ENHANCED glucose processing during oral glucose tolerance testing (OGTT) significantly improves the accuracy and equity of gestational diabetes diagnosis, identifying more cases compared to standard processing methods.
Gestational diabetes is typically diagnosed using the OGTT; however, this method has notable limitations in accuracy, reproducibility, and practicality. This study aimed to evaluate the impact of enhanced pre-analytical glucose processing on glucose levels, gestational diabetes diagnoses, and pregnancy outcomes. It also investigated whether HbA1c could serve as an alternative diagnostic marker. Improving diagnostic accuracy is critical for ensuring appropriate management of gestational diabetes and addressing health equity concerns.
A prospective observational cohort study was conducted across nine UK centres, recruiting 1308 pregnant women with at least one risk factor for gestational diabetes. Participants underwent a 75 g OGTT following National Institute for Health and Care Excellence (NICE) criteria. Standard glucose processing was compared to enhanced processing, which involved rapid centrifugation, aliquoting, freezing within 2.5 hours, and storage on ice. Enhanced glucose processing yielded glucose levels approximately 0.6 mmol/L higher than standard methods, increasing gestational diabetes diagnosis rates from 9% to 22%. Among the additional 165 women diagnosed under enhanced processing, participants were younger (mean age 31.9 vs. 33.2 years, p=0.035), had a higher BMI (36.5 vs. 33.9 kg/m², p=0.003), and exhibited a different ethnic distribution (p=0.025). These women also delivered more large-for-gestational-age infants (37.0% vs. 22.3%, p=0.006). HbA1c was found unsuitable as a diagnostic alternative, with an area under the receiver operating characteristic curve of 0.74 (95% CI 0.68–0.79).
The findings highlight the potential of enhanced glucose processing in OGTT to provide more accurate and equitable gestational diabetes diagnoses, thereby improving clinical management and pregnancy outcomes. However, increased diagnosis rates may have implications for resource allocation and patient care pathways. Future research should explore the cost-effectiveness of this approach and develop strategies to support its integration into routine clinical practice while addressing potential challenges in implementation.
Abigail Craig, EMJ
Reference
Jones DL et al, Enhanced glucose processing in gestational diabetes diagnosis: Effects on health equity and clinical outcomes. Diabet Med. 2024. DOI: 10.1111/dme.15476.
