Presenter(s): Jazmin Cole—Human Physiology, Biology
Faculty Mentor(s): Ashley Walker
Session 6: Interact & React
Advancing age is characterized by not only an increased risk for cardiovascular diseases (CVDs), but also a decline in functional reserve and impaired adaptive capacity across multiple physiologic systems, also known as frailty . Impaired vascular function is a known contributor to CVDs and potentially has a role in increased frailty . In patients with overt disease, measures of frailty are related to vascular endothelial cell dysfunction . However, the relation between vascular endothelial function and frailty in a non-disease population is unknown .
To examine the relation between vascular function and frailty in the context of similar genetics and environment, we studied wildtype C57BL/6 mice . In young (9 mo, n=7) and old (23-30 mo, n=27) male and female mice, we assessed endothelial-dependent dilation (EDD) ex vivo in isolated, pressurized mesentery arteries and middle cerebral arteries (MCA) . Mouse frailty was assessed using a previously established non-invasive 31-item frailty index based on clinical signs of deterioration . The severity of each deficit was assessed by two independent observers and assigned a value between 0-1, with a higher score indicating more severe frailty .
Frailty index was ~6 fold greater in old compared with young mice (p<0 .001) . Among the old mice, frailty index was correlated with mesentery artery maximal EDD (r=-0 .53 p=0 .002), and remained significant after controlling for age (partial correlation: r=-0 .38, p=0 .03) .
This study demonstrates that frailty, independent of age, is associated with mesentery artery endothelial dysfunction in wildtype, non-diseased mice . However, it remains unknown whether the mesentery artery dysfunction is a cause or consequence of the greater frailty . Interestingly, we found a lack of association between frailty and cerebral artery endothelial function . Future research is needed to determine the mechanisms linking frailty and mesentery artery dysfunction .