Social Isolation Decreases Survival and Worsens Cardiac Function in a Novel Murine Model of Coronary Atherosclerosis

ABSTRACT

Introduction: With more people working from home after the COVID pandemic, it is of utmost importance to further understand the impact of social isolation on outcomes of patients with coronary atherosclerosis. Our preliminary studies have shown that the novel diet-inducible, fatal mouse model of coronary atherosclerosis, SR-BIDELTACT/LDLR KO, tend to die on average around 4-6 weeks after starting a high-fat Paigan diet (HFD). This mouse model can be used to further understand the effect of social isolation on cardiovascular disease. We hypothesize that social isolation will decrease survival and worsen cardiac function. Method(s) Male and female SR-BIDELTACT/LDLR KO mice were put into social isolation (n=11), in a group of 2-3 (n=13), or in a group of 4-5 (n=22). At six-weeks-old, mice were started on a HFD to induce pathology. Echocardiography was performed to assess cardiac function. Analysis was performed using one-way Analysis of Variance tests and hoc-Tukey's Honest Significant Difference tests. A log-rank test was used to calculate the difference in survival distributions. Result(s) Mice living in groups of 1, 2-3, and 4-5 lived for an average of 34.9, 35.6, and 41.5 days, respectively, after starting the HFD (Fig. 1A). The survival distribution is significantly different between the mice in isolation versus the mice in groups of 4-5 (p<;0.01). Mice in social isolation have significantly lower ejection fractions than mice living in groups of 4-5 after two weeks of being on the HFD (Fig. 1B, p=0.028). Conclusion(s) Mice in social isolation exhibited decreased survival and reduced ejection fractions compared to mice in groups of 4-5. More mice would be needed to determine whether single isolation is different from mice in groups of 2-3. Further studies should be performed to understand the mechanism underlying the effect of social isolation on heart function. Such studies may influence future prevention strategies to positively affect outcomes of patients with atherosclerosis. (Figure Presented).