Altered left ventricular performance in aging physically active mice with an ankle sprain injury

Area of Science:

• Cardiovascular Physiology
• Exercise Science
• Aging Research

Background:

• Age-related changes in cardiac structure and function are a significant concern.
• The role of lifelong physical activity in mitigating these changes requires further investigation.
• Musculoskeletal injury models can provide insights into the long-term effects of physical activity.

Purpose of the Study:

• To assess the impact of varying lifelong physical activity levels on age-related left ventricular (LV) parameters.
• To investigate how different running wheel interventions influence cardiac function over time.
• To determine the relationship between physical activity volume and cardiac diastolic function.

Main Methods:

• Forty male mice were divided into four groups: SHAM, transected CFL, transected ATFL/CFL, and SHAM Sedentary.
• Left ventricular parameters were measured every six weeks using echocardiography under isoflurane anesthesia.
• Distance run was monitored to quantify physical activity levels across groups and ages.

Main Results:

• Lifelong physical activity, particularly in the SHAM group, was associated with improved LV posterior wall thickness-to-radius ratios (h/r) with age.
• SHAM mice exhibited greater passive filling velocity (E wave) and E/A ratios compared to ATFL/CFL and SHAMSED groups.
• Physical activity volume correlated significantly with diastolic filling parameters by 9 months and at the end of lifespan.

Conclusions:

• Regular physical activity throughout the lifespan significantly improves left ventricular structure and diastolic function in mice.
• Lifelong exercise attenuates age-related negative cardiac alterations, particularly in the second half of life.
• The amount of physical activity performed is directly related to beneficial changes in cardiac diastolic filling.