Sex differences in obesity: cardiovascular and metabolic protection in female mice compared to male mice

Abstract

Introduction: Obesity is major cardiovascular risk factor characterized by excessive body fat, which differs between women and men through the genoid and android phenotypes, respectively. Android phenotype has been correlated with increased cardiovascular risk. However, it having been search to assess the effects of obesity between males and females to understand the differences in risk factors. It is known fertile females' cardiovascular protection resulting by estrogen bioavailability can be impaired with body fat increase. Aim: To compare the effects of a high-fat diet on metabolic, hemodynamic and cardiovascular autonomic parameters of male and female mice. Methods: 32 C57BL/6J mice were divided into 4 groups (n=8 each): male fed low-fat diet (ML) or high-fat (MH), females fed a low-fat diet (FL) or high-fat (FH). Diets were administrated for 10 weeks. Body weight and food consumption were measured throughout protocol. At the end, fasting blood glucose, oral glucose tolerance direct recording blood pressure, baroreflex sensitivity and cardiovascular autonomic modulation were measured. Results: High-fat diet increased body weight (ML: 4.2±0.4; MH: 10.5±0.9; FL: 5.8±0.4; FH: 11.7±0.3 g) and body fat in both sexes (ML: 0.8±0.09; MH: 2.6±0.2; FL: 1.0±0.09; FH: 2.4±0.3 g). As well as basal glycemia, which was higher in animals fed a high-fat diet (ML: 114±5.7; MH: 136±8.2; FL: 90±4.9; FH: 147±2.5mg/ dL). Interestingly, the area under the curve on the OGTT was greater in MH group (ML: 21541±1102; MH: 26266±891; FL: 16123±546; FH: 22149±574 AUC) than in the other groups, indicating glucose intolerance. Systolic blood pressure was higher in male groups (ML: 148±2.7; MH: 152±2.4; FL: 130±3.5; FH: 132±2.5 mm/Hg). There was no difference in pulse interval variability in the time domain (DP-PI) or (VAR-PI). However, RMSSD was influenced by the high-fat diet regardless sex factor. In the frequency domain females and male fed the high-fat diet showed a reduction in very low frequency band (VLF). There were sex influences on the low (LF) and high frequency (AF) bands, as well as in the variance of systolic blood pressure in female. Conclusion: Males and females fed a high-fat diet showed the same gain in weight and adipose tissue. However, females did not show glucose tolerance, changes in blood pressure levels, suggesting a cardioprotective factor compared to males, even during obesity. Sex differences have been shown to influence cardiovascular autonomic parameters. Financial support: CAPES-PROSUP; CNPq 435123/20181; Anima Institute. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.