Hyperinsulinemia is associated with endometrial hyperplasia and disordered proliferative endometrium: a prospective cross-sectional study

Objective: To explore the relationship between metabolic abnormalities and DPE (disordered proliferative endometrium), EH (endometrial hyperplasia) and type I EC (endometrial cancer).

Methods: We conducted a prospective cross-sectional study that lasted from September 2011 to September 2012 at the Obstetrics and Gynecology Hospital of Fudan University. 314 cases were enrolled, including 56 cases of DPE, 194 cases of EH and 25 cases of type I EC. 39 healthy female cases were collected as a control group. General information was collected, and blood tests, including blood lipids, OGTT (75-g oral glucose tolerance test) and insulin release tests were examined. Statistical analysis was performed using SPSS 19.0 (Chicago, USA), and 0.05 was chosen as the significance test level.

Results: The median (inter-quartile) age of the 314 study subjects was 44 (12) years, with the ages ranging from 21 to 75 years. Elevated insulin level was correlated with DPE, EH without/with atypia and EC. The risk increased when HOMA-IR (homeostasis model assessment-insulin resistance)≥ 2.95 (the lower limit of the top quartile of HOMA-IR distribution in non-diabetic patients); the OR (odds ratio) for DPE was 9.973 (95% CI (coefficient interval): 2.038-48.789, P=0.005), that for EH without atypia was 8.481 (95% CI:1.860-38.672, P=0.006), that for EH with atypia was 18.716 (95% CI: 3.091-113.335, P=0.001) and that for type I EC was 45.199 (95% CI: 5.886-347.065, P<0.001). Opposite trends were observed for the QUICKI (Quantitative Insulin Sensitivity Check Index).

Conclusions: Hyperinsulinemia is associated with DPE and EH without/with atypia, not only with type I EC, and it might be a key factor that initiates and promotes endometrial hyperplastic lesions.