Underestimation of risk for large babies in rural and remote Australia: Time to change plasma glucose collection protocols

Emma L Jamieson; Erica P Spry; Andrew B Kirke; Carly Roxburgh; David N Atkinson; Julia V Marley

doi:10.1016/j.jcte.2020.100247

Underestimation of risk for large babies in rural and remote Australia: Time to change plasma glucose collection protocols

J Clin Transl Endocrinol. 2021 Jan 1:23:100247. doi: 10.1016/j.jcte.2020.100247. eCollection 2021 Mar.

Authors

Emma L Jamieson¹, Erica P Spry^{2

3}, Andrew B Kirke¹, Carly Roxburgh⁴, David N Atkinson³, Julia V Marley^{2

3}

Affiliations

¹ The University of Western Australia, The Rural Clinical School of Western Australia, Building 3 Edith Cowan University Campus, Robertson Drive, PO Box 412, Bunbury 6230, Australia.
² Kimberley Aboriginal Medical Services, 12 Napier Terrace, Broome 6725, Australia.
³ The University of Western Australia, The Rural Clinical School of Western Australia, 12 Napier Terrace, PO Box 1377, Broome 6725, Australia.
⁴ The University of Western Australia, The Rural Clinical School of Western Australia, 35 Stirling Terrace, Albany 6330, Australia.

Abstract

Aims: Preanalytical glycolysis in oral glucose tolerance tests (OGTT) leads to substantial underestimation of gestational diabetes mellitus (GDM) and hence risk for large-for-gestational-age (LGA) babies. This paper quantified the impact of glycolysis on identification of LGA risk in a prospective rural and remote Australian cohort.

Methods: For 495 women, OGTT results from room temperature fluoride-oxalate (FLOX) tubes were algorithmically corrected for estimated glycolysis compared to 1) the Hyperglycaemia and Adverse Pregnancy Outcomes (HAPO) study protocol (FLOX tubes in ice-slurry); and 2) room temperature fluoride-citrate (FC) tubes. GDM was defined by International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria. Unadjusted and corrected OGTT were related to LGA outcome.

Results: Correction for FC tubes increased GDM incidence from 9.7% to 44.6%. After correction for HAPO protocol, GDM incidence was 27.7% and prediction of LGA risk (RR 1.82, [1.11-2.99]) improved compared to unadjusted rates (RR 1.12, [0.51-2.47]). To provide similar results for FC tube correction (29.3% GDM; RR 1.81, [1.11-2.96]) required + 0.2 mmol/L adjustment of IADPSG criteria.

Conclusions: FC tubes present a practical alternative to the HAPO protocol in remote settings but give + 0.2 mmol/L higher glucose readings. Modification of IADPSG criteria would reduce perceived 'overdiagnosis' and improve LGA risk-assessment.

Keywords: Diagnostics; Gestational diabetes; Glycolysis; Indigenous health; Pregnancy outcomes; Rural and remote health.

Grants and funding

UL1 TR002548/TR/NCATS NIH HHS/United States