First‐trimester fasting plasma glucose levels and progression to type 2 diabetes: A 5‐year cohort study.

Objective: Impaired fasting glucose is a prediabetic condition defined as glucose levels of 100–125 mg/dL and is considered a risk factor for type 2 diabetes. However, this definition does not confer to pregnancy. The significance of first‐trimester fasting glucose and future progression to diabetes is not well defined. Therefore, we aimed to evaluate the progression to type 2 diabetes according to first‐ trimester fasting plasma glucose levels, as compared with gestational diabetes, a well‐established risk factor for diabetes, in up to 5‐year follow‐up postpartum. Methods: A retrospective analysis of 69 001 parturients, evaluating fasting plasma glucose levels measured during the first trimester. The primary outcome was the incidence of type 2 diabetes within 5 years post‐delivery. Fasting plasma glucose levels were categorized in 10 mg/dL increments. Receiver operating characteristic‐area under the curve (ROC‐AUC) statistics and the Youden index were employed to identify the optimal fasting plasma glucose cutoff for progression to type 2 diabetes. Survival analysis was applied to calculate the adjusted hazard ratios (aHRs) for type 2 diabetes progression with further stratification to maternal obesity status. Results: The identified fasting plasma glucose cutoff for progression to type 2 diabetes was 86.5 mg/dL. This cut‐off demonstrated superior performance compared with gestational diabetes diagnosis. Stratification by maternal obesity revealed enhanced predictive capabilities for type 2 diabetes, particularly among patients without obesity. Conclusions: Increased first‐trimester fasting plasma glucose levels are associated with progression to type 2 diabetes, at least as gestational diabetes. For patients without obesity, first‐trimester fasting plasma glucose has a more pronounced impact on progression to diabetes. Synopsis: First‐trimester fasting plasma glucose levels exceeding 86.5 mg/dL carry at least a comparable risk for type 2 diabetes progression as gestational diabetes, regardless of obesity status. [ABSTRACT FROM AUTHOR]