(884) Mean OGTT Deviation as a Predictor of GDMA2 and Subsequent Glycemic Control

The oral glucose tolerance test (OGTT) is a key diagnostic tool for identifying gestational diabetes mellitus (GDM), and the number of abnormal values correlates with adverse obstetric outcomes. However, the clinical significance of the average degree of glycemic deviation above the normal ranges of OGTT has yet to be investigated. We aimed to evaluate whether an average OGTT deviation exceeding 10% is associated with an increased risk of requiring medical therapy for glycemic control (GDMA2) and the degree of glycemic control among treated patients.

Study Design:

This retrospective cohort study included 1,038 women diagnosed with GDM who had at least two abnormal values on the OGTT over 8 years. For each participant, we calculated the mean percentage deviation above the OGTT diagnostic thresholds. Patients were classified according to their average OGTT deviation: >10% vs. ≤10%.  GDMA2 rates were assessed and compared between the two groups. A subgroup analysis was performed to evaluate glycemic control among women with GDMA2.

Results:

Among the 1,038 women included, 532 (51.3%) had an average OGTT deviation >10%, and 506 (48.7%) had a deviation ≤10%. Women in the >10% group had a significantly higher rate of GDMA2 (adjusted OR 1.39; 95% CI 1.06–1.82, p=0.02). When modeled as a continuous variable, increasing OGTT deviation was also associated with greater odds of GDMA2 (p=0.04). Among those with GDMA2, A mean OGTT deviation greater than 10% was significantly associated with a higher proportion of unbalanced gestational diabetes (73.4% vs 62%, p = 0.042). No significant differences were observed between the groups in maternal or neonatal composite outcomes.

Conclusion:

Among women with GDM and ≥2 abnormal OGTT values, a mean glycemic deviation >10% is associated with increased likelihood of requiring pharmacologic treatment and poorer glycemic control at delivery. These findings suggest that quantifying the extent of glycemic abnormality at diagnosis may serve as an early risk stratification tool in GDM management.