Age-Dependent Correlation of Pulmonary Function Impairment and Aortic Arch Stiffness in Mice.

Progressive aging is known to negatively affect cardiopulmonary function, which increases the risk of developing cardiac/respiratory diseases. However, the relationship between the decline in pulmonary function and aortic arch stiffness in aging is not well understood. This study investigated the correlation between lung function impairment and aortic arch stiffness in male and female C57BL/6 mice from 2 to 52 weeks of age. Lung function was assessed using forced oscillation ventilation and aortic arch stiffness was measured through echocardiography. Our results show a progressive decline in lung function markers such as respiratory system resistance (Rrs) and tissue elastance (H) with age, alongside an increase in inspiratory capacity (IC) and compliance of the respiratory system (Crs). Aortic arch stiffness significantly increased with age, particularly during early adulthood, and was found to be a strong predictor of lung function impairment in both sexes. While linear regression models indicated that body weight was a more accurate predictor of lung function variability, aortic arch stiffness emerged as a reliable marker for the decline in pulmonary function. These findings suggest that aortic arch stiffness can serve as an early indicator of declining lung function and therefore provide a noninvasive method to assess cardiopulmonary health in aging populations. Future studies should explore the molecular mechanisms underlying these changes and extend the investigation to older mice to fully understand the long-term impacts of aging on cardiopulmonary function.