Role of high-fat diet on letrozole-induced polycystic ovarian syndrome in rats

Polycystic ovary syndrome (PCOS) is one of the most prevalent hormonal disorders in women of reproductive age. Letrozole (LET)-induced PCOS is a good model but has drawbacks such as the absence of metabolic changes. Hence, in the present study, we aimed to develop a new animal model combining a high-fat diet (HFD) and LET. Female Wistar rats were divided into a control group, LET group, and LET + HFD (45% energy from fat) group. Compared with the control group, the LET and LET + HFD groups showed ovarian cysts and elevated testosterone levels, whereas oestradiol and progesterone levels were reduced. The LET + HFD group displayed significant changes in body weight, as well as in levels of triglycerides, fasting blood glucose, direct bilirubin, alanine aminotransferase, and uric acid; in terms of glucose intolerance and insulin resistance, the LET + HFD group showed better results than the LET group. Compared with the control group, elevated levels of tumour necrosis factor-α were detected in both the LET and LET + HFD groups. The addition of HFD to the LET model afforded good metabolic aberrations, along with ovarian cysts. In contrast, the LET-only model failed to demonstrate metabolic anomalies observed in the human PCOS condition.