Exploratory association of OGTT area under the curve with early-night glycemic patterns and pharmacotherapy use in gestational diabetes mellitus.

BACKGROUND: In gestational diabetes mellitus (GDM), the relationship between baseline 75-g oral glucose tolerance test (OGTT) area under the curve (AUC), subsequent continuous glucose monitoring (CGM)-derived glycemic patterns, and pharmacotherapy use remains incompletely understood. This study aimed to examine the association of OGTT AUC with 14-day CGM profiles, with particular attention to nocturnal glycemic patterns, and pharmacotherapy use under routine clinical management. METHODS: This single-center retrospective study included 64 singleton women with GDM identified from an institutional CGM registration cohort. Participants were stratified into quartiles according to baseline OGTT AUC. CGM-derived metrics were evaluated overall and across prespecified time windows. Hierarchical regression models were used to examine the associations of OGTT AUC with overall TAR and pharmacotherapy use. ROC analysis was performed as an exploratory assessment of discriminatory ability. RESULTS: Women in the highest OGTT AUC quartile showed less favorable CGM-derived glycemic profiles, with higher hyperglycemic exposure and greater glycemic variability, particularly during waking hours (06:00-22:00) and the early-night (22:00-02:00) period. Higher OGTT AUC was associated with greater overall TAR in linear regression models and with higher odds of pharmacotherapy use in logistic regression models. The association persisted in sensitivity models additionally adjusted for CGM-derived mean glucose, although these models were interpreted cautiously because mean glucose may lie downstream of OGTT AUC. ROC analysis yielded an AUC of 0.770, with a potential cut-off of 17.34. CONCLUSIONS: In this exploratory CGM cohort of women with GDM, higher baseline OGTT AUC was associated with less favorable CGM-derived glycemic profiles, more apparent early-night glycemic abnormalities, and greater pharmacotherapy use under routine clinical management. OGTT AUC may help characterize subsequent glycemic burden and identify women who warrant closer glucose monitoring, but its clinical utility and candidate treatment-related thresholds require validation in larger prospective cohorts with standardized treatment-initiation criteria.