Persistence of Risk for Type 2 Diabetes After Gestational Diabetes Mellitus

Area of Science:

• Reproductive Health
• Endocrinology
• Diabetes Research

Background:

• Gestational diabetes mellitus (GDM) affects approximately 6% of pregnancies.
• GDM is a strong predictor of future type 2 diabetes (T2D).
• The long-term impact of GDM history on T2D risk and duration of elevated risk is not fully understood.

Purpose of the Study:

• To investigate the relationship between reproductive history, specifically the number of pregnancies with GDM, and the subsequent risk of developing T2D.
• To determine how long the increased risk of T2D persists after pregnancies complicated by GDM.

Main Methods:

• A nationwide cohort study involving 50,884 women was conducted.
• Reproductive histories were assessed, and participants were followed for 10 years for T2D diagnosis.
• Cox proportional hazards models were used, accounting for age, cumulative GDM pregnancies, time since the last GDM pregnancy, BMI, education, and race/ethnicity.

Main Results:

• A history of one or more GDM pregnancies was associated with a significantly elevated age-specific risk of T2D (HR 3.87, 95% CI 2.60-5.75, 6-15 years post-GDM).
• The risk of T2D increased substantially with each additional pregnancy affected by GDM.
• While the T2D risk hazard ratio decreased by an estimated 24% per decade after a GDM pregnancy, the risk remained elevated for over 35 years.

Conclusions:

• Gestational diabetes mellitus is a significant predictor of markedly increased T2D rates.
• The relative risk for T2D escalates with multiple GDM-affected pregnancies and persists for decades.
• Regular T2D screening is crucial for women with a history of GDM, even late in life.