What is the most common cause of abnormal uterine bleeding in a premenopausal patient with obesity?

The most common cause of abnormal uterine bleeding in a premenopausal patient with obesity is endometrial hyperplasia. Obesity is a significant risk factor for the development of endometrial hyperplasia due to increased estrogen levels that occur when fat tissue converts androgens to estrogen. In premenopausal women, this elevated estrogen exposure can result in excessive proliferation of the endometrial lining, leading to hyperplasia. This condition can present with abnormal uterine bleeding, particularly heavy or irregular menstrual cycles.

While other conditions such as uterine fibroids and polycystic ovary syndrome (PCOS) can also cause abnormal bleeding, they are not as directly linked to obesity as endometrial hyperplasia. Uterine fibroids are benign tumors that can cause bleeding but are not predominantly associated with obesity-related hormonal changes. PCOS can lead to menstrual irregularities and is associated with insulin resistance and obesity; however, it is more complex and varies in presentation. Endometrial carcinoma, though a concern in obese patients, is less common than endometrial hyperplasia and typically arises after prolonged hyperplasia or unopposed estrogen exposure.

Thus, in the context of a premenopausal patient with obesity, endometrial