Diagnostic Accuracy of Capillary Blood Glucometer Testing for Gestational Diabetes

Abstract

Purpose

Few pregnant women in low-resource settings are screened for gestational diabetes mellitus (GDM) using the gold standard oral glucose tolerance test (OGTT). This study compared capillary blood glucose testing with 2-h plasma glucose measurements obtained using the 75-g OGTT to screen for GDM at primary healthcare clinics in Mexico.

Patients and Methods

Pregnant women who participated in a previous prospective multicenter longitudinal cohort study and who had not been previously diagnosed with diabetes were included. Participants were evaluated using the plasmatic 2-h 75-g OGTT with simultaneous capillary blood glucose measurements using a glucometer. The study endpoint was the comparability of the glucometer results to the gold standard OGTT when collected simultaneously. Sensitivity, specificity, and area under the curve of the glucose measurements obtained for capillary blood compared with venous plasma (gold standard) were calculated to determine diagnostic accuracy.

Results

The study included 947 pregnant women who had simultaneous glucose measurements available (blood capillary [glucometer] and venous blood OGTT). Overall, capillary blood glucose testing was very sensitive (89.47%); the specificity was 66.58% and the area under the curve (95% confidence interval) was 0.78 (0.74–0.81). The sensitivity, specificity and area under the curve of each capillary measurement were: 89.47%, 66.58% and 0.78 (0.74–0.82) for the fasting measurement, 91.53%, 93.24% and 0.92 (0.88–0.96) for the one-hour measurement, and 89.80%, 93.32%, 0.91 (0.87–0.95) for the second-hour measurement, respectively. No adverse events were reported.

Conclusion

Capillary OGTT is a valid alternative to the gold standard OGTT for screening of GDM in low-resource situations or in situations where there are other limitations to performing the OGTT as part of primary healthcare services.

Keywords:

• capillary blood glucose
• gestational diabetes mellitus
• low-resource
• Mexico
• oral glucose tolerance test
• screening

Data Sharing Statement

The full deidentified dataset is shown in Supplementary Appendix 1. The full study protocol is available from the corresponding author upon request.

Ethics Approval and Informed Consent

The cohort protocol was approved by each site’s institutional review board, and all participants provided written informed consent. The study was conducted in accordance with the Declaration of Helsinki, the International Conference on Harmonization guidelines for Good Clinical Practice, and applicable laws and regulations. The study was registered at researchregistry.com (researchregistry7405).

Consent for Publication

All authors agree to the publication of this paper.

Acknowledgments

This study was funded by Global Health Partnerships Eli Lilly and Company. The authors thank Sarah Bubeck, PhD, of Edanz (www.edanz.com) for providing medical writing support, which was funded by the Carlos Slim Foundation, in accordance with Good Publication Practice (GPP3) guidelines (http://www.ismpp.org/gpp3). Preliminary results of this study were previously presented at the American Diabetes Association’s 80th Scientific Sessions (June 12–16, 2020). The abstract has been published (Gallardo H et al Diabetes 2020;69 (Supplement_1):1358-P). We acknowledge the support of the Centre for Maternal and Infant Research (CIMIGEN) and the Ministry of Health of the States of Hidalgo and Guanajuato for their help in performing this study.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

HGR, JLG, LAMJ, AM, JOM, VGH, DAAH, RAD and RMR, are employees of the Carlos Slim Foundation. The authors report no other conflicts of interest in this work.

Additional information

Funding

Funding for this study was provided by Global Health Partnerships Eli Lilly and Company. The funder had no role in the study design; collection, analysis, and interpretation of data; writing of the report; or the decision to submit the report for publication. Carlos Slim Foundation developed the study design, analysis and interpretation of data, and was involved in the writing of the report; the Ministry of Health Guanajuato was involved in the collection of data; the Ministry of Health Hidalgo was involved in the collection of data; and CIMIGEN was involved in the collection of data.