Ovariectomy and Chemical Ovarian Failure Exacerbate Atherosclerosis Without Impairing Recovery From Hindlimb Ischemia

Peripheral artery disease is a major manifestation of atherosclerotic cardiovascular disease (ASCVD) that affects both men and women. In women, menopause increases the ASCVD risk. However, preclinical ASCVD research has historically been conducted predominantly in men, with relatively few studies focused on women and even fewer incorporating menopause models that more closely reflect human ASCVD pathobiology. Herein, we tested whether the chemical 4-vinylcyclohexene diepoxide (4-VCD)-induced ovarian failure or ovariectomy would drive atherosclerotic development and worsen ischemic limb pathophysiology.

Female C57BL/6J mice were injected with adeno-associated virus-mediated encoding a gain-of-function mutant PCSK9 (proprotein convertase subtilisin/kexin type 9) and fed an atherogenic diet for 23 weeks. Based on the baseline body weight, mice were randomly assigned to normally cycling controls, 4-VCD, or ovariectomy groups. Three weeks after the conformation of ovarian failure (4-VCD) or surgical ovarian removal (ovariectomy), hindlimb ischemia was induced via femoral artery ligation, and limb perfusion recovery and limb muscle performance were assessed.

Both 4-VCD treatment and ovariectomy reduced uterus mass, without affecting body weight or composition, or circulating cholesterol levels compared with control mice. Despite the similar metabolic and cholesterol profiles, atherosclerotic lesion areas were 1.5 to 1.7-fold greater in 4-VCD and ovariectomy mice than control mice. Perfusion recovery following hindlimb ischemia and plantar flexor muscle function in the ischemic limb were similar across groups, though muscle oxygenation was reduced in 4-VCD and ovariectomy groups.

Ovarian failure and removal exacerbated atherosclerotic development but had minimal impacts on perfusion recovery and limb function following hindlimb ischemia. These findings confirm the inclusion of menopausal models, whether through ovarian failure or ovariectomy, should be carefully considered to improve translatability of preclinical ASCVD studies, especially for women's health.