Abstract 14712: Cardiometabolic Differences Between Male and Female Obese-insulin Resistant Rats Following Sex Hormone Deprivation

Abstract

Introduction: Male gender and menopause increase the risk for cardiovascular incidence. However, less is known about gender differences in cardiometabolic disorders, particularly under obese-insulin resistant and sex hormone-deprived conditions. Hypothesis: Male have worse cardiometabolic disorders than female under obese-insulin resistant and sex hormone-deprived conditions. Methods: Adult Wistar rats of both sexes (n=20) were randomly assigned into four groups (n = 5/group): male normal diet sham (M-NDS), male high fat-diet with orchiectomy (M-HFO), female normal diet sham (F-NDS) and female high fat-diet with ovariectomy (F-HFO). Rats were fed either a normal diet (19.77% of energy fat) or a high-fat diet (57.60% of energy fat) for 12 weeks following the induction of sex hormone deprivation by either bilateral orchiectomy or ovariectomy. Temporal determinations of metabolic parameters, heart rate variability (HRV), left ventricular (LV) function, and cardiac mitochondrial function at 4, 8, and 12 weeks were done after starting each feeding program. Results: Insulin resistance was initially observed after 8 weeks of high-fat diet consumption in both M-HFO and F-HFO groups. In addition, M-HFO had depressed HRV, impaired LV performance indicated by decreased ejection fraction (%EF) and cardiac mitochondrial dysfunction indicated by increased mitochondrial ROS level, depolarization and swelling, as early as week 4, whereas F-HFO exhibited them at week 8 or 12. Moreover, at week 12, M-HFO have worse cardiometabolic disorders than F-HFO, particularly %EF and HRV. Conclusions: Under sex hormone-deprived condition, male are generally more susceptible to cardiometabolic disorders and cardiac mitochondrial dysfunction, especially in the presence of obese-insulin resistant condition.