Association of Endometrial Hyperplasia or Cancer with a History of Gestational Diabetes
Excess circulating insulin may contribute to endometrial cancer (EC) development. Some, but not all, studies suggest increased risk of EC in women with type 2 diabetes mellitus. We investigated the association of gestational diabetes mellitus (GDM) with EC and its precursor, endometrial hyperplasia (EH).
We conducted a population-based case-control study of women in Washington State with a live birth or fetal death record from 1987-2013. Cases were women with a hospital discharge record indicating presence of EH/EC after delivery (n=588). Controls were selected from remaining deliveries, frequency matched 10:1 with cases on delivery year and age (n=6013). Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), stratified by body mass index and adjusted for birth year, maternal age, and race/ethnicity.
EH/EC was associated with GDM in obese women (both obese class I: OR 2.89, 95% CI 1.94-4.31 and obese class II&III: OR 4.17, 2.87-6.05), but not in normal and underweight (OR 1.41, 95% CI 0.67-2.97) or overweight women (OR 1.31, 95% CI: 0.92-1.86). Similar results were observed when considering EH and EC separately.
We observed evidence of an association between EH/EC with GDM in obese women. Excess circulating insulin may act synergistically with the excess endogenous estrogen associated with obesity, increasing risk of EH/EC. Future research with improved exposure and outcome measurement, a longer latency/induction period, and more complete information on body mass index will help to confirm this relationship.