Fayolle C, Brun J F, Bringer J, Mercier J, Renard E
Département de Physiologie Clinique (CERAMM), Hôpital Lapeyronie, Montpellier, France.
Diabetes Metab. 2006 Sep;32(4):313-20. doi: 10.1016/s1262-3636(07)70285-9.
The GlucoDay allows continuous glucose monitoring by subcutaneous microdialysis in sedentary conditions. To validate it when glycaemia may undergo rapid and dramatic changes, we investigated its accuracy during two exercise sessions with markedly different glucose disposal rates.
Nine male diabetic patients, aged 32-61, treated by insulin pumps, first underwent a standard maximal exercise-test designed for determining the maximal oxygen consumption and the first ventilatory threshold (Vt1). Then two 30 min steady-state workloads at 15% below and 15% above the Vt1 were performed in random order with the GlucoDay, and measurement of CHO oxidation rates was made by indirect calorimetry.
CHO oxidation during exercise at +15% Vt1 was higher (+943.5 mg/min, ie +45.5%, P<0.01) than during exercise at -15% Vt1 No hypoglycaemia occurred. Due to breakages of 39% of subcutaneous probes, eleven steady-state sessions in 7 subjects allowed to compare 141 paired glucose (sensor vs. venous) determinations. The Clarke error grid situates 92.9% of glucose values within the A zone and 6.4% within the B zone, while only one pair of values (0.7%) falls in the D zone. Venous glucose tended to decrease more rapidly than sensor glucose during exercise. Bland-Altman plots evidence for a few cases of underestimation of venous glucose at high intensity.
This study showed satisfactory accuracy of the GlucoDay during exercise. A slight lag time in sensor values likely explains a few discrepancies that do not appear as clinically meaningful. Reduction of probe fragility and confirmed sensor accuracy in hypoglycaemia would further support applicability of GlucoDay at exercise.
GlucoDay可在静息状态下通过皮下微透析进行连续血糖监测。为了验证其在血糖可能发生快速剧烈变化时的准确性，我们在两次葡萄糖处置率明显不同的运动期间研究了其准确性。
9名年龄在32 - 61岁之间、接受胰岛素泵治疗的男性糖尿病患者，首先进行一项标准的最大运动试验，以确定最大耗氧量和第一通气阈值（Vt1）。然后使用GlucoDay以随机顺序进行两次30分钟的稳态工作量运动，一次低于Vt1 15%，另一次高于Vt1 15%，并通过间接量热法测量碳水化合物氧化率。
在高于Vt1 15%的运动期间碳水化合物氧化量更高（+943.5毫克/分钟，即+45.5%，P<0.01），高于低于Vt1 15%的运动期间。未发生低血糖。由于39%的皮下探头出现故障，7名受试者的11次稳态运动期间的测定结果可用于比较141对葡萄糖（传感器与静脉血）测定值。克拉克误差网格显示92.9%的葡萄糖值位于A区，6.4%位于B区，而只有一对值（0.7%）落在D区。运动期间静脉血糖往往比传感器血糖下降得更快。布兰德 - 奥特曼图表明在高强度时有少数情况下静脉血糖被低估。
本研究表明GlucoDay在运动期间具有令人满意的准确性。传感器值的轻微滞后时间可能解释了一些差异，这些差异在临床上似乎并无意义。降低探头易碎性并在低血糖时确认传感器准确性将进一步支持GlucoDay在运动中的适用性。
