Capillary glucose concentration during oral glucose tolerance test for the diagnosis of gestational diabetes.

OBJECTIVE

To assess concordance between two point-of-care testing (POCT) devices and the standard laboratory method in screening for gestational diabetes mellitus (GDM) in Huesca.

METHODS

Pregnant women who met criteria for an oral glucose tolerance test (OGTT) and attended the laboratory between October 2017 and November 2018 were recruited in this prospective observational study. Glucose was measured in venous (laboratory) and capillary blood (Accu-Chek or Contour Next glucometers). GDM was diagnosed attending to NDDG criteria for venous samples or capillary-specific cut-off. Linear regression, Passing-Bablok, Bland-Altman, and the kappa coefficient were used to study concordance between POCT and laboratory method.

RESULTS

Data from 109 women were analyzed (57 for Accu-Chek, 52 for Contour Next). Statistical analyses showed good agreement between both POCT and laboratory method. There were no statistical differences in fasting glucose measurements between capillary and venous samples and both POCT devices meet the ISO 15197 standard. Accu-Chek showed good agreement (k=0.629) regarding the laboratory method in classifying GDM, with an acceptable inter-evaluator bias of 3.5% (P<0.001).

CONCLUSION

POCT can be used to obtain fasting values and reduce overall waiting times for patients. Additionally, Accu-Chek can be used to diagnose GDM in remote areas applying specific cut-off values.