差范围内.Clarke误差栅格分析显示YSI-CGMS配对数据值进入A区和B区的比例分别为88％、12％,共识误差栅格分析显示进入A区和B区的比例分别为96.2％、3.8％.连续误差栅格分析显示YSI-CGMS配对数据值在准确数据区、良性错误区及错误数据区分别为94.4％、2.8％及2.8％.ARD的均值为10.5％,中位数为8.4％,Bland-Altman分析均值为0.47 mmol/L(95％ CI:- 1.90 ～3.01).趋势分析显示82.5％的两者变化率差异集中在0.06 mmol·L-1·min -1的变化范围内,只有1.7％的数据对绝对差异超过0.17 mmol·L-1·min-1.结论 无论对点时血糖还是对血糖变化趋势的反映,CGMS均有较好的准确性；但对低血糖事件进行评判时,尚需结合临床实际情况具体分析.

abstractsObjective To assess the accuracy of continuous glucose monitoring system (CGMS) in type 2 diabetic patients by frequent venous blood collection.Methods A total of 11 patients with type 2 diabetes treated from August to October 2010 were enrolled in this study.The Medtronic GOLDTM CGMS was used to monitor the continuous changes of the blood glucose levels for 3 successive days in all subjects,meanwhile the fingertip blood glucose was tested at least 4 times each day for calibration.The venous blood of the subjects was randomly collected every 15 min per hour for 7 successive hours on one day when the subjects wore the sensor,and was tested using the YSI 2300 STAT PlusTM glucose&lactate analyzer.The accuracy was comprehensively evaluated by using statistical methods including the rate of agreement between the sensor readings and the paired YSI values within ± 20％ and ± 30％ of deviations,the error grid analysis,absolute relative difference (ARD), Bland-Altman analysis and trend analysis. Correlation analysis of two variables was done with Pearson correlation analysis. Results A total of 319 paired YSI-sensor values were collected from the 11 patients.Total 88.4％ of the sensor readings (95％ CI:0.84-0.92) were within ±20％ of the YSI values,and 96.9％ within ±30％ of the YSI values.Clarke error grid analyses showed that the ratios of the YSI-sensor values in region A to region B were 88％ and 12％ ;Consensus error grid analyses showed that the ratios of the YSI-sensor values in region A to region B were 96.2％ and 3.8％ ; Continuous error grid analyses showed that the ratios of the YSI-sensor values in region of accurate reading,benign errors,erroneous reading were 94.4％,2.8％,2.8％,respectively.The mean ARD for all subjects was 10.5％ and the median ARD was 8.4％. The Bland-Altman analysis detected the mean blood glucose level of 0.47 mmol/L (95％ CI:- 1.90-3.01 mmol/L).Trend analysis revealed that 82.5％ of the difference of the rates of change between the YSI values and sensor readings occurred within the range of 0.06 mmol · L-1 · min -1,and only 1.7％ of the absolute differences of the paired values were more than 0.17 mmol · L-1 · min-1.Conclusions The CGMS has high accuracy both in monitoring the blood glucose at a specific time and reflecting the trend of changes of the blood glucose level. However,actual clinical manifestations should be taken into account for diagnosis of hypoglycemia.