Quality Assessment of Euglycemic Glucose Clamp Test

  Objective  To explorethe quality of euglycemic glucose clamptest performed in the West China Hospital from 2014 to 2017 and to evaluate whether the quality control indexes are suitable for the quality assessment of the clamp test.

  Methods  The data collected from 80 euglycemic glucose clamp tests performed between 2014 and2017 were divided into 4 groups according to the coefficient of variation of the blood glucose concentrations (CVBG): group A (CVBG≤4.5%), group B (4.5% < CVBG≤5.0%), group C (5.0% < CVBG≤5.5%) and group D(CVBG > 5.5%).The differences in percentage of glucose excursion from target range (GEFTR), the duration of GEFTR, the area under curve (AUC) of GEFTR, the mean value of excursion from target glucose (GEFT) and the AUC of GEFT were calculated and compared.

  Results  In group A, the mean value of CVBG was 3.75%. In group B, the mean value of CVBG was 4.76%. In group C, the mean value of CVBG was 5.28%. The median value of CVBG in group D was 6.07%. The percentage of GEFTR, the duration of GEFTR, the AUC of GEFTR, the mean value of GEFT and the AUC of GEFT in group A were all less than those of other groups (P < 0.05).For the same indexes, there were no significant differences between group B and C, while they were higher in group D compared with the other three groups. CVBG was positively correlated with other quality control indexes (correlation coefficient r was 0.770-0.805). Based on the cut-off point 5% of CVBG, the cut-off points of the percentage of GEFTR, the duration of GEFTR, the AUC of GEFTR, the mean value of GEFT and the AUC of GEFT were 5.8%, 14.6 min, 22.82 mg/dL×min, 3.23 mg/dL, 216.25 mg/dL×min/h respectively, with the sensitivity range from 79.3% to 100% and the specificity range from 74.5% to 89.7%.Combined with these indexes, 8.11% of euglycemic clamps were found to havepoor quality in group A, while 66.67% of euglycemic clamps showed acceptable quality in group C.

  Conclusion  The investigators should provide an estimation of the quality of the clamps when reporting the results of the insulin analogues' PK/PD characteristics using euglycemic clamps. CVBG less than 4.5% indicates a good quality, and the above-mentioned quality control indexes especially the AUC of GEFT(cut-off point: 216.25 mg·/dL×min/h) should be evaluated when CVBG is more than 4.5%.False high quality and false low quality euglycemic clamps will be detected and a more precise estimation of quality assessment should be made by the combination of these indexes.